Skip to main content
  • Research Article
  • Open access
  • Published:

Real-Time Signal Processing for Multiantenna Systems: Algorithms, Optimization, and Implementation on an Experimental Test-Bed

Abstract

A recently realized concept of a reconfigurable hardware test-bed suitable for real-time mobile communication with multiple antennas is presented in this paper. We discuss the reasons and prerequisites for real-time capable MIMO transmission systems which may allow channel adaptive transmission to increase link stability and data throughput. We describe a concept of an efficient implementation of MIMO signal processing using FPGAs and DSPs. We focus on some basic linear and nonlinear MIMO detection and precoding algorithms and their optimization for a DSP target, and a few principal steps for computational performance enhancement are outlined. An experimental verification of several real-time MIMO transmission schemes at high data rates in a typical office scenario is presented and results on the achieved BER and throughput performance are given. The different transmission schemes used either channel state information at both sides of the link or at one side only (transmitter or receiver). Spectral efficiencies of more than 20 bits/s/Hz and a throughput of more than 150 Mbps were shown with a single-carrier transmission. The experimental results clearly show the feasibility of real-time high data rate MIMO techniques with state-of-the-art hardware and that more sophisticated baseband signal processing will be an essential part of future communication systems. A discussion on implementation challenges towards future wireless communication systems supporting higher data rates (1 Gbps and beyond) or high mobility concludes the paper.

References

  1. Foschini GJ: Layered space-time architecture for wireless communication in a fading environment when using multi-element antennas. Bell Labs Technical Journal 1996, 1(2):41-59.

    Article  Google Scholar 

  2. Telatar IE: Capacity of multi-antenna Gaussian channels. AT&T Bell Labs Internal Technical Memorandum, Murray Hill, NJ, USA; June 1995.

    Google Scholar 

  3. Foschini GJ, Gans MJ: On limits of wireless communications in a fading environment when using multiple antennas. Wireless Personal Communications 1998, 6(3):311–335. 10.1023/A:1008889222784

    Article  Google Scholar 

  4. Knopp R, Humblet PA: Information capacity and power control in single-cell multiuser communications. Proceedings of IEEE International Conference on Communications (ICC '95), June 1995, Seattle, Wash, USA 1: 331–335.

    Article  Google Scholar 

  5. Jakes WC: Microwave Mobile Communications. IEEE Press, New York, NY, USA; 1974.

    Google Scholar 

  6. Telatar IE: Capacity of multi-antenna Gaussian channels. European Transactions on Telecommunications 1999, 10(6):585–595. 10.1002/ett.4460100604

    Article  MathSciNet  Google Scholar 

  7. Salz J: Digital transmission over cross-coupled linear channels. AT&T Technical Journal 1985, 64(6):1147–1159.

    Article  Google Scholar 

  8. Raleigh GG, Cioffi JM: Spatio-temporal coding for wireless communication. IEEE Transactions on Communications 1998, 46(3):357–366. 10.1109/26.662641

    Article  Google Scholar 

  9. Caire G, Shamai S: On the achievable throughput of a multiantenna Gaussian broadcast channel. IEEE Transactions on Information Theory 2003, 49(7):1691–1706. 10.1109/TIT.2003.813523

    Article  MathSciNet  MATH  Google Scholar 

  10. Zheng L, Tse DNC: Diversity and multiplexing: a fundamental tradeoff in multiple-antenna channels. IEEE Transactions on Information Theory 2003, 49(5):1073–1096. 10.1109/TIT.2003.810646

    Article  MATH  Google Scholar 

  11. Wolniansky PW, Foschini GJ, Golden GD, Valenzuela RA: V-BLAST: an architecture for realizing very high data rates over the rich-scattering wireless channel. In Proceedings of URSI International Symposium on Signals, Systems, and Electronics (ISSSE '98), September-October 1998, Pisa, Italy. IEEE; 295–300. Invited paper

    Google Scholar 

  12. Winters JH: The diversity gain of transmit diversity in wireless systems with Rayleigh fading. IEEE Transactions on Vehicular Technology 1998, 47(1):119–123. 10.1109/25.661038

    Article  MathSciNet  Google Scholar 

  13. Haustein T, von Helmolt C, Jorswieck E, Jungnickel V, Pohl V: Performance of MIMO systems with channel inversion. Proceedings of IEEE 55th Vehicular Technology Conference (VTC '02), May 2002, Birmingham, Ala, USA 1: 35–39.

