ICI reduction in OFDM Decode-and-Forward mobile relay systems

In this paper we analyze performance improvement of dual-hop OFDM based Decode-and-Forward (DF) mobile relay system attained through inter-carrier interference (ICI) reduction by pulse shaping techniques. We compare different pulse shaping techniques for ICI reduction in the considered system through analytical derivation of closed-form bit error rate (BER) performance. The communication scenario assumes time selective fading channel on the first hop, and Ricean fading channel on the second hop. We analyzed two possible realistic cases for the fading statistics on the first hop, i.e. Ricean and Rayleigh fading. Closed form BER expressions are derived for the case of BPSK (Binary Phase Shift Keying) modulated assumed system implementing four different pulse shapes. Among them, Improved Sinc Power (ISP) pulse shaping technique is identified as the optimal solution, because it attains BER performances which almost completely match with the case of no ICI present.