Cooperative spectrum sensing via sequential detection for cognitive radio networks

• Published in: 2009 IEEE 10th Workshop on Signal Processing Advances in Wireless Communications pp. 121 - 125
• Main Authors: Qiyue Zou, Songfeng Zheng, Sayed, A.H.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2009
• Subjects: Bandwidth; Base stations; Cognitive radio; Fading; FCC; Frequency; Mathematics; Standards development; Testing
• ISBN: 9781424436958; 1424436958
• ISSN: 1948-3244
• DOI: 10.1109/SPAWC.2009.5161759

Efficient and reliable spectrum sensing plays a critical role in cognitive radio networks. This paper presents a cooperative sequential detection scheme to minimize the average sensing time that is required to reach a detection decision. In the scheme, each cognitive radio computes the Log-Likelihood ratio for its every measurement, and the base station sequentially accumulates these Log-Likelihood statistics and determines whether to stop making measurement. The average number of required samples depends on the Kullback-Leibler distance between the distributions of the two hypotheses under test. This suggests a criterion for selecting the most efficient radios to facilitate spectrum sensing. The paper also studies how to implement the scheme in a robust manner when the assumed statistical models have uncertainties. These ideas are illustrated through an example that assumes both the signal and noise are Gaussian distributed.