Cognitive Radio System

In recent decades, cognitive radio technology devices has appeared, it can adjust its operating parameters according to the data that has been sensed from the surrounding environment, where cognitive radio networks manages a spectrum sharing process between several users, by classifying them to a primary user, which is the license owner and has the full authority to use the bandwidth, and secondary user, has right to use the bandwidth but without influencing the main user. Some factors play an important role in determining the efficiency and performance of cognitive radio system, one of these factors is the bit error rate of the transmitted data, which must be as minimum as possible to get the best results.