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James K. Cavers

Bio: James K. Cavers is an academic researcher from Simon Fraser University. The author has contributed to research in topics: Fading & Phase-shift keying. The author has an hindex of 32, co-authored 108 publications receiving 5639 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the bit error rate in binary-phase-shift-keying (BPSK) and in quadrature phase-shift keying (QPSK), for a tight upper bound on the symbol error rate for 16-QAM was presented.
Abstract: The author presents pilot-symbol-assisted modulation (PSAM) on a solid analytical basis, a feature missing from previous work. Closed-form expressions are presented for the bit error rate (BER) in binary-phase-shift-keying (BPSK) and in quadrature-phase-shift-keying (QPSK), for a tight upper bound on the symbol error rate in 16 quadrature-amplitude-modulation (16-QAM), and for the optimized receiver coefficients. The error rates obtained are lower than for differential detection for any combination of signal-to-noise ratio (SNR) and Doppler spread, and the performance is within 1 dB of a perfect reference system under slow-fading conditions and within 3 dB when the Doppler spread is 5% of the symbol rate. >

1,475 citations

Journal ArticleDOI
TL;DR: A method is described for linearizing a power amplifier by predistorting its input, particularly well suited to baseband implementation with digital signal processor hardware and its ability to suppress intermodulation products using only a small table is demonstrated.
Abstract: A method is described for linearizing a power amplifier by predistorting its input. It is particularly well suited to baseband implementation with digital signal processor hardware. In comparison with the most powerful previously published predistorter, it requires four orders of magnitude less memory, reduces convergence time by over three orders of magnitude, eliminates reconvergence time following a channel switch, and eliminates the need for a phase shifter in the feedback path. The predistorter structure is described. Its ability to suppress intermodulation products using only a small table is demonstrated. The effect of predistorter nonidealities (especially limited table size) on the power amplifier's output are analyzed. A fast adaptation algorithm is introduced. >

504 citations

Journal ArticleDOI
TL;DR: This paper focuses on the three principal impairments of analog quadrature modulators and demodulators: gain imbalance, phase imbalance, and DC offset.
Abstract: The current interest in linear modulation and multilevel signals has resulted in an emphasis on DSP implementations to achieve precision signal manipulation. However, most transceivers, and direct conversion designs in particular, rely on analog implementations of the quadrature modulator and demodulator, thereby sacrificing much of the precision gained through DSP. The present paper focuses on the three principal impairments of analog quadrature modulators and demodulators: gain imbalance, phase imbalance, and DC offset. The paper contains three main contributions. First is an analysis and quantitative assessment of the losses-primarily a degraded BER and out-of-band power in the transmitted signal-due to imbalances and offsets. The second contribution is an adaptive compensation technique for the quadrature modulator at the transmitter, and the third is a compensation technique for the quadrature demodulator at the receiver. Both compensation methods converge quickly and present only a modest computational load. >

297 citations

Journal ArticleDOI
TL;DR: This work presents an exact expression for the pairwise error event probability of trellis-coded modulation (TCM) transmitted over Rayleigh-fading channels, which includes phase shift keying and multilevel quadrature amplitude modulation (QAM) codes, as well as coherent and partially coherent codes.
Abstract: This work presents an exact expression for the pairwise error event probability of trellis-coded modulation (TCM) transmitted over Rayleigh-fading channels. It includes phase shift keying (PSK) and multilevel quadrature amplitude modulation (QAM) codes, as well as coherent and partially coherent (e.g. differential, pilot tone, etc.) detection. Due to the form of the exact pairwise error event probabilities, this calculation technique cannot be used with the transfer function technique to obtain an upper (union) bound on the overall bit error probability. For this reason, the authors estimate the bit error probability by considering only a small number of short error events. Through simulations, they found that the estimation is usually very accurate at high signal-to-noise ratios but not as accurate at lower signal-to-noise ratios. They study several coded modulation schemes this way. Among the results are the fact that TCM provides significant improvement in the error floor when detected differentially, and an asymmetry in the pairwise error event probability for 16 QAM. >

