Performance Analysis of Multiple Relay Multi-cellular Interference Networks

We consider a single-input multiple-output (SIMO) multiple-access channel (MAC) multi-cellular communication scenario in which two base stations having a group of users each, are situated in two adjacent cells. In order to provide cooperative diversity at the base stations (BSs), multiple relays are used. Each group of users transmits information to its corresponding BS directly as well as via relays, but at the same time it provides interference at the BS of adjacent cell. The BSs are equipped with multiple antennas while the users of each group and relays are equipped with single antenna. We are interested to study the capacity of the each base station in both the optimal and normal cases with and without interference. Considering maximal ratio combining (MRC) at the BSs, at first, we derive the expression of combiner output signal-to-interference plus noise ratio (SINR) using optimum weighting vector. Then we use this SINR to calculate the optimal ergodic capacity. Finally, we derive the expression of normal ergodic capacity for both the base stations. Our results show that, optimization of combiner output SINR by weighting vector at the base stations enhances the ergodic capacity in multi-cellular interference channels.