Optimal power allocation in relay-based CR system with enhanced network lifetime

This paper proposes an optimal strategy for power allocation algorithm for source and relay nodes in multihop cognitive radio network that minimizes the outage probability of data transmission while meeting the constraints of interference to primary user and total transmit power of cognitive radio users. Overall objective is to enhance the network lifetime along with an increase in sum (total) transmission capacity. Extensive simulations are done for both energy aware (EA) and non-energy aware (NEA) power allocation schemes. Simulation results show that EA based power allocation not only enhances network lifetime but also reduces interference to primary user at the cost of slight decrease in sum transmission capacity compared to NEA based scheme.