OSTBC transmission in MIMO AF relaying with 1-FSK modulation

This paper investigates multiple-input multiple-output (MIMO) amplify-and-forward (AF) relaying networks with orthogonal space-time block codes (OSTBC) and M-ary frequency-shift-keying (FSK) modulation. A non-coherent detection scheme is proposed and analyzed in a situation where the fading channels undergo temporal correlation. Specifically, the destination employs the linear minimum mean square error (LMMSE) estimation algorithm to estimate the overall channels by properly exploiting the implicit pilot-symbol-assist property of FSK transmission. It then utilizes the maximal ratio combining (MRC) to detect the transmitted information. An upper bound on the probability of errors is derived for a network with arbitrary numbers of transceiver antennas and relays. Based on the obtained bit-error-rate, the full achievable diversity order is verified. Simulation results are presented to show the validity of the analytical results.