Spectrum Sensing Based on Enhanced Energy Detector in Cognitive Radio Communications

Spectrum Sensing Based on Enhanced Energy Detector in Cognitive Radio Communications
Authors:DEEPIKA.B, CH.USHA KUMAR

Abstract: Cognitive radio communication has emerged as an efficient mean of utilization of spectrum for wireless communication. In cognitive radio communication the energy detector logic for spectrum estimation is the most eminent part for estimation of used spectrum over unused spectrum. The estimation error rate for such a system is dependent on the probability based hypothetical estimation approach. Wherein conventional energy detectors make the probability estimation based on derived threshold, the error rate is purely dependent on the accuracy of the threshold limits. In this paper a bi-level threshold modeling is proposed. The bi-level estimation approach presents an approach for non-linearity factor consideration for secondary users in Cognitive Radio communication. The obtained simulative observation illustrates the significance of bilevel estimator logic over conventional estimator logic. 

Keywords: Cognitive Radio, Spectrum Estimation, Energy Detector, Bi-Level Limits. 

INTRODUCTION 

        Cognitive radio is an exciting emerging communication model which may be considered as a solution to inefficient usage of fixed allocated licensed frequency spectrum. Significant improvement in spectrum utilization can be achieved by allowing an unlicensed or secondary user (SU) to access a licensed frequency band when the licensed or primary user (PU) is absent. In cognitive radio, SU senses an idle frequency band of a PU, and if a band is found to be idle, SU may transmit over that band. But as soon as PU returns, SU must vacate the band immediately. This complete process requires accurate spectrum sensing to avoid harmful interference to PU. There have been a lot of spectrum sensing techniques. Among those energy detector gives an effective spectrum sensing performance. The energy detector is a very useful non-coherent detector used to detect the presence of PU. It detects the presence of a PU‟s signal by measuring its energy and comparing the measured energy with a predetermined threshold. 

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