MAXIMAL-RATIO EIGEN-COMBINING FOR SMARTER ANTENNA ARRAY WIRELESS COMMUNICATION RECEIVERS

The conventional single-antenna receiver suffers in wireless fading channels from limitations that preclude deployment of envisioned wireless applications. By increasing complexity, improvements are possible using multi-branch receivers. In particular, smart antenna arrays employ maximal-ratio combining (MRC) or statistical beamforming (BF) to exploit diversity and array gain. However, varying azimuth spread creates unfavorable spatial correlation conditions that diminish these gains, while BF and MRC complexity remains constant. On the other hand, adaptive eigen-combining can yield near-optimum performance for more efficient resource usage. This motivates our study of maximal-ratio eigen-combining (MREC). We unravel the relationship between MREC, BF, and MRC performance, and evaluate their complexity. Outage and average error probability expressions are derived for MREC assuming perfectly and imperfectly known channel gains. These results are specialized to MRC and BF, as well as to well-accepted pilot-symbol-based channel estimation techniques. In the process, new performance analyses are provided. Numerical results for typical urban scenarios with variable correlation demonstrate MREC’s advantages. Existing criteria for optimum eigen-mode selection in MREC are reviewed, and a new adaptation approach that accounts for channel condition, algorithm complexity, resource availability, and intended performance level, is proposed and evaluated. These singleand multi-branch receivers are then evaluated on a field-programmable gate array (FPGA) in terms of symbol-detection performance and resource and power consumption.

[1]  Alex B. Gershman,et al.  Space-time processing for MIMO communications , 2005 .

[2]  Arogyaswami Paulraj,et al.  Recursive adaptive beamforming for wireless CDMA , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[3]  Laurence B. Milstein,et al.  Performance analysis of linear diversity-combining schemes on Rayleigh fading channels with binary signaling and Gaussian weighting errors , 2005, IEEE Transactions on Wireless Communications.

[4]  B. Parlett The Symmetric Eigenvalue Problem , 1981 .

[5]  Gerhard Fettweis,et al.  From Smart Antennas to Reduced Dimension Space-Time Processing , 2001 .

[6]  Norman C. Beaulieu,et al.  Closed-form BER results for MRC diversity with channel estimation errors in Ricean fading channels , 2005, IEEE Transactions on Wireless Communications.

[7]  W. Beyer CRC Standard Probability And Statistics Tables and Formulae , 1990 .

[8]  L. C. Godara,et al.  Handbook of Antennas in Wireless Communications , 2001 .

[9]  Christopher Brunner Efficient Space-time Processing Schemes for WCDMA , 2000 .

[10]  Wolfgang Utschick,et al.  On the effective spatio-temporal rank of wireless communication channels , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[11]  M. Rupp,et al.  Rapid prototyping design of a 4/spl times/4 BLAST-over-UMTS system , 2001, Conference Record of Thirty-Fifth Asilomar Conference on Signals, Systems and Computers (Cat.No.01CH37256).

[12]  Ashok Ambardar,et al.  Analog and Digital Signal Processing , 1995 .

[13]  Carl Ebeling,et al.  Implementing an OFDM receiver on the RaPiD reconfigurable architecture , 2003, IEEE Transactions on Computers.

[14]  Bernard H. Fleury,et al.  First- and second-order characterization of direction dispersion and space selectivity in the radio channel , 2000, IEEE Trans. Inf. Theory.

[15]  Steven D. Blostein,et al.  PERFORMANCE OF SMART ANTENNA ARRAYS WITH MAXIMAL-RATIO EIGEN-COMBINING , 2004 .

[17]  Josef A. Nossek,et al.  Exploiting the short - term and long - term channel properties in space and time: Eigenbeamforming concepts for the BS in WCDMA , 2001, Eur. Trans. Telecommun..

