Enormous Spectral Efficiency of Isolated Multiple Antenna Links Emerges In a Coherently Coordinated Cellular Network

Intercell interference limits the capacity of wireless networks. To mitigate this interference we explore coherently coordinated transmission (CCT) from multiple base stations to each user. To treat users fairly, we explore equal rate (ER) networks. We evaluate the downlink network e±ciency of CCT as compared to serving each user with single base transmission (SBT) with a separate base uniquely assigned to each user. Efficiency of ER networks is measured as total network throughput relative to the number of network antennas at 10% user outage. Efficiency is compared relative to the baseline of full power, single base transmission, (FP-SBT), where each base antenna transmits at full power, and, apart from the assignment of 10% of the users to outage, nothing is done to mitigate interference. We control the transmit power of ER systems to maximize the common rate for ER-SBT, ER-CCT based on zero forcing and ER-CCT employing dirty paper coding. We do so for (No. Transmit antennas per base, No Receive antennas per user) equal to (1; 1), (2; 2) and (4; 4). We observe that CCT mutes intercell interference enough, so that enormous spectral e±ciency improvement associated with using multiple antennas in isolated communication links occurs as well for the base to user links in a cellular network.