Asymmetric Pilot Subcarrier Allocation for OFDMA-Based Regenerative Dual-Hop Links

An asymmetric pilot subcarrier allocation scheme (APSA) is proposed for orthogonal frequency division multiple access (OFDMA) systems which use regenerative relays. To achieve the best performance of regenerative relay systems, the performance of each hop should be balanced. When there is a direct link between the source and destination, APSA allocates pilot subcarriers asymmetrically to each hop to balance the performance. We show that APSA can improve the performance of the system based on the symbol error rate (SER) analysis and simulation results.