Analysis of outage capacity performance for cooperative DF and AF relaying in dissimilar Rayleigh fading channels

Cooperative relaying permits one or more relay to transmit a signal from source to destination, thereby increasing network coverage and spectral efficiency. The performance of cooperative relaying is often measured as outage probability. However, appropriate measure for the channel quality is outage capacity. Although outage probability for cooperative relaying protocol has been analyzed before, very little research has been addressed for outage capacity. This paper is the first of its kind in which we derive a closed-form analytical solution of outage capacity using fixed decode and forward relaying and amplify and forward relaying in dissimilar Rayleigh fading channels, considering channel coefficients known to the receiver side. Analytical results show a tradeoff between SNR and number of relays for specific outage capacity. From the comparison between decode and forward relaying and amplify and forward relaying, it is observed that decode and forward relaying outperforms amplify and forward relaying for a large number of relays.