Optimization of secondary user access in cognitive radio networks

This paper presents optimization of secondary user (SU) access in sensing-transmission structure for dynamic spectrum access in cognitive radios. In opportunistic spectrum access, the white spaces in the transmissions of primary users (PUs) have to be sensed and utilized by SUs. There is a continuous tradeoff between the competing goals of PU transmission protection and SU access maximization. A threshold based sensing-transmission structure is developed. To maximize the SU access its reward is optimized with respect to collision cost using simulations. The results are presented in the form of traces of thresholds for different reward values and collision costs. This scheme optimizes SU throughput while safeguarding PU interests. It sets a standard and gives an insight for the design of sensing-transmission scheduling in cognitive radio networks such as IEEE 802.2.