基于双门限的新型协作频谱感知算法

New collaborative spectrum sensing algorithm based on dual-threshold

针对传统认知无线电双门限能量感知算法在可靠性和带宽受限上存在的不足,提出一种基于两比特硬合并的新型双门限协作频谱感知算法。该算法同时利用了认知用户的单比特局部判决结果和解决感知失败问题的两比特局部判决结果两种信息,并由融合中心结合两种局部判决信息做出最终判决从而确定主用户存在与否。仿真结果表明,与传统双门限算法相比,该算法仅以平均感知比特位略微提高为代价(感知失败概率较低时大约平均提高1%),不仅消除了感知失败问题,而且显著提高了感知性能(虚警概率较低时最大可提高21%)。

Concerning the shortcomings in reliability and limited bandwidth of conventional dual-threshold energy sensing for cognitive radio, this paper introduced a new dual-threshold collaborative spectrum sensing algorithm based on two-bit hard combination. The algorithm made use of two kinds of information which included one-bit local decisions and two-bit local decisions of secondary users for eliminating the sensing failure. Then fusion center made a final decision based on the two kinds of decisions to determine whether the primary user was present or not. Compared to the conventional dual-threshold algorithm, the simulation results indicate that the new algorithm not only eliminates the sensing failure, but also improves the detection performance significantly （maximum increasing by about 21% at low false alarm probabilities） at the cost of slightly increasing the average number of sensing bits （ on average increasing by about 1% at low sensing failure Drobabilitiesg.