Optimal Spectrum Sensing Interval to Minimize the Transmission Delay for Cognitive Radio

In this work, we have studied the optimal spectrum sensing interval, which is the time between two consecutive spectrum sensing activities, such that the delay of the cognitive transmission is minimized. The throughput maximization of the cognitive radio is always a common goal of the researchers, which is keenly related to the delay of the cognitive transmission. Whereas the delay is mostly decided by the spectrum sensing interval for a given primary user (PU) channel. Therefore, we have studied the setting of the spectrum sensing interval to minimize the transmission delay of the secondary user (SU). Especially, the retransmission is considered, which deteriorates the delay of the cognitive transmission; however, neglected by the most studies. Finally, we provide both the optimal setting of the spectrum sensing interval and the numerical values.