Robust cooperative spectrum sensing schemes for fading channels in cognitive radio networks

Abstract

In cognitive radio systems, cooperative spectrum sensing can detect the presence of the primary user accurately. In practice, however, since the sensing observations are forwarded to a data collector through fading channels, the sensing performance is severely degraded. To deal with this problem, in this paper, we first propose a secondary user selection based cooperative spectrum sensing method to improve sensing performance by decreasing the reporting errors introduced by the fading channels. More specifically, only the secondary users with better signal-to-noise ratio (SNR) for reporting channels are allowed to send their local binary decisions (0 or 1) to the data collector while the others will send nothing. Additionally, we further propose a diversity based cooperative spectrum sensing method which applies existing space-time coding. By exploiting space diversity in CR network, the reporting errors introduced by the fading channel can be decreased and then the sensing performance is improved significantly. For either proposed cooperative spectrum sensing method, the sensing performance is derived and the analytical performance results are given. Our analysis and numerical results verify that proposed methods outperform the conventional cooperative spectrum sensing with OR-rule by taking into account the error effect on the reporting channels. CitationYue W J, Zheng B Y, Meng Q M, et al. Robust cooperative spectrum sensing schemes for fading channels in cognitive radio networks.

Adaptive double threshold energy detection based on Markov model for cognitive radio

“…Cognitive radio (CR) is a key enabling technology which effectively provides the capability to used underutilized part of the spectrum and serves it as a remedy for plausible spectrum shortage problem. In the CR-based system, the secondary user (SU) exploits the spectrum opportunity, which is defined as the frequency channel that is temporarily not used by the primary users (PUs) [ 2 ]. CR which includes spectrum sensing, spectrum accessing, power control and intelligent management is widely used in a new generation of wireless communication system [ 3 ].…”

Dynamic dual threshold cooperative spectrum sensing for cognitive radio under noise power uncertainty

“…Since it is impossible to give an accurate local decision by relying on those detection values, we consider sending them to the fusion center for further process. Soft fusion will be more reasonable choice, which enables the above fuzzy test statistics to participate in the final decision [38]. Therefore, the credibility degree can be defined to quantify the reliability of the test statistics lying between two thresholds.…”

A blind signal detection algorithm for passive location system based on troposcatter

“…According to decision fusion, u i stands for the decision of node i , here u i = 1 for the signal is present and u i = 0 for the decision of absent signal. AND-rule and OR-rule can be adopted for decision fusion, the latter has a good performance and wide application [14]. According to OR-rule, FC can make global decision under an ideal condition aswhere Q FA stands for the global probability of false alarm, Q D the global probability of detection, L the number of terminal nodes, P FA the terminal probability of false alarm, P D the terminal probability of detection.…”