中文摘要：

提出了一种基于功率分配的双向协作频谱接入方法。在该方法中，认知用户通过双向协作的方式接入授权用户频谱，使用一部分功率转发授权用户信息，帮助授权用户达到目标速率，然后使用剩余的功率发送自己的信息。该方法研究了认知用户如何对功率进行分配，在保证授权用户达到目标速率的条件下，最大化认知用户的速率。仿真结果验证了所提频谱接入方法的有效性，同时说明授权用户和认知用户都能够从所提频谱接入方法中获得好处。

英文摘要：

In this paper ,a two‐way cooperative spectrum access strategy based on power allocation has been proposed ,in w hich a secondary user can have access to the licensed spectrum of a primary system and use a fraction of the power to forward primary signals help the primary user achieve the target rate .Then it can use the remaining power to send its own signal .The optimal power allocation of the secondary user has been studied ,such that the transmission rate of the secondary system is maximized ,w hile guaranteeing the two primary users to achieve their target transmission rates .Numerical results verify the efficiency of the proposed strategy and show that both of the secondary user and the two primary users can gain benefit from the proposed strategy .