Accurate Estimation of the Minimum Primary Channel Activity Time in Cognitive Radio Based on Periodic Spectrum Sensing Observations

The minimum duration of idle/busy periods in a primary channel is an important parameter in Cognitive Radio (CR) systems since it determines the minimum amount of time the primary channel will be available for opportunistic transmission (in the case of idle periods) or the minimum amount of time the CR system will have to wait before a busy primary channel can become available again for opportunistic transmission (in the case of busy periods). Recent research has demonstrated that the value of the minimum period plays a critical role in the estimation of primary channel activity statistics, which can be estimated accurately only if the minimum period duration is accurately known. Given the importance of this parameter, this work analyses the problem of estimating the minimum (idle/busy) period in a primary channel based on periodic spectrum sensing observations and proposes novel methods to enable an accurate estimation. The obtained simulation results demonstrate that the proposed methods can provide an accurate estimation of the minimum period regardless of the employed sensing period (i.e., the main aspect that constrains the available time resolution).