Cooperative joint precoding for relay enhanced cellular system: Design and performance evaluation

In this paper, we introduce the notion of a relay enhanced cellular system, where a relay station is located in the overlap area served by two base stations, and propose a cooperative joint precoding scheme for the relay enhanced cellular system. We consider a system in which two base stations apply linear precoding to minimize the interference at the relay station and the mobile stations and formulate the optimization problem to maximize the system capacity and design the multiuser precoding vector for each base station. We quantify the ergodic rate performance of the proposed multiuser precoding scheme through statistical analysis. Numerical results show that the proposed scheme can effectively cancel the interference and improve the sum rate performance for cell edge users.