Performance of decorrelator detector in space-time CDMA systems over quasi-static and frequency non-selective Nakagami-m fading channels

The performance of space-time spreading (STS) transmit diversity is examined in a multiuser direct-sequence code division multiple access (DS-CDMA) system over Nakagami-m slowly-fading channels. The space-time system employs N=2 transmit antennas and L receive antennas at the user side and base-station (BS) receiver, respectively. To combat the effect of multiuser interference, we employ the linear decorrelator multiuser detector. We derive theoretical expression for the bit-error-rate (BER), and assess the performance under different system loads and fading figures m. In particular, these results show that the diversity order of 2 mL is achieved and only a signal- to-noise ratio (SNR) loss is incurred.