Cooperative versus noncooperative cellular wireless systems

The cellular systems with base station (BS) coordination are known for increasing the cell edge user throughput considerably. They process signals captured by geographically distributed BSs coherently. In contrast, noncooperative BSs with large number of antennas are also known for achieving both high spectral and energy efficiency. The fully cooperative BSs have several drawbacks such as ideal backhaul requirements, need for BS synchronization, and channel state information (CSI). These drawbacks hinder fully cooperative cellular systems considerably. Therefore, in this paper, the prospect of designing noncooperative cellular systems with comparable performance in some sense to ideal cooperative cellular systems with no additional power or spectrum is systematically pursued. The approach is based on the information theoretic rate characterization for finite size systems. The size of systems is in terms of the number of BS antennas and users. We show in this paper that under certain conditions, such noncooperative cellular systems can be designed. We devise a framework to compare two systems and obtain necessary conditions for making the performance of two seemingly unrelated access technologies closely comparable.