[18]  Preben E. Mogensen,et al.  From antenna spacings to theoretical capacities - guidelines for simulating MIMO systems , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[19]  Luca Benini,et al.  Clock-tree power optimization based on RTL clock-gating , 2003, Proceedings 2003. Design Automation Conference (IEEE Cat. No.03CH37451).

[20]  Asrar U. H. Sheikh,et al.  Adaptive equalization and diversity combining for mobile radio using interpolated channel estimates , 1991 .

[21]  J. Craig A new, simple and exact result for calculating the probability of error for two-dimensional signal constellations , 1991, MILCOM 91 - Conference record.

[22]  S. Applebaum,et al.  Adaptive arrays , 1976 .

[23]  Norman C. Beaulieu,et al.  Quality measures for random variate generation , 1998, ICC '98. 1998 IEEE International Conference on Communications. Conference Record. Affiliated with SUPERCOMM'98 (Cat. No.98CH36220).

[24]  J. H. Winters,et al.  Effect of fading correlation on adaptive arrays in digital mobile radio , 1994 .

[25]  Gerhard Fettweis,et al.  Reduced dimension space-time processing for multi-antenna wireless systems , 2002, IEEE Wirel. Commun..

[26]  Steven Kay,et al.  Fundamentals Of Statistical Signal Processing , 2001 .

[27]  Theodore S. Rappaport,et al.  Wireless communications - principles and practice , 1996 .

[28]  Brian L. Evans,et al.  Optimum Wordlength Search Using Sensitivity Information , 2006, EURASIP J. Adv. Signal Process..

[29]  Daniel Zwillinger,et al.  CRC Standard Probability and Statistics Tables and Formulae, Student Edition , 1999 .

[30]  Robert Schober,et al.  Effect of channel estimation errors on MRC diversity in Rician fading channels , 2005, IEEE Transactions on Vehicular Technology.

[31]  Jinho Choi,et al.  Diversity gain for CDMA systems equipped with antenna arrays , 2003, IEEE Trans. Veh. Technol..

[32]  Terrence Mak,et al.  Embedded computation of maximum-likelihood phylogeny inference using platform FPGA , 2004 .

[33]  David Tse,et al.  Fundamentals of Wireless Communication , 2005 .

[34]  M. Gans The Effect of Gaussian Error in Maximal Ratio Combiners , 1971 .

[35]  D. G. Brennan,et al.  Linear diversity combining techniques , 2003 .

[36]  Jack Dongarra,et al.  Templates for the Solution of Algebraic Eigenvalue Problems , 2000, Software, environments, tools.

[37]  Athanasios Papoulis,et al.  Probability, Random Variables and Stochastic Processes , 1965 .

[38]  Antti Toskala,et al.  Wcdma for Umts , 2002 .

[39]  Rupert Baines,et al.  A total cost approach to evaluating different reconfigurable architectures for baseband processing in wireless receivers , 2003, IEEE Commun. Mag..

[40]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[41]  G. Golub,et al.  Tracking a few extreme singular values and vectors in signal processing , 1990, Proc. IEEE.

[42]  Preben E. Mogensen,et al.  A stochastic model of the temporal and azimuthal dispersion seen at the base station in outdoor propagation environments , 2000, IEEE Trans. Veh. Technol..

[43]  William C. Y. Lee,et al.  Mobile Communications Engineering , 1982 .

[44]  Don H. Johnson,et al.  Array Signal Processing: Concepts and Techniques , 1993 .

[45]  Rodney G. Vaughan,et al.  Channels, Propagation and Antennas for Mobile Communications , 2003 .

[46]  Luca Benini,et al.  A scalable ODC-based algorithm for RTL insertion of gated clocks , 2004, Proceedings Design, Automation and Test in Europe Conference and Exhibition.

[47]  Luca Benini,et al.  Saving power by synthesizing gated clocks for sequential circuits , 1994, IEEE Design & Test of Computers.

[48]  G. Dunteman Principal Components Analysis , 1989 .

