MIMO cooperative multiple-relay networks with OSTBCs over Nakagami-m fading

In this paper, the performance of a dual-hop multiple-input multiple-output (MIMO) cooperative multiple-relay network using orthogonal space-time block coding (OS-TBC) transmission is examined. The fading environment is modeled as independent, not identical distributed (i.n.i.d.) Nakagami-m fading. Also, we consider the case that each terminal in the network has multiple-antennas, the relays operate in channel state information (CSI)-assisted amplify-and-forward (AF) relaying mode, and the direct transmission from the source to the destination is applicable. In particular, we derive a closed-form expression for the moment generating function (MGF) of the instantaneous signal-to-noise ratio (SNR). Utilizing this derivation, we can analyze the SER performance of the considered system for M-ary phase shift-keying (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) scheme. Also, the outage performance of the considered relay networks is evaluated. We further investigate the cooperative diversity behavior by deriving asymptotic approximations for the outage probability and the SER. Finally, numerical results are provided showing very close agreement between the analytical results and the Monte-Carlo simulations.