    Google Scholar 

  14. Jungnickel V, Haustein T, Jorswieck E, von Helmolt C: On linear pre-processing in multi-antenna systems. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '02), November 2002, Taipei, Taiwan 1: 1012–1016.

    Google Scholar 

  15. Weber T, Meurer M: Optimum joint transmission: potentials and dualities. Proceedings of 6th IEEE International Symposium on Wireless Personal Multimedia Communications (WPMC '03), October 2003, Yokosuka, Japan 1: 79–83.

    Google Scholar 

  16. Barreto AN, Fettweis G: Capacity increase in the downlink of spread spectrum systems through joint signal precoding. Proceedings of IEEE International Conference on Communications (ICC '01), June 2001, Helsinki, Finland 4: 1142–1146.

    Google Scholar 

  17. Baier PW, Meurer M, Weber T, Tröger H: Joint transmission (JT), an alternative rationale for the downlink of time division CDMA using multi-element transmit antennas. Proceedings of IEEE 6th International Symposium on Spread Spectrum Techniques and Applications (ISSTA '00), September 2000, Parsippany, NJ, USA 1: 1–5.

    Article  Google Scholar 

  18. Haustein T, Forck A, Gäbler H, von Helmolt C, Jungnickel V, Krüger U: Implementation of adaptive channel inversion in a real-time MIMO system. Proceedings of 15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '04), September 2004, Barcelona, Spain 4: 2524–2528.

    Google Scholar 

  19. Brunner C, Hammerschmidt JS, Seeger A, Nosek JA: Space-time eigenRAKE and downlink eigenibeamformer: exploiting long-term and short-term channel properties in WCDMA. Proceedings of IEEE Global Telecommunications Conference (GLOBECOM '00), November-December 2000, San Francisco, Calif, USA 1: 138–142.

    Article  Google Scholar 

  20. Hammerschmidt JS, Brunner C, Drewes C: Eigenbeamforming—a novel concept in array signal processing. Proceedings of European Wireless Conference (EW '00), September 2000, Dresden, Germany

    Google Scholar 

  21. Boixadera Espax F, Boutros JJ: Capacity considerations for wireless MIMO channels. Workshop on Multiaccess, Mobility and Teletraffic for Wireless Communications (MMT '99), October 1999, Venice, Italy 283–292.

    Chapter  Google Scholar 

  22. Poon ASY, Tse DNC, Brodersen RW: An adaptive multi-antenna transceiver for slowly flat fading channels. IEEE Transactions on Communications 2003, 51(11):1820–1827. 10.1109/TCOMM.2003.819206

    Article  Google Scholar 

  23. Samuelsson D, Jaldén J, Zetterberg P, Ottersten B: Realization of a spatially multiplexed MIMO system. EURASIP Journal on Applied Signal Processing March 2005.

    Google Scholar 

  24. Goeckel DL: Adaptive coding for time-varying channels using outdated fading estimates. IEEE Transactions on Communications 1999, 47(6):844–855. 10.1109/26.771341

    Article  Google Scholar 

  25. Chung ST, Goldsmith AJ: Degrees of freedom in adaptive modulation: a unified view. IEEE Transactions on Communications 2001, 49(9):1561–1571. 10.1109/26.950343

    Article  MATH  Google Scholar 

  26. Berrou C, Glavieux A, Thitimajshima P: Near Shannon limit error-correcting coding and decoding: turbo-codes. 1. Proceedings of IEEE International Conference on Communications (ICC '93), May 1993, Geneva, Switzerland 2: 1064–1070.

    Article  Google Scholar 

  27. Gallager RG: Low-density parity-check codes. IRE Transactions on Information Theory 1962, 8(1):21–28. 10.1109/TIT.1962.1057683

    Article  MathSciNet  MATH  Google Scholar 

  28. Levine B, Reed Taylor R, Schmit H: Implementation of near Shannon limit error-correcting codes using reconfigurable hardware. Proceedings of 8th IEEE Symposium on Field-Programmable Custom Computing Machines (FCCM '00), April 2000, Napa Valley, Calif, USA 217–226.

