A Convergent Version of Maximum SINR Algorithm for MIMO Interference Channel

Abstract: The problem of designing linear transmits signaling strategies for the multiple inputs, multiple output (MIMO) interference channel is considered. One of the first algorithms inspired by Interference alignment (IA) is Minimum Leakage Algorithm (Min Leakage Algorithm) for the MIMO Interference Channel. Iterative algorithm, Max SINR, was proposed in [5] that gives better sum rate performance. The Max SINR algorithm starts with arbitrary transmits beamforming vectors and then designs receivers to optimize the signal-to-interference-plus-noise ratio (SINR) at each receiver. Next, the algorithm alternates the direction of communication and repeatedly optimizes the SINR at each receiver. This algorithm outperforms the other algorithms mentioned before, but there is no proof that it actually converges. Modified Max SINR is the modified version of Max SINR in which thesum rate converges. Modified Max SINR follows the same basic principleas Max SINR with two key differences. First, Modified Max SINR usesthe sum stream metric as a convergence criterion. Second, Modified MaxSINR changes the powers for each stream when it reverses the direction ofcommunication to achieve SINR duality. Computing Power Allocation to Achieve SINR Duality: In order to achieve SINR duality Algorithm need to compute the appropriate power allocation every time change the direction of communication using a distributed power control algorithmThis algorithm monotonically increases the sum stream and therefore converges.

Keywords: SINR, MIMO Interference Channel, Interference alignment (IA).