Outage probability of cooperative relay networks in two-wave with diffuse power fading channels

This paper analyzes the performance of cooperative relay networks using adaptive decode-and-forward (DF) relaying in two-wave with diffuse power (TWDP) fading channels. Among the multiple parallel relays that participate in transmission, only the relays that successfully decode the source message retransmit the signals to the destination. At the destination, the direct signals from the source and the indirect signals via the relays are combined using maximal-ratio combining (MRC). We first derive a new closed-form expression for the outage probability, which encompasses the Rayleigh fading and Rician fading as special cases. We then derive a tight lower bound on the outage probability to reduce computational complexity. The correctness of our derivation is validated through Monte Carlo simulations. It is shown that increasing the number of relays decreases the outage probability at high signal-to-noise ratio (SNR), but increases the outage probability at low to medium SNR.