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Published May 2011 | public
Journal Article

Optimization of Cooperative Spectrum Sensing in Cognitive Radio

Abstract

In this paper, we consider cooperative spectrum sensing when two secondary users (SUs) collaborate via the relaying scheme. We investigate two cooperative sensing strategies, i.e., SUs exchange data information locally, and SUs relay information to a central controller. The relaying scheme at each SU is optimized via functional analysis with either the average or peak power constraints. For the local cooperative sensing strategy, the optimal relaying schemes look like amplify-and-forward (AF) in the low-signal-to-noise-ratio (SNR) region and behave like decode-and-forward (DF) in the high-SNR region. The fundamental performance limit using local cooperative sensing is discussed. For the global cooperative sensing strategy, we propose both coherent and noncoherent sensing, depending on whether SUs are synchronized. In the coherent case, a decentralized approach is designed, and each SU optimizes its relaying function locally. In the noncoherent case, we use linear energy combination detector to decouple the relaying function from weight coefficient optimization. Simulation results demonstrate that the proposed protocols achieve much better performance over the existing protocols.

Additional Information

© 2011 IEEE. Manuscript received July 19, 2010; revised November 24, 2010; accepted January 20, 2011. Date of publication February 17, 2011; date of current version May 16, 2011. This work was supported in part by the Engineering and Physical Sciences Research Council Engineering and Physical Sciences Research Council under Grant EP/I000054/1. The work of F. Gao was supported in part by the German Research Foundation (DFG) under Grant GA 1654/1-1. This paper was presented in part at the 10th IEEE International Workshop on Signal Processing Advances for Wireless Communications, Perugia, Italy, June 2009. The review of this paper was coordinated by Prof. B. Hamdaoui.

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023