Performance of wideband CDMA using adaptive space-time spreading over multipath Nakagami fading channels

Abstract

An adaptive space-time spreading (ASTS) assisted transmit diversity scheme is proposed for improving the throughput of wideband code-division multiple-access (W-CDMA) systems. The performance of the system is investigated, when frequency-selective Nakagami-m fading channels, multiuser interference and background noise are considered. Our numerical results demonstrate that the proposed ASTS-based transmission scheme is capable of significantly improving the effective throughput of W-CDMA systems. Specifically, the studied W-CDMA system's bitrate can be increased by a factor of three at the modest cost of requiring an extra 0.4 dB or 1.2 dB transmitted power in the context of the investigated urban or suburban areas, respectively.