SDR08 Papers and Presentations
26-30 October 2008
Washington, DC

Comprehensive Downloads

SDR’08 Paper and Presentation Abstracts

links to paper and presentation downloads when available are next to title

Session 1.1

The Implications of .7 GHz to 3 GHz Terrestrial Band Characterization on Vehicular SDR (paper)
Andrew Macdonald, General Motors

Automobile manufacturers are intrigued by SDRs. Long design cycles and long service lives make vehicles particularly vulnerable to obsolescence. This is particularly evident when the devices and services of vehicular and consumer electronics overlap. A recent example is the disabling of older OnStar Telematics modules when analog cellular service was discontinued in the US. This inconvenienced OnStar customers and financially burdened OnStar and GM. An SDR that could adapt to changes in existing protocols and support the introduction of new protocols (and associated services) would go a long way to bridging the vehicular and consumer electronics divide.

Indoor Navigation using a Software Defined Radio (paper)
Alison Brown, Ben Mathews, NAVSYS

Time of Arrival (TOA) observations from local beacon signals can be used to augment and provide a back-up navigation source for GPS signals in a Software Defined Radio (SDR). The addition of inertial sensor inputs to the SDR offers the ability to track down to much lower power levels for both the GPS and TOA signals, effectively deal with multipath, and recover more quickly from signal outages. In this paper, multipath mitigation algorithms that leverage combined TOA and inertial measurements are presented to enhance tracking performance in indoor and urban environments.

Cognitive Geolocation: Learning Location by Listening to the Radio (paper)
Arash Farhang, Neal Patwari, University of Utah

Global positioning system (GPS)-based localization is often unavailable in indoor environments, in urban areas, and is susceptible to jamming. We evaluate cognitive geolocation, the use of local ambient wireless signals for the estimation of a receiver’s position. Cognitive geolocation can be seen as localization fingerprinting, in which a database of pre- measured spectrum vs. location is stored, and a receiver’s current spectrum measurement is compared to the database to estimate location. The database includes spectral measurements at different locations and times of day. We present a feasibility study, in which extensive measurements of spectral activity are recorded across time and space in a campus building, in both a training and test set. In the study, receiver locations are correctly identified between 80 to 90% of the time. Our results show the capability of cognitive geolocation and point to a promising area of localization research.

A Reconfigurable SDR Receiver for Multi-Mode GNSS Applications (paper)
Alper Ucar, Ediz Cetin, Izzet Kale, University of Westminster

This paper describes a novel reconfigurable Software Defined Radio (SDR) receiver for the next-generation GPS and Galileo Global Navigation Satellite Systems (GNSS). The proposed receiver utilizes variable–rate BandPass Sampling (BPS) to downconvert the signal of interest to an Intermediate Frequency (IF) thereby simplifying the Analog Front-End (AFE) as well as rendering the simplified AFE mostly free of the perennial RF-impairments. A Continuous-Time (CT) quadrature bandpass sigma-delta (ΣΔ) modulator is used for data conversion which circumvents the need for an anti–alias filter and relaxes the RF band select filter specifications by attenuating adjacent band interference through its loop filter. System level simulations demonstrate that the BPS receiver with a CT ΣΔ–ADC is a feasible option that leads to reduced power consumption and high levels of integration making single chip radio receivers realistically viable.

Session 1.2

Low-Power Spectrum Survey Measurements for Cognitive Radio Applications (paper)
Christopher R. Anderson, Charles B. Cameron, USNA

Spectrum sensing cognitive radios are an emerging technology that promises greater efficiency in utilizing the available wireless spectrum. In particular, spectrum-sensing cognitive radios provide the ability to search for and utilize an unoccupied portion of the wireless spectrum during periods of time when the incumbent user is inactive. A key requirement to operating cognitive radios, therefore, is accurately and reliably identifying unutilized frequency bands, even when those bands may contain extremely weak signals.

700MHz Band Spectrum-Usage Measurements From Denver To Washington DC During November 2007 (paper)
Keith E. Nolan, CTVR at Trinity College Dublin

This paper presents key outcomes from mobile spectrum measurements research covering in excess of 4500km along a route from Denver, CO to Washington DC during November 2007. The main focus was on the 698MHz – 806MHz band covering a variety of busy urban and quiet rural areas along the chosen route. This paper describes how the spectrum measurement data are being used for offline prototype wireless communications research by CTVR. This database is being made available for other academic and industrial research work worldwide in a bid to narrow the gap between simulation and real-world tests, significantly reduce the time to market and costs of conducting field tests and accelerate the development of SDR-based dynamic spectrum access systems.

Combined Blind Equalization and Automatic Modulation Classification for Cognitive MIMO (paper)
Barathram Ramkumar, Miloje S. Radenkovic, Tamal Bose, Virginia Tech

Blind equalization and Automatic Modulation Classification (AMC) have been of significant importance for cognitive radios when the receiver has no information about the channel or modulation type. Choosing an appropriate equalizer is difficult when the channel is Multi Input Multi Output (MIMO), and when there is no information about the channel. In this paper, an AMC based on cyclostationary feature detection and MIMO based Constant Modulus Algorithm (CMA) blind equalizers are used in conjunction. The probability of classification of the AMC is used as a metric and fed back to update the blind equalizer order. The equalizer and the AMC enhance the performance of each other. Computer simulations are given to illustrate the concept and yield promising results.

Robust Signal Classification Using the Wavelet Transform for Feature Extraction (paper)
Frank Brickle, ACPT, Inc.

The success of a classification method will depend largely on the independence and expressivityof the features it chooses to observe. In that regard the Discrete Wavelet Transform ought to be especially useful, thanks to its orthogonality properties. We have already developed applications which use Wavelet Transforms of Power Spectrum estimates as the basic observations for classifying a variety of digital signals in adverse HF environments. Even with the simplest of scoring and modeling techniques, these applications have proved to be extremely accurate, robust, and efficient. However, these applications represent only a first step into a more systematic exploitation of Wavelet-based observations for general signal classification. Starting with an informal illustration of the original applications, we describe ongoing work at refining and extending Wavelet techniques towards a comprehensive system for signal classification. In particular we address issues in multiway classification, markovity versus cyclostationarity, online training and updating, and heuristic methods for reducing the computational overhead associated with complex Wavelets and quadrature signals.

Modulation Forensics for Space Time Coding in Wireless Communications (paper)
W. Sabrina Lin, K.J. Ray Liu, T. Clancy, University of Maryland

Modulation forensics detect the modulation type in wireless communications by the received signal only. It provides a powerful tool for spectrum sensing since by identifying the modulation type, the secondary users in cognitive radio systems can detect whether the primary user occupies the spectrum. In this paper, we investigate modulation forensics of linear digital modulations and space-time diagonal algebraic codes in slowly varying, frequency-selective fading channels. With unknown channel vector, and phase distortion at the receive side, we derive a composite test consisting of second-moment nonlinearity and maximum likelihood tests, and discuss the performance and the forensics system confidence measure. It is shown that the proposed algorithm achieves almost perfect identification of the space-time coding, and high accuracy rate of the modulation type.

Session 1.3

An OFDM based Sensing Information Exchange for Cooperative Sensing in Cognitive Radio (paper)
Mai Ohta, Takeo Fujii, Kanashi Muraoka, Masayuki Ariyoshi, U of Electro-Communication

In cognitive radio systems, secondary cognitive users have to recognize wireless environment around the users. As one of the methods for improving the recognition sensitivity of the wireless environment, cooperative sensing techniques have attracted attention. The cooperative sensing requires exchanging the observed information like the detected primary user’s signal level at each sensing node to the master detection node. However, conventional cooperative sensing techniques have not considered information exchange methods. In this paper, we propose a novel information exchange method based on mapping the information to a subcarrier signal of an OFDM signal structure for reducing the required information symbols for the cooperative sensing. We confirm that the proposed method obtains almost the same sensing performance compared to the soft information based cooperative sensing with perfectly exchanging the observed information.

Cognitive Spectrum Assignment (paper)
Pooyan Amini, Arash Farhang, Daryl Wasden, Ehsan Azarnasab, Peiman Amini, Salam Akoum, Behrouz Farhang-Boroujeny, University of Utah

The concept of cognitive radio has put together a vast area of expertise from signal processing and communication to data mining algorithms. This is possible because of the recent advances in development of Software Defined Radio (SDR). A cross layer approach in SDR network supplies the MAC layer with more information to take advantage of opportunistic channel access. One major requirement of cognitive radio is to be aware of other legacy radios and avoid using active channels. Using a basestation for channel allocation and node coordination, collaborative spectrum sensing (by filterbanks) determines the best estimate for background noise. Afterwards, the noise temperature is used to profile the presence of the active users in the spectrum based on the location and time of the experiment. A probabilistic approach identifies the model of the spectrum activity as arrival/departure of many narrowband radios in the spectrum. A game theoretic approach for spectrum selection is then developed which sets spectrum usage prices according to space-time statistics of spectrum activity pattern. Furthermore, using a filterbank multicarrier technique, cognitive nodes can keep their transmission power under the noise level in the active parts of the spectrum while filling the spectrum holes.

Performance Evaluation of Cooperative Sensing for Cognitive Radio (paper)
Hiroyuki Shiba, Munehiro Matsui, Kazunori Akabane, Kazuhiro Uehara, NTT

The increase in the number of wireless systems is creating a serious shortage of space in the radio spectrum. Cognitive radio technology is receiving particular attention as a technology that solves this problem. A cognitive radio system dynamically uses vacant spectrum and works adaptively by sensing channel environments and their availability.Spectrum sensing technology is an important elemental technology for recognizing channel environments. Energy detection, cyclostationary detection and cooperative sensing methods have been studied as spectrum sensing technology. Cooperative sensing methods can decrease the miss detection rate of a primary system (PS) in a secondary system (SS) because it determines whether a PS is present or not based on the detection results of multiple terminals. The problem is that the performance of cooperative sensing is affected by the method used to determine whether the PS is present and the information used to make that decision. We have developed a cooperative sensing method that takes into account the reliability of information gathered from each terminal. We evaluated the method’s performance by computer simulation. Moreover, we demonstrated that our proposed method is effective on a laboratory test bed consisting of a cognitive radio system.

Spectrum Occupancy Detection for Cognitive Radios Using Wavelet Transform Analysis (paper) (presentation)
D.Thilakawardana, S. Thilakawardana, K.Moessner, University of Surrey

With the introduction of 2G and 3G services, wireless cellular networks around the world have experienced an exponential increase in service demand. This ever increasing demand seems to put more pressure on the limited radio spectrum in the coming years; as a consequence, spectrum policy makers and network operators are now seeking solutions for this apparent spectrum scarcity. Cognitive radios (CR) have been identified as one of the solutions to this problem and cognitive terminals are capable of sensing the neighboring environment, locating spectrum holes within a short period of time and opportunistically utilizing such frequency bands without causing harmful interference. Therefore, for CR deployment sensing and identification of spectrum holes to make communication is one of the main tasks. This paper examines the application of wavelet transform techniques assisting in identifying spectrum holes in non overlapping spectrum bands. Wavelets are used to identify the spectrum sub band edges on the basis of signal irregularities and power spectral density levels.

