Performance Improvement of Multiantenna Cellular System Using Cooperation of Base Stations and Relay Stations

In cellular system, user terminals (UTs) are sometimes suffered from the attenuation of target signal from base stations (BSs) and severe interferences from adjacent cells, and their influence is serious particularly in the cell edge. This paper considers the performance improvement of multi-antenna cellular system under such a bad situation utilizing cooperative works of BSs and relay stations (RSs). We deal with downlink case assuming perfect channel state information (CSI) and amplify and forward (AF) relay transmission. Following SINR (signal to interference plus noise ratio) based analysis of the system, several cooperation schemes are investigated and their performances are compared through computer simulations. The advantage of BS and RS cooperation under sufficient relay SINR, particularly in case of BS-RS data sharing is shown.