Antenna splitting in a distributed antenna system for a multiuser MIMO transmission

Abstract

A distributed antenna system, where antennas at a base station are spatially distributed over the cell, can improve throughput at the cell edge compared to a centralized antenna system. However, the peak capacity degrades when a remote antenna unit has a few antenna elements due to rank deficiency. In general, the number of antennas at the base station is limited by the number of pilot sequences. Thus, it is difficult to increase the number of antennas. In this paper, we use antenna splitting to increase the number of antennas without increasing the number of pilot sequences and evaluate the impact of antenna splitting on the sum capacity in a multiuser MIMO system. From computer simulations, it is shown that we can obtain higher sum capacity by increasing the number of antennas even though the number of pilot sequences is limited.