基于解码转发的认知无线电机会功率控制算法

频谱感知是认知无线电网络正常工作的基础,而功率控制问题的解决是认知网络和主用户网络正常运行的保证。文中研究协作认知无线电通信,在保证授权用户服务质量和认知用户最大功率受限条件下,将高信噪比时的解码转发(decode-and-forward,DF)和基于频谱感知结果的机会功率控制算法结合,提出新的机会DF功率算法。通过基于对主用户感知结果的最优中继选择策略,在保证主用户正常通信不受影响的前提下,最大程度提高次用户信道信噪比,提高认知网络容量,并且认知系统能够获得空间满分集度。理论和仿真结果同时表明,基于主用户出现概率的最优中继选择最大程度的消除了次用户对主用户的干扰,提高了认知系统容量。

Opportunistic Power Control in Cognitive Radios Based on Decode-and-forward

Spectrum perception is based on the network operation of Cognitive Radios(CR),and to solve the problem of power control is the premise of both network cognitive and the normal operation of the primary user network.In this paper,on the condition that authorized users’ service quality and cognitive users ’maximum power are limited,we propose a new opportunistic DF power algorithm combined the high Signal-to-Noise(SNR) of decoding forward(DF) with the opportunistic power control algorithm based on the results of spectrum perception.On the premise that primary users’ optimal relay selection strategy is applied and the normal communication would not be affected,the secondary user channel SNR ratio and cognitive network capacity are improved by our algorithm.Theory and simulation results both indicate that based on the primary user’ optimal relay selection strategy,the cognitive system capacity is greatly improved while eliminating the inference from secondary users to primary users.