Heterogeneous cellular network performance analysis under open and closed access

Abstract

We study the downlink signal-to-interference ratio (SIR) in a multi-tier heterogeneous cellular network under the open and closed access schemes. Each tier is characterized by a base-station (BS) arrangement according to a homogeneous Poisson point process with certain density, constant transmission power and random shadow fading factors with arbitrary distribution. The mobile-station (MS) communicates with the BS that has the maximum instantaneous received power among those to which it is allowed access. The chosen BS provides coverage to the MS if the SIR is above a certain threshold determined by the BS's tier. The coverage probability and average rate expressions are derived for the open access scheme for any arbitrary SIR threshold assigned for each tier, and for the closed access scheme when the SIR thresholds are greater than one.

Downlink analysis for a heterogeneous cellular network

“…The results shown here are generalizations of the existing results in [2], [3], [23], [27], [29]. In [25], [26], the coverage probability results are obtained for the hetnets under the max-SINR connectivity, but for the case where the fading coefficients for the BS transmissions are independent and identically distributed (i.i.d.)…”

“…In [29], the authors study the hetnet coverage probability for the maximum biased received power (MBRP) connectivity model (which is a special case of the nearest-BS connectivity model, as will be seen later), and again for the exponential fading assumption for all BS transmissions. In [1]- [3], we derived the hetnet coverage probability for the case when the i.i.d. fading coefficients have an arbitrary distribution and the path-loss exponents are different for different tiers, for the maximum instantaneous received power (MIRP) connectivity model, which is a special case for the max-SINR connectivity model, as will be discussed later.…”

“…In light of the above motivations, it is well-justified to study the hetnet performance by viewing the hetnet as composed of multiple tiers of networks (e.g. macrocell, microcell, picocell and femtocell networks), each modeled as an independent homogeneous Poisson point process, and such studies have been done in [22]- [29] and by us in [1]- [3]. These studies mathematically characterize important performance metrics such as coverage probability (1 -outage probability), average ergodic rate, average load carried by BSs of each tier and load-awareness.…”

“…Further, the BSs in each of these networks have different transmission powers, traffic-load carrying capabilities and different radio environment that is based on the locations in which they are deployed. The many parameters involved in A special cases of the results in this paper were presented in [1]- [3] the design and modeling of the individual networks makes it difficult to narrow all the possibilities down to a limited set of simulation scenarios based on which one can make design decisions for the entire network. Under these circumstances, the development of an analytical model that captures all the design scenarios of interest is of great importance.…”

Improving Log-Likelihood Ratio Estimation with Bi-Gaussian Approximation under Multiuser Interference Scenarios

“…In this paper, we focus on the scenario where a point-to-point communication is polluted by both the Gaussian noise and the non-Gaussian interference from nearby stations. This scenario may be typical for today’s heterogeneous networks consisting of an overlay of several dense, irregularly, and often completely randomly deployed networks with a limited coverage area [ 36 ]. For such complicated networks, the overhead of acquiring the CSI of the interfering channel and the modulation and coding scheme (MCS) of interfering signals may be impractically high, implying that the joint detection or successive interference cancellation may not be possible at least for some situations, especially when the interfering station belongs to a different system or operator.…”