认知无线电网络中基于D-S证据理论的合作频谱感知方法

Cooperative Spectrum Sensing Based on Dempter-Shafer Theory of Evidence in Cognitive Radio Network

认知无线电网络因主从用户共享频谱资源,具有频谱利用率高的优点,同时对从用户提出了一定的要求。在研究D-S证据理论的基础上,提出了一种新的合作频谱感知方法,对冲突证据源和融合规则进行了修正,并通过模糊度计算公式预估不确定性,重新定义了基础概率分配(BPA)函数。仿真结果表明,同"与"、"或"融合及以往的D-S融合方法相比,所提方法能很好地感知认知无线电网络的空闲频谱,并可作为高斯白噪声(AWGN)信道及瑞利(Rayleigh)多径衰落信道等网络环境的通用频谱感知方法 。

Cognitive radio has the advantage of high spectrum utilization since the spectrum can be shared by primary and secondary user. Meanwhile, the new adaptable characteristic is required for the secondary user. On the basis of analyzing D-S theory of evidence, a novel distributed cooperative spectrum sensing scheme was presented, which modified the combination equation for conflicting evidence source, and the BPA function based on fuzzy degree calculation was redefined. Simulation results show that the proposed scheme can sense the available spectrum in the cognitive radio networks very well, and can be used as a general spectrum sensing scheme in AWGN and Rayleigh fading channel when compared with the traditional ＂and＂, ＂or＂ fusion rules and other D-S theory of evidence schemes in the previous literature.