- Research Article
- Open Access
Multipass Channel Estimation and Joint Multiuser Detection and Equalization for MIMO Long-Code DS/CDMA Systems
EURASIP Journal on Wireless Communications and Networking volume 2006, Article number: 024132 (2006)
The problem of joint channel estimation, equalization, and multiuser detection for a multiantenna DS/CDMA system operating over a frequency-selective fading channel and adopting long aperiodic spreading codes is considered in this paper. First of all, we present several channel estimation and multiuser data detection schemes suited for multiantenna long-code DS/CDMA systems. Then, a multipass strategy, wherein the data detection and the channel estimation procedures exchange information in a recursive fashion, is introduced and analyzed for the proposed scenario. Remarkably, this strategy provides, at the price of some attendant computational complexity increase, excellent performance even when very short training sequences are transmitted, and thus couples together the conflicting advantages of both trained and blind systems, that is, good performance and no wasted bandwidth, respectively. Space-time coded systems are also considered, and it is shown that the multipass strategy provides excellent results for such systems also. Likewise, it is also shown that excellent performance is achieved also when each user adopts the same spreading code for all of its transmit antennas. The validity of the proposed procedure is corroborated by both simulation results and analytical findings. In particular, it is shown that adopting the multipass strategy results in a remarkable reduction of the channel estimation mean-square error and of the optimal length of the training sequence.
Dahlman E, Beming P, Knutsson J, Ovesjo F, Persson M, Roobol C: WCDMA-the radio interface for future mobile multimedia communications. IEEE Transactions on Vehicular Technology 1998,47(4):1105–1118. 10.1109/25.728481
Madhow U: Blind adaptive interference suppression for direct-sequence CDMA. Proceedings of the IEEE 1998,86(10):2049–2069. 10.1109/5.720252
Wang X, Poor HV: Blind multiuser detection: a subspace approach. IEEE Transactions on Information Theory 1998,44(2):677–690. 10.1109/18.661512
Weiss AJ, Friedlander B: Channel estimation for DS-CDMA downlink with aperiodic spreading codes. IEEE Transactions on Communications 1999,47(10):1561–1569. 10.1109/26.795824
Xu ZD, Tsatsanis MK: Blind channel estimation for long code multiuser CDMA systems. IEEE Transactions on Signal Processing 2000,48(4):988–1001. 10.1109/78.827533
Escudero CJ, Mitra U, Slock DTM: A Toeplitz displacement method for blind multipath estimation for long code DS/CDMA signals. IEEE Transactions on Signal Processing 2001,49(3):654–665. 10.1109/78.905897
Tripathi V, Mantravadi A, Veeravalli VV: Channel acquisition for wideband CDMA signals. IEEE Journal on Selected Areas in Communications 2000,18(8):1483–1494. Special issue on Wideband CDMA 10.1109/49.864012
Buzzi S, Poor HV: Channel estimation and multiuser detection in long-code DS/CDMA systems. IEEE Journal on Selected Areas in Communications 2001,19(8):1476–1487. 10.1109/49.942510
Buzzi S, Poor HV: A multipass approach to joint data and channel estimation in long-code CDMA systems. IEEE Transactions on Wireless Communications 2004,3(2):612–626. 10.1109/TWC.2003.821125
Telatar IE: Capacity of multi-antenna Gaussian channels. European Transactions on Telecommunications 1999,10(6):585–595. 10.1002/ett.4460100604
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
Marzetta TL, Hochwald BM: Capacity of a mobile multiple-antenna communication link in Rayleigh flat fading. IEEE Transactions on Information Theory 1999,45(1):139–157. 10.1109/18.746779
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.
Foschini GJ, Golden GD, Valenzuela RA, Wolniansky PW: Simplified processing for high spectral efficiency wireless communication employing multi-element arrays. IEEE Journal on Selected Areas in Communications 1999,17(11):1841–1852. 10.1109/49.806815
Hochwald BM, Marzetta TL, Papadias CB: A transmitter diversity scheme for wideband CDMA systems based on space-time spreading. IEEE Journal on Selected Areas in Communications 2001,19(1):48–60. 10.1109/49.909608
Reynolds D, Wang X, Poor HV: Blind adaptive space-time multiuser detection with multiple transmitter and receiver antennas. IEEE Transactions on Signal Processing 2002,50(6):1261–1276. 10.1109/TSP.2002.1003052
Alamouti SM: A simple transmit diversity technique for wireless communications. IEEE Journal on Selected Areas in Communications 1998,16(8):1451–1458. 10.1109/49.730453
Golub GH, Van Loan CF: Matrix Computations. 3rd edition. The Johns Hopkins University Press, Baltimore, Md, USA; 1996.
Mailaender L: Capacity bound for linear MIMO systems with channel estimation. Proceedings of IEEE 6th Workshop on Signal Processing Advances in Wireless Communications (SPAWC '05), June 2005, New York, NY, USA 1048–1052.
Yoo T, Goldsmith A: Capacity of fading MIMO channels with channel estimation error. Proceedings of IEEE International Conference on Communications (ICC '04), June 2004, Paris, France 2: 808–813.
About this article
Cite this article
Buzzi, S. Multipass Channel Estimation and Joint Multiuser Detection and Equalization for MIMO Long-Code DS/CDMA Systems. J Wireless Com Network 2006, 024132 (2006). https://doi.org/10.1155/WCN/2006/24132
- Channel Estimation
- Training Sequence
- Data Detection
- Multiuser Detection
- Spreading Code