Luo Tao

Impact of Relay Location According to SER for Amplify-and-Forward Cooperative Communications

In this paper, we analyze the symbol-error-rate (SER) performance for a two-user amplify-and-forward cooperative system. By making use of M-PSK modulation, the closed-form SER formulation and corresponding upper bound are derived first. According to the SER performance analysis, the impact of relay location is discussed by making use of a simple line topology. If the power allocation to the source and relay is equal, we can draw an interesting conclusion that the SER performance in such topology shows a symmetry property and the optimum relay location is just in the middle with respect to the source and destination.

Performance Estimating for Space-Time Block Coded Cooperative Communication System

A new cooperative communication system based on space-time block coding (WCC-STBC) is proposed in this paper, and a closed-form expression of bit error rate for this WCC-STBC system is also deduced. The results through theoretical analysis and computer simulation show that the diversity gain, which is dependent on the characteristics of the users individual channel and the inter-user channel between them, could be obtained in the WCC-STBC system. When BER is 10-3, and if the inter-user channel is 5 dB better than their individuals, about 3 dB gain could be gotten in WCC-STBC system; and if one users channel is 5 dB better than his partners, 5 dB gain for the performance of the worse user could be improved while that of the better one is less loss, only about 0.5 dB or so