1Coverage and Rate Analysis for Limited Information Cell Association in Stochastic-Layout Cellular Networks

Abstract—The complexity and uncertainty inherent in large cellular networks make the acquisition of loca-tion and channel information of all but perhaps a few neighbouring network nodes (base stations) difficult for a given user. Therefore, a cell association policy must operate with sparse information. Thus, the serving base station (BS) is proposed to be the one that provides the highest instantaneous signal-to-interference ratio (SIR) from among all BSs providing average received signal power exceeding a predetermined minimum. This policy is evaluated for the downlink of single-tier (homogeneous) and two-tier (heterogeneous) networks, and for the latter the key advantage of the proposed policy is its capability to enable traffic off-loading. Two methods to determine the minimum average signal power are given. Coverage probabilities and average rates of MSs in coverage are derived accounting for path loss, multipath fading and random locations of BSs in each tier. Analysis is verified by Monte-Carlo simulations. We observe that the instantaneous SIR and average received power of a few BSs are sufficient to achieve the coverage corresponding to the highest-SIR association, which in general requires instantaneous SIR information of a larger subset of a network. We also observe that in a two-tier network, the effect of strong interference from high power BSs, such as macro-BSs, can be limited by proper choice of minimum average received power for low power BSs. Index Terms—Heterogeneous cellular networks, cell association, downlink transmission, stochastic geome-try, point process theory, coverage probability, average data rate