Low complexity spectrum sensing technique for cognitive radio using Farrow Structure Digital Filters

Abstract

In recent years, Cognitive Radio (CR) is found to be a viable solution to meet the next generation spectrum utilization challenges. The basic requirement for CR is spectrum sensing, in which the unlicensed users or secondary users (SU) need to continuously monitor the spectrum for the presence of authorized users or primary users (PU). The spectral efficiency of a CR system depends on the implementation of the spectrum sensing part such that the smallest possible inactive portion of the spectrum is identified. Most of the filter bank based spectrum sensing methods available in the literature are based on fixed filter banks. In this paper, the idea of variable bandwidth filter, based on Farrow structure, is exploited to implement the spectrum sensing technique. It is seen that the proposed method is more efficient than the existing filter bank based techniques and the hardware complexity is drastically reduced. Keywords: Digital filters, Farrow structure, variable bandwidth filter, energy detection, spectrum sensing