Signal Interception with Multiple Antennas for Cognitive Radio (paper)
L. Bixio, G. Oliveri, M. Ottonello, M. Raffetto, C. S. Regazzoni, University of Genoa

In the present contribution the problem of signal interception in a virtual MIMO scenario is considered. A possible distributed signal interception algorithm which is able to detect and discriminate between two similar OFDM signals is analyzed. Distributed and stand-alone algorithms are compared through simulations in a multipath environment and the different levels of cooperation required among the terminals are discussed.

Rapid Radio: Human-Assisted Signal Classification and Receiver Implementation (paper)
Jorge A. Surís, Adolfo Recio, Peter Athanas, Virginia Tech

An analysis-based framework for the rapid development of a radio receiver for signals with unknown parameters is proposed, exploiting the reconfiguration capabilities of FPGAs. The framework guides a non-expert user through the process of signal classification and FPGA-based receiver implementation. System efficiency is traded off with implementation time in order to allow fast radio creation. A set of high-level transformations are applied to the unknown signal based on different hypothesis about the modulation scheme. The results of the transformations are presented to the user, who can steer the process of analysis. The parameters of the radio are then mapped by means of an Implementation Engine to modules implemented in a general purpose FPGA-based receiver.

Session 1.4

A Modulation Classification Technique for Software-Defined Radio Using Inphase–Quadra (paper)
Okhtay Azarmanesh and Sven G. Bilén, Penn State

The technique discussed here is being designed for a real- time SDR system using General Purpose Processors and SDR development boards and it is robust and efficient with a processing time overhead low enough to allow the software radio to maintain its real-time operating objectives. A decision-theoretic approach is being used in this technique. The method uses the waveforms’ I–Q diagrams and, by employing pattern-recognition techniques on them, determines the type of modulation being transmitted. This new Modulation Classification method will be capable of determining the type of modulation scheme among different PAM, QAM, PSK and OFDM modulations.

OFDM Signal Classification and Synchronization for Cognitive Radio Systems (paper)
Ying Wang, Alex Young, Qinqin Chen, Sujit Nair, Charles W. Bostian, Virginia Tech

This paper presents an Orthogonal frequency division multiplexing (OFDM) signal classification and synchronization system design for a cognitive radio system that extracts key features from an incoming OFDM signal to accomplish classification, synchronization and demodulation, all without any prior knowledge of the signal characteristics. This system is combined with our previously implemented narrowband signal classification and synchronization system[2]. The combined system supports a variety of modulations, including digital OFDM, MPSK, FSK, QAM, as well as analog AM and FM. This system has been implemented and tested on a variety of platforms, including a Microsoft Windows-based Anritsu signal analyzer, and Linux-based GNU Radio with Universal Software Radio Peripheral (USRP) RF front end.

QAM Carrier Tracking for Software Defined Radio (paper) (presentation)
James Schreuder, Schreuder Engineering

This paper investigates Quadrature Amplitude Modulation (QAM) carrier tracking techniques for Software Defined Radio implementations. These techniques were developed during a recent investigation project into the baseband signal processing requirements of a draft TIA Public Safety Radio standard proposal Scalable Adaptive Modulation (SAM) [1]. The proposal specified use of frequency multiplexed QAM channels incorporating Pilot Symbol Assisted Modulation (PSAM) [2]. This proposal has since been further updated and now forms the basis of the current P34 standard.

OFDM Modulation Using Square-Root Nyquist Time Domain Kernels To Obtain Reduced Peak (paper)
Chris Dick, fred harris, Xilinx

The waveform of choice for OFDM signaling is the sinusoid with an integer number of cycles per interval and with an appended cyclic prefix to obtain circular convolution with the channel. This combination makes the channel inversion particularly simple; performed as a ratio between the DFT of the received signal and the DFT of the channel. In fact, this relationship is valid for any periodic function formed as a sum of the basis sinusoids of the DFT. One particularly simple example of this class of signals is the Dirichlet kernel (the periodically extended sinc function). This kernel is used in single carrier OFDM [1]. An advantage of this kernel relative to the complex sinusoid kernel is a 3.4 dB reduction in peak to average power ratio (PAPR). We show here that a windowed version of this kernel exhibits a significantly lower, in fact up to a 10.0 dB reduction in PAPR. The cost to obtain the reduced PAPR is excess bandwidth but that may be a fair trade to obtain higher average transmitted power for a given peak power limited amplifier.

Session 1.5

Activities of SDR Forum MLM Working Group on a Language for Advanced Communication Systems (paper)
Mark Cummings, Bruce Fette,Mitch Kokar, Shujun Li, envia

The MLM Working Group in the SDR Forum has been working on developing a language which will allow mobile radio network elements to autonomously specify and configure networks by exchanging information such as: 1) Hardware capabilities of the nodes (Frequency bands, modulations, MAC protocols, access authorizations, etiquettes, bandwidths, interconnections etc.), 2) Networks available to a user (parameters, restrictions, costs), 3) Security / privacy (constraints, policies), 4) Information types (QoS, Priorities), 5) Local spectrum situation (spectrum activity, propagation properties), 6) Network to subscriber & subscriber to network control (policies), 7) Manufacturer matters (Hardware and software policy), 8) Types of users (Authority, Priority, etc.), 9) Types of data (Async., Isoc., narrow band, broad band, etc.), or 10) Local regulatory framework (e.g., policies at a given geo location, time of day, emergency situation, etc.). This paper describes the process that the Working Group is using, the current status of the work and the planned schedule going forward. A key element of the Working Group’s effort is outreach and coordination with the broadest possible cross section of the industry.

Ontology-Based Radio for Public Safety Use Cases (paper)
Shujun Li, Mieczyslaw M.Kokar, Northeastern University

Cognitive radios can lead to more reconfigurable and heterogeneous systems due to their flexibility, spectrum efficiency and interoperability. Two main limitations of the current radio systems are: (1) the prescribed, inflexible control structure in the radios; (2) the lack of understanding of their own structure by the radios. Hence, it is impossible to query the capabilities and current state of other nodes and modify their functioning in real-time. In this paper, we show that Ontology-Based Radio driven by policy can be useful in scenarios where dynamic change of radio behavior is required, e.g. dynamic network extension for coverage and reach-back. The combination of ontology and policy provides a more flexible control mechanism in which a program segment is invoked whenever the condition is satisfied. Any modification of the control structure can be accomplished by simply changing the policy.

A Policy Strategy for the Software Defined Radio Enabling Cognitive Radio Technology (paper) (presentation)
Lynn Grande, General Dynamics

Communicating mission goals to the Software Defined Radio in the tactical network requires a policy driven approach. The bulk of policy distribution is currently a manual, paper intensive process. Creating a more automated policy strategy brings the Software Defined Radio a step closer to creating the Cognitive Radio layer. This strategy includes policy management, decision making, enforcement and distribution. Definition of this policy strategy shall include standard policy models developed by the DMTF, facets of reasoning technologies in the decision processes and Object Oriented device models. This paper will address policy issues and solutions that enable the next step toward Cognitive Radio.

FP7 E3 Project: Technical, Business, Standardization and Regulatory Perspectives (paper)
D. Bourse, W. Koenig, M. Doubrava, J.M. Temerson, K. Nolte, M. Siebert, K. Kalliojarvi, E. Buracchin6, D. Bateman, Motorola

E³ [1] is aiming at integrating cognitive wireless systems in the Beyond 3G (B3G) world, evolving current and future heterogeneous wireless system infrastructures into an integrated, scalable and efficiently managed B3G cognitive system framework from a technical, regulatory, standardization and business perspective.  

Session 1.6

Network Access Security Policies for Cognitive Radio (paper) (presentation)
Tulin Mangir, Mukul Khairatkar, California State Univ

In this paper we explore security access methods and techniques for Cognitive Radio (CR) and compare different methods for complexity of implementation, effectiveness and applicability. In Cognitive radio (CR), which changes frequency band of operation with software while technology is being developed and actually fielded in certain tactical applications and operations, security of accessing the spectrum is still undefined. With the cognitive approach any radio spectrum can be accessed with certain hardware and software combination. In order to use the spectrum efficiently, spectrum of use must be well defined for specific radio operation. Here, we first discuss different attacks in wireless communication at the physical layer. These generalized attacks apply to CR communications. The types of attacks are physical layer attacks which can cause network operation to malfunction or to stop completely. We then present three different methods for secured cognitive access over a defined spectrum. We conclude by comparing these methods over different parameters and for different networks.

Cognitive Gateway Design to Promote Universal Interoperability (paper)
Qinqin Chen, Charles W. Bostian, Virginia Tech

Cognitive gateways (CG) are conceived as a kind of special cognitive radio (CR) node that interconnects different systems. This paper presents a CG design which will facilitate universal interoperability between incompatible waveforms used by a variety of heterogeneous communication systems. In specific scenarios, a CG can act as a signal repeater, a waveform gateway or a network gateway to provide an extended service coverage area. The term “waveform” is defined as a protocol stack specification suite, namely a set of parameters describing the format of a communication signal (PHY) and its related processing protocols (MAC, LLC, NET, etc.).

Multi-radio Scheduling and Resource Sharing on a Software Defined Radio Computing Platform (paper)
Ari Ahtiainen, Kees van Berkel, David van Kampen, Orlando Moreira, Antti Piipponen, Tommi Zetterman, Nokia

Architecting Software Defined Radio (SDR) for handheld multimedia devices has become a major challenge in bringing mobile internet services to consumer markets. This paper describes a multiradio computer driven approach to software radio design. A model for a unified radio system is presented as the key concept to bring different radio applications under a common multiradio resource management scheme. This architecture provides basis for designing a multiradio operating system to guarantee that simultaneously executing radios can meet their real-time behavior requirements while sharing the computing, communication and hardware resources of the radio computer.

