基于序贯与能量联合检测的频谱感知技术研究

认知无线电(CR)技术是一种提高频谱资源利用率的有效方法,频谱感知是其实现的前提和关键技术。针对序贯检测在个别情况下所需要的采样点数过多,达不到次级用户(SU)要求的问题,提出了一种序贯与能量联合检测(SEJD)的算法。首先同时用序贯与能量检测两统计量进行采样统计,先使用序贯检测进行判决,若当采样点数超过次级用户的要求,则直接用能量检测算法进行判决,得出判决结果。仿真结果表明:在相同的检测条件前提下,相比于能量检测(ED)算法和截断型序贯检测(truncated SD)算法,所提出的算法在检测概率和最大采样点数上有很大的提升,为确保频谱感知技术在信号检测上的快速性和准确性提供了理论依据。

Study on Spectrum Sensing Technology Based on Sequential and Energy Joint Detection

Cognitive radio (CR) technology is an effective method to improve the utilization of spectrum resources, spectrum sensing is a prerequisite and key technology of its implementation. As for the problem that excessive number of samples required by sequential testing in some cases cannot meet the requirements of secondary user (SU), this paper presents a sequential energy joint detection (SEJD) algorithm. Firstly, the statistical sampling is implemented by simultaneously using two statistic of sequential and energy detection. Then, the sequential detection is used to decide, and if the number of samples exceeds the requirements of secondary users, the energy detection algorithm is directly used for decision to get the verdict. Simulation results show that under the same test conditions premise, compared with the energy detection (ED) and truncated sequential detection (truncated SD) algorithm, the proposed algorithm has greatly improved the probability of detection and the maximum number of samples, which provides a theoretical basis for ensuring speed and accuracy of signal detection by spectrum sensing technology.