Transmitter preprocessing aided inter-cell relay cooperation for interference management in downlink communications

In this correspondence, we investigate the performance of transmitter preprocessing (TP) aided relay assisted multi-cell downlink (DL) communications where, co-channel interference (CCI) due to the co-located relays in the adjacent cells is a major channel impairment. The TP considered in our work needs the channel impulse response (CIR) matrix of all the interfering relays which is obtained by assuming the so called `inter-cell relay cooperation'. Further, the TP employed in our work is based on the regularized block diagonalization (RBD) approach. We also analyze the performance of the considered system with the aid of an optimal power allocation (OPA) regime. Our simulation study shows that TP aided inter-cell relay cooperation assisted DL communications can provide better achievable bit error rate (BER) compared to a conventional relay assisted system invoking linear multi-user detection (MUD) at the mobile terminals (MTs) for signal detection. Moreover, when OPA regime is invoked, the performance of the system in terms of achievable BER is considerably better than a system without OPA.