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Journal of Electrical and Computer Engineering
Volume 2015, Article ID 591627, 6 pages
Research Article

Fast Two-Step Energy Detection for Spectrum Sensing

1Institute of Communications Technology, Huaqiao University, Xiamen 361021, China
2School of Information Science and Technology, Jishou University, Jishou 416000, China

Received 22 January 2015; Accepted 20 March 2015

Academic Editor: John N. Sahalos

Copyright © 2015 Meiling Lai 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.


Spectrum sensing is one of the key tasks in cognitive radio. This paper proposes a fast two-step energy detection (FED) algorithm for spectrum sensing via improving the sampling process of conventional energy detection (CED). The algorithm adaptively selects -point or 2-point sampling by comparing its observed energy with prefixed double thresholds, and thereby is superior in sampling time and detection speed. Moreover, under the constraint of constant false alarm, this paper optimizes the thresholds from maximizing detection probability point of view. Theoretical analyses and simulation results show that, compared with CED, the proposed FED can achieve significant gain in detection speed at the expense of slight accuracy loss. Specifically, within high signal-to-noise ratio regions, as much as 25% of samples can be reduced.