Low Energy Consumption for Cooperative and Non-cooperative Cognitive Radio


Recently the subject of energy-efficient is very important in cognitive radio (CR), especially during spectrum sensing, since the large energy consumption (EC) cost, produces a restriction in their implementation especially in devices with limited power, i.e battery. In these design, energy detector consumes a significant part of energy during spectrum sensing to detect the activity of the primary user (PU). In this paper, we investigated a method for improving EC in two scenarios: non-cooperative and cooperative. The idea behind the improvement is based on sensing the spectrum with low-density samples. The optimization concept for reducing EC through controlling the number of frequency samples to be sensed is illustrated as well as the probability of detection in both scenarios. To evaluate the proposed method a comparison is made between the proposed method and censoring method. The performance of energy detection system is evaluated in AWGN and Rayleigh fading channels. The simulation results show that in non-cooperative scenario at Eb/No equal 10 dB, and for sensing ratio equal 50%, EC decreases by 50% and 46% with sma loss in of detection probability of 5% in AWGN channel and 12% in Rayleigh channel. In cooperative scenario, the results show that as the number of cognitive users (CU) increased the average EC per user decreased with an improvement in probability of detection. In case of sensing ratio 50%, the EC is decreased by 43.6% as compared with censoring method.