On the Power Allocation of Base Station with Energy Efficient Relay Cooperation

In this paper, we consider cooperative downlink communication. The communication between base station and destination is assisted by multiple relays in the absence of direct connection between base station and destination. To maximize the utilization of the relay batteries we consider energy efficient transmit power allocation at relays. This is achieved by maximizing the number of bits that can be transferred per joule of energy spent. We show that the transmit power of base station can be adjusted in accordance with the transmit power allocation of relays. In this context, a novel algorithm is proposed that optimize the energy efficiency at the relays and also adjust the transmit power of the base station. Simulation results show that considerable savings in energy can be achieved at the base station with the proposed algorithm as compared to fix transmit power allocation at the base station.