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Enhancing Performance of DSTC-Coded OFDM Relay Link by Subcarrier Pairing

For wireless network, spatial diversity similar to multiple-input and multiple-output (MIMO) scheme can be obtained by the use of cooperative relaying technique such as distributed space-time coding (DSTC), which can improve bandwidth utilization, power efficiency and reliability of the wireless terminal. On the other hand, the subcarrier pairing strategy of the first hop and the second hop may obviously enhance the performance of the OFDM relay link. In this article, the subcarrier pairing for OFDM systems in DSTC-coded cooperative network is studied by theoretical analysis, and the optimal pairing strategy is proposed and evaluated by simulation. The simulation results show that the performance of the OFDM systems in DSTC-coded cooperative network can be improved further using subcarrier pairing strategy compared with no subcarrier pairing strategy.