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  • Research Article
  • Open Access

Relay Techniques for MIMO Wireless Networks with Multiple Source and Destination Pairs

EURASIP Journal on Wireless Communications and Networking20062006:064159

  • Received: 1 November 2005
  • Accepted: 16 August 2006
  • Published:


A multiple-input multiple-output (MIMO) relay network comprises source, relay, and destination nodes, each of which is equipped with multiple antennas. In a previous work, we proposed a MIMO relay scheme for a relay network with a single source and destination pair in which each of the multiple relay nodes performs QR decompositions of the backward and forward channel matrices in conjunction with phase control (QR-P-QR). In this paper, we extend this scheme to a MIMO relay network employing multiple source and destination pairs. Towards this goal, we use a group nulling approach to decompose a multiple S-D MIMO relay channel into parallel independent S-D MIMO relay channels, and then apply the QR-P-QR scheme to each of the decomposed MIMO relay links. We analytically show the logarithmic capacity scaling of the proposed relay scheme. Numerical examples confirm that the proposed relay scheme offers higher capacity than existing relay schemes.


  • Destination Node
  • Relay Node
  • Relay Network
  • Destination Pair
  • Logarithmic Capacity


Authors’ Affiliations

DoCoMo Communications Laboratories Europe GmbH, 312 Landsbergerstreet, Munich, 80687, Germany
NTT DoCoMo, Inc., Japan


  1. Gastpar M, Vetterli M: On the capacity of wireless networks: the relay case. Proceedings of the 21st Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM '02), June 2002, New York, NY, USA 3: 1577–1586.Google Scholar
  2. Telatar IE: Capacity of multi-antenna Gaussian channels. European Transactions on Telecommunications 1999,10(6):585–595. 10.1002/ett.4460100604View ArticleGoogle 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:1008889222784View ArticleGoogle Scholar
  4. Raleigh GG, Cioffi JM: Spatio-temporal coding for wireless communication. IEEE Transactions on Communications 1998,46(3):357–366. 10.1109/26.662641View ArticleGoogle Scholar
  5. Winters JH: On the capacity of radio communication systems with diversity in a Rayleigh fading environment. IEEE Journal on Selected Areas in Communications 1987,5(5):871–878. 10.1109/JSAC.1987.1146600View ArticleGoogle Scholar
  6. Goldsmith A, Jafar SA, Jindal N, Vishwanath S: Capacity limits of MIMO channels. IEEE Journal on Selected Areas in Communications 2003,21(5):684–702. 10.1109/JSAC.2003.810294View ArticleGoogle Scholar
  7. 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.2003.813523MATHMathSciNetView ArticleGoogle Scholar
  8. Vishwanath S, Jindal N, Goldsmith A: Duality, achievable rates, and sum-rate capacity of Gaussian MIMO broadcast channels. IEEE Transactions on Information Theory 2003,49(10):2658–2668. 10.1109/TIT.2003.817421MATHMathSciNetView ArticleGoogle Scholar
  9. Yu W, Cioffi JM: Sum capacity of Gaussian vector broadcast channels. IEEE Transactions on Information Theory 2004,50(9):1875–1892. 10.1109/TIT.2004.833336MATHMathSciNetView ArticleGoogle Scholar
  10. Bölcskei H, Nabar RU, Oyman Ö, Paulraj AJ: Capacity scaling laws in MIMO relay networks. IEEE Transactions on Wireless Communications 2006,5(6):1433–1444.View ArticleGoogle Scholar
  11. Nabar RU, Oyman Ö, Bölcskei H, Paulraj AJ: Capacity scaling laws in MIMO wireless networks. Proceedings of Allerton Conference on Communication, Control, and Computing, October 2003, Monticello, Ill, USA 378–389.Google Scholar
  12. Shi H, Abe T, Asai T, Yoshino H: A relaying scheme using QR decomposition with phase control for MIMO wireless networks. Proceedings of IEEE International Conference on Communications (ICC '05), May 2005, Seoul, Korea 4: 2705–2711.Google Scholar
  13. Cover TM, Thomas JA: Elements of Information Theory. John Wiley & Sons, New York, NY, USA; 1991.MATHView ArticleGoogle Scholar
  14. Choi L-U, Murch RD: A transmit preprocessing technique for multiuser MIMO systems using a decomposition approach. IEEE Transactions on Wireless Communications 2004,3(1):20–24. 10.1109/TWC.2003.821148View ArticleGoogle Scholar
  15. Bölcskei H, Nabar RU: Realizing MIMO gains without user cooperation in large single-antenna wireless networks. Proceedings of IEEE International Symposium on Information Theory, June-July 2004, Chicago, Ill, USA 18.Google Scholar


© Abe et al. 2006

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.