Fixed-Point Implementation of a Multistage Receiver

(ABSTRACT) This dissertation provides a study of synchronization and quantization issues in implementing a multistage receiver in fixed-point Digital Signal Processing (DSP) hardware. Current multistage receiver analysis has neglected the effects of synchronization and quantization; however, these effects can degrade system performance and therefore decrease overall system capacity. The first objective is to analyze and simulate various effects of synchronization in a multi-stage system. These effects include the effect of unsynchronized users on the bit error rate (BER) of synchronized users, and determining whether interference cancellation can be used to improve the synchronization time. This information is used to determine whether synchronization will limit overall system capacity. Both analytical and simulation techniques are presented. The second objective is to study the effects of quantization on the performance of the multistage receiver. A DSP implementation of a practical receiver will require a DSP chip with a fewer number of bits than the computer chips typically used in simulation of receiver performance. Therefore, the DSP implementation performs poorer than the simulation results predict. In addition, a fixed-point implementation is often favored over a floating-point implementation, due to the high processing requirements necessitated by the high chip rate. This further degrades performance because of the limited dynamic range available with fixed-point arithmetic. The performance of the receiver using a fixed-point implementation is analyzed and simulated. We also relate these topics to other important issues in the hardware implementation of multistage receivers, including the effects of frequency offsets at the receiver and developing a multiuser air protocol interface (API). This dissertation represents a contribution to the ongoing hardware development effort in multistage receivers at Virginia Tech. Acknowledgments First and foremost, I would like to thank Linda Maddux for her friendship, support, and endless patience and understanding as I have pursued my graduate degrees. I owe a special thanks to my advisor, Dr. Brian Woerner, for his guidance and support throughout my graduate career. I would also like to thank my committee, Dr. VanLandingham for their insights and comments during my research. I would like to thank the sponsors of my research, DARPA and the MPRG Industrial Affiliates, for providing the equipment and support that enabled me to pursue my research. In my many years at Virginia Tech and specifically in MPRG, I have made countless friends with the students and staff and owe them all a great deal of thanks. I would like to …

[1]  P. F. Panter,et al.  PCM distortion analysis , 1947, Electrical Engineering.

[2]  P. Teder,et al.  CDMA with interference cancellation: A technique for high capacity wireless systems , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[3]  P. Teder,et al.  CDMA-IC: A proposal for future high capacity digital cellular systems , 1993, IEEE 43rd Vehicular Technology Conference.

[4]  R. Michael Buehrer,et al.  The application of multiuser detection to cellular CDMA , 1996 .

[5]  Andrew J. Viterbi,et al.  Performance of power-controlled wideband terrestrial digital communication , 1993, IEEE Trans. Commun..

[6]  K. Schneider.  Optimum Detection of Code Division Multiplexed Signals , 1979, IEEE Transactions on Aerospace and Electronic Systems.

[7]  Yu Ted Su.  Rapid code acquisition algorithm employing PN matched filters , 1988, IEEE Trans. Commun..

[8]  Michael B. Pursley,et al.  Multipath Diversity Reception of Spread-Spectrum Multiple-Access Communications , 1987, IEEE Trans. Commun..

[9]  Alexandra Duel-Hallen,et al.  Equalizers for Multiple Input/Multiple Output Channels and PAM Systems with Cyclostationary Input Sequences , 1992, IEEE J. Sel. Areas Commun..

[10]  Craig K. Rushforth,et al.  A Family of Suboptimum Detectors for Coherent Multiuser Communications , 1990, IEEE J. Sel. Areas Commun..

[11]  Peter F. Driessen,et al.  PN code acquisition for asynchronous CDMA communications based on interference cancellation , 1993, Proceedings of IEEE Pacific Rim Conference on Communications Computers and Signal Processing.

[12]  Andrew J. Viterbi,et al.  Very Low Rate Convolutional Codes for Maximum Theoretical Performance of Spread-Spectrum Multiple-Access Channels , 1990, IEEE J. Sel. Areas Commun..

[13]  Ryuji Kohno,et al.  Cancellation techniques of co-channel interference in asynchronous spread spectrum multiple access systems , 1983 .

