Lower-overhead coherent CoMP scheme in future cellular networks

Coordinated multi point(CoMP) transmission/reception has been regarded as a promising technique of future cellular network to achieve higher spectral efficiency. In practice, latency and throughput constraints on the backhaul allow the organization of only small clusters of base stations where coherent joint transmission can be implemented. In this paper, we focus on downlink CoMP-joint transmission (CoMP-JT). The main contribution of this paper is to develop a new precoding method to reduce the amount of shared channel state information. Align matrix is newly introduced to coherently combine the signals transmitted from multiple base stations with a lower overhead. The user throughput performance is evaluated through both link level and system level simulations. In addition, the overhead is also analyzed in terms of the amount of channel state information to be shared.