Pulse shaping techniques for ICI reduction in OFDM Decode-and-Forward relay systems

In this paper we compare different pulse shaping techniques for ICI (inter-carrier interference) reduction in dual-hop OFDM based Decode-and-Forward (DF) relay system. For that purpose, analytical derivation of closed-form bit error probability relations is presented. Scenarios corresponding to downlink communication in cellular systems are considered, assuming Ricean flat fading channel on the first hop, and time selective fading channel on the second hop. Two different fading statistics are analyzed for the second hop, i.e. Ricean and Rayleigh time selective fading channels. Closed form bit error probability (BEP) expressions are derived for four specific pulse shaping techniques, assuming BPSK (Binary Phase Shift Keying) mapping of the input signal. It is shown that, for the considered relay system, ISP (Improved Sinc Power) represents the optimal solution from the point of the ICI reduction.