Interference-throughput tradeoff in dynamic spectrum access: Analysis based on discrete-time queuing subjected to bursty preemption

This article considers the issue of dynamic spectrum access in time domain, in which the secondary user seeks spectrum vacancy between bursty transmissions of the primary user to communicate. Since spectrum sensing and data transmission can not be done simultaneously in the same band, the secondary user should employ the sense-then-transmit strategy to detect the presence of primary user before accessing the licensed band. We model the behavior of the secondary user as a discrete-time queuing subjected to bursty preemption, which is an abstraction of temporal channel unavailability due to the random presence of the primary user. We formulate an interference-throughput tradeoff problem under the discrete-time queuing framework, and find the optimal slot duration to maximize the throughput of the secondary user, yet to ensure the primary interfered time ratio (PITR) is less than a tolerable threshold. Finally, the computer simulation results validate our theoretical approach.