Distributed coding for OFDM-based transmission in cooperative broadcast networks

In this paper, we propose a distributed turbo-like coding scheme for wireless broadcast networks with relays. We first consider a scenario where a base station communicates with a mobile station with the help of a relay. The relay decodes the information from the base station and it re-encodes it to generate some extra redundancy, which is transmitted to the mobile station. Orthogonal frequency division multiplexing (OFDM) transmission is considered where the available bandwidth is divided into a total number of subcarriers allocated between the base station and the relays. The proposed scheme achieves a significant gain with respect to the non-cooperation case. Furthermore, we extend the proposed system to a two-relay scenario where two relays assist the transmission between the base station and the mobile station. Single frequency network (SFN)-like transmission is used at the relays, i.e., the relays are allocated the same subcarriers, in order to efficiently exploit the radio spectrum.