Diversity Gains of Generalized Distributed Antenna Systems with Cooperative Users

A geometry-based channel model is proposed to describe the topology of a generalized distributed antenna system with cooperative diversity (GDAS-CD). The system architecture comprises a number of largely separated access points (APs) each with multiple antennas within an AP at one side of the link, and several geographically closed user terminals (UTs) each having multiple antennas within a UT at the other side. The UTs are assumed to be cooperative devices. The average cross-correlation of signals received from non-collocated APs and UTs is derived based on the system topology and the empirical models proposed by Sorensen. Subsequently, we investigate the diversity gains obtainable from the GDAS-CD based on the proposed model, which would provide insight into the degree of possible performance improvement when combining multiple copies of the received signal.