Modified LMMSE receiver for DS-CDMA-Part I. Performance analysis and adaptive implementations

Linear minimum mean squared error (LMMSE) criterion can be used to obtain near-far resistant receivers in direct-sequence code-division multiple-access (DS-CDMA) systems. The standard version of the LMMSE receiver minimizes the mean squared error between the filter output and the true transmitted data sequence. Since the detector depends on the channel coefficients of all users, it cannot be implemented adaptively in fading channels due to severe convergence problems. In this paper, a modified criterion for deriving LMMSE receivers in fading channels is presented. The modified LMMSE receiver is independent from the users' complex channel coefficients. The performance of the LMMSE receivers in fading channels is studied via computer simulations and numerical analysis. The results show that the modified LMMSE receiver has remarkably larger capacity than the conventional RAKE receiver at the SNRs of practical interest.

[1]  Matti Latva-aho,et al.  Multiuser receivers for CDMA systems in Rayleigh fading channels , 2000, IEEE Trans. Veh. Technol..

[2]  H. Vincent Poor,et al.  Probability of error in MMSE multiuser detection , 1997, IEEE Trans. Inf. Theory.

[3]  Scott L. Miller,et al.  A modified MMSE receiver for detection of DS-CDMA signals in fading channels , 1996, Proceedings of MILCOM '96 IEEE Military Communications Conference.

[4]  M. Luise,et al.  Blind adaptive interference-reject linear detectors for CDMA receivers , 1996, Proceedings of ISSSTA'95 International Symposium on Spread Spectrum Techniques and Applications.

[5]  Matti Latva-aho,et al.  Frames FMA2 wideband-CDMA for UMTS , 1998, Eur. Trans. Telecommun..

[6]  Markku J. Juntti,et al.  Multiuser demodulation for DS-CDMA systems in fading channels , 1997 .

[7]  Antti Toskala,et al.  FRAMES multiple access mode 2-wideband CDMA , 1997, Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97.

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

[9]  Savo Glisic,et al.  Advanced CDMA for Wireless Communications , 1997 .

[10]  Jeffrey H. Reed,et al.  Blind CDMA interference rejection in multipath channels , 1997, 1997 IEEE 47th Vehicular Technology Conference. Technology in Motion.

[11]  John F. Doherty,et al.  Generalized projection algorithm for blind interference suppression in DS/CDMA communications , 1997 .

[12]  Sergio Verdú,et al.  Minimum probability of error for asynchronous Gaussian multiple-access channels , 1986, IEEE Trans. Inf. Theory.

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

[14]  Scott L. Miller.  An adaptive direct-sequence code-division multiple-access receiver for multiuser interference rejection , 1995, IEEE Trans. Commun..

[15]  S. Moshavi,et al.  Multi-user detection for DS-CDMA communications , 1996, IEEE Commun. Mag..

[16]  Scott L. Miller,et al.  Adaptive detection of DS/CDMA signals in fading channels , 1998, IEEE Trans. Commun..

[17]  Michael J. Barrett,et al.  Error Probablity for Optimal and Suboptimal Quadratic Receivers in Rapid Rayleigh Fading Channels , 1987, IEEE J. Sel. Areas Commun..

[18]  Branka Vucetic,et al.  Adaptive receiver structures for asynchronous CDMA systems , 1994, IEEE J. Sel. Areas Commun..

[19]  M. Latva-aho,et al.  Reconfigurable adaptive RAKE receiver for wideband CDMA systems , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[20]  Zoran Zvonar,et al.  Multiuser detection for CDMA systems , 1995, IEEE Wirel. Commun..

[21]  Scott L. Miller.  Training analysis of adaptive interference suppression for direct-sequence code-division multiple-access systems , 1996, IEEE Trans. Commun..

[22]  S. Haykin,et al.  Adaptive Filter Theory , 1986 .