BER performance degradation in OFDM DF relay system due to intercarrier interference

In this paper we analytically examine the level of bit error rate (BER) performance degradation of dual-hop OFDM based Decode-and-Forward (DF) relay system due to presence of intercarrier interference (ICI). Scenarios which correspond to downlink communication in cellular systems are considered. This assumes Rician fading channel on the first hop, and time selective fading channel on the second hop. Both possible realistic cases are analyzed, i.e. with Rician and with Rayleigh fading statistics on the second hop. Closed form BER expression is derived for the case of BPSK modulated assumed system. The obtained results are used for analysis of intercarrier interference (ICI) impact on BER performance of dual-hop OFDM DF relay system.