A recursive algorithm for joint time-frequency wideband spectrum sensing

In wideband spectrum sensing, secondary or unlicensed users take signal measurements over a given wide spectrum band and attempt to determine subbands for which the spectrum is idle and thus available for use. Some recent approaches to finding such spectrum holes generally employ some form of edge detection or energy detection. We propose an algorithm for joint time-frequency wideband spectrum sensing based on applying a form of temporal spectrum sensing together with a recursive tree search. The algorithm is able to detect spectrum holes accurately even in the presence of bursting primary signals and primary signals whose power spectral densities have smooth band edges. Numerical results are presented which show the performance gain of the proposed algorithm over earlier approaches to wideband spectrum sensing.