On the coherent precoding performance for downlink CoMP-MIMO networks

In this paper, we consider an LTE downlink Multiple Input Multiple Output (MIMO) Coordinated Multipoint (CoMP) network. We propose a new adaptive precoding method applied on the signals being transmitted by the set of active antennas. Based on Joint Processing (JP) technique and the precoding method, we define a joint cellular area of cooperation between different evolved NodeBs (eNodeBs) serving a given user equipment (UE). The set of active antennas is selected based on the channel information at the transmitters. Simulations are performed in terms of throughput and Bit Error Rate (BER) for the cell edge users. Results show that an optimized number of the active antennas exists. Moreover, results show that additional increase of this number has a limited throughput and BER improvement. The latter comes at the detriment of additional backhaul loading and reduced overall user capacity.