Opportunistic Spectrum Access Using Greedy and Optimal Approach in Cognitive Radios
In cognitive radio networks, the secondary user network are allowed to utilize the underutilized frequency bands of primary user network on non-interfering basis. To achieve this task, the Secondary Users (SU) are required to sense the RF environment, and once the Primary User (PU) is found to be active, the SU have to give up the channel within certain amount of time. There are two restrictions related to spectrum sensing: probability of detection and probability of false alarm. The higher the detection probability, the better the PU can be protected. However, from the SUs' point of view, the lower the false alarm probability, the more chances the channel can be utilized, thus the higher the achievable throughput for the SU's.