Codebook-based hybrid opportunistic interference alignment

In this paper, we propose a codebook-based hybrid opportunistic interference alignment (OIA) in a three-cell MIMO downlink system. Rather than transmitting data by only one beamforming vector set in the conventional OIA, the transmitters select a preferred transmit beamforming vector set from a codebook in the proposed scheme. Hence, more selection diversity is developed compared to the conventional OIA approaches, The sum rate performance increases as the size of the codebook grows. Furthermore, a hybrid criterion of MAX-SNR and OIA is put forward which enhances the system performance at both high and low SNR. Monte-Carlo simulations illustrate that the proposed scheme provides a significant improvement in terms of sum rates with a slight complexity increase