Space-time spreading for MIMO CDMA-based systems over fast-fading channels

In this paper, a transmit diversity scheme based on space-time spreading for code-division multiple-access (CDMA) systems in fast-fading channels is introduced. The proposed transmit diversity scheme employs orthogonal Walsh spreading codes to exploit the time diversity introduced by the channel, and hence achieves two-fold of the diversity order obtained using conventional space-time spreading schemes. A generalization of the proposed coding scheme to systems with different antenna configurations is also discussed. For slowly-fading channels, we show that the proposed transmit diversity scheme reduces to that of conventional transmit diversity schemes with no performance degradation. For nonorthogonal spreading codes, we propose a receiver structure that employs an interference cancellation scheme to compensate for signal interference. Our results show a large performance improvement when using such an interference cancellation scheme relative to the conventional matched filter receiver.

[1]  M. J. Gans,et al.  On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas , 1998, Wirel. Pers. Commun..

[2]  Thomas L. Marzetta,et al.  A transmitter diversity scheme for wideband CDMA systems based on space-time spreading , 2001, IEEE J. Sel. Areas Commun..

[3]  Gerhard Bauch,et al.  Improved codes for space-time trellis-coded modulation , 2000, IEEE Communications Letters.

[4]  Branka Vucetic,et al.  Space-time TCM with improved performance on fast fading channels , 2001, IEEE Communications Letters.

[5]  Jian-Ching Guey Concatenated coding for transmit diversity systems , 1999, Gateway to 21st Century Communications Village. VTC 1999-Fall. IEEE VTS 50th Vehicular Technology Conference (Cat. No.99CH36324).

[6]  Siavash M. Alamouti,et al.  A simple transmit diversity technique for wireless communications , 1998, IEEE J. Sel. Areas Commun..

[7]  Robert Schober,et al.  Noncoherent MMSE interference suppression for DS-CDMA , 2001, ICC 2001. IEEE International Conference on Communications. Conference Record (Cat. No.01CH37240).

[8]  Dariush Divsalar,et al.  Improved parallel interference cancellation for CDMA , 1998, IEEE Trans. Commun..

[9]  Jack M. Holtzman,et al.  Analysis of a simple successive interference cancellation scheme in a DS/CDMA system , 1994, IEEE J. Sel. Areas Commun..

[10]  Emre Telatar,et al.  Capacity of Multi-antenna Gaussian Channels , 1999, Eur. Trans. Telecommun..

[11]  Rick S. Blum,et al.  Improved space-time codes using serial concatenation , 2000, IEEE Communications Letters.

[12]  Ran Gozali,et al.  Space-Time Codes for High Data Rate Wireless Communications , 2002 .

[13]  A. Robert Calderbank,et al.  Space-Time Codes for High Data Rate Wireless Communications : Performance criterion and Code Construction , 1998, IEEE Trans. Inf. Theory.

[14]  Vahid Tarokh,et al.  Trellis-coded modulation and transmit diversity: design criteria and performance evaluation , 1998, ICUPC '98. IEEE 1998 International Conference on Universal Personal Communications. Conference Proceedings (Cat. No.98TH8384).

[15]  Michael P. Fitz,et al.  Signal design for transmitter diversity wireless communication systems over Rayleigh fading channels , 1999, IEEE Trans. Commun..

[16]  Youjian Liu,et al.  Full rate space-time turbo codes , 2001, IEEE J. Sel. Areas Commun..

[17]  Ali Ghrayeb,et al.  Performance of convolutionally-coded MIMO systems with antenna selection , 2005, Journal of Communications and Networks.

[18]  Gerard J. Foschini,et al.  Layered space-time architecture for wireless communication in a fading environment when using multi-element antennas , 1996, Bell Labs Technical Journal.

[19]  Robert W. Heath,et al.  Space-time block codes versus space-time trellis codes , 2001, ICC 2001. IEEE International Conference on Communications. Conference Record (Cat. No.01CH37240).

[20]  A. Robert Calderbank,et al.  Space-Time block codes from orthogonal designs , 1999, IEEE Trans. Inf. Theory.