Signal Enhancement in Wireless Communication Systems J¨orgen Nordberg Karlskrona, November 2002 Signal Enhancement in Wireless Communication Systems J¨orgen Nordberg Karlskrona, November 2002 Department of Telecommunications and Signal Processing Blekinge Institute of Technology, S-372 25 Ronneby, Sweden c J¨orgen Nordberg ISBN 91-7295-018-8 ISSN 1650-2159 Published 2002 Printed by Kaserntryckeriet AB Karlskrona 2002 Sweden v Preface This doctoral thesis summarizes my work in the field of subband and array signal processing. The work focuses on two main areas: interference cancellation and channel equalization in wireless communication systems. The work has been carried out at the Department of Telecommunications and Signal Processing at Blekinge Institute of Technology. Some of the work has been conducted in collabo- ration with Australian Telecommunications Research Institute. The thesis consists of five stand-alone parts: Part I Beamforming and Interference Cancellation for Capacity Gain in Mobile Networks. Part II Performance Improvements for Sector Antennas Using Feature Extraction and Spatial Interference Cancellation Part III Fractionally Spaced Spatial Adaptive Equalization of S-UMTS Mobile Terminals. Part IV Signal Separation Using Multi-rate Signal Processing. Part V Blind Subband Adaptive Equalization. vii Acknowledgements First, I would like to especially thank my main supervisor, Professor Sven Nord- holm, at Blekinge Institute of Technology, presently at Western Australia Telecom- munication Research Institute, for his inspiration, support and constructive criti- cism. I would also like to express my gratitude to Professor Ingvar Claesson for his valuable advice, supervision and support during all these years. Many thanks go to my friend and coauthor Dr. Hai Huyen Dam at Western Australia Telecommu- nication Research Institute for a very pleasant and productive collaboration. Further, my gratitude goes to my colleagues in the radio communication group, Associate Professor Abbas Mohammed and Ronnie Gustafsson, and all my other colleagues at the Department of Telecommunication and Signal Processing, Blekinge Institute of Technology, Sweden and the Western Australia Telecommunication Research Institute, University of Western Australia, Perth, Australia for the nice atmosphere during my studies. Finally, I would like to thank my family and all my friends for putting up with me during the years of study. J¨orgen Nordberg Karlskrona, November 2002 ix Contents Publication list ........................................................... 11 Introduction .............................................................. 15 Part I Beamforming and Interference Cancellation for Capacity Gain in MobileNetworks .................................................... 47-70 II Performance Improvements for Sector Antennas Using Feature Extraction andSpatialInterferenceCancellation ................................ 71-86 III Fractionally Spaced Spatial Adaptive Equalization ofS-UMTSMobileTerminals ...................................... 87-106 IV SignalSeparationUsingMulti-rateSignalProcessing ............... 107-122 V Blind Subband Adaptive Equalization. ...................... 123-146 11 Publication list Part I comprises parts of the following publications, J. Nordberg, S. Nordholm and I. Claesson Spatial Filtering Generalized Sidelobe Canceller as a Means for Interference Can- cellation, Proceedings of PIERS 97, Cambridge, Massachusetts, pp. 801, July 1997. J. Nordberg, S. Nordholm, S. Nordebo and I. Claesson Digital Beamforming as a Means for Interference Cancellation, Proceedings of ICOTA 98, Perth, Australia, pp. 1093–1100, July 1998. J. Nordberg, S. Nordholm, S. Nordebo and I. Claesson Digital Beamforming as a Means of Interference Cancellation, Research Report 21/98, University of Karlskrona/Ronneby, December 1998. S. Nordholm, J. Nordberg and I. Claesson Beamforming and Interference Cancellation for Capacity Gain in mobile Networks, Annals of Operational Research, vol. 1, pp. 235–253, December 2000. Part II comprises the following publications, J. Nordberg, N. Grbi´c, S. Nordholm Spatial Interference Cancellation using Blind Signal Separation and Sector Anten- nas, Proceedings of IEEE International Conference on Telecommunications ICT 2001, Romania, June 2001. J. Nordberg, S. Nordholm, N. Grbic, A. Mohammed and I. Claesson Performance Improvements for Sector Antennas using Feature Extraction and Spa- tial Interference Cancellation, accepted for publication at IEEE Transactions on Vehicular Technology, vol. 51, no. 6, November 2002. Part III comprises the following publications, A. Mohammed, J. Nordberg, S. Nordholm, I. Claesson Equalisation Techniques for Satellite-UMTS, IEEE First International Symposium on Communication Systems and Digital Signal Processing Sheffield Hallam Uni- versity, UK, pp. 538–541, April 1998. J. Nordberg, S. Nordholm, A. Mohammed and I. Claesson Adaptive Spatial Equalisation in S-UMTS System, Proceedings of ACTS ’98, Rhodes, Greece, pp. 721–726, June, 1998. 