[49]  Jan J. Gerbrands,et al.  On the relationships between SVD, KLT and PCA , 1981, Pattern Recognit..

[50]  Kamil Zigangirov,et al.  Theory Of Code Division Multiple Access Communication , 2004 .

[51]  Lajos Hanzo Intelligent Wireless Networking, Smart Antennas and Adaptive Modulation , 2002 .

[52]  Steven D. Blostein,et al.  Maximal-Ratio Eigen-Combining for Smarter Antenna Arrays , 2007, IEEE Transactions on Wireless Communications.

[53]  Norman C. Beaulieu,et al.  Bit error rate analysis of hybrid selection/maximal-ratio diversity combining with channel estimation error , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[54]  Guanghan Xu,et al.  Performance of CDMA smart antenna systems , 1995, Conference Record of The Twenty-Ninth Asilomar Conference on Signals, Systems and Computers.

[55]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[57]  Norman C. Beaulieu,et al.  The generation of correlated Rayleigh random variates by inverse discrete Fourier transform , 2000, IEEE Trans. Commun..

[58]  Ernst Bonek,et al.  A real-time DOA-based smart antenna processor , 2002, IEEE Trans. Veh. Technol..

[59]  B. Widrow,et al.  Adaptive antenna systems , 1967 .

[60]  Robert Schober,et al.  Effect of imperfect channel estimation on MRC diversity in fading channels , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[61]  Andrea Goldsmith,et al.  Wireless Communications , 2005, 2021 15th International Conference on Advanced Technologies, Systems and Services in Telecommunications (TELSIKS).

[62]  François Gagnon,et al.  Comments on "New method of performance analysis for diversity reception with correlated Rayleigh-fading signals" , 2003, IEEE Trans. Veh. Technol..

[63]  J. Chouinard,et al.  Eigen analysis of wide-band fading channel impulse responses , 1999 .

[64]  Ramesh Annavajjala A simple approach to error probability with binary signaling over generalized fading channels with maximal ratio combining and noisy channel estimates , 2005, IEEE Transactions on Wireless Communications.

[65]  Fabian Vargas,et al.  A FPGA-based Viterbi algorithm implementation for speech recognition systems , 2001, 2001 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.01CH37221).

[66]  Jinho Choi,et al.  A novel adaptive beamforming algorithm for antenna array CDMA systems with strong interferers , 2002, IEEE Trans. Veh. Technol..

[67]  P. Bello,et al.  Predetection Diversity Combining with Selectively Fading Channels , 1962 .

[68]  E. Parzen 1. Random Variables and Stochastic Processes , 1999 .

[69]  John G. Proakis,et al.  Digital Communications , 1983 .

[70]  Mohamed-Slim Alouini,et al.  Digital Communication Over Fading Channels: A Unified Approach to Performance Analysis , 2000 .

[71]  Seungwon Choi,et al.  Adaptive beamforming technique based on eigen-space method for a smart antenna in IS2000 1X environment , 2002, IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313).

[72]  M. Abramowitz,et al.  Handbook of Mathematical Functions With Formulas, Graphs and Mathematical Tables (National Bureau of Standards Applied Mathematics Series No. 55) , 1965 .

[73]  Klaus I. Pedersen,et al.  Spatial channel characteristics in outdoor environments and their impact on BS antenna system performance , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[74]  Gene H. Golub,et al.  Matrix computations , 1983 .

[75]  Thomas W. Parsons,et al.  Digital signal processing: theory, applications, and hardware , 1991 .

[76]  G. Turin The characteristic function of Hermitian quadratic forms in complex normal variables , 1960 .

[77]  Georgios B. Giannakis,et al.  Optimal transmitter eigen-beamforming and space-time block coding based on channel correlations , 2002, 2002 IEEE International Conference on Communications. Conference Proceedings. ICC 2002 (Cat. No.02CH37333).

[78]  Jaehoon Choi,et al.  A survey of essential problems in the design of smart antenna system , 2002 .