Opportunistic RADIO for multi-channel usage in WLAN Ad hoc networks (paper)
Soamsiri Chantaraskul, Klaus Moessner, Univ Surrey

This paper proposes an implementation of opportunistic radio for multi-channel usage in the IEEE 802.11-based ad hoc networks. Terminals in mobile ad hoc networks have to organize and manage the network since there is no base station to act as the central control unit. For this reason, terminals in current WLAN ad hoc networks employ the approach of “listen before talk” which means that once the network is set up, only one channel can be observed and used throughout. A great deal of work has been done to develop methods to allow the usage of multiple channels since there are three non-overlapping channels for 802.11b/g and twelve non-overlapping channels for 802.11a. However, these approaches mostly focus on the modification of MAC protocol to support the multi-channel usage. In this work, the proposed method employs a physical spectrum sensing, which is one of the opportunistic radio functionalities, to determine resource availability and make decision accordingly. The simulation results are provided to illustrate the potential benefits of the proposed approach in terms of system performance in comparison with the current WLAN ad hoc networks as well as with the multi-channel MAC approaches.

Session 2.1

Jitter Analysis of Time Interleaved ADC/DAC Systems (paper)
Chowdhury Shahriar, Bashirul A. Polash, Chris Anderson, Virginia Tech

In the case of time interleaved ADCs (round robin sampling with multiple ADCs), timing jitter can create harmonics in the sampled signal. One potential way to deal with this is to intentionally jitter the sampling instances using a pseudo-random sequence to jitter the timing. The result is a signal that's non-uniformly sampled which could then be run through a simple filter/interpolating algorithm to reconstruct it without the added noise. This may lead to a method for compensating mismatches in the ADC array without the need for precise calibration of the individual ADC timing delays. A special ADC/DAC structure suitable for high- sample rate SDR based on time-interleaving, implementation issues, limitations, impairments and possible solution using PN sequence is presented. It is found that using PN sequence to mimic the jitter along with the uses of interpolator/filtering reduces harmonics.

Digital-Self calibration of CMOS Mixers (paper)
Amneh Akour, Sheung Yan Ng, S. Rodriguez, Ohio State University

The integration of analog RF mixed signal circuits in System-on-Chip require designing analog circuits with high yield under process, temperature and power supply variations. This research introduces a built-in digital self- calibration Gilbert-cell mixer for Bluetooth application to meet the specifications under all process and temperature variations. Gain and linearity are calibrated by controlling the biasing points of the circuit using variable current mirror. This mixer is built and tested in TSMC 0.18 um CMOS technology at several corner conditions to validate the proposed technique.

Design of Manufacturable 60GHz CMOS LNAs (paper)
Amneh Akour, Mohammed Ismail, Roberto-Teran Rojas, Ohio State University

Emerging broadband applications are pushing for the need to build high data rate wireless transceivers at 60GHz for high volume low cost mobile devices. Central to the success of implementing such transceivers is the robust design of 60GHz CMOS RF front ends, especially the low noise amplifiers (LNAs). Two different topologies are used to build LNAs; two-stage CG-CS LNA and three-stage CS LNA. The performance of these topologies is compared to select the best one with the best transmission line type. This paper proposes a digital self-calibration technique for LNAs’ to enhance the yield to at least 90%. The proposed technique is shown to maintain typical specified performance at worst case corners and hence allowing for manufacturable 60GHz RF CMOS design for high volume applications without leading to over-design or increasing power consumption. The LNA has been designed and tested in IBM 90nm technology.  It is shown that the proposed calibration restores LNA performance in the presence of random process, supply and temperature variations.

Multiband Multimode Public Safety Radio Using a Multiband RFIC with a RF Multiplexer (paper)
S.M. Hasan, S.W. Ellingson, Virginia Tech

Various public safety personnel often cannot readily communicate with one another due to the lack of interoperability in their radios. One of the solutions to this problem is to provide user a multi-band multi-mode radio (MMR). In this paper we present the design of an experimental prototype multiband radio, which operates in public safety frequency bands from 100 MHz to 1 GHz. In our design we use a direct conversion CMOS transceiver RFIC developed by Motorola Research Laboratories, which covers the frequency range 100 MHz to 2.5 GHz and contains multiple receivers and transmitters. Although direct conversion has some significant advantages over superhet-based design particularly due to its low power consumption and cost, there is a significant challenge to achieve performance comparable to existing single and dual-band radios. Furthermore, it is difficult to cover all of these bands using the same type of monopole antennas already in common use. Our design employs a multiband antenna-transceiver interface consisting of an RF multiplexer which yields acceptable overall performance for operation in public safety frequency bands using a simple monopole antenna. An FPGA is used to implement all the digital signal processing and a small Gumstix computer including a touch screen LCD is used as a user interface.

A 65NM CMOS RF Front End Dedicated to Software Radio (paper) (presentation)
François Rivet, Yann Deval, Dominique Dallet, Jean-Baptiste Bégueret, Didier Belot, IMS

The next generation of mobile terminals is faced with the emergence of the Software Radio concept. The Software Radio concept aims at designing a reconfigurable radio architecture accepting any cellular or non-cellular standards working in the 0-5 GHz frequency range. But technical challenges have to be overcome in order to address this concept. The main bottleneck is the Analog to Digital conversion which cannot be done at Radio Frequencies, at an acceptable resolution and at an acceptable level of power consumption. The idea proposed here was to interface an analog pre-processing circuit between the antenna and a Digital Signal Processor (DSP). It pre-conditions the RF signal. It uses the principle of an analog Fast Fourier Transform (FFT) to carry out basic functions with high accuracy in a low-cost technology like 65nm CMOS. This paper presents the schematics, the design and the behavioral simulations of this analog discrete-time device which gives the hardware flexibility required for a cognitive radio component.

Session 2.2

IDROMel: an Open Platform Adressing Advanced SDR Challenges (paper)
Christophe MOY, Amor Nafka, Pierre LeRoy, Julien Delorme, Jacques Palicot, Dominique Nussbaum, Karim Kalfallah, Hervé Callewaert, Jérôme Martin, Fabien Clermidy, Bertrand Mercier, Renaud Pacalet, Supelec

This paper presents the ANR project IDROMel, which aims at developing reconfigurable SDR (Software Defined Radio) equipments. IDROMel is a 3 years project that started early 2005 and finishes at the end of year 2008. The main objective of IDROMel is to define, develop and validate a powerful SDR platform combining very last technology progresses. The platform includes software parts (reconfigurable protocol stacks) and hardware parts (a base band board and a Radio Frequency Front end, RF). Both parts are presented in this paper.

An SDR based Wireless Laboratory: Introducing Multi-Dimensional Signal Analysis (paper)
Sabih Guzelgoz, Ahmed Hesham, Omar Zakaria, Huseyin Arslan, University of South Florida

In this article, a novel Software-Defined Radio (SDR) based wireless communication systems laboratory is introduced. The laboratory teaches students how to design, test, and simulate SDR based wireless systems using modern instrumentation and computer aided design software. The laboratory mainly discusses signal characteristics in multiple domains such as time, spectrum, modulation, and code leading to the concept of multi-dimensional signal analysis. Multi-dimensional signal analysis is very important to understand challenges and trade-offs introduced by emerging wireless technologies. Learning multi-dimensional signal analysis helps students grasp difficult wireless concepts in laboratory environment.

Software Defined Radio Architectures Evaluation (paper) (presentation)
Álvaro Palomo Navarro, Rudi Villing, Ronan Farrell, NUI Maynooth

This paper presents an performance evaluation of GNU Radio and OSSIE, two open source Software Defined Radio (SDR) architectures. The two architectures were compared by running implementations of a BPSK waveform utilising a software loopback channel on each. The upper bound full duplex throughput was found to be around 700kbps in both cases, though OSSIE was slightly faster than GNU Radio. CPU and memory loads did not differ significantly.

The VITA Radio Transport as a Framework for Software Definable Radio Architectures (paper) (presentation)
Robert Normoyle, Paul Mesibov, DRS Signal Solutions

The VITA Radio Transport (VRT) protocol is an emerging standard for Software Definable Radio (SDR) applications. It was developed to provide interoperability between a diversity of SDR components by defining a transport protocol to convey digitized signal data and receiver settings. As such it provides an infrastructure to maintain sample-accurate alignment of signal data and discrete events between multiple receivers that are either collocated or separated by large distances.

Session 2.3

On the Challenges of Building Multi-antenna Software Defined Packet Radio (paper)
Ketan Mandke, Robert C. Daniels, Scott M. Nettles, Robert W. Heath, Jr., University of Texas

The development of software-defined radios presents a set of challenges that is uniquely different from those faced in the development of traditional hardware radios. This paper examines problems and design challenges encountered in the development of Hydra, a multi-antenna multihop wireless testbed. In particular, we address the impact of design choices in the software architecture of this prototype, software performance issues, and practical issues dealing with the radio frequency (RF) front-end.  

Distributed SDR Applications for Distance Learning (paper)
Carlos R. Aguayo Gonzalez, Carl Dietrich, Jeffrey H. Reed, Virginia Tech

Software-defined radio (SDR) has become a key technology in the development of wireless communications systems because of the flexibility it provides and its potential to enable exciting applications such as cognitive radio (CR). In order to maintain the innovation pace in this area, it is necessary to train future generations of engineers in the techniques, and crafts, of SDR development. This can only be achieved by complementing theoretical coursework with hands-on, practical labs, exposing engineering students to the latest SDR standards and development practices. To facilitate the acquisition of lab equipment for SDR training and reduce its cost, we present a distributed platform that allows remote users and distance learners to share key hardware resources, allowing them to perform complete experiments at a fraction of the cost. its cost, we present a distributed platform that allows remote users and distance learners share key hardware resources, allowing them to benefit from practical education at a fraction of the cost.

Use of Legacy Components in an SDR Rapid Prototyping Development Environment (paper)
Okhtay Azarmanesh and Sven G. Bilén, Penn State

A rapid prototyping procedure is being developed in this project. As an example, a GMSK demodulator is simulated in a SIMULINK environment and the result is then being programmed in FPGA using Xilinx toolbox’s block sets in SIMULINK. This method will enable us to easily develop and test different systems before implementing them completely. It will enable us to study the feasibility of a new SDR system on the hardware and, thus, it will considerably reduce the process time of testing new systems and waveforms on FPGA. This is particularly important when we wish to use legacy codes in a new system and be able to test the system as quickly and efficiently as possible.

UWB Wave-Radio (paper) (presentation)
M.S. AlJerjawi, Y.S. Xu, C. Nerguizian, C. Caloz, K. Wu, R.G. Bosisio, University of Montreal

In this work, new six-port interferometer architecture is used for wave-radio modulation and de-modulation. In transmission mode, the interferometer phase-modulates a monocycle pulse, while in receiving mode, and with the same architecture it demodulates the transmitted ultra-wide- band (UWB) signal. Results show that the new interferometer architecture operates efficiently in the 3.0 GHZ - 4.0 GHz UWB channel. As a testing criterion for overall wide band wave-radio performance, it is shown that the proposed wave-radio interferometer architecture exhibits a favourable bit error rate (BER) performance compared with other wideband radio communication systems utilizing QPSK modulation and related software radio engineering.