    Chapter  Google Scholar 

  29. Zimmermann E, Pattisapu P, Bora PK, Fettweis G: Reduced complexity LDPC decoding using forced convergence. Proceedings of 7th International Symposium on Wireless Personal Multimedia Communications (WPMC '04), September 2004, Abano Terme, Italy

    Google Scholar 

  30. Bingham JAC: Multicarrier modulation for data transmission: an idea whose time has come. IEEE Communications Magazine 1990, 28(5):5–14. 10.1109/35.54342

    Article  Google Scholar 

  31. Campello J: Optimal discrete bit loading for multicarrier modulation systems. Proceedings of IEEE International Symposium on Information Theory (ISIT '98), August 1998, Cambridge, Mass, USA 193.

    Google Scholar 

  32. Chow PS, Cioffi JM, Bingham JAC: A practical discrete multitone transceiver loading algorithm for data transmission over spectrally shaped channels. IEEE Transactions on Communications 1995, 43(2–4):773–775.

    Article  Google Scholar 

  33. Campello J: Practical bit loading for DMT. Proceedings of IEEE International Conference on Communications (ICC '99), June 1999, Vancouver, BC, Canada 2: 801–805.

    Google Scholar 

  34. Alouini M-S, Tang X, Goldsmith AJ: An adaptive modulation scheme for simultaneous voice and data transmission over fading channels. IEEE Journal on Selected Areas in Communications 1999, 17(5):837–850. 10.1109/49.768199

    Article  Google Scholar 

  35. Armada AG, Cioffi JM: Multi-user constant-energy bit loading for M-PSK-modulated orthogonal frequency division multiplexing. Proceedings of IEEE Wireless Communications and Networking Conference (WCNC '02), March 2002, Orlando, Fla, USA 2: 526–530.

    Google Scholar 

  36. Seyedi A, Saulnier GJ: A CDM based Robust bit-loading algorithm for wireless OFDM systems. Proceedings of IEEE Vehicular Technology Conference (VTC '04), September 2004, Los Angeles, Calif, USA

    Google Scholar 

  37. Mutti C, Dahlhaus D, Hunziker T, Foresti M: Bit and power loading procedures for OFDM systems with bit-interleaved coded modulation. Proceedings of 10th International Conference on Telecommunications (ICT '03), February–March 2003, Papeete, French Polynesia, France 2: 1422–1427.

    Google Scholar 

  38. Dardari D: Ordered subcarrier selection algorithm for OFDM-based high-speed WLANs. IEEE Transactions on Wireless Communications 2004, 3(5):1452–1458. 10.1109/TWC.2004.833471

    Article  Google Scholar 

  39. Prasad N, Varanasi MK: Analysis of the Decision Feedback Detection for MIMO Rayleigh Fading Channels and Optimum Allocation of Transmitter Powers and QAM Constallations. Draft, March 2002

    Google Scholar 

  40. Varanasi MK, Guess T: Optimum decision feedback multiuser equalization with successive decoding achieves the total capacity of the Gaussian multiple-access channel. Proceedings of 31st Asilomar Conference on Signals, Systems & Computers, November 1997, Pacific Grove, Calif, USA 2: 1405–1409.

    Google Scholar 

  41. Haustein T, Boche H: Optimal power allocation for MSE and bit-loading in MIMO systems and the impact of correlation. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP '03), April 2003, Hong Kong 4: 405–408.

    Google Scholar 

  42. Haustein T, Boche H, Lehmann G: Bitloading for the SIMO multiple access channel. Proceedings of 14th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '03), September 2003, Beijing, China 2: 1678–1682.

    Google Scholar 

  43. Li J, Narayanan KR, Georghiades CN: Product accumulate codes: a class of codes with near-capacity performance and low decoding complexity. IEEE Transactions on Information Theory 2004, 50(1):31–46. 10.1109/TIT.2003.821995

    Article  MathSciNet  MATH  Google Scholar 

  44. Zheng H, Lozano A, Haleem M: Multiple ARQ processes for MIMO systems. EURASIP Journal on Applied Signal Processing 2004, 2004(5):772–782. 10.1155/S1110865704311042

    Google Scholar 

  45. Falahati S, Svensson A: Hybrid type-II ARQ schemes for Rayleigh fading channels. Proceedings of International Conference on Telecommunications (ICT '98), June 1998, Chalkidiki, Greece 1: 39–44.

