Impact of Mobility on the Estimation of Primary Channel Activity Statistics

Dynamic Spectrum Access (DSA)/Cognitive Radio (CR) has emerged as an effective paradigm to solve problem of inefficient spectrum utilization. Spectrum sensing is the key in DSA/CR. Spectrum sensing decisions can be utilized to accurately estimate the primary channel activity statistics (PAS) like mean of idle/busy period, Duty cycle etc. Such estimated statistics can be used by CR to improve performance. However, when the secondary user (SU) is mobile, estimating these statistics becomes challenging. Taking this into account, this work provides a thorough review on the estimation of PAS for mobile SUs, considering vehicular scenario. The random way-point based mobility model is adopted for modelling SU mobility. Specifically, this work provides a set of closed form expressions for the estimated statistics under SU mobility as a function of the true PAS, SU velocity, initial distance between PU and SU, PU's protection range (R), SU's sensing range (S).