Performance analysis of full-rate, full-diversity space-time code in asynchronous DS/CDMA

Full-rate, full-diversity space-time codes can be applied in the framework of multiple-input multiple-output asynchronous direct-sequence code-division multiple access (MIMO-ACDMA) to increase the system capacity. First, the performance of these codes in this framework is investigated analytically assuming known channel fading coefficients. An upper bound on the pair-wise error probability is derived. It is shown that the determinant of an effective SINR matrix can serve as a metric to select chip waveforms. Next, different expurgated union bounds are derived to approximate the bit error rate (BER) at different SNR levels. Results show that a chip-level oversampling technique can effectively suppress the multiple-access interference (MAI) when used jointly with high-rate space-time codes.