中文摘要：

合作差异是减轻无线隧道的褪色的效果并且在无线网络获得空间获得的最有效的方法之一。在这份报纸，为用 amplify-and-forward ( AF )的一个合作通讯系统的一个最佳的功率分配( OPA )计划与多重继电器用户一起播送策略被在总数的限制下面在目的地最小化 bit-error-rate ( BER )建议播送来源用户和继电器用户的功率。模拟结果比使用相等的力量分配(EPA ) 显示建议力量分配方法能完成重要 BER 表演改进策划，当静止时到达低复杂性。系统表演与在高信号噪音比率(SNR ) 增加继电器用户的数字显著地被改进。在低 SNR，当继电器数字增加时，然而，系统性能减少。因此，一个适应继电器选择计划可以被用来在不同传播情形选择适当继电器数字提供系统表演改进并且与低复杂性保留力量分配计划。

英文摘要：

Cooperative diversity is one of the most effective ways to mitigate the fading effect of wireless channels and obtain the spatial gain in wireless networks. In this paper, an optimal power allocation （OPA） scheme for a cooperative communication system using the amplify-and-forward （AF） transmit strategy with multiple relay users is proposed by minimizing the bit-error-rate （BER） at the destination under the constraint of the total transmit power of both the source user and the relay users. Simutation resutts indicate that the proposed power allocation method can achieve significant BER performance improvement than using the equal power allocation （EPA） scheme, while still attains low complexity. The system performance is improved significantly with the increasing of the number of relay users at high signal-noise ratio （SNR）. However, at low SNR, the system performance decreases when the relay number increases. Thus, an adaptive relay selection scheme may be used to choose the appropriate relay numbers in different transmission scenarios to provide system performance improvement and keep the power allocation scheme with low complexity.