Distributed coding/modulation scheme with OFDM/OQAM based transmission for wireless cooperative relays systems

In this paper, we propose a distributed coding/modulation scheme for wireless broadcast networks with relays. We consider a scenario where a source communicates with a single destination assisted by a relay which aids transmission to the destination. Orthogonal frequency division multiplexing (OFDM) transmission is considered where the available bandwidth is allocated simultaneously to the source and the relay. Real value data symbols are transmitted by the source. The relay decodes the information from the sources and it re-encodes them to generate some extra redundancy, which is modulated onto real data symbols and transmitted to the destination with a time offset equal to half the signal interval. Hence, the proposed scheme can be regarded as a distributed OFDM/OQAM scheme between the source and the relay. The proposed scheme achieves good performance in terms of bit error rate. Moreover, it does not require insertion of guard interval achieving therefore spectral efficiency gain.