Ingeniare. Revista chilena de ingeniería
On-line version ISSN 0718-3305
PEDRAZA, Luis Fernando; FORERO, Felipe and PAEZ, Ingrid Patricia. Spectrum sensing for cognitive radio. Ingeniare. Rev. chil. ing. [online]. 2012, vol.20, n.2, pp. 197-210. ISSN 0718-3305. http://dx.doi.org/10.4067/S0718-33052012000200007.
This survey article focuses on the physical layer for cognitive radio (CR) networks, namely the techniques to detect the presence/absence of licensed users in the different spectrum bands. The techniques presented in this article, including their advantages and disadvantages, are organized in a hierarchical fashion as follows: fundamental detection techniques (energy-based detection, matched filter, and cyclostationarity features), fundamental-detection-based techniques (waveform detection, radio identification, local-oscillator leakage power), and alternative techniques that are typical of the image analysis domain (Hough and Wavelet transforms). Additionally, the main challenges associated to licensed user detection are described together with the various spectral dimensions where cognitive radio devices can find new spectrum opportunities.
Keywords : Cognitive radio; spectrum sensing; primary users; secondary users; dynamic spectrum allocation; spectrum holes.