12 J. Nordberg, S. Nordholm and I. Claesson Spatial Adaptive Channel Equalisation in a S-UMTS System, Research Report 20/98, University of Karlskrona/Ronneby, December 1998. J. Nordberg, S. Nordholm, A. Mohammed and I. Claesson Blind Adaptive Equalisation in SUMTS-system, Proceedings of 1999 SNRV and NUTEKConference on Radio Sciences and Telecommunications, Karlskrona,Swe- den, pp. 389–392, June 1999. J. Nordberg, A. Mohammed, S. Nordholm and I. Claesson Fractionally Spaced Spatial Adaptive Equalisation of S-UMTS Mobile Terminals, Special issue of Wiley’s International Journal of Adaptive Control and Signal Pro- cessing entitled: Advances in Signal Processing for Mobile Communication Sys- tems, vol. 16, no. 8, pp. 541–555, October 2002. Part IV comprises the following publications, J. Nordberg, H. H. Dam, and S. Nordholm Signal Seperation Using Multi-rate Signal Processing, Proceedings of International Conference on Optimization Techniques and Applications (ICOTA’01), Hong Kong, China, vol. 4, pp. 1755-1762, December 2001. J. Nordberg, H. H. Dam and S. Nordholm Subband Signal Separation, Proceedings of 2002 SNRV and NUTEKConference on Radio Sciences and Telecommunications, Stockholm, Sweden, pp. 625–629, June 2002. Part V comprises the following publications, H. H. Dam, J. Nordberg and S. Nordholm, “Non–Causal Delayless Subband Adap- tive Equalizer,” Proceedings of International Conference on Acoustic, Speech and Signal processing (ICASSP) 2002, Orlando, USA, vol. 3, pp. 2649–2652, May 2002. J. Nordberg Blind Subband Adaptive Equalization, Research Report 2002:11 , ISSN: 1103–1581, Blekinge Institute for Technology, Ronneby, Sweden, October 2002. Other publications in conjunction with the thesis, J. Nordberg, M. Dahl, I. Claesson, S. Nordholm and S. Nordebo Acoustic Echo Cancellation Employing Delayless Subband Adaptive Filters,Pro- ceedings of SNRV and NUTEKConference on Radio Sciences and Telecommuni- cations in Lulea and Kiruna 1996, Lulea, pp. 222–226, Sweden, June 1996. 13 S. Nordholm, J. Nordberg and J. Skoog An Acoustic Echo Canceller Using Subband Adaptive Filters Proceedings of 4th UK/Australian Symposium on DSP for Communication Systems, Perth, Australia, pp. 447–453, October 1996. S. Nordholm and J. Nordberg Delayless Subband Echo Cancellation, Proceedings of Fifth International Congress on Sound and Vibration Adelaide ICSV’5, South Australia, Austrlia, pp. 319–326, December 1997. S. Nordholm, J. Nordberg and S. Nordebo Subband Acoustic Echo Cancellation Research Report 7/97, University of Karl- skrona/Ronneby, August 1997. N. Grbi´c, J. Nordberg, S. Nordholm Subband Acoustic Echo Cancelling using LMS and RLS, Research Report 1999:5, ISSN: 1103-1581, University of Karlskrona/Ronneby, May 1999. N. Grbi´c, S. Nordholm, J. Nordberg, I. Claesson A New Pilot-Signal based Space-Time Adaptive Algorithm, Proceedings of IEEE International Conference on Telecommunications ICT 2001, Bucharest, Romania, June 2001. H. H. Dam, H.-J. Zepernick, J. Nordberg, and S. Nordholm Design of Complex Spreading Sequences, Proceedings of International Conference on Optimization Techniques and Applications (ICOTA), Hong Kong, vol. 4, pp. 1489-1496, December 2001. H. H. Dam, J. Nordberg, S. Nordholm, and H.-J. Zepernick Stacking Methods for Non-Causal Delayless Subband Adaptive Equalizer, Proceed- ings of International Conference on Telecommunications (ICT), June 2002. H.H. Dam, H.-J. Zepernick, J. Nordberg, and S. Nordholm Complex Spreading Sequence Design, Proceedings of SNRV and NUTEKConfer- ence on Radio Sciences and Telecommunications, Stockholm, Sweden, pp. 601–605, June 2002. H. H. Dam, H.-J. Zepernick, S. Nordholm, and J. Nordberg Design of Spreading Sequences Using a Modified Bridging Method, accepted for IEEE Globecom, Taipei, Taiwan, November 2002. 14 H.H. Dam, H.-J. Zepernick, J. Nordberg, and S. Nordholm Application of a Global Optimization Method to the Design of Complex Spread- ing Sequences, 3rd Australian Communications Theory Workshop, Canberra, Aus- tralia, February 2002. Introduction 15 Introduction During the last decades, more and more telecommunication applications have moved towards the wireless concept. This change started during the late 70s and early 80s when the first commercial analog cellular systems (first generations cellu- lar systems (1G)) were launched: Advanced Mobile Phone Service (AMPS) in the US in 1979 and Nordic Mobile Telephone (NMT) system in the Scandinavian coun- tries during 1982-1986 [1]. One of the limitations of the 1G systems