[14]  H. R. Schindler.  Delta modulation , 1970, IEEE Spectrum.

[15]  Peter F. Driessen,et al.  Automated threshold control for acquisition in spread spectrum packet radio communication , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[16]  B. D. Woerner,et al.  An analysis of adaptive multistage interference cancellation for CDMA , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[17]  Hideki Imai,et al.  An Adaptive Canceller of Cochannel Interference for Spread-Spectrum Multiple-Access Communication Networks in a Power Line , 1990, IEEE J. Sel. Areas Commun..

[18]  J. Andel.  Sequential Analysis , 2022, The SAGE Encyclopedia of Research Design.

[19]  M. Ewerbring,et al.  CDMA-IC: a novel code division multiple access scheme based on interference cancellation , 1992, [1992 Proceedings] The Third IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[20]  Andrew J. Viterbi,et al.  On the capacity of a cellular CDMA system , 1991 .

[21]  M.B. Pursley,et al.  Crosscorrelation properties of pseudorandom and related sequences , 1980, Proceedings of the IEEE.

[22]  J.E. Mazo,et al.  Digital communications , 1985, Proceedings of the IEEE.

[23]  C.L. Weber,et al.  Performance considerations of code division multiple-access systems , 1981, IEEE Transactions on Vehicular Technology.

[24]  D. Varberg,et al.  Calculus with Analytic Geometry , 1968 .

[25]  Hideki Imai,et al.  Combination of an Adaptive Array Antenna and a Canceller of Interference for Direct-Sequence Spread-Spectrum Multiple-Access System , 1990, IEEE J. Sel. Areas Commun..

[26]  Dariush Divsalar,et al.  Pseudocoherent Demodulation Of DPSK Radio Signals , 1995 .

[27]  R. Michael Buehrer,et al.  Analysis of DS-CDMA Parallel Interference Cancellation with Phase and Timing Errors , 1996, IEEE J. Sel. Areas Commun..

[28]  P. W. Wong.  Quantization noise, fixed-point multiplicative roundoff noise, and dithering , 1990, IEEE Trans. Acoust. Speech Signal Process..

[29]  Evaggelos Geraniotis,et al.  Performance of Coherent Direct-Sequence Spread-Spectrum Communications Over Specular Multipath Fading Channels , 1985, IEEE Trans. Commun..

[30]  R. Ward,et al.  Acquisition of Pseudonoise Signals by Sequential Estimation , 1965 .

[31]  Leland B. Jackson,et al.  On the interaction of roundoff noise and dynamic range in digital filters , 1970, Bell Syst. Tech. J..

[32]  Robert M. Gray,et al.  Quantization noise spectra , 1990, IEEE Trans. Inf. Theory.

[33]  J. Holmes,et al.  Acquisition Time Performance of PN Spread-Spectrum Systems , 1977, IEEE Trans. Commun..

[34]  James S. Lehnert.  An efficient technique for evaluating direct-sequence spread-spectrum multiple-access communications , 1989, IEEE Trans. Commun..

[35]  Jack M. Holtzman,et al.  Analysis of a simple successive interference cancellation scheme in a DS/CDMA system , 1994, IEEE J. Sel. Areas Commun..

[36]  B. Widrow.  A Study of Rough Amplitude Quantization by Means of Nyquist Sampling Theory , 1956 .

[37]  Zoran Zvonar,et al.  Multiuser detection for CDMA systems , 1995, IEEE Wirel. Commun..

[38]  Stavros Striglis.  A multistage RAKE receiver for CDMA systems , 1994 .

[39]  G. Sage,et al.  Serial Synchronization of Pseudonoise Systems , 1964 .

[40]  K. Shanmugan,et al.  Random Signals: Detection, Estimation and Data Analysis , 1988 .

[41]  Fu-Chun Zheng,et al.  On the performance of near-far resistant CDMA detectors in the presence of synchronization errors , 1995, IEEE Trans. Commun..

[42]  R. Cameron,et al.  Synchronization of CDMA systems employing interference cancellation , 1996, Proceedings of Vehicular Technology Conference - VTC.

