@article {VazquezValcarceTSP11, title = {Spectrum Sensing Exploiting Guard Bands and Weak Channels}, journal = {IEEE Trans. on Signal Processing}, volume = {59}, number = {12}, year = {2011}, month = {12/2011}, pages = {6045-6057}, abstract = {
We address the problem of primary user detection\ in Cognitive Radio from a wideband signal comprising multiple\ primary channels, exploiting a priori knowledge about the\ primary network: channelization and spectral shape of primary\ transmissions. Using this second-order statistical information, a\ multichannel Gaussian model is formulated. In order to obtain\ a Generalized Likelihood Ratio Test, we first address Maximum\ Likelihood (ML) estimation of the power levels at the different\ channels, as well as of the noise variance. The ML conditions\ suggest a suboptimal closed-form estimate, which takes the form\ of a constrained Least Squares estimator whose asymptotic\ efficiency is shown for flat bandpass spectra in white noise, a\ case of practical importance. The resulting detectors exploit those\ frequency bins corresponding to guard bands and to primary\ channels perceived as weak to improve noise variance estimation.\ Analytical expressions for the probabilities of detection and false\ alarm are presented. Performance is evaluated via simulations\ in the setting of a terrestrial TV primary network with realistic\ channelization parameters.
}, keywords = {cognitive radio, dynacs, spectrum sensing}, doi = {10.1109/TSP.2011.2167615}, author = {Gonzalo V{\'a}zquez-Vilar and R. L{\'o}pez-Valcarce} }