Picoceptor, Advanced Architecture for Miniature Software Definable Radio Systems (paper)
Clark Pope, Mike Kessler, DRS Signal Solutions

This paper introduces a novel software definable radio (SDR) architecture, called Picoceptor[1], which combines tight RF integration, a reconfigurable field- programmable gate array (FPGA) system on a chip (SOC), embedded Linux, and a USB 2.0 on-the-go (OTG) interface in a low-cost, low-power platform that fits into a shirt pocket. This advanced SDR system technology provides extensive savings in size, weight, and power (SWaP) by both increasing the functionality and flexibility of the processing hardware as well as eliminating the need for several typical system components. This paper also provides a brief history of SDR approaches and technology as well as a detailed description of the design objectives and choices when developing the Picoceptor architecture. The development tool set and environment are described. Finally, applications such as geo-location and spectral search are discussed with detailed implementation notes to highlight the adaptability and flexibility of the architecture for a wide range of SDR functions.

Session 2.4

FPGA Design for Supporting CORBA Component (paper)
Changhoon Lee, Jun Kim, Seungheon Hyeon, Seungwon Choi, Hanyang University

The Common Object Request Broker Architecture (CORBA) standard that supports the Field Programmable Gate Array (FPGA) is not generally used because it is difficult to implement and to develop using Hardware Description Language (HDL). In this paper, we propose a way to design an FPGA to support a CORBA. For FPGA to support the CORBA, an embedded microprocessor implemented in FPGA, a peripheral component interconnect (PCI)-based CORBA software, is used. The PCI-based CORBA improves data transfer throughput.

Design and Implementation of high-speed data transfer protocol in CORBA environment (paper)
June Kim, Seungheon Hyeon, Seungwon Choi, Hanyang University

The heavy burden of CORBA(Common Object Request Broker Architecture ) is one of the most serious hindrances in implementing the SDR(Software Defined Radio) System. As most GIOP(General Inter Object Request Broker Protocol) implementations are based on TCP/IP (Transmission Control Protocol/Internet Protocol) based IIOP (Internet Inter Object Request Broker Protocol), data exchange between CORBA components operating independently should pass through the TCP/IP layer. With such an inefficient operation, the waveform application required in SDR systems can hardly be provided in real- time. This paper presents a novel protocol that enables ORB(Object Request Broker) to exchange CORBA message through PCI bus.

An Adaptive Beamforming Technique for OFDM-Based Smart Antenna System in a Multipath Fading (paper)
Yongjin Jo, Taeyoul Oh, Seungwon Choi, Hanyang University

Multiple antenna technology, such as multiple-input multiple-output (MIMO) or beamforming has been known as the most promising technology for broadband wireless communication. In OFDM environment, however beamforming system cannot fully exploit beamforming gain because each path is divided in multipath fading channel. In this paper, we propose a beamforming technique for the OFDMA system and analyze the performance of the proposed beamforming technique for WiBro/WiMAX, which is based on an OFDMA wireless broadband multimedia environment. The proposed beamforming technique can further improve the required SNR (Signal to Noise Ratio) by approximately 3dB and 1.5dB compared to conventional beamforming technique in vehicular and pedestrian channel environment, respectively.

A Beamforming Algorithm for Collaborative MIMO System with Array Antenna (paper)
Chang-eui Shin, Yusuk Yun, Seungwon Choi, Hanyang University

Collaborative spatial multiplexing (CSM) allows individual handsets to transmit each signal at the same carrier and same time as independent signals are transmitted through each antenna of one device in MIMO system. In this paper, we propose algorithm to combine CSM and beamforming technique for OFDM system. When the base station has 8 antenna elements, it is observed that the BER is improved by 6 dB compared to CSM without beamforming. In order to detect MIMO signals, we adopt ML (Maximum Likelihood) detection.

Development of Waveform Component for SDR System Supporting Mobile WIMAX (paper)
Mijin Baek, Seungheon Hyeon, Seungwon Choi, Hanyang University

In this paper, we develop waveform components for software defined radio (SDR) based mobile WiMAX. Waveform components are developed in accordance with the "PIM and PSM for Software Radio components" specification that is promoted by Object Management Group (OMG). This specification defines standard components and application programming interfaces (API) for developing waveform components. A developing procedure of the waveform component is focused on composability and substitutability of components. Even though developed waveform components are to Mobile WiMAX, the proposed procedure can be adopted to any waveform.

Implementation of a WLAN Waveform Under Cost-Effective Novel Software and Hardware (paper)
Huijing Qiang, Omar Granados; Jean Andrian; Jun Luo; Matthew Woolley, Florida International University

Research and development of software defined radio (SDR) systems has been on the rise in recent years. However, there are still many challenges to overcome. Among these, the issue of creating an affordable software architecture that supports different types of waveforms for possible commercial use is a critical one. In this paper, based on our novel low cost system software architecture design, we will describe the implementation of an IEEE 802.11a WLAN waveform by using GNU Radio. In order to realize low cost and real time application, middleware such as CORBA will not be used in our system. By using GNU Radio software and Universal Software Radio Peripheral (USRP) hardware, the overall development period will be greatly shortened. Algorithms are first simulated in Matlab and then tested in a real environment. Multi-band, multi-protocol communication systems and cognitive radio capabilities will also be discussed in this paper as a future extension of our prototype as well as using the proposed SDR as the data communications platform for the “Enhanced Image Capture and Transfer” (EICT) application.

Session 2.5

Multi Giga-hertz Software Defined Ratio Platform for Modular DSP Architectures (paper)
Benjamin Egg, Chris Dick, Todd Thornton, fred harris, Mike Rupar, Ivan Corretjer, Aethercomm, Inc.

Higher data rate communication system demands and multi-function, multi-band, devices have driven the theoretical software defined radio (SDR) toward a maturing reality. Although a plethora of SDR prototypes have been and are being developed, one of the most common characteristics of each is high R&D costs. Common proprietary data confidentiality keeps many advanced architectures and discoveries unpublished, leading to ‘reinventing of the wheel’. We have chosen to discuss three areas we consider key building blocks to a successful and timely SDR prototype. These three key points may be obvious to some and surprising to others, or as the reader delves deeper, possibly both— surprisingly obvious.

Multi-Core and Optical Processor Related Applications Research at Oak Ridge National Lab (paper)
Mark A. Buckner, Jacob Barhen, Ryan Kerekes, Oak Ridge

High-speed parallelization of common tasks holds great promise as a low-risk approach to achieving the significant increases in signal processing and computational performance required for next generation innovations in reconfigurable radio systems. Researchers at the Oak Ridge National Laboratory have been working on exploiting the parallelization offered by this emerging technology and applying it to a variety of problems. This paper will highlight recent experience with four different parallel processors applied to signal processing tasks that are directly relevant to signal processing required for SDR/CR waveforms. The first is the EnLight Optical Core Processor applied to matched filter (MF) correlation processing via fast Fourier transform (FFT) of broadband Doppler- sensitive waveforms (DSW) using active sonar arrays for target tracking. The second is the IBM CELL™ Broadband Engine applied to 2-D discrete Fourier transform (DFT) kernel for image processing and frequency domain processing. And the third is the NVIDIA graphical processor applied to document feature clustering.

The sb3500 Processor Implementation (paper)
John Glossner, Mayan Moudgill, Sitij Agarwal, Gary Nacer, Sandbridge

The Sandblaster architecture is a high-performance vector architecture targeted at digital signal processing applications. The Sandblaster 1.0 architecture was targeted at implementing the physical layer of 3G wireless standards, with peak data rates of up to 15 Mbps. In this paper, we describe an object code compatible version 2.0 of the Sandblaster architecture, which is targeted at the 4G standards, which have support higher data-rates and more complex algorithms.

Multi-Mode Basestation Common Platform Software Defined Radio: Whats In A Name (paper)
Manuel Uhm, Xilinx

It is commonly known that Software Defined Radio (SDR) technology is rapidly maturing and coming to fruition in the military through programs like the Joint Tactical Radio System (JTRS). This coincides with the trend in commercial wireless infrastructure towards “multi-mode base stations” and “common platforms” driving the concept of base stations (BTSes) that can support more than one air interface protocol and be upgraded after deployment to add new applications or services. The advantage for operators is the ability to significantly reduce capital expenditures (CAPEX) and operating expenditures (OPEX) by remote upgrades through software. Infrastructure vendors also benefit from reduced costs due to lower development costs, economies of scale, and a greatly simplified supply chain. Ironically, SDR technology is enabling this evolution in commercial platforms, despite its strongly held affiliation with military applications. This paper will examine the trends in commercial wireless and the impact of SDR technology for infrastructure applications.

Teledensity Growth in the Developing World through SDR Technology (paper)
John Chapin, Vanu

Vanu, Inc. has exploited software defined radio (SDR) technology in its Anywave™ and MultiRAN™ cellular radio access network products to help bring low-cost cellular telephone and wireless data access to rural areas in developing countries. This is a counterintuitive application of SDR, which is normally regarded as a way of designing high-end devices. We explain this application of SDR from both technical and business perspectives. We discuss India as a case study.

Session 2.6

Design and Implementation of the SDR Digital Control System (SDR-DCS) for the Baseband (paper)
Khalid Eltahir Mohamed. Borhanuddin Mohd. Ali, S.S. Jamuar, Sabira Khatun, Alyani Ismail, University Putra Malaysia

In this paper, SDR Digital Control System (SDR-DCS) has been developed to perform the multi standard protocol of the handset using GSM and CDMA systems. This system has been designed for SDR baseband digital transceiver for the handset such that it could roam between different wireless systems. The SDR-DCS controls the download of the specific air interface environment, to the unique hardware accordingly. The Synopsys™ software has been used with combination of VHDL and Verilog languages. The simulation tools used are Model Sim and System Studio. Xilinx ISE 9.2i has been used as synthesis tool. The results of the simulated and synthesized top-level design files were downloaded into the Xilinx XSA-3S1000 FPGA board.

Flexible Base Stations and Associated Management Functionality in the B3G World (paper)
Aggelos Saatsakis, Panagiotis Demestichas, Siegfried Walter, Thomas Loewel, Ferenc Noack, Klaus Nolte, Wolfgang Koenig, University of Piraeus

Management functionality in the wireless B3G will have to solve complex problems, due to the existence of versatile options for satisfying stringent requirements, under difficult environment conditions. The introduction of Flexible Base Stations (FBSs) in the B3G world is a direction for achieving efficient management, exploiting the reconfiguration capabilities in software and hardware level. In this paper, the FBS architecture and the management functionalities are described. Furthermore, the efficiency gained through the use of the management functionalities on FBSs will be shown from indicative results.

