On the achievability of interference alignment for three-cell MIMO interfering broadcast channel

Interference alignment (IA) is a promising technique to effectively mitigate interference in wireless communication systems. In this paper, a novel IA based scheme is proposed, which is jointed design of transmit precoding matrices and receive beam forming matrices for the three-cell multiple-input multiple-output (MIMO). Gaussian interfering broadcast channels (MIMO-IFBC) with constant channel between each node, where each base station (BS) is equipped with M antennas, each mobile station (MS) is equipped with N antennas on the cell boundary, and each BS sends d data streams to each user in its cell. This corresponds to a down link scenario for cellular networks, where K users with the user cooperation in each cell. It is also analytically shown that total 3Kd degrees of freedom (Do F) is achievable if M = N ≥ 2Kd. The simulations demonstrate the sum-rate of our proposed scheme also out performs those of conventional techniques, especially in the high signal-to-noise ratio (SNR) regime.