Impact of Pilot Assisted Channel State Estimation on Multiple Antenna Multiuser TDD Systems with Spatial Filtering

In this paper we study a multiple antenna multiuser TDD system that uses pilot assisted channel state estimation. Specifically, we consider a wireless system with multiple antennas at the base station and a number of mobile terminals each with a single antenna. We analyze the performance of the uplink multiuser detection and downlink transmitter optimization that are based on linear spatial filtering. Using a block fading channel model we analyze how a lower bound on the achievable rates depends on the power allocated to the pilots as well as the background noise level. Effects of the coherence time and temporal correlations in wireless channels are also analyzed.