Human opinion dynamics-based optimisation for in-band spectrum sensing in cognitive radio networks

Abstract

In cognitive radios, the primary user sensing plays an important role in defining a compromise between spectrum efficiency and licensed user interference. In this paper, the performance of cognitive radio is optimised using human opinion dynamics (HOD) inspired continuous opinion dynamics optimiser (CODO) with sensing parameters and throughput as arguments of objective function. The optimisation parameters are throughput, probability of false alarm and sensing time under varying signal to noise ratio (SNR) conditions with fixed frame period and at least 90 % probability of detection. Further, a new concept of human interaction for forming opinions is proposed to explore the idea of sensing-throughput optimisation. A statistical analysis showed that the proposed algorithm exhibits an improvement of 0.2 % in probability of detection with the condition that probability of detection is at least 90 %, as per the Federal Communication Commission (FCC) guidelines. Here, the frame period is kept fixed at 224.25 ms and the sensing time does not exceed 31.59 ms. There is also a drop of 5.25 % in false reports and an enhancement of 0.08 % in normalised throughput as compared to swarm intelligence technique when probability of detection is 95 % for the above frame period and sensing time. This implies that the cognitive user will not have to vacate the band on wrong reporting and can continue transmitting the data until the primary signal is indeed detected. Further, a maximum normalised throughput of 0.9088 is recorded at a minimum sensing time of 17.10 ms indicating that only ~8 % of the frame is utilised for sensing.