Improvement of energy consumption in cognitive radio by reducing the number of sensed samples

Abstract

High energy consumption is one of the main challenges faced in cognitive radio (CR) networks, which may limit their implementation especially in battery-powered devices. In these networks, significant part of the energy is consumed in the energy detector during spectrum sensing for possible vacancy for secondary user transmission. In this paper, we have investigated reducing the energy consumption of single cognitive user (CU) by reducing the number of sensed samples. Also we have explained the optimization criteria for improving energy consumption by controlling number of sensed samples, detection probability and threshold of energy detector. The performance of energy detection system is evaluated in AWGN and Rayleigh fading channels. The simulation results show that at Eb/No of 10 dB 50% and 46 % of the energy consumed in detection are saved when the number of sensed samples is reduced by 50% with acceptable loss in detection probability of 5% and 12% in AWGN and Rayleigh channel respectively. The results also shows the impact of changing the threshold of energy detector on energy consumed in spectrum sensing.