    Google Scholar 

  46. Agustín A, Vidal J, Calvo E, Muñoz O: Evaluation of turbo H-ARQ schemes for cooperative MIMO transmission. Proceedings of International Workshop on Wireless Ad-hoc Networks (IWWAN '04), May--June 2004, Oulu, Finland

    Google Scholar 

  47. Agustín A, Vidal J, Calvo E, Lamarca M, Muñoz O: Hybrid turbo FEC/ARQ systems and distributed space-time coding for cooperative transmission in the downlink. Proceedings of 15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '04), September 2004, Barcelona, Spain 1: 380–384.

    Google Scholar 

  48. Liu Q, Zhou S, Giannakis GB: Cross-Layer combining of adaptive modulation and coding with truncated ARQ over wireless links. IEEE Transactions on Wireless Communications 2004, 3(5):1746–1755. 10.1109/TWC.2004.833474

    Article  Google Scholar 

  49. Haustein T, Forck A, Gäbler H, von Helmolt C, Jungnickel V, Krüger U: Real-time MIMO transmission experiments with adaptive bit loading. Proceedings of 4th IASTED Conference on Wireless and Optical Communications Conference (WOC '04), July 2004, Banff, AB, Canada

    Google Scholar 

  50. Boche H, Jorswieck E, Haustein T: Channel aware scheduling for multiple antenna multiple access channels. Proceedings of 37th Asilomar Conference on Signals, Systems and Computers, November 2003, Pacific Grove, Calif, USA 1: 992–996.

    Google Scholar 

  51. Boche H, Wiczanowski M: Stability region of arrival rates and optimal scheduling for MIMO-MAC-a cross-layer approach. Proceedings of International Zurich Seminar on Communications (IZS '04), February 2004, Zurich, Switzerland 18–21.

    Google Scholar 

  52. Boche H, Wiczanowski M: Queueing theoretic optimal scheduling for multiple input multiple output multiple access channel. Proceedings of 3rd IEEE International Symposium on Signal Processing and Information Technology (ISSPIT '03), December 2003, Darmstadt, Germany 576–579. Invited paper

    Google Scholar 

  53. Boche H, Wiczanowski M: Optimal scheduling for high speed uplink packet access—a cross-layer approach. Proceedings of IEEE 59th Vehicular Technology Conference (VTC '04), May 2004, Genoa, Italy 5: 2575–2579.

    Google Scholar 

  54. Boche H, Wiczanowski M: Optimal transmit covariance matrices for MIMO high speed uplink packet access. Proceedings of IEEE Wireless Communications and Networking Conference (WCNC '04), March 2004, Atlanta, Ga, USA 2: 771–776.

    Google Scholar 

  55. Haustein T, Zhou C, Forck A, et al.: Implementation of channel aware scheduling and bit-loading for the multiuser SIMO MAC in a real-time demonstration test-bed at high data rate. Proceedings of IEEE 60th Vehicular Technology Conference (VTC '04), September 2004, Los Angeles, Calif, USA 2: 1043–1047.

    Google Scholar 

  56. Higuchi K, Kawai H, Maeda N, et al.: Likelihood function for QRM-MLD suitable for soft-decision turbo decoding and its performance for OFCDM MIMO multiplexing in multipath fading channel. Proceedings of 15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '04), September 2004, Barcelona, Spain 2: 1142–1148.

    Google Scholar 

  57. Jungnickel V, Haustein T, Forck A, et al.: Real-time concepts for MIMO-OFDM. Proceedings of 1st CIC/IEEE Global Mobile Congress (GMC '04), October 2004, Shanghai, China

    Google Scholar 

  58. Bourdoux A, Come B, Khaled N: Non-reciprocal transceivers in OFDM/SDMA systems: impact and mitigation. Proceedings of Radio and Wireless Conference (RAWCON '03), August 2003, Boston, Mass, USA 183–186.

