Coordinating Base Stations for Greater Uplink Spectral Efficiency: Proportionally Fair User Rates

To overcome the spectral efficiency limits imposed by cochannel interference on the uplink of a cellular network, we propose coordinating each base station with several of its neighbors in the reception of user signals, and decoding each user at one such cluster of base stations. We evaluate the impact on the user rate distribution due to such coordination when there is 1 user per base station antenna in the network, each user has 1 transmitting antenna, all users transmit at maximum power, and the data rates of the users assigned to each cluster are subject to a proportional fairness criterion. We highlight the dependence of the user rate distribution on the number of rings of neighbors with which each base station is coordinated, as well as the underlying signal-to-noise ratio (SNR) distribution in the network. Our results point to the possibility of increasing cell- edge user rates almost tenfold, while simultaneously doubling the overall system throughput, in high-SNR conditions.