275 citations

Journal ArticleDOI
TL;DR: An analytical expression is provided for the union bound on the average symbol-error rate for an arbitrary number of users and diversity antennas in a fading environment, for both perfect and imperfect channel state information (CSI).
Abstract: Joint detection based on exploiting differences among the channels employed by several users allows a receiver to distinguish cochannel signals without reliance on spectrum spreading. This paper makes a number of new contributions to the topic; it provides an analytical expression for the union bound on the average symbol-error rate for an arbitrary number of users and diversity antennas in a fading environment, for both perfect and imperfect channel state information (CSI), and it compares the performance of joint detection with diversity antennas against classical minimum-mean-square-error (MMSE) combining. The performance is remarkable. With accurate CSI, several users can experience good performance with only a single antenna; moreover, for perfect CSI, only a 2-dB penalty is incurred for each additional user. With several antennas, many more users than the number of antennas may be supported with a slow degradation in performance for each additional user. Furthermore, high accuracy is not required from the channel estimation process. In all cases, the performance of joint detection exceeds that of MMSE combining by orders of magnitude.

198 citations


Cited by
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Journal ArticleDOI
Siavash Alamouti1
TL;DR: This paper presents a simple two-branch transmit diversity scheme that provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas.
Abstract: This paper presents a simple two-branch transmit diversity scheme. Using two transmit antennas and one receive antenna the scheme provides the same diversity order as maximal-ratio receiver combining (MRRC) with one transmit antenna, and two receive antennas. It is also shown that the scheme may easily be generalized to two transmit antennas and M receive antennas to provide a diversity order of 2M. The new scheme does not require any bandwidth expansion or any feedback from the receiver to the transmitter and its computation complexity is similar to MRRC.

13,706 citations

Book
01 Jan 2005

9,038 citations

Proceedings Article
01 Jan 2005
TL;DR: This book aims to provide a chronology of key events and individuals involved in the development of microelectronics technology over the past 50 years and some of the individuals involved have been identified and named.
Abstract: Alhussein Abouzeid Rensselaer Polytechnic Institute Raviraj Adve University of Toronto Dharma Agrawal University of Cincinnati Walid Ahmed Tyco M/A-COM Sonia Aissa University of Quebec, INRSEMT Huseyin Arslan University of South Florida Nallanathan Arumugam National University of Singapore Saewoong Bahk Seoul National University Claus Bauer Dolby Laboratories Brahim Bensaou Hong Kong University of Science and Technology Rick Blum Lehigh University Michael Buehrer Virginia Tech Antonio Capone Politecnico di Milano Javier Gómez Castellanos National University of Mexico Claude Castelluccia INRIA Henry Chan The Hong Kong Polytechnic University Ajit Chaturvedi Indian Institute of Technology Kanpur Jyh-Cheng Chen National Tsing Hua University Yong Huat Chew Institute for Infocomm Research Tricia Chigan Michigan Tech Dong-Ho Cho Korea Advanced Institute of Science and Tech. Jinho Choi University of New South Wales Carlos Cordeiro Philips Research USA Laurie Cuthbert Queen Mary University of London Arek Dadej University of South Australia Sajal Das University of Texas at Arlington Franco Davoli DIST University of Genoa Xiaodai Dong, University of Alberta Hassan El-sallabi Helsinki University of Technology Ozgur Ercetin Sabanci University Elza Erkip Polytechnic University Romano Fantacci University of Florence Frank Fitzek Aalborg University Mario Freire University of Beira Interior Vincent Gaudet University of Alberta Jairo Gutierrez University of Auckland Michael Hadjitheodosiou University of Maryland Zhu Han University of Maryland College Park Christian Hartmann Technische Universitat Munchen Hossam Hassanein Queen's University Soong Boon Hee Nanyang Technological University Paul Ho Simon Fraser University Antonio Iera University "Mediterranea" of Reggio Calabria Markku Juntti University of Oulu Stefan Kaiser DoCoMo Euro-Labs Nei Kato Tohoku University Dongkyun Kim Kyungpook National University Ryuji Kohno Yokohama National University Bhaskar Krishnamachari University of Southern California Giridhar Krishnamurthy Indian Institute of Technology Madras Lutz Lampe University of British Columbia Bjorn Landfeldt The University of Sydney Peter Langendoerfer IHP Microelectronics Technologies Eddie Law Ryerson University in Toronto

