感知频谱共享下的多天线功率优化分配算法研究

Optimal Power Allocation Algorithm with Multi-antenna in Sensing-based Spectrum Sharing Networks

本文构建了一种在感知结果下具有多天线次用户的频谱共享模型,该模型由单入单出主用户对和多入单出认知用户对构成。当认知用户感知到主用户占用信道时,主用户向认知用户发送Message信息,使得认知用户发射端能够得知主用户对干扰总功率的限制要求,通过自适应地调整认知用户发射机的发射功率,以保证其对主用户不造成有害干扰;如果主用户未占用信道,认知用户立刻以最大发射功率占用信道。并分别在主用户存在和不存在两种情况下,优化认知用户发射机各天线的发射功率来最大化系统总的数据传输率。最后,通过数值仿真来验证推导出的功率分配策略,并对其进行分析和讨论。仿真结果表明:相比于机会频谱接入(Opportunistic Spectrum Access,OSA)和基于感知的频谱共享(Sensing-based spectrum sharing)模式,推导的功率分配策略在提出的模型中可以获得更高的信息传输率。

A sensing-based spectrum sharing network with multi-antenna is suggested,which is consisted of a single-input single-output（SISO） primary user（PU） pair and a multi-input single-output（MISO） secondary user（SU） pair. In proposed network model,PU sends message to the SU when PU occupies the channel. So the SU calculates total interference power constraint by received PU message and adaptively adjusts its transmit power in order to avoid harmful interference to PU. If the licensed band is empty,the SU immediately occupies the channel with maximum transmitted power.Simultaneously,in order to maximize the system achievable rate,the optimal power allocation strategies among transmitter antennas are derived under the primary interference power constraint. Finally,the derived optimal power control policies are validated through simulations. The results show that,compared to the opportunistic spectrum access and sensing-based spectrum sharing,derived power control policies in suggested system model exhibits better performance.