Outage probability approximations for dual-hop amplify-and-forward MIMO relay systems in rayleigh fading

In this paper we present tight approximations of the outage probability (OP) for the entire signal-to-noise ratio (SNR) range of practical interest for an amplify and forward (AF) relaying system with channel state information (CSI) at the relay and destination, which employs multiple antennas at the nodes and orthogonal space-time block coding (OSTBC) transmission over a flat Rayleigh fading. In the AF relay, the incoming signal is decoupled, amplified and forwarded to the destination. The results for the outage probability obtained by the approximations are compared with exact results of the outage probability obtained by numeric inversion of the Laplace transform of the Moment Generating Function (MGF) and with the results obtained by the Monte Carlo simulations. The comparison shows close matching of the results.