Stochastic Geometry Perspective of Unlicensed Operator in a CBRS System

摘要

In this work, we model and analyze a cellular system that operates in the licensed band of the 3.5 GHz spectrum and consists of a licensed and an unlicensed operator. Using tools from stochastic geometry, we study the co-existence of these networks from the perspective of the unlicensed operator. We model the licensed base station (BS) locations as a homogeneous Poisson point process with protection zones (PZs) around each BS. Since the unlicensed BSs can not operate within PZs, their locations are modeled as a Poisson hole process. In addition, we also consider contention-based channel access mechanism for the unlicensed BSs. We provide useful lower bound for the medium access probability for a typical BS of the unlicensed operator. Further, approximate results for coverage probability are also presented, by effectively handling the correlation in the interference powers induced due to correlation in locations of the licensed and unlicensed BSs. Using the derived expressions, we study the effect of the density of licensed BSs on the average number of active unlicensed BSs per unit area and coverage probability for a typical unlicensed user. To the best of our knowledge, this work presents the first comprehensive stochastic geometry-based analysis of the CBRS system.