Partial Interference Alignment for Multi-Cell and Multi-User MIMO Downlink Transmission

As a promising technology to effectively mitigate interference and improve the performance of a wireless communication network, interference alignment (IA) has been attracted extensive concern. In order to solve the problem that perfect IA needs a large number of antennas and facing the cell selection, this paper proposes a partial interference alignment scheme based on user grouping for a network with multi-cell multi-user multiple- input and multiple-output (MIMO) under downlink transmission scenario. In the proposed scheme, the interference at different directions does not need to be aligned to the same subspace. Furthermore, each BS eliminates inter-user interference within its cell and the dominant interference to users in its neighboring cells. Analysis and simulation results show that the proposed approach outperforms the extension of grouping method in terms of antenna number and sum capacity.