Performance of amplify-and-forward relay networks with interference-limited destination in rician fading environments

A study on the effect of co-channel interference (CCI) on the performance of fixed-gain amplify-and-forward (AF) relay networks is presented in this paper. The analysis assumes a noise-limited relay and an interference-limited destination. Furthermore, both the source-relay, the relay-destination channels of the desired user and interferers' channels are assumed to follow the Rician distribution. Approximate but accurate expressions are derived in this work for the outage probability and the average symbol error rate (SER) for independent non-identically distributed (i.n.d.) and independent identically distributed (i.i.d.) cases of desired user channels. Furthermore, a look into the asymptotical high signal-to-noise ratio (SNR) performance has been taken and the diversity order and coding gain of the considered system are determined. The accuracy of the analytical results are validated by Monte-Carlo simulations. Findings show that when the second hop SNR is kept fixed, a noise floor appears in the results and hence, a zero diversity gain is achieved by the system. Also, results illustrate that the system performance is dominated by interference affecting the worst hop. Finally, findings illustrated the inaccuracy of approximating the Rician fading by the Nakagami-m model in systems with Line-of-Sight (LoS) components.