Threshold Adaptation in Spectrum Sensing For Cognitive Radio using Particle Swarm Optimization

Cognitive radio concerns primarily with the detection of primary (licensed) users in the radio frequency spectrum. In the case of a primary user is not transmitting in its allocated frequency band, the band is made available to a secondary (unlicensed) user for better spectrum utilization. However, the threshold of detecting a primary user should take into consideration sensing error minimization which includes minimum interference on the primary users and high spectrum utilization. In this paper, an improved energy detector equipped with particle swarm optimization is proposed to dynamically adapt the decision threshold according to the received signal conditions. The problem is formulated as a multi-dimensional constrained optimization and solved using penalty functions approach. Simulation results have shown significant improvement over the conventional energy detection technique that uses fixed threshold Keywords—Cognitive radio, energy detection, dynamic threshold, particle swarm optimization