Interference alignment scheme for three-cell constant cellular interfering networks

This paper investigates the design of interference alignment (IA) for a three-cell constant cellular interfering network, where three base stations in the cellular network simultaneously transmit signals to a group of users in their own cells while causing interference to each other. While determining the existence of IA with reaching the degrees of freedom (DoF) outer bound is still a very challenging problem. We propose an efficient alignment scheme for this system, where the transmit beamforming matrices are jointly designed in loop structure. We theoretically derive the antenna source of this system. Numerical results show that our proposed IA scheme requires less antenna source in contrast to that of the existing IA schemes, while the total achievable DoF of the system is identical.