Programmable RF Transceivers for Femtocells (paper)
Erik L. Org, Russell J. Cyr, Geoff Dawe, John Kilpatrick, BitWave

The Home Base Station or Femtocell Market is a market segment that can be well served by programmable RF platforms. Many business cases describe the advantages of offloading both cellular voice and data traffic from the wide area network (WAN) onto the IP backbone via a residential broadband connection. This significantly reduces operator CapEx and OpEx. However, the long term success of this strategy may depend on identifying a suitable low cost architecture for the radio. Due to the relatively low initial volume in the Femtocell market (as compared to that of the mature handset market), integrated RF transceiver solutions which meet industry requirements for cost and performance have been slow to appear. Carriers need Femtocells which will directly support voice and data connectivity over multiple bands within the carrier’s licensed spectrum and which will also enable channel sniffing. Existing design approaches quickly converge to architectures employing multiple RF transceivers to support both the Femtocell and channel sniffing functionality.

What Does the "Mainstream" Need to Adopt "True" Software Defined Radio? (paper)
Steve Jennis, PrismTech

Let’s start with the title of this paper. By mainstream we mean the original equipment manufacturers (OEMs) of wireless data and telecommunications equipment for markets beyond government use (e.g. military, aerospace, public safety). In other words, commercial telecom network equipment and terminal OEMs – such as cellular base transceiver station (BTS), femtocell, and terminal manufacturers.

Session 3.5

OMG Introduction (paper)
Kevin Richardson, MITRE

Flexibility of established RAN architectures is limited due to missing standard/frequency band adaptability of the infrastructure to the environment. There are no means to adapt the RAN dynamically to the actual mix of terminals within a cell and to changing traffic demands e.g. caused by extraordinary events e.g. such as large sport events. Furthermore deployed terminals need to support a multitude of existing radio standards. This leads to longer time to market, higher complexity and shorter battery lifetime of the terminals.

Session 3.6

STRS Compliant FPGA Waveform Development (paper)
Jennifer Nappier, Joseph Downey, NASA

The Space Telecommunications Radio System (STRS) Architecture Standard describes a standard for NASA space software defined radios (SDRs). It provides a common framework that can be used to develop and operate a space SDR in a reconfigurable and reprogrammable manner. One goal of the STRS Architecture is to promote waveform reuse among multiple software defined radios. Many space domain waveforms are designed to run in the special signal processing (SSP) hardware. However, the STRS Architecture is currently incomplete in defining a standard for designing waveforms in the SSP hardware. Therefore, the STRS Architecture needs to be extended to encompass waveform development in the SSP hardware. The extension of STRS to the SSP hardware will promote easier waveform reconfiguration and reuse. A transmit waveform for space applications was developed to determine ways to extend the STRS Architecture to a field programmable gate array (FPGA). These extensions include a standard hardware abstraction layer for FPGAs and a standard interface between waveform functions running inside a FPGA. A FPGA-based transmit waveform implementation of the proposed standard interfaces on a laboratory breadboard SDR will be discussed.

Case Study: Using the OMG UML Profile for Software Radio on NASA"s Space Telecommunications (paper)
Richard C. Reinhart, NASA

The Space Telecommunication Radio System (STRS) standard is a Software Defined Radio (SDR) architecture standard developed by NASA. The goal of STRS is to reduce NASA’s dependence on custom, proprietary architectures with unique and varying interfaces and hardware and support reuse of waveforms across platforms. The STRS project worked with members of the Object Management Group (OMG), Software Defined Radio Forum, and industry partners to leverage existing standards and knowledge. This collaboration included investigating the use of the OMG’s Platform-Independent Model (PIM) SWRadio as the basis for an STRS PIM. This paper details the influence of the OMG technologies on the STRS update effort, findings in the STRS/SWRadio mapping, and provides a summary of the SDR Forum recommendations.

Session 4.1

Applying Design Patterns to SCA Implementations (paper) (presentation)
Adem Zumbul, Tubitak

This paper provides insights into applying common design patterns while developing SCA compliant Core Frameworks and Waveforms. This paper also presents an approach to leverage SCA as a means of abstracting the Core Framework and Waveform implementations from the Operating System and Object Request Brokers. In addition to these, the experimental results of implementing a fully functional SCA Core Framework and some Waveforms in ACE/TAO and ORBExpress Object Request Brokers on Linux and VxWorks operating systems in terms of applying common design patterns are summarized.

Experience report on the use of CORBA as the sole middleware solution in SCA-based SDR env (paper)
Fabio Casalino, Dominick Paniscotti, Selex

This paper is an experience report detailing SELEX Communications’ findings in the use of CORBA as the sole middleware in SCA-based Software Defined Radios. This paper describes the different approaches used historically by SCA based systems to connect general- purpose processors to resource constrained processing elements such as FPGAs and DSPs. Following this, focus is turned to asserting that CORBA technology is ready to be fully exploited on SDRs, by describing how CORBA pluggable transports in SCA-based radio systems can be used to reduce the latency and throughput overhead associated with using CORBA’s default transport (TCP/IP).  

An SCA Waveform Development Process Integrating Waveform Modelling and Component Dev (paper) (presentation)
Shaw Ping Lee, Mark Hermeling, Thales

Of great value to the Software Defined Radio (SDR) application developer is an integrated tool chain that combines a domain-specific SCA tool for the development of SCA artifacts with a general-purpose UML-based tool for the development of component artifacts. We have defined a process which integrates Zeligsoft CE™ with Telelogic Rhapsody to achieve waveform modeling and component development in tandem in three independent and repeatable steps. The three steps involve reverse-engineering a component C++ worker class in Rhapsody, modeling the component function in UML, and configuring the Operating Environment (OE) to compile the framework code with the component code. This process has been applied to develop successfully two waveforms from a single architecture model for two OEs. Engineers truly benefit from using this process in term of time saving, shorter learning curve, and reduced porting effort.

Model Driven Testing and the SCA (paper)
Toby McClean, Mark Hermeling, Francis Bordeleau, Zeligsoft

One of the key objectives of the Software Communication Architecture (SCA) is the decoupling of applications (waveforms) and platforms, which aims to enable the porting of waveforms from one radio platform to another. The work done in the last decade has resulted in the development of technologies and commercial products that have significantly reduced the complexity and risk associated with the development of SCA-compliant. However, in spite of the fact that testing accounts for a large percentage of the development effort in embedded systems and that the SCA introduces new testing challenges, the key aspects of SCA application testing have not been seriously addressed yet by the industry.

Session 4.2

Comparative study of two Software Defined Radio Environments (paper)
Frédéric LeRoy, Gaël Abgrall, Jean-Philippe Delahaye, Jean-Philippe Diguet, Guy Gogniat, Ensieta

The aim of this paper is to compare the performances of two free SDR platforms: GNU Radio and OSSIE which are deployed on the same computer. SDR applications development or waveforms conception are pretty close in these two systems but the software architectures are totally different. In order to quantify the cost of inter-components communication, the same waveform has been characterized on both platforms. Three critical points are evaluated: latency, CPU load and memory utilization. The results show that the average CPU load in OSSIE is five times higher than GNU Radio. The issue is the same for the inter- component latency where GNU Radio is almost 25 times faster than OSSIE.

Bridging Design Stages of an FPGA-based System with a Structured Abstraction Methodology (paper)
K. Wagner, MITRE

Modeling a complex system at increasing levels of abstraction reduces cost and schedule risks by providing early feedback on the effects of design decisions while also speeding up the overall design process, but it also introduces complexities to the design flow. Each level of abstraction requires a different skill set to design and analyze. Even the types of tools used vary between the abstraction levels. Transferring system requirements down through the levels and propagating results back up can be a complicated and error-prone process. Using a well-defined incremental approach with design artifacts that overlap the abstraction levels simplifies the process while still allowing designers to leverage the available features of their abstraction level. The MITRE Programmable Radio Technology (PRT) Laboratory demonstrated this approach through the implementation of a highly portable FPGA- based high bandwidth high throughput (HBHT) high data rate (HDR) modem.

Dynamic Mapping of Waveforms within the PHAL Execution Environment (paper)
Vuk Marojevic, Ismael Gomez, José Salazar, A. Gelonch, Universitat Politècnica de Catalunya

This paper presents a computing resource management approach within the SDR execution environment PHAL. PHAL provides several features, including timing management and resource awareness, for an efficient computing resource management. Simulations show its capability for mapping a modular SDR application or waveform to the distributed computing resources in real- time, thus, facilitating the dynamic reconfiguration of SDR platforms.

Automating FPGA-Based System Implementation with Common Interfacing (paper)
John Bradley, Karl Wagner, MITRE

A challenge in component-based design is reliably and efficiently instantiating the transport and any translation functions required to transfer data between each component comprising the entire system. While the components may involve complicated manipulation of the data stream, the transport between them is typically much simpler. It can be abstractly defined in terms of data flow characteristics qualified by various properties of the targeted hardware platform. If the interface between the components of the system is well defined, automated tools can easily create the required transport based on a high level structural view of the system. This paper will describe a complete solution for automating the process of interconnecting all components of a system. First, we defined a set of three component interfaces based on Open Core Protocol (a low-level hardware interface definition standard) that, as a group, we refer to as Common Interfaces. Next, we defined an XML representation and created a GUI for describing the high-level characteristics of the component interfaces and the interconnection of the components within the system. Lastly, we developed scripts to generate hardware description language source for the entire system besides the components. In so doing, we have freed the system designer to focus on developing the components, the heart of the system.

Session 4.3

SCA Compatible Software Defined Wideband Receiver for Real-Time Energy Detection and Mod (paper)
Peter Andreadis, Robin Addison, Paolo Mancini, Giovanni Scialanca, LOG.IN

In this paper, a low-cost SCA compatible Software Defined Wideband Receiver (SDWR) prototype is described. The SDWR consists of off-the-shelf basic hardware components and a sophisticated software component. It is designed to detect and recognize an RF signal using Automatic Energy Detection (AED) and Automatic Modulation Recognition (AMR) software algorithms, developed by LOG.IN, in conjunction with common SCA compliant waveforms. The AED operates a real-time, blind wideband search of the electromagnetic energy, whereas the AMR identifies the parameters of a specific detected energy. The main focus of this paper is the integration of the hardware and software using SCA compatible devices and resources. The hardware includes a WiNRADiO Wintuner front end with an Ettus Inc. USRP device connected to a COTS laptop computer. The radio controller and waveforms are all developed in software using the CRC SCARI ++ suite and wrapping the LOG.IN AED and AMR resources for SCA compatibility.

