Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Review Article A Review on Spectrum Sensing for Cognitive Radio: Challenges and Solutions | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 381465 15 pages doi 2010 381465 Review Article A Review on Spectrum Sensing for Cognitive Radio Challenges and Solutions Yonghong Zeng Ying-Chang Liang Anh Tuan Hoang and Rui Zhang Institute for Infocomm Research A STAR Singapore 138632 Correspondence should be addressed to Yonghong Zeng yhzeng@ Received 13 May 2009 Accepted 9 October 2009 Academic Editor Jinho Choi Copyright 2010 Yonghong Zeng et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Cognitive radio is widely expected to be the next Big Bang in wireless communications. Spectrum sensing that is detecting the presence of the primary users in a licensed spectrum is a fundamental problem for cognitive radio. As a result spectrum sensing has reborn as a very active research area in recent years despite its long history. In this paper spectrum sensing techniques from the optimal likelihood ratio test to energy detection matched filtering detection cyclostationary detection eigenvalue-based sensing joint space-time sensing and robust sensing methods are reviewed. Cooperative spectrum sensing with multiple receivers is also discussed. Special attention is paid to sensing methods that need little prior information on the source signal and the propagation channel. Practical challenges such as noise power uncertainty are discussed and possible solutions are provided. Theoretical analysis on the test statistic distribution and threshold setting is also investigated. 1. Introduction It was shown in a recent report 1 by the USA Federal Communications Commission FCC that the conventional fixed spectrum allocation rules have resulted in low spectrum usage efficiency in almost all currently deployed frequency bands. Measurements in