    Google Scholar 

  59. Lin J, Tsui E: Joint adaptive transmitter/receiver IQ imbalance correction for OFDM systems. Proceedings of 15th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC '04), September 2004, Barcelona, Spain 2: 1511–1516.

    Google Scholar 

  60. Windisch M, Fettweis G: Standard-independent I/Q imbalance compensation in OFDM direct-conversion receivers. Proceedings of 9th International OFDM Workshop (InOWo '04), September 2004, Dresden, Germany

    Google Scholar 

  61. Windisch M, Fettweis G: Blind I/Q imbalance parameter estimation and compensation in low-IF receivers. Proceedings of 1st International Symposium on Control, Communications and Signal Processing (ISCCSP '04), March 2004, Hammamet, Tunisia

    Google Scholar 

  62. Ylamurto TM: Frequency domain IQ imbalance correction scheme for orthogonal frequency division multiplexing (OFDM) systems. Proceedings of IEEE Wireless Communications and Networking (WCNC '03), March 2003, New Orleans, La, USA 1: 20–25.

    Google Scholar 

  63. Jungnickel V, Krüger U, Istoc G, Haustein T, von Helmolt C: A MIMO system with reciprocal transceivers for the time-division duplex mode. Proceedings of IEEE Antennas and Propagation Society International Symposium, Special Session: Antennas and Propagation in MIMO System, June 2004, Monterey, Calif, USA 2: 1267–1270.

    Article  Google Scholar 

  64. Jungnickel V, Forck A, Haustein T, et al.: 1 Gbit/s MIMO-OFDM transmission experiments. Proceedings of IEEE 62nd Semiannual Vehicular Technology Conference (VTC '05), September 2005, Dallas, Tex, USA

    Google Scholar 

  65. Borgmann M, Bölcskei H: Interpolation-based efficient matrix inversion for MIMO-OFDM receivers. Proceedings of 38th Asilomar Conference on Signals, Systems, and Computers, November 2004, Pacific Grove, Calif, USA Invited paper

    Google Scholar 

  66. Henkel O, Michel T, Wunder G: Moderate complexity approximation to MMSE for MIMO-OFDM systems. Proceedings of IEEE 61st Semiannual Vehicular Technology Conference (VTC '05), May–June 2005, Stockholm, Sweden

    Google Scholar 

  67. Schiffermüller S: Effiziente Implementierung von MIMO-Algorithmen für die Echtzeitübertragung in mobilen Funksystemen, Master's thesis. Technical University of Berlin, Berlin, Germany; 2004.

    Google Scholar 

  68. Gantmacher FR: Matrizentheorie. Springer, Berlin, Germany; 1986.

    Book  Google Scholar 

  69. Press WH, Flannery BP, Teukolsky SA, Vetterling WT: Numerical Recipes in C: The Art of Scientific Computing. 2nd edition. Cambridge University Press, Cambridge, UK; 1992.

    MATH  Google Scholar 

  70. Fischer RFH, Windpassinger C: Real versus complex-valued equalisation in V-BLAST systems. Electronics Letters 2003, 39(5):470–471. 10.1049/el:20030331

    Article  Google Scholar 

  71. Wübben D, Böhnke R, Rinas J, Kühn V, Kammeyer KD: Efficient algorithm for decoding layered space-time codes. Electronics Letters 2001, 37(22):1348–1350. 10.1049/el:20010899

    Article  Google Scholar 

  72. Haustein T, Forck A, Gäbler H, Schiffermüller S: From theory to practice: MIMO real-time experiments of adaptive bit-loading with linear and non-linear transmission and detection schemes. Proceedings of 61st IEEE Vehicular Technology Conference (VTC '05), May–June 2005, Stockholm, Sweden

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Thomas Haustein.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License ( https://creativecommons.org/licenses/by/2.0 ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and permissions

About this article

Cite this article

Haustein, T., Forck, A., Gäbler, H. et al. Real-Time Signal Processing for Multiantenna Systems: Algorithms, Optimization, and Implementation on an Experimental Test-Bed. EURASIP J. Adv. Signal Process. 2006, 027573 (2006). https://doi.org/10.1155/ASP/2006/27573

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1155/ASP/2006/27573

Keywords