Power Allocation in Orthogonal Frequency-division Multiplexing (OFDM) Based Two-way Relaying with Relay Selection

In this paper, error performance analysis of relay selection in orthogonal frequency-division multiplexing (OFDM) based amplify-and-forward (AF) relaying two-way cooperative communication system is examined over frequency selective Nakagami-m fading channels with power allocation at source, relay and destination nodes. Furthermore, we allocated the power to the sub-channels at three terminals. Power allocation is done under the total power constraints based on scaling factor obtained by available channel knowledge of links between the nodes. It is shown that as relay selection can achieve full diversity and improves bit error rate (BER) performance, the power allocation can further improve the performance. Results show that BER performance of proposed system increases with the power allocation and it improves through higher value of fading parameter m.