Iterative interference alignment for joint degrees of freedom and sum capacity optimization

In this paper, we aim to design a set of linear precoding matrices and the corresponding decoding matrices via maximizing the sum capacity to achieve the maximal degrees of freedom (DoF) on K-user MIMO interference channel. The existing iterative interference alignment (IIA) algorithms provided a suboptimal solution to maximum the sum capacity, which minimize the interference caused by others. While the IIA has attracted much attention in recent years, joint consideration of sum capacity and distribution of DoF is less address. Besides, the achievable DoF has been still an open issue for K-user MIMO interference channels. In this paper, an IIA algorithm is presented for joint DoF and sum capacity optimization. The number of data streams for each user is optimized and power allocation is also considered. Simulation results are compared to existing IIA schemes and show that the proposed algorithm outperforms in terms of sum capacity.