Bit error probability for space-time block code with coherent and differential detection

Abstract

Exact, closed-form expressions of bit error probability (BEP) are derived for space-time block codes (STBC) based on Alamouti's (1998) scheme and utilizing M-ary phase shift keying (MPSK) modulation. The analysis is carried out for the slow, flat fading Rayleigh channel with coherent detection and with differential encoding/decoding. With these closed-form expressions, we prove that a signal to noise ratio (SNR) loss of approximately 3 dB is paid for deferential detection compared to coherent detection. Numerical results are provided for analysis and simulations for BPSK and QPSK modulations.