关键词: 认知无线电, 频谱感知, 能量检测, 决策融合, 阴影相关性

Abstract:

The existing solutions of cooperative spectrum sensing (CSS) based on decision fusion are mostly built on the assumption of ideal decision transmission without considering any fading or noise corruption in common control channels. For this, the sensing channels and control channels are extend as Suzuki characteristics. A cooperation scheme is proposed under imperfect decision transmission model, in which a detector based on minimum error probability rule is used for decision estimation. The final decision combination is accomplished with K out of N rule. As demonstrated both by simulation, there is some performance deterioration in the proposed scheme, when compared with the ideal case that assumes errorfree decision transmission. It is even inferior to the local sensing when the average signal to noise ratio of the control channels is very low. Further, the spatial correlation of shadowing effects is investigated. It is shown that the negative impacts of correlated shadowing on the CSS gets weaker with the increasing distance between each other of the secondary users.

Key words: cognitive radio, spectrum sensing, energy detection, decision fusion, correlated shadowing