Precoded Differential OFDM for Relay Networks

We study the performance of differential spacetime codes with linear constellation precoding (LCP) for orthogonal frequency division multiplexing (OFDM) cooperative networks over frequency selective channels. Through exploiting the unitary structure of the orthogonal STBCs, we design a low complexity differential STBC-LCP-OFDM receiver for cooperative networks. We assume the amplify-and-forward protocol and consider both single relay and multi-relay scenarios. Under the assumption of perfect power control for the relay terminal and high signal-to-noise ratio for the underlying links, our performance analysis demonstrates that the considered scheme is able to exploit fully the spatial diversity. Index Terms — Linear constellation precoding, orthogonal frequency division multiplexing, differential detection, cooperative communications.