Is SCA Aligned? Business Approach to SDR Development (paper) (presentation)
Rafael Aguado Munoz, Indra

Almost 10 years ago, SCA (Software Communications Architecture) appears as solutions to deal with the needs of govern in the structure and correct operation of SDR (Software Defined Radio). Today, as organizations, we are defined by our software; furthermore, as the software gets more and more relevance, we are abstracting the hardware almost to the point of commoditization, so we need to find a way to measure how good the software is and how to measure its value. Due to this situation we have to define govern guidelines to assure that the services agreements are aligned with the business needs, by defining a set of best practices and a framework to measure and show how right we are doing IT.

The application of SCA in the design of high data rate (HDR) JTRS radios and waveforms (paper)
Shahzad Aslam-Mir, Wallace Davis, DataSoft

The JTRS SCA architecture is designed to promote reuse of software elements that are primarily GPP and in limited instances, DSP bound. The SCA provides a uniform harmonizing foundational platform upon which waveform software element reuse becomes more attractive.

The deployment of software components into heterogeneous SCA platforms (paper) (presentation)
Steve Bernier, Charles Auger; Hugues Latour, CRC

This paper examines the JTRS goal of maximizing reusability of common software and hardware for different software defined radios. It does so by analyzing the different aspects of reusability through portability of SCA applications. It looks at binary reuse as well as at source code portability. For the latter, the paper describes how the SCA enhances portability when dealing with aspects such as Operating Systems, Middleware and Platform Devices. The paper also describes the different mechanisms provided by the Software Communications Architecture (SCA) to deploy software components. In doing so, it provides a detailed discussion on how the SCA addresses operating environments that support multiple processes as well as those that don't. Finally, the paper provides guidelines on how to map the SCA Loadable and Executable Devices to the different Computational Elements (GPPs, DSPs and FPGAs) that can be found on an SDR system.

Session 4.4

Error budget Analysis of a software defined radio – predicting BER and improving (paper) (presentation)
Richard Overdorf, Agilent

Ideally a Software Defined Radio (SDR) is designed to accept a multitude of waveforms at any carrier frequency. This paper will discuss the importance of PHY layer measurements made in both the digital and analog domains including the additive effects impairments can have on BER. The paper will consider interoperability of a SDR with respect to three different modulation formats; OFDM, CDMA, and QAM. The importance of BER budgeting and a multitude of critical measurements including EVM, CCDF, ACP, spectrum mask, constellation displays, noise figure, phase noise will be discussed.

PCET: A Tool for Rapidly Estimating Statistics of Waveform Components Implemented on Digit (paper)
James Neel, Shareef Sayed, Mathew Carrick, Carl Dietrich, Jeff Reed, Cognitive Radio Technologies

The Processor Cycle Estimation Tool (PCET) is an extensible open-source tool for rapidly estimating the cycles, power, and memory requirements of waveform components across disparate DSP architectures. This paper reviews the methodologies employed in PCET and compares estimated values with vendor-provided library code and from measured implementations.

A Software Development and Validation Framework for SDR Platforms (paper) (presentation)
Jeroen Declerck, Erik Umans, Antoine Dejonghe, Martin Trautmann, Miguel Glassee, Liesbet Van der Perre, IMEC

The trend towards reconfigurable radio has moved the software design for radio systems to a new level of complexity. Not only have some of the hardware components been replaced by software kernels on general purpose or application specific processors, but also the system level software has moved down the latter from MAC level towards the PHY level. This paper describes the software framework used for the PHY and MAC software development, simulation and validation on the IMEC SDR platform and illustrates it with several use cases.  

Certification for SDRs in new Public and Governmental Security Systems (paper)
Stefan Nagel, Volker Blaschke, Jens Elsner, Friedrich K. Jondral, Dimitrios Symeonidis, Univ Karlsruhe

The today's networks of Public and Governmental Security (P&GS) systems are characterized by a heterogeneous structure. Since the last years the demand for interoperability between such networks has been increased, significantly. Furthermore, flexible hardware platforms and portable waveform applications are required in order to provide flexible and adaptable solutions to costumers. In order to ensure interoperability between terminals of different vendors and compatibility of waveforms leads to a certification process which each system has to pass. Both aspects, platform as well as waveform certification needs will be discussed in the following paper.

Session 4.5

Proposal for an Efficient Software Optimization Method for Software Defined Radio (paper)
Yuji Ikeda, Kosuke Yamazaki, Toshiyuki Maeyama, Yoshio Takeuchi, KDDI

Recently, various digital signal processors (DSP) for Software defined Radio (SDR) have been released. To develop SDR software, the processing time must be within the interval required by the wireless communication system. If this period is too short, the SDR software needs to be optimized to maximize the potential of the DSP. However, as each DSP has its own specialized hardware architecture, the software optimization takes a very long time. Moreover, the software optimized for one DSP does not work well on other DSPs.

An RF "aware" Software Defined Radio Design and Verification Methodology (paper)
Frank Ditore, David Leiss, Greg Jue, Agilent

Design goals and development schedules make simulation an essential tool in the development of new communication systems and SDR waveforms. For today's radios, this means the simulation must be able to model the mixed-domain design of the waveform PHY so that baseband impairments can be examined together with accurate RF impairments modeled both behaviorally and at the circuit level. Additionally, links between waveform simulation and physical test can greatly facilitate the implementation of the simulated waveform design in hardware.

Techniques for Commercial SDR Waveform Development (paper)
Annalies Squires, Etherstack

Software Defined Radio (SDR) hardware platforms have been used in commercial defence and Land Mobile Radio (LMR) communications for several years now. However the real value of SDR - software reusability, upgradeability and portability – is still often not achieved because the software itself fails to exploit the full potential of these platforms.

Dataflow programming: Building Portable and Efficient Designs in Heterogeneous Programmable (paper)
Jorn Janneck, Chris Dick, Xilinx

The development of modern electronic systems increasingly faces qualitative pressures coming from a growing techni- cal diversity and heterogeneity of the computational elements used to build them, as well as move toward parallel computing resulting from the fact that sequential processors are not becoming faster at the rate they used to. These two developments require a fundamental shift in the way systems are conceived and implemented. We propose a dataflow design methodology built around a notion of transactional execution of asynchronously communicating elements (”actors”). This model permits efficient implementation on a variety of computating platforms. It is based on simple, understandable abstractions which are a natural medium for expressing the various levels of parallelism in an application. Its parallelism naturally scales with application size, i.e. larger programs tend to include more parallel execution than smaller ones. In addition, this dataflow methodology also provides the foundation for an entirely new approach to the profiling and analysis of concurrent programs, which can be used to guide the implementation of a dataflow program and its mapping to a computing platform.

Session 4.6

A Practical View of SDR Baseband Processing Portability (paper) (presentation)
T. Kempf, E. M. Witte, V. Ramakrishnan, G. Ascheid, M. Adrat, M. Antweiler, Aachen Univ

Software Defined Radios (SDRs) are a promising approach to efficiently use the resources of a wireless communication platform for multi-standard systems. Contrary to this advantage, the SDR concept imposes new and huge design challenges for software and hardware designers. One key issue is the trade-off between energy efficiency, architecture efficiency, flexibility as well as portability. In this paper key aspects of the SDR design space are investigated: The selection of processing elements (e.g. GPPs or DSPs) and the selection of software implementation strategies (e.g. C or Assembly). Measurements and analysis support these trade-off discussions along with the identification of key issues for portable and efficient SDR implementations.

Experiences in the Co-Design of Software and Hardware Elements in a SDR Platform (paper)
M.S. Mora, Gerry Corley, Jorg Lotze, Ronan Farrell, CTVR, National University of Ireland

The Center for Telecommunications Value-Chain Research (CTVR) has developed an integrated software radio plat- form, which consists of a RF transceiver, called the Maynooth Adaptive Radio System (MARS), and a software radio framework, called Implementing Radio in Software (IRiS). Developing a complete SDR system involves a wide range of disciplines. For example, the construction of our integrated software radio platform requires the interaction between the two subsystems: MARS and IRIS, which result in design challenges at hardware, firmware and software level. The experiences and challenges faced in achieving this integration will be described as well as a demonstration showing the working condition of the integrated software radio platform. The demonstration consists of an image re- ception using DQPSK modulation with IRIS and MARS at 2.41GHz. This demonstrates the capability to implement more complex experiments in future, such as audio or video transmission, and cognitive radios for dynamic spectrum access techniques. The MARS platform’s software interface also opens new research opportunities for integration with other third party software radio frameworks.

Algorithm-Architecture Co-Design for Energy Efficient Software Defined Radio Baseband (paper) (presentation)
Min Li, David Novo, Bruno Bougard, Liesbet Van Der Perre, Francky Catthoor, IMEC

The diversity and evolution of wireless communication standards are fast pacing. This requires a wide variety of baseband implementations within a short time-to-market. Besides, the deep sub-micron technology significantly increases design complexity and associated cost. These yield an increasing need for reconfigurable/programmable baseband solutions. Implementing all baseband functionalities on programmable architectures, as foreseen in the tier-2 SDR, will become a must. However, the energy efficiency of SDR baseband platforms is unavoidably worse than ASICs, this brings a challenging gap to bridge. The gap is broadening with the exploding baseband complexity. We advocate a system level approach to bridge the gap with a holistic view. First of all, we explicitly introduce architecture and compiler friendliness from the very beginning of the design flow, this enables highly efficient mapping on the targeted architecture. Furthermore, we fully leverage the advantages (programmability) of SDR platforms to compensate its disadvantages (energy efficiency). Highly flexible baseband implementations are developed to exploit the abundant dynamics in the environment and the user requirement to reduce energy consumption.

From Requirements Capture to Silicon: A Model-Driven Systems Engineering Approach to Rapid (paper)
Mark A. Buckner, Brian Kaldenbach, Oak Ridge

The performance and complexity of the signal processing hardware accessible to SDR/CR/RADAR designers has quickly out-paced the available design tools. The advances in Digital Signal Processors (DSP) both fixed- and floating- point, Field Programmable Gate Arrays (FPGA), and multi- core processors have enabled rapid prototyping and deployment of platforms that can be dynamically reconfigured in the field to implement a variety of SDR/CR/RADAR waveforms. Until recently the process of creating waveforms meant starting with high-level mathematical models and simulations and then creating production quality code that can operate on this variety of specialized hardware using either hand coding or vendor specific tools, which are typically limited to single processor solutions.

Systems Architecting and Engineering Processes and Methodologies: Essential Enablers (paper) (presentation)
James Rodenkirch, Bill Bolick, Diversified Technology

Future mainstream users of Cognitive Radios are eager for solutions to the problems and constraints associated with wireless space. Myriad user activities and functions, legacy communication systems and competing agencies overseeing the user communities signal a rich environment for Systems Architected solutions. Cooperation between the user and the builder, along with a melding of overarching visions and concepts with pragmatic outlooks, will be pivotal for the correct solution to materialize.

