Rate bounds for multicell cellular networks with coordinated beamforming

The mean achievable rate of downlink in multicell networks, where coordinated beamforming is applied to mitigate inter-cell interference, is investigated. The upper and lower bounds for the mean achievable rate are derived by using Gamma distribution to characterise the probability distributions of the signal and interference power. A closed-form expression for the mean achievable rate is proposed to approximate the theoretical value. Analysis and simulation results show that the bounds are tight and the approximation is effective. The mean achievable rate increases with the number of transmit antennas while it first increases with the transmit power and then keeps a constant.