Joint Design of Precoder and Power Allocation for Downlink Multi-Cell Multi-User Wireless Systems with Interference Alignment

Abstract

In the paper, we propose a joint design of precoder and power allocation for downlink multi-cell multi-user wireless systems with interference alignment (IA). This non-iterative method is decomposed into two separate steps. First, we design the precoding and decoding matrices using IA, fully eliminating the interference between the effective channels. Then, on the basis of the pre-canceling, each base station performs equal power allocation among different users and adopts a joint optimization of precoding matrix and power allocation to maximize the information rate of the corresponding noninterfering effective channel. Meanwhile, we present the corresponding detection method for each noninterfering effective channel. It is analytically shown that the proposed IA scheme exploits less antenna resources than the search IA scheme does to achieve the same degrees of freedom. Moreover, the simulation results demonstrate that the proposed IA scheme shows better performance than the original IA scheme.