Spectrum Hole Geolocation for Database-Driven IoT-Enabled Dynamic Spectrum Access

The effective realization of dynamic spectrum access (DSA) subsumes that, when a secondary terminal seeks a vacant band, the geolocation of the candidate spectrum hole coincides with the position of the terminal. Otherwise, stemming from a spectrum hole detection not corresponding to the terminal location, harmful interference to the primary network may occur. Non-cooperative spectrum sensing can inherently deliver accurate spectrum hole geolocation, as it corresponds to the position of the spectrum sensor. However, performance is degraded due to propagation-induced phenomena in the environment. While the performance of cooperative spectrum sensing is less prone to such phenomena, the accurate geolocation of the spectrum hole is compromised. This is because a vacant band is determined by a collective of spectrum sensors whose dispersed spatial distribution prevents from achieving high resolution concerning where in space the band is in fact vacant. This article delves into the problem of spectrum hole geolocation for DSA. As a solution, it is introduced a cooperative spectrum sensing scheme based on overlapped-clustering, integrated with a database-driven Internet of Things-enabled DSA framework. It is shown that the proposed solution achieves a high rate of correct estimations of spectrum hole geolocation, with small variance and under diverse system conditions.