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International Journal of Antennas and Propagation
Volume 2014, Article ID 506457, 13 pages
http://dx.doi.org/10.1155/2014/506457
Research Article

Application of a Channel Estimation Algorithm to Spectrum Sensing in a Cognitive Radio Context

1IETR-Supélec, 35000 Rennes, France
2ECAM Rennes-Louis de Broglie, 35170 Rennes, France
3Zodiac Data Systems, 14000 Caen, France

Received 7 November 2013; Accepted 27 January 2014; Published 26 March 2014

Academic Editor: Ali El-Hajj

Copyright © 2014 Vincent Savaux 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.

Abstract

This paper deals with spectrum sensing in an orthogonal frequency division multiplexing (OFDM) context, allowing an opportunistic user to detect a vacant spectrum resource in a licensed band. The proposed method is based on an iterative algorithm used for the joint estimation of noise variance and frequency selective channel. It can be seen as a second-order detector, since it is performed by means of the minimum mean square error criterion. The main advantage of the proposed algorithm is its capability to perform spectrum sensing, noise variance estimation, and channel estimation in the presence of a signal. Furthermore, the sensing duration is limited to only one OFDM symbol. We theoretically show the convergence of the algorithm, and we derive its analytical detection and false alarm probabilities. Furthermore, we show that the detector is very efficient, even for low SNR values, and is robust against a channel uncertainty.