Interference-constrained access opportunity distribution for secondary communication in TV white space

Abstract

To better utilize TV white space, the paper considers deploying secondary users (SUs) on vacant channels inside TV coverage. In this heterogeneous case, TV and SU receivers suffer not only mutual adjacent channel interference (ACI) from each other, but also co-channel interference (CCI) from cellular network (CN) outside TV coverage. Therefore SU access opportunity is formulated as the maximal capacity of available SU channels under both TV and SU receiver outage probability constraints. To facilitate the maximization, the analytical interference from both CN and SUs is deduced using Poisson Point Process model. Since the exact interference distribution is too complex to analyze, we approximate it as Gaussian and prove the accuracy of our approximation with Kolmogorov-Smirnov test. Main results include that SU access opportunity follows a volcano-shaped distribution geographically and optimal network-status-aware SU transmit power exists to maximize the access opportunity, which can contribute to the practical deployment of secondary system and the utilization improvement of white space.