Session 5.1

Vertical Handoff in Wireless Overlapping Networks (paper)
Andres Marquez, Wilfrido Moreno, Huseyin Arslan, University of South Florida

As wireless communications services continue increasing, continuous coverage and QoS parameters must be guaranteed to the end user. Due to the fact that in most places several wireless networks might be available, handing off between them can significantly enhance network efficiency and user satisfaction. In such a scenario, continuous environment monitoring is required for estimating links’ conditions in real time from which the network selection process is executed. This paper presents a vertical handoff architecture relying on SDR capable devices for simultaneous diverse networks’ parameters identification and dynamic communication link adaptation.

Using SDR to Embed WiMAX Channels Within the Tetra Framework (paper)
Ling Gao, Ronan Farrell, NUI Maynooth

In recent years there has been a move to increase the data capabilities of TErrestrial Trunked Radio (TETRA) so as to provide secure broadband data capabilities. An initial enhancement (TETRA Enhanced Data Service, TEDS) has been agreed but there is a need to access additional spectrum. An investigation was carried out by European Telecommunications Standards Institute (ETSI) has concluded that a single standardised frequency band cannot be agreed and the concept of a tuning range for enhanced TETRA services can be deployed is gaining acceptance. In addition to needing flexibility in frequency, the enhanced TETRA services allows for more flexibility in the communication modes used so as to provide adaptability in applications. We propose that it is possible to deploy Software Defined Radio (SDR) technologies into the basestation to economically provide this level of flexibility, and to further extend the capability of TETRA services by deploying a WiMAX channel into the proposed TETRA tuning range and deliver true broadband data service while simultaneously support the original and enhanced TETRA services.

Software Defined Radio in Wireless Ad-hoc Network (paper)
Ajay Kr.Singh, G. Singh and DS Chauhan, Jaypee University

The parameters of communication in ad-hoc network such as the distance between nodes and channel characteristics changes frequently with the position of the user. For efficient use of such a communication systems, we can change software specification rather than changing any hardware (such as chip), because change of hardware is difficult and cost effective as compared to that of software. On such way software defined radio (SDR) is simple and economically beneficial. In this paper, we are using concept of M-ary phase shift keying (MPSK) technique for adaptive detection. Implementation of MPSK adaptive detection is performed by using software programming of MPSK modulation and it can be reprogrammed according to the requirement. Use of radio signal makes this network more reliable and flexible because of its property.

Throughput-Enhancement for CSMA-based Mobile Ad Hoc Networks (paper) (presentation)
Rainer Storn, Rohde & Schwarz

Mobile ad-hoc networks (MANETs) are considerably appealing especially for military and desaster recovery communication applications since they offer two distinct advantages: easy setup due to the absence of an infrastructure, and robustness because MANETs have no single point of failure. As MANETs generally allow a flexible number of participating nodes the preferred medium access protocol is CSMA/CA as in IEEE802.11 [1]. CSMA/CA not only supports the required node flexibility but also a mixture of traffic types. MANETs are also able to cover large distances by means of multi-hopping. Data transport via multiple hops, however, suffers from the disadvantage of throughput decrease. The main reason for this is that the radios transmit over a shared medium the access to which must be controlled to avoid transmission collisions. With increasing number of nodes and increasing traffic load the probability for transmission collisions increases which results in a decreased medium utilization due to waiting times imposed by the MAC protocol and hence reduced throughput. The throughput also decreases with decreasing data packet size. Small data packets are prevalent in voice and network control traffic with voice still constituting one of the most important applications in wireless communications, and hence the efficient handling of small packets is imperative. In this contribution several measures are proposed which have the potential to yield a significant throughput increase, especially for small data packets and under high network load while delay is affected as little as possible. The improved transmission scheme is exemplified by means of a CSMA/CA MAC protocol.

Session 5.2

Line Enhancer Methods for Carrier Tracking in QAM/PSK Data Signals (paper)
Randall Flint, Behrouz Farhang-Boroujeny, University of Utah

In mobile communication systems, the Doppler shift is a very common cause of time-varying changes in the carrier- frequency offset. This paper discusses two adaptive line enhancer algorithms which are used to aid in the process of detecting and tracking these time-varying changes. Specifically, it describes the use of an adaptive line enhancer in a quadrature amplitude modulation (QAM), or phase shift keying (PSK), carrier-recovery system. It shows that finite-impulse response (FIR) adaptive line enhancers are not well- suited for tracking changes in the carrier-frequency offset. Then, based on the LMS algorithm, an infinite-impulse response (IIR) adaptive line enhancer algorithm is presented, which is much more effective at tracking the carrier frequency offset. Next, an FIR post-filtering operation is described that is optimal for out-of-band noise rejection, and is used in conjunction with the IIR adaptive line enhancer to further improve its line-enhancement capabilities. Finally, simulation results are presented to compare the effectiveness of the FIR and IIR adaptive line enhancer algorithms at tracking changes in the carrier-frequency offset.

Implementing the TETRA physical layer on Lyrtech"s SFF SDR Development Platform (paper)
Stefan Nagel, Dennis Epple, Friedrich K. Jondral, Univ Karlsruhe

This paper presents the implementation of the TETRA physical layer on an FPGA/DSP based development platform. The objective is to implement a highly portable waveform and to determine the optimal boundary between FPGA-functions and DSP-functions. Due to the portability aspect, we tried to implement as much functionality as possible on the DSP and followed a design process proposed from the Model Driven Architecture. The Lyrtech Small Form Factor SDR Development Platform is used as the hardware platform. It is equipped with a Virtex-4 SX35 FPGA from Xilinx and a TMS320DM6446 DSP system-on- chip from Texas Instruments.

FlexSphere: An FPGA Configurable K-best Sphere Detector for SDM/SDMA Wireless Systems (paper)
Kiarash Amiri, Chris Dick, Raghu Rao, Joseph R. Cavallaro, Rice University

Spatial division multiplexing (SDM) in MIMO technology significantly increases the spectral efficiency, and hence capacity, of a wireless communication system: it is a core component of the next generation wireless systems, e.g. WiMAX, 3GPP LTE and other OFDM-based communication schemes. Moreover, spatial division multiple access (SDMA) is one of the widely used techniques for sharing the wireless medium between different mobile devices. Sphere detection is a prominent method of simplifying the detection complexity in both SDM and SDMA systems while maintaining BER performance comparable with the optimum maximum-likelihood (ML) detection. There are several approaches for realizing sphere detectors, and the algorithmic landscape is rich with methods that enable the designer to make various tradeoffs between performance, e.g. throughput of the wireless channel, BER, and implementation complexity, e.g. silicon area for an ASIC implementation or FPGA resource envelope for an FPGA implementation. This paper describes the FPGA realization of a configurable and flexible sort-free sphere detector, Flex-Sphere, that supports 4, 16, 64-QAM modulations as well as a combination of 2, 3 and 4 antenna/user configuration for uplink transmission. The detector provides a data rate of up to 849.9 Mbps. The algorithmic optimizations employed to produce an FPGA friendly realization are discussed.

Digital Down Converter Implementation, FPGAs Offer New Possibilities (paper) (presentation)
Rodger Hosking, Pentek

Digital Down Converters (DDCs) represent a cornerstone technology in SDR communication system. Over the past several years, the tuning, data reduction and filtering functions associated with DDCs have shifted from ASIC implementations towards IP cores in FPGAs. This shift brings many critical advantages including architectural flexibility, higher precision processing, higher channel density, and lower power and cost per channel.

Session 5.3

Polyphase Channelization utilizing General-Purpose Computing on a GPU (paper)
Ambrose Slone, Wil Myrick, Joe Hecker, SAIC

Polyphase channelization is essential for a variety of applications involving bandwidth reduction and signal separation. Implementations of polyphase channelizers based on a general purpose processor (GPP) or field-programmable gate array (FPGA) platform have been investigated in the past. A novel approach to implementing a polyphase channelizer based on a graphics processing unit (GPU) is presented. Current GPUs have been shown to provide up to 500 GFlops for problems that do not have stringent size, weight and power (SWaP) requirements and are well suited for a parallel processing architecture. This paper compares the implementation of a polyphase channelizer based on a NVIDIA® 8800 GTX Graphics Card (NVIDIA Corporation) with one based on a central processing unit (CPU). The practical issues of implementation are presented and the performance measurements are discussed.

Recursive Blind Equalization of MIMO Channels (paper)
Barathram Ramkumar, Tamal Bose, Miloje S. Radenkovic, Virginia Tech

An adaptive filtering method is proposed for blind deconvolution of multiple input multiple output (MIMO) IIR channels. This method consists of two algorithms. The adaptive blind identification algorithm estimates the MIMO system impulse response. These estimates are used in an adaptive Weiner type filter to extract the instantaneous mixture of input sources. Such a mixture can be further processed by a blind source separation algorithm to obtain the individual sources. Only second order (SOS) statistics is used, and precise knowledge of the system order is not required as long as it is over- modeled. The developed algorithms are globally convergent.

Implementation of Advanced Two-Dimensional Interpolation-Based Channel Estimation for OFDM (paper)
Chiyoung Ahn, Hakmin Kim, Jaeho Chung, Seungwon Choi, Hanyang University

In this paper, we show an implementation of orthogonal frequency-division multiplexing (OFDM) systems including advanced Two-Dimensional (2D) interpolation-based channel estimation. The presented channel estimation technique improves the performance of OFDM system in terms of bit error rate (BER). The technique is based on planar equations to find accurate channel information of carriers in the edge of the user burst area. We have implemented proposed channel estimation technique using Digital Signal Processor (DSP), TMS320C6416T. The performance of proposed system is verified through Matlab® simulations in various signal environments and is compared with the performance of system including conventional channel estimation.

OFDM Transmitter and Receiver Performance Improvements for Small Form Factor SDR Hand-Held (paper)
John E. Kleider, Tony Smith, Xiaoli Ma, General Dynamics

OFDM exhibits high peak-to-average power ratios (PAPR) which requires high power amplifier (PA) backoff at the transmitter to minimize spectral regrowth due to clipping of the high signal peaks of the OFDM waveform. PA backoff is often also necessary to minimize receiver bit error rate (BER) degradations due to the interference induced from the PA spectral regrowth. This work utilizes two transmitter mitigation techniques to improve transmit spectral quality, which also improves receiver demodulation performance. We propose using both PAPR reduction and PA pre-distortion (linearization) to provide performance improve- ments. We use a novel OFDM waveform which superimposes known joint synchronization pilot sequences (JSPS) to provide PAPR reduction capability, while utilizing a piecewise linear polynomial (PWLP) pre-distortion (lineari- zation) technique to provide further reductions in spectral regrowth. We also show that optimal placement and power (OPAP) of the pilot sequence provides further improvements in receiver BER performance over uniformly spaced constant power (USCP) pilot schemes common today in many OFDM commercial standards. We demonstrate that greater than 10 dB reduction in spectral regrowth is possible from the emitted transmit spectrum, while the combined effect of PAPR reduction, predistortion (linearization), and pilot optimization provides greater than a 4 dB improvement in received data constellation variance.