7,826 citations

Journal ArticleDOI
TL;DR: In this paper, the authors consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas and derive performance criteria for designing such codes under the assumption that the fading is slow and frequency nonselective.
Abstract: We consider the design of channel codes for improving the data rate and/or the reliability of communications over fading channels using multiple transmit antennas. Data is encoded by a channel code and the encoded data is split into n streams that are simultaneously transmitted using n transmit antennas. The received signal at each receive antenna is a linear superposition of the n transmitted signals perturbed by noise. We derive performance criteria for designing such codes under the assumption that the fading is slow and frequency nonselective. Performance is shown to be determined by matrices constructed from pairs of distinct code sequences. The minimum rank among these matrices quantifies the diversity gain, while the minimum determinant of these matrices quantifies the coding gain. The results are then extended to fast fading channels. The design criteria are used to design trellis codes for high data rate wireless communication. The encoding/decoding complexity of these codes is comparable to trellis codes employed in practice over Gaussian channels. The codes constructed here provide the best tradeoff between data rate, diversity advantage, and trellis complexity. Simulation results are provided for 4 and 8 PSK signal sets with data rates of 2 and 3 bits/symbol, demonstrating excellent performance that is within 2-3 dB of the outage capacity for these channels using only 64 state encoders.

7,105 citations

BookDOI
01 Jan 2001
TL;DR: This book presents the first comprehensive treatment of Monte Carlo techniques, including convergence results and applications to tracking, guidance, automated target recognition, aircraft navigation, robot navigation, econometrics, financial modeling, neural networks, optimal control, optimal filtering, communications, reinforcement learning, signal enhancement, model averaging and selection.
Abstract: Monte Carlo methods are revolutionizing the on-line analysis of data in fields as diverse as financial modeling, target tracking and computer vision. These methods, appearing under the names of bootstrap filters, condensation, optimal Monte Carlo filters, particle filters and survival of the fittest, have made it possible to solve numerically many complex, non-standard problems that were previously intractable. This book presents the first comprehensive treatment of these techniques, including convergence results and applications to tracking, guidance, automated target recognition, aircraft navigation, robot navigation, econometrics, financial modeling, neural networks, optimal control, optimal filtering, communications, reinforcement learning, signal enhancement, model averaging and selection, computer vision, semiconductor design, population biology, dynamic Bayesian networks, and time series analysis. This will be of great value to students, researchers and practitioners, who have some basic knowledge of probability. Arnaud Doucet received the Ph. D. degree from the University of Paris-XI Orsay in 1997. From 1998 to 2000, he conducted research at the Signal Processing Group of Cambridge University, UK. He is currently an assistant professor at the Department of Electrical Engineering of Melbourne University, Australia. His research interests include Bayesian statistics, dynamic models and Monte Carlo methods. Nando de Freitas obtained a Ph.D. degree in information engineering from Cambridge University in 1999. He is presently a research associate with the artificial intelligence group of the University of California at Berkeley. His main research interests are in Bayesian statistics and the application of on-line and batch Monte Carlo methods to machine learning. Neil Gordon obtained a Ph.D. in Statistics from Imperial College, University of London in 1993. He is with the Pattern and Information Processing group at the Defence Evaluation and Research Agency in the United Kingdom. His research interests are in time series, statistical data analysis, and pattern recognition with a particular emphasis on target tracking and missile guidance.

6,574 citations