Large System Analysis of Zero-Forcing Precoding in MISO Broadcast Channels With Limited Feedback
In this paper, the authors analyze the sum rate of Zero-Forcing (ZF) precoding in MISO broadcast channels with limited feedback, transmit correlation and path loss. Their analysis assumes that the number of transmit antennas M and the number of users K are large, while their ratio remains bounded. By applying recent results from random matrix theory they derive a deterministic equivalent of the Signal-to-Interference plus Noise Ratio (SINR) and compute the sum rate maximizing number of users as well as the limiting sum rate for high Signal-to-Noise Ratios (SNR), as a function of the channel errors and the channel correlation pattern. Simulations show that theoretical and numerical results match well, even for small system dimensions.