Linear space-time multiuser detection for multipath CDMA channels

We consider the problem of detecting synchronous code division multiple access (CDMA) signals in multipath channels that result in multiple access interference (MAI). It is well known that such challenging conditions may create severe near-far situations in which the standard techniques of combined power control and temporal single-user RAKE receivers provide poor performance. To address the shortcomings of the RAKE receiver, multiple antenna receivers combining space-time processing with multiuser detection have been proposed in the literature. Specifically, a space-time detector based on minimizing the mean-squared output between the data stream and the linear combiner output has shown great potential in achieving good near-far performance with much less complexity than the optimum space-time multiuser detector. Moreover, this space-time minimum mean-squared error (ST-MMSE) multiuser detector has the additional advantage of being well suited for adaptive implementation. We propose novel trained and blind adaptive algorithms based on stochastic gradient techniques, which are shown to approximate the ST-MMSE solution without requiring knowledge of the channel. We show that these linear space-time detectors can potentially provide significant capacity enhancements (up to one order of magnitude) over the conventional temporal single-user RAKE receiver.

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

[2]  Alexander M. Haimovich,et al.  Space-time optimum combining for CDMA communications , 1996, Wirel. Pers. Commun..

[3]  Sergio Verdú,et al.  Linear multiuser detectors for synchronous code-division multiple-access channels , 1989, IEEE Trans. Inf. Theory.

[4]  He Huang,et al.  Linear space-time multiuser receivers for wireless CDMA systems , 1998, Ninth IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (Cat. No.98TH8361).

[5]  Carlos J. Escudero,et al.  A blind signal separation method for multiuser communications , 1997, IEEE Trans. Signal Process..

[6]  Stuart C. Schwartz,et al.  Integrated spatial-temporal detectors for asynchronous Gaussian multiple-access channels , 1995, IEEE Trans. Commun..

[7]  Peter Jung,et al.  Joint detection with coherent receiver antenna diversity in CDMA mobile radio systems , 1995 .

[8]  Thomas Kailath,et al.  Capacity improvement with base-station antenna arrays in cellular CDMA , 1994 .

[9]  J. Treichler,et al.  A new approach to multipath correction of constant modulus signals , 1983 .

[10]  Matti Latva-aho Advanced receivers for wideband CDMA systems , 1998 .

[11]  S. Verdu,et al.  Combined multipath and spatial resolution for multiuser detection: potentials and problems , 1995, Proceedings of 1995 IEEE International Symposium on Information Theory.

[12]  L. Castedo,et al.  Performance analysis of a CMA-based adaptive multiuser detector , 1997, First IEEE Signal Processing Workshop on Signal Processing Advances in Wireless Communications.

[13]  D. Godard,et al.  Self-Recovering Equalization and Carrier Tracking in Two-Dimensional Data Communication Systems , 1980, IEEE Trans. Commun..

[14]  Ming Gu,et al.  Geometrical characterizations of constant modulus receivers , 1999, IEEE Trans. Signal Process..

[15]  Constantinos B. Papadias Globally convergent algorithms for blind source separation , 2000, 2000 10th European Signal Processing Conference.

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

[17]  R. Kohno,et al.  A spatially and temporally optimal multi-user receiver using an array antenna for DS/CDMA , 1995, Proceedings of 6th International Symposium on Personal, Indoor and Mobile Radio Communications.

[18]  C. Papadias,et al.  A constant modulus algorithm for multiuser signal separation in presence of delay spread using antenna arrays , 1997, IEEE Signal Processing Letters.

[19]  Subbarayan Pasupathy,et al.  Decorrelators for multi-sensor systems in CDMA networks , 1995, Eur. Trans. Telecommun..

[20]  Richard D. Gitlin,et al.  The impact of antenna diversity on the capacity of wireless communication systems , 1994, IEEE Trans. Commun..

[21]  Upamanyu Madhow,et al.  MMSE interference suppression for direct-sequence spread-spectrum CDMA , 1994, IEEE Trans. Commun..

[22]  Sangarapillai Lambotharan,et al.  On the surface characteristics of a mixed constant modulus and cross-correlation criterion for the blind equalization of a MIMO channel , 1999, Signal Process..

[23]  Philip Schniter,et al.  Blind equalization using the constant modulus criterion: a review , 1998, Proc. IEEE.

[24]  Michail K. Tsatsanis Inverse filtering criteria for CDMA systems , 1997, IEEE Trans. Signal Process..

[25]  Steven D. Gray,et al.  Multiuser detection in a horizontal underwater acoustic channel using array observations , 1997, IEEE Trans. Signal Process..

[26]  S. Haykin Unsupervised adaptive filtering, vol. 1: Blind source separation , 2000 .

[27]  Y. Sato,et al.  A Method of Self-Recovering Equalization for Multilevel Amplitude-Modulation Systems , 1975, IEEE Trans. Commun..

[28]  Subbarayan Pasupathy,et al.  Multi-user multi-sensor detectors for CDMA networks , 1995, IEEE Trans. Commun..

[29]  Peter Jung,et al.  Simulation of the uplink of JD-CDMA mobile radio systems with coherent receiver antenna diversity , 1994, Wirel. Pers. Commun..

[30]  Sergio Verdu,et al.  Multiuser Detection , 1998 .

[31]  Nathalie Delfosse,et al.  Adaptive separation of independent sources: a deflation approach , 1994, Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing.

[32]  Arogyaswami Paulraj,et al.  Performance of Wireless CDMA with M-ary Orthogonal Modulation and Cell Site Antenna Arrays , 1996, IEEE J. Sel. Areas Commun..

[33]  Constantinos B. Papadias Blind source separation based on multi-user kurtosis criteria , 2000, 2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060).

[34]  G. J. Foschini,et al.  Equalizing without altering or detecting data , 1985, AT&T Technical Journal.

[35]  Upamanyu Madhow,et al.  Blind adaptive multiuser detection , 1995, IEEE Trans. Inf. Theory.

[36]  João Marcos Travassos Romano,et al.  Least-squares CMA with decorrelation for fast blind multiuser signal separation , 1999, 1999 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258).