An interference alignment scheme for symmetric multicell multiuser channels

The problem of interference alignment (IA) for uplink channels in multicell multiuser cellular networks with arbitrary numbers of transmit and receive antennas is considered. The proposed IA scheme aligns the interference from K users into a subspace established by the interference from p users among those K users. The value of p can be adaptively chosen based on the network configuration. The IA solution is realized by designing precoder matrices from a system of linear equations built upon the IA constraints. The closed-form result for the degrees of freedom (DoF) achievable by the proposed scheme is derived. Numerical analysis shows that, in most cases, the proposed scheme provides higher DoF than other related schemes.