Impact of the geometry, path-loss exponent and random shadowing on the mean interference factor in wireless cellular networks
Impact of the geometry, path-loss exponent and random shadowing on the mean interference factor in wireless cellular networks
复制标题
无线蜂窝网络中的几何形状、路径损耗指数和随机遮蔽对平均干扰因子的影响
DOI：
10.1109/wmnc.2010.5678764
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
François
中科院分区：
文献类型：
--
作者：
B. Błaszczyszyn;M. Karray;François
干扰因子针对网络中的给定位置定义为来自干扰基站 (BS) 的路径增益之和与来自服务 BS 的路径增益之比，是无线蜂窝网络分析中的一个重要因素。它取决于网络中基站的几何布局以及这些基站与给定位置之间的传播增益。在本文中，我们研究平均干扰因素，考虑到这两个因素的影响。关于几何形状，我们既考虑了BS的完美六边形网格，又考虑了BS的完全随机泊松图案。关于信号传播模型，我们不仅考虑仅取决于发射器和接收器之间的距离且主要由所谓的路径损耗指数来表征的确定性信号功率损耗函数，而且还考虑以统计方式表征给定路径上的各种障碍物修改该确定性函数的方式的随机阴影。我们详细分析了六边形和泊松网络架构中路径损耗指数、阴影方差和网络大小对平均干扰因子的影响。正如人们普遍预期的那样，我们观察到，小而中等的阴影会对常规网络产生负面影响，因为它会增加平均干扰因子。然而，正如开创性论文[16]中所指出的，如果选择提供最小路径损耗的服务基站，则可以大大减少这种影响。重新审视后一篇论文中研究的模型，我们得到了一个也许更令人惊讶的结果，即在大型不规则（泊松）网络中，阴影根本不会影响所有干扰因子，其平均值可以在仅取决于路径损耗指数的简单表达式中明确评估。此外，在中小型网络中，阴影的强烈变化对于六边形和泊松网络来说甚至是有益的。
The interference factor, defined for a given location in the network as the ratio of the sum of the path-gains form interfering base-stations (BS) to the path-gain from the serving BS is an important ingredient in the analysis of wireless cellular networks. It depends on the geometric placement of the BS in the network and the propagation gains between these stations and the given location. In this paper we study the mean interference factor taking into account the impact of these two elements. Regarding the geometry, we consider both the perfect hexagonal grid of BS and completely random Poisson pattern of BS. Regarding the signal propagation model, we consider not only a deterministic, signal-power-loss function that depends only on the distance between a transmitter and a receiver, and is mainly characterized by the so called path-loss exponent, but also random shadowing that characterizes in a statistical manner the way various obstacles on a given path modify this deterministic function. We present a detailed analysis of the impact of the path loss exponent, variance of the shadowing and the size of the network on the mean interference factor in the case of hexagonal and Poisson network architectures. We observe, as commonly