Equilibrium efficiency improvement via pricing in MIMO interference channels

A Nash equilibrium exists in the MIMO interference channel where users maximize their rates in a fully competitive manner. In this paper, we propose a distributed algorithm to improve the equilibrium efficiency. In the algorithm, some kind of coordination is introduced by exchanging interference prices among users, where the price function is derived from the KKT conditions of the global sum rate maximization problem. Taking the concept of price into consideration, each user will suppress interference to others while maximizing his own rate, thus enhancing the sum rate performance. Numerical results show that the proposed algorithm can achieve higher sum rate than the equilibrium which is obtained by iterative waterfilling.