Power Allocation for OFDM-DF Cooperative Communication

A minimized power allocation scheme in a cooperative communication manner is studied to low power consumption and extent service life for transmission nodes. The model of the minimizing transmission power allocation for each sub-carrier of source node and relay node is not a convex problem, so it is difficult to find the global optimal solution. A new scheme of Decode-and-Forward Power Allocation (OFDM-DF-PA) is proposed. First, the power is allocated between source and relay node after sub-carrier is allocated under a given transmission power for each sub-carrier. Second, the power of each sub-carrier is allocated individually in source and relay node. Then, three different schemes of Non-cooperative Power Allocation (NPA), Equal Power Allocation (EPA) and OFDM-DF Power Allocation are compared. Simulation results show that OFDM-DF-PA consumes less power than the EPA and the NPA under the same BER performance in cooperative OFDM system with Frequency Reuse Factor of 1.