On Trading Excess Bandwidth for Reduced Peak to Average Power Ratio in Single Carrier Shape (paper)
fred harris, Chris Dick, SDSU

The waveform of choice for OFDM signaling is the sinusoid with an integer number of cycles per interval and with an appended cyclic prefix to obtain circular convolution with the channel. This combination makes the channel inversion particularly simple; performed as a ratio between the DFT of the received signal and the DFT of the channel. In fact, this relationship is valid for any periodic function formed as a sum of the basis sinusoids of the DFT. One particularly simple example of this class of signals is the Dirichlet ker- nel (the periodically extended sinc function). This kernel is used in single carrier OFDM [1]. An advantage of this ker- nel relative to the complex sinusoid kernel is a 3.4 dB re- duction in peak to average power ratio (PAPR). We show here that a windowed version of this kernel exhibits a sig- nificantly lower, in fact up to a 10.0 dB reduction in PAPR. The cost to obtain the reduced PAPR is excess bandwidth but that may be a fair trade to obtain higher average trans- mitted power for a given peak power limited amplifier.

Session 5.4

Verification of Equivalence of Policy-selected Software Components in a Cognitive Radio (paper)
Mieczyslaw M. Kokar, Leszek Lechowic, Northeastern University

In this paper we consider a scenario in which a declaratively specified policy on a cognitive radio recommends to use a specific type of functionality for communication with another peer radio. The requested functionality is given in terms of a specification in a formal policy language. The specification includes some behavioral aspects, e.g., delays introduced by particular sub- functions. The peer composes a module out of components it has in its library according to its component composition policies. To ensure that the composed functionality will perform correctly, the module needs to be verified against the specification. In this paper we look at two ways of achieving this goal – through direct inference (derivation) within the policy language, and through checking a model automatically constructed for this purpose. For instance, instead of trying to use a theorem prover on a collection of facts in the knowledge base, one could construct a semantic model based on those facts and then check the model to see if a given logical proposition holds. The specific goal of this paper is to discuss advantages and disadvantages of the two approaches to verification mentioned above. One of the aspects to compare is the time complexity of verification. It is known that the inference within a first-order language is undecidable, while checking a specific model is time linear in the size of the data. In this paper we describe our experiments with both approaches. composition is an important step in the interoperability scenario and is discussed in this paper in some detail.

Software Defined Radio Execution Latency (paper)
Feng Ge, Alex Young, Terry Brisebois, Qinqin Chen, Charles W. Bostian, Virginia Tech

Software Defined Radio (SDR) achieves multi-band multi- mode reconfigurability by moving digital signal processing functions progressively closer to the radio antenna and utilizing software’s flexibility. This requires an easy development environment, which is very challenging for digital signal processors (DSP) or field-programmable gate arrays (FPGA). General purpose processors (GPP) are therefore widely used in SDR architectures like GNU Radio and OSSIE.

Security Architecture for SDR System Using OTA Download Sequence (paper)
Ajay Kr.Singh, Ankita Taneja,Ved. P. Mishra, Ajay Kr. Singh, G. Singh, S.P. Ghrera, Jaypee University

Over The Air (OTA) software downloads can provide seamless interoperability without relying on any additional equipment or spectral assets. By using OTA software downloads, arriving first responders can download the interoperability parameters and immediately gain access to the host radio system. Software Defined Radio (SDR) is also expected to solve the compatibility problem among various mobile communication standards so that people can use the same device for different mobile environment. If these mobile communication environment are constructed, integrity and confidentiality of data in between terminal and service provider or each network server authentication become very important. In this paper, we propose a method for authentication and transmission security for OTA software download sequence.

Global Frequency Management Using Cognitive Radio (paper)
Michael Furman, Furman LLC

Global Frequency Management (GFM) is a daunting problem because agility is required to select transmission frequencies, at the moment they are needed while regulatory agencies may take years to approve frequency plans from the initial planning steps to becoming a regulated user. This problem is further complicated when the transmitting platform is mobile and may be anywhere on the earth. Typical scenarios may involve aircraft, missiles and satellites. Each platform has a need to communicate with a receiver that may be in the receptive field of interfering RF emitters. This resulting interference could introduce unstable to catastrophic outcomes for the platform mission. This paper describes some issues concerning dynamic frequency allocation and the use of cognitive radio concepts that suggest some functions for an operational protocol that may resolve some of the frequency allocation problems. The functions are compared to standard communications techniques to demonstrate that part of the solution may be a combination of adapted these techniques to the problem of GFM.

Session 5.5

The GNU SPE Scheduler and Asynchronous RPC Mechanism (paper)
Eric Blossom, Blossom Research - gcell

The Cell Broadband Engine is one of today's most potent floating point signal processing platforms. Effectively a 9-way heterogeneous SIMD system on a single die, the Cell is capable of 200 GFLOPS peak.

Design and Implementation of a Portable Software Radio (paper)
Michael L. Dickens, Brian P. Dunn, and J. Nicholas Laneman, Notre Dame University

We summarize the design and implementation of a portable software radio prototype built primarily using commercial off-the-shelf components and open-source software. The device components include a general-purpose processor (GPP) on a small-form-factor motherboard, radio hardware, touchscreen and LCD, audio microphone and speaker, and an internal battery enabling hours of mobile operation. Significant advances over the past decade have made GPP- based software radio a viable solution in many areas, and this work demonstrates that today’s processors are capable of enabling a new generation of software radio in portable form-factor devices. Our research group leverages these prototypes for several funded projects focusing on issues including interoperable public safety communications, cognitive wireless networking, and educational initiatives.

Open Source Transparency for OFDM Synchronization Experimentation (paper)
Thomas W. Rondeau, Matt Ettus, Robert W. McGwier, Trinity College

Many developments in communications systems begin as a theoretical model and then analyzed in a simulation environment such as Matlab. Often, these simulations do not provide the complexity of a real implementation where one must deal with real circuitry and channels. The open source GNU Radio platform offers an easy transition between the theoretical models and an affordable solution to test the models under real-world conditions. We present the concept of GNU Radio for this purpose here by discussing and analyzing a flexible OFDM transceiver. This design offers research and development of different methods of OFDM symbol transmission, reception, and synchronization. These concepts are currently being applied to develop waveforms such as WiMAX.

Development of an Open-Source Integrated Development Environment for SCA-based Components (paper)
Jason Snyder, Stephen H. Edwards, Carl B. Dietrich, Virginia Tech

Developing software-defined radio components and waveforms based on the Software Communications Architecture can be tedious. Commercial SDR tools provide a wide range of capabilities to address this. Meanwhile, existing open source work has provided some graphical tools for designing such assets, but full support across the development process is lacking. This paper describes work to combine graphical tools from the Open Source SCA Implementation:  Embedded with a modern, extensible, integrated development environment: Eclipse.

OpenSpaceRadio: An Open Source Implementation of STRS 1.01 (paper)
Carl Dietrich, Dileep Kumaraswamy, Sahana B. Raghunandan., Lillian Le, Jeffrey H. Reed, Virginia Tech

The Space Telecommunications Radio System (STRS) details high level specifications for the development, testing operation and maintenance of software defined radios (SDR) used by NASA for space communications. As it provides a broad framework for SDR development across different mission classes, radio designers can apply this open architecture to their individual requirements and build an end-to-end system. In this paper, we describe an open source implementation based on an excerpt of the STRS 1.01 standard and its applications. The development of Open Space Radio was initially motivated by the need for an STRS based proof-of-concept system for a space application being developed by AeroAstro, Inc. This proof-of-concept space radio system involves interfacing the General Processing Module (GPM) with a Signal Processing Module (SPM) based on a commercial FPGA board. It is hoped that the availability of Open Space Radio will facilitate SDR research for space applications.

Session 5.6

Intelligent Traffic Management System Using Software Defined Radio (SDR) Technique (paper)
Ahmed Bakraiba, Chong Jin Hui, Sabira Khatun, UPM

This paper presents an approach supplemented to manage the traffic system using the FPGA based (Radio Frequency Identification) RFID readers, stating the requirements, the problem solving approach and the best practice design to fulfill those requirements.

Spectrum Management in Public and Government Security (P&GS) Systems (paper) (presentation)
Shyamalie Thilakawardana, Klaus Moessner, University of Surrey

The WINTSEC project, a Preparatory Action on the enhancement of the European industrial potential in the field of Security research (PASR), investigates the possibilities and functionality required for wireless interoperability for security relevant communications.

Development Approaches for an International Tactical Radio Cryptographic API (paper)
Antonio Martin, Timothy Newman, David Murotake, SCA Technica, Inc and Virginia Tech

Currently, there are no internationally available application programming interfaces (APIs) for the embedded cryptographic module of modern tactical radios which comply with the Joint Tactical Radio System (JTRS) Software Communications Architecture (SCA). We survey relevant, internationally released documents including recommendations from the SDR Forum Security Working Group, publicly released information on the Common Interfaces to Cryptographic Modules (CICM) project and SCA specifications including the SCA 3.0 Security Supplement. These and other documents are examined as the possible basis for a draft Cryptographic API employing common interfaces for an embedded cryptographic module usable by an International Tactical Radio (ITR) and Waveform Development Environment (WDE). The draft Cryptographic API can be used as the basis for a future recommendation by the SDR Forum Security Working Group.

SCA-Based Implementation of Stanag 4285 in a Joint Effort Under the NATO RTO/IST Panel (paper) (presentation)
Sarvpreet Singh, M. Adrat, S. Couturier, M. Antweiler Martin Phisel, Steve Bernier, Research Establishment for Applied Science (FGAN)

The NATO RTO/IST Regular Task Group on Software Defined Radio (RTG on SDR) is working on the portability and interoperability of waveforms in a Software Communications Architecture (SCA) based environment using the STANAG 4285 as a test waveform. This paper presents several SCA based realizations of this waveform at different granularity levels (number of divisions). The paper discusses the overheads incurred by dividing the SCA based transmitter resource into two and four resources. It shows that the overheads increase linearly with the increase in the number of resource divisions. An important result from the analysis is that, an SCA resource should perform considerable signal processing to overcome the overheads associated for its functioning. It is also seen that there are some fixed overheads for running an SCA resource along with some variable costs, depending on the amount of data processed by the waveform.

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