Effects of power allocation and reuse distance in relay-assisted wireless communications with mutual interference

Cooperative communication techniques effectively improve performance and coverage of wireless networks. This requires to find proper methods to allocate power among source and relay nodes. When others cells with sources, destinations, and relays are present, the mutual interference can be a limiting factor which needs to be characterized. In this paper we investigate the effects of relay position and power allocation strategy for cooperative communications employing space-time codes (STCs) under interference constraints due to a second cell with relay that reuse the resources. We characterize links between each source, relay, and destination to analyze power allocation methods with interference in realistic scenarios. The frame error rate at the destination for various channel conditions, available diversity, relays positions, power allocation, and amount of interference is then obtained. Results are shown for cooperative pragmatic STC in block fading channel (BFC) and provide insights on how to allocate the power based on links geometry and mutual interference considerations.