[79]  Thomas Kaiser When will smart antennas be ready for the market? Part II - results , 2005 .

[80]  George V. Tsoulos,et al.  Performance enhancement of DS-CDMA microcellular networks with adaptive antennas , 1996, Proceedings of Vehicular Technology Conference - VTC.

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

[82]  A.J. Paulraj,et al.  Space-time processing for wireless communications , 1997, 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[83]  Norman C. Beaulieu,et al.  Optimal maximal ratio combining with correlated diversity branches , 2002, IEEE Communications Letters.

[84]  Alex ChiChung Kot,et al.  New method of performance analysis for diversity reception with correlated Rayleigh-fading signals , 2000, IEEE Trans. Veh. Technol..

[85]  Steven D. Blostein,et al.  Smart antenna arrays for correlated and imperfectly-estimated Rayleigh fading channels , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[86]  Matthias Patzold,et al.  A deterministic digital simulation model for Suzuki processes with application to a shadowed Rayleigh land mobile radio channel , 1996 .

[87]  Thomas Kaiser When will smart antennas be ready for the market? Part I , 2005 .

[88]  P. Polydorou,et al.  Error performance of MPSK with diversity combining in non-uniform Rayleigh fading and non-ideal channel estimation , 2000, VTC2000-Spring. 2000 IEEE 51st Vehicular Technology Conference Proceedings (Cat. No.00CH37026).

[89]  Michael T. Chryssomallis,et al.  Smart antennas , 2000 .

[90]  Wolfgang Utschick,et al.  Maximum ratio combining of correlated Rayleigh fading channels with imperfect channel knowledge , 2003, IEEE Communications Letters.

[91]  P.E. Mogensen,et al.  Preliminary measurement results from an adaptive antenna array testbed for GSM/UMTS , 1997, 1997 IEEE 47th Vehicular Technology Conference. Technology in Motion.

[92]  Bin Yang,et al.  Projection approximation subspace tracking , 1995, IEEE Trans. Signal Process..

[93]  Rohit U. Nabar,et al.  Introduction to Space-Time Wireless Communications , 2003 .

[94]  M. Viberg,et al.  Two decades of array signal processing research: the parametric approach , 1996, IEEE Signal Process. Mag..

[95]  L. B. Milstein,et al.  Detection with spatial diversity using noisy channel estimates in a correlated fading channel , 2002, MILCOM 2002. Proceedings.

[96]  Gregory D. Durgin,et al.  Space-Time Wireless Channels , 2002 .

[97]  Charlie Jenkins LOW-POWER SOFTWARE-DEFINED RADIO DESIGN USING FPGAS , 2006 .

[98]  M. Rupp,et al.  From basic concept to real-time implementation: prototyping WCDMA downlink receiver algorithms-a case study , 2000, Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154).

[99]  S. Amari,et al.  Closed-form expressions for distribution of sum of exponential random variables , 1997 .

[100]  M. J. Gans,et al.  On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas , 1998, Wirel. Pers. Commun..

[101]  William W. Lu Broadband Wireless Mobile: 3G and Beyond , 2002 .

[102]  Akbar M. Sayeed,et al.  Pilot-based estimation of time-varying multipath channels for coherent CDMA receivers , 2002, IEEE Trans. Signal Process..

[103]  Ayman Fawzy Naguib,et al.  Adaptive antennas for CDMA wireless networks , 1996 .

[104]  BTexact Technologies,et al.  Future mobile networks : 3G and beyond , 2001 .

[105]  J. Cavers An analysis of pilot symbol assisted modulation for Rayleigh fading channels (mobile radio) , 1991 .

[106]  Antti Toskala,et al.  WCDMA for UMTS: Radio Access for Third Generation Mobile Communications , 2000 .

[107]  Pieter van Rooyen,et al.  CDMA Techniques for Third Generation Mobile Systems , 1998 .

[108]  C. Burrus,et al.  Array Signal Processing , 1989 .

