Performance Analysis of $M$ -PSK/ $M$ -QAM Modulated Orthogonal Space–Time Block Codes in Keyh

It is known that the keyhole or pinhole effect can severely degrade the performance of multiple-input-multiple-output (MIMO) communication systems. In this paper, the outage probability and error probability of orthogonal space-time block codes with m transmit and n receive antennas over keyhole fading channels are analyzed. Closed-form outage probability and symbol/bit error rate expressions are derived with M-ray phase-shift keying (M-PSK) and M-ray quadrature amplitude modulation (M-QAM) signaling. It is found that the exact error probability expressions have two different forms for m = n and m ne n, respectively. Furthermore, when m ne n, approximate error rate expressions are derived at high signal-to-noise ratios (SNRs), whereas there are no asymptotic expressions for m = n. Simulation results are provided to verify our analytical results.