Throughput Analysis of Dense Multi-Antenna Downlink Cellular Networks With CSIT Errors

This letter investigates the throughput of a dense multi-antenna network in the presence of channel state information (CSI) errors at transmitter. The Gauss-Markov auto-regressive model is put forth to characterize CSI errors. We focus on a class of cases that the variance of CSI error is independent of serving distances between users and BSs. An original expression for area spectral efficiency (ASE) is derived with the tools of stochastic geometry. Based on the expectations of effective channel gains, a more tractable approximation for ASE is further obtained. With the help of the tractable approximation, we consider the optimization problem for ASE maximization with respect to the number of active users. We demonstrate that ASE scales linearly with the number of antennas when the number of antennas is larger than a certain value. The CSI errors determine the increasing slope.