基于噪声不确定的双门限能量检测合作频谱感知算法

摘要

频谱感知作为认知无线电的关键技术之一,得到了广泛深入的研究.能量检测为常见的频谱感知方法,然而其检测性能极易受到未知多变的噪声的影响,在噪声大时,甚至不能准确的检测到授权频段内授权用户的状态.本文针对噪声不确定性对能量检测性能的影响,研究了传统双门限能量检测合作频谱感知算法的改进方案,并对所提方案做了理论研究与算法仿真,与传统的双门限能量检测方案做了比较.分析结果表明,所提方案在一定程度上减弱了噪声不确定性对能量检测检测性能的影响,在不额外增加系统传输开销的同时,提升了系统的检测性能.实现了频谱利用率与传输开销的较好权衡.是一种有效可行的频谱感知方案.%As a key technology of cognitive radio spectrum sensing has been extensively researched. Energy is one of the most common and useful methods of spectrum sensing,but the performance can be easily affected by the variety noise.It's even impossible to detect whether the primary users are using the channel or not when the noise is very high.Here we proposed a new double-threshold energy detection cooperative spectrum sensing scheme which takes noise uncertainty into consideration.At the same time, we have an analysis of this proposed scheme and we also compare the performance of it with traditional double-threshold energy detection. After doing some theoretic analysis and simulation by computer,we found that the proposed scheme can greatly improve the detection performance with some immunity to noise uncertainty,and doesn't need more overhead transmission. Obviously we can come to the conclusion that the newly double-threshold energy detection scheme achieved a good trade-off between detection performance and system complexity.It is a feasible spectrum sensing scheme.