Although cooperative spectrum sensing improves sensing accuracy in cognitive radio systems, additional reporting time is required to report the local test statistics until the existence of the primary user is verified, resulting in detection delay. To reduce the reporting time, we propose controlling the reporting order of the local test statistics, so that the local test statistics are reported to the fusion center in descending order of magnitude. As a result, the global test statistic at the fusion center accumulates faster than the case without reporting order control, reducing the reporting time needed to determine when the threshold for detecting the primary user has been exceeded. To do this, we propose, based on distributed access control, a combination of order identification, which finds the order of the local test statistic, and transmission probability calculation according to the identified order. Simulation results show that the proposed reporting order control significantly reduces the reporting time for detecting the primary user.
Bibliographical noteFunding Information:
Manuscript received November 1, 2010; revised June 13, 2011; accepted August 9, 2011. Date of publication October 3, 2011; date of current version October 20, 2011. This work was supported by the National Research Foundation of Korea Grant 2010-0018938 funded by the Korea government through the Ministry of Education, Science, and Technology. The review of this paper was coordinated by Prof. Y. Ma.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Aerospace Engineering
- Electrical and Electronic Engineering
- Applied Mathematics