[109]  Preben E. Mogensen,et al.  Experimental analysis of the joint statistical properties of azimuth spread, delay spread, and shadow fading , 2002, IEEE J. Sel. Areas Commun..

[110]  M. Rupp,et al.  Rapid Prototyping Design of a 4 × 4 BLAST-over-UMTS System , 2001 .

[111]  Steven D. Blostein,et al.  FPGA-Based Communications Receivers for Smart Antenna Array Embedded Systems , 2006, EURASIP J. Embed. Syst..

[112]  Robert W. Brodersen,et al.  Low-Power CMOS Wireless Communications: A Wideband CDMA System Design , 1997 .

[113]  Kareem E. Baddour,et al.  Autoregressive models for fading channel simulation , 2001, GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270).

[114]  D. Perels,et al.  ASIC implementation of a MIMO-OFDM transceiver for 192 Mbps WLANs , 2005, Proceedings of the 31st European Solid-State Circuits Conference, 2005. ESSCIRC 2005..

[115]  Martin C. Herbordt,et al.  Rigid Molecule Docking: FPGA Reconfiguration for Alternative Force Laws , 2006, EURASIP J. Adv. Signal Process..

[116]  Steven D. Blostein,et al.  Using signal cancellation for optimum beamforming in a cellular CDMA system , 1998, Proceedings of the 1998 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP '98 (Cat. No.98CH36181).

[117]  Mohamed-Slim Alouini,et al.  PCC: principal components combining for dense correlated multipath fading environments , 2000, Vehicular Technology Conference Fall 2000. IEEE VTS Fall VTC2000. 52nd Vehicular Technology Conference (Cat. No.00CH37152).

[118]  R. Steele,et al.  GSM, cdmaOne and 3G Systems , 2001 .

[119]  Gordon L. Stuber,et al.  Principles of Mobile Communication , 1996 .

[120]  P. Maher,et al.  Handbook of Matrices , 1999, The Mathematical Gazette.

[121]  Randy L. Haupt,et al.  Introduction to Adaptive Arrays , 1980 .

[122]  Luca Benini,et al.  Energy-efficient design of battery-powered embedded systems , 1999, Proceedings. 1999 International Symposium on Low Power Electronics and Design (Cat. No.99TH8477).

[123]  Michael A. Jensen,et al.  Modeling the statistical time and angle of arrival characteristics of an indoor multipath channel , 2000, IEEE Journal on Selected Areas in Communications.

[124]  Brent E. Nelson,et al.  GigaOp DSP on FPGA , 2004, J. VLSI Signal Process..

[125]  R. Michael Buehrer,et al.  The impact of AOA energy distribution on the spatial fading correlation of linear antenna array , 2002, Vehicular Technology Conference. IEEE 55th Vehicular Technology Conference. VTC Spring 2002 (Cat. No.02CH37367).

[126]  S.D. Blostein,et al.  Maximal-ratio eigen-combining: a performance analysis , 2004, Canadian Journal of Electrical and Computer Engineering.

[127]  J.H. Winters,et al.  Optimum combining in digital mobile radio with cochannel interference , 1984, IEEE Transactions on Vehicular Technology.

[128]  L. B. Milstein,et al.  On the performance of diversity combining schemes on Rayleigh fading channels with noisy channel estimates , 2003, IEEE Military Communications Conference, 2003. MILCOM 2003..

[129]  Mohamed-Slim Alouini,et al.  Outage probability of diversity systems over generalized fading channels , 2000, IEEE Trans. Commun..

[130]  Robert W. Brodersen,et al.  Low-Power CMOS Wireless Communications , 1998 .

[131]  P. Welch The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , 1967 .

[132]  Norman C. Beaulieu,et al.  General forms for maximal ratio diversity with weighting errors , 1999, IEEE Trans. Commun..

[133]  Enrico Macii,et al.  Designing low-power circuits: practical recipes , 2001 .