A general iterative algorithm to align interference along spatial dimension

A general iterative method to achieve interference alignment along spatial dimension for the K-user constant MIMO interference channel with arbitrary antenna configuration is proposed. Compared with present iterative methods to jointly optimize on precoding and equalizing vectors, we show that the iterative opimization can be made only on precoding vectors. Based on the constraint on the total stream number L ≤ [K/K+1(M+N)] with M antennas at all transmitters and N antennas in all receivers, we establish a set of unified interference alignment equations and align the interference using an general iterative method with the confirmation of the convergence. This general solution gives a simple implementation for interference alignment to replace present case-by-case solutions.