[43]  Evaggelos Geraniotis,et al.  Performance of Noncoherent Direct-Sequence Spread-Spectrum Communications Over Specular Multipath Fading Channels , 1985, IEEE Trans. Commun..

[44]  C. Weber,et al.  Statistical Performance of Single Dwell Serial Synchronization Systems , 1980, IEEE Trans. Commun..

[45]  Sergio Verdú,et al.  Linear multiuser detectors for synchronous code-division multiple-access channels , 1989, IEEE Trans. Inf. Theory.

[46]  D. Schilling,et al.  A Two-Level Coarse Code Acquisition Scheme for Spread Spectrum Radio , 1980, IEEE Trans. Commun..

[47]  James S. Lehnert,et al.  Bit-to-bit error dependence in slotted DS/SSMA packet systems with random signature sequences , 1989, IEEE Trans. Commun..

[48]  Alexandra Duel-Hallen,et al.  Decorrelating decision-feedback multiuser detector for synchronous code-division multiple-access channel , 1993, IEEE Trans. Commun..

[49]  Shu Hung Leung,et al.  On the statistics of fixed-point roundoff error , 1985, IEEE Trans. Acoust. Speech Signal Process..

[50]  W. van Etten,et al.  Maximum Likelihood Receiver for Multiple Channel Transmission Systems , 1976, IEEE Trans. Commun..

[51]  Brian D. Woerner,et al.  Performance analysis of CDMA with imperfect power control , 1996, IEEE Trans. Commun..

[52]  R. Gagliardi,et al.  Signal Design for Digital Multiple Access Communications , 1975, IEEE Trans. Commun..

[53]  Sergio Verdú,et al.  Minimum probability of error for asynchronous Gaussian multiple-access channels , 1986, IEEE Trans. Inf. Theory.

[54]  R. M. Buehrer,et al.  A comparison of multiuser receivers for cellular CDMA , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[55]  R. Padovani,et al.  Implications of mobile cellular CDMA , 1992, IEEE Communications Magazine.

[56]  B. Woerner,et al.  Measurement-based performance analysis of CDMA systems in multipath fading , 1993, IEEE 43rd Vehicular Technology Conference.

[57]  Ning Yang.  Multiuser detection for CDMA systems with convolutional coding , 1995 .

[58]  Henry Stark,et al.  Probability, Random Processes, and Estimation Theory for Engineers , 1995 .

[59]  Peter No,et al.  Digital Coding of Waveforms , 1986 .

[60]  G.L. Turin,et al.  Introduction to spread-spectrum antimultipath techniques and their application to urban digital radio , 1980, Proceedings of the IEEE.

[61]  Andreas Polydoros,et al.  A Unified Approach to Serial Search Spread-Spectrum Code Acquisition - Part I: General Theory , 1984, IEEE Transactions on Communications.

[62]  D.L. Schilling,et al.  Spread spectrum goes commercial , 1990, IEEE Spectrum.

[63]  Someshwar C. Gupta,et al.  Direct-Sequence Spread-Spectrum Parallel Acquisition in Nonselective and Frequency-Selective Rician Fading Channels , 1992, IEEE J. Sel. Areas Commun..

[64]  Sumit Roy,et al.  An adaptive multiuser receiver for CDMA systems , 1994, IEEE J. Sel. Areas Commun..

[65]  S. Rappaport,et al.  Spread-spectrum signal acquisition: Methods and technology , 1984, IEEE Communications Magazine.

[66]  K. H. Barratt.  Digital Coding of Waveforms , 1985 .

[67]  P. Agashe,et al.  Analysis of interference cancellation for a multicellular CDMA environment , 1995, Proceedings of 6th International Symposium on Personal, Indoor and Mobile Radio Communications.

[68]  Mahesh K. Varanasi,et al.  Near-optimum detection in synchronous code-division multiple-access systems , 1991, IEEE Trans. Commun..

[69]  Donald Ervin Knuth,et al.  The Art of Computer Programming , 1968 .

[70]  Andreas Polydoros,et al.  A Unified Approach to Serial Search Spread-Spectrum Code Acquisition - Part II: A Matched-Filter Receiver , 1984, IEEE Transactions on Communications.

[71]  Behnaam Aazhang,et al.  Multistage detection in asynchronous code-division multiple-access communications , 1990, IEEE Trans. Commun..

[72]  Sergio Verdú,et al.  Near-far resistance of multiuser detectors in asynchronous channels , 1990, IEEE Trans. Commun..

[73]  B. D. Woerner,et al.  An analysis of CDMA with imperfect power control , 1992, [1992 Proceedings] Vehicular Technology Society 42nd VTS Conference - Frontiers of Technology.

[74]  A. Sripad,et al.  A necessary and sufficient condition for quantization errors to be uniform and white , 1977 .

[75]  Theodore S. Rappaport,et al.  Reverse channel performance improvements in CDMA cellular communication systems employing adaptive antennas , 1993 .

[76]  R. Michael Buehrer,et al.  Analysis of adaptive multistage interference cancellation for CDMA using an improved Gaussian approximation , 1996, IEEE Trans. Commun..

[77]  Someshwar C. Gupta,et al.  Direct-sequence spread-spectrum parallel acquisition in a fading mobile channel , 1990, IEEE Trans. Commun..

[78]  Joel Max,et al.  Quantizing for minimum distortion , 1960, IRE Trans. Inf. Theory.

[79]  Anja Klein,et al.  Linear Unbiased Data Estimation in Mobile Radio Systems Applying CDMA , 1993, IEEE J. Sel. Areas Commun..

[80]  Michael B. Pursley,et al.  Error Probabilities for Binary Direct-Sequence Spread-Spectrum Communications with Random Signature Sequences , 1987, IEEE Trans. Commun..

[81]  Jack M. Holtzman,et al.  A simple, accurate method to calculate spread-spectrum multiple-access error probabilities , 1992, IEEE Trans. Commun..

[82]  P. E. Green,et al.  A Communication Technique for Multipath Channels , 1958, Proceedings of the IRE.

[83]  Ashish Kaul.  An adaptive multistage interference cancellation receiver for CDMA , 1995 .

[84]  Earl William Swokowski,et al.  Calculus with analytic geometry , 1975 .

[85]  A. G. Clavier,et al.  Distortion in a Pulse Count Modulation System , 1947, Transactions of the American Institute of Electrical Engineers.

[86]  Andrew J. Viterbi,et al.  Nonlinear estimation of PSK-modulated carrier phase with application to burst digital transmission , 1983, IEEE Trans. Inf. Theory.

[87]  Brian D. Woerner,et al.  Analytic limits on performance of adaptive multistage interference cancellation for CDMA , 1994 .

[88]  W. R. Bennett,et al.  Spectra of quantized signals , 1948, Bell Syst. Tech. J..

[89]  Rodger E. Ziemer,et al.  Introduction to digital communication , 1992 .

[90]  Takeshi Hattori,et al.  Overview of wireless personal communications , 1995, IEEE Commun. Mag..

[91]  Rick Cameron.  Performance analysis of CDMA systems in multipath channels , 1993 .

[92]  Ashish Kaul,et al.  A multistage RAKE receiver for improved capacity of CDMA systems , 1994, Proceedings of IEEE Vehicular Technology Conference (VTC).

[93]  Marvin K. Simon,et al.  Spread Spectrum Communications Handbook , 1994 .

[94]  L. B. Milstein,et al.  Spread spectrum access methods for wireless communications , 1995, IEEE Commun. Mag..

[95]  W. Braun.  Performance Analysis for the Expanding Search PN Acquisition Algorithm , 1982, IEEE Trans. Commun..

[96]  I. Tokaji,et al.  Roundoff error statistics for a continuous range of multiplier coefficients , 1987 .

[97]  Joseph J. F. Cavanagh.  Digital Computer Arithmetic: Design And Implementation , 1984 .

[98]  C. Weber,et al.  Multiple Dwell Serial Search: Performance and Application to Direct Sequence Code Acquisition , 1983, IEEE Trans. Commun..