Interference Performance Evaluation of Secondary Users in Cognitive Radio Networks

In this paper, we analyze the probability of error for secondary users employed in a cognitive radio network operating within the vicinity of several primary users. Secondary( unlicensed) users must coexist with primary(licensed) users, ensuring that the legacy rights of the primary user transmissions are respected. Consequently, the secondary users must either sense the channel periodically, which has some detection delay, or must check a spectrum availability database, which may not be updated in real-time. Hence, there will be times when the primary user and the secondary user will occupy the same band and interfere with each other. The aim of this paper is to quantify the impact of the probability of error of the secondary user when it does not react quickly enough to the presence of a primary user. Several numerical examples are provided in order to illustrate the analytical results.