Interference aware inter-cell rank coordination for 5G wide area networks

Multiple receive and transmit antennas can be used to improve the spectral efficiency by transmitting over multiple independent streams. In addition, multiple receive antennas facilitate interference suppression through the use of interference rejection combining receivers. Rank adaptation algorithms are aimed at balancing the trade-off between increasing the spatial gain, and improving the interference resilience property. In this paper, we propose an inter-cell rank coordination scheme whereby a serving base station coordinates the preferred maximum interference rank with the dominant interfering BS through exchange of coordination messages over the Xn interface. The proposed scheme is computationally efficient and requires minimum control overhead. Matlab based system-level simulation results indicate around 65% gain in terms of the outage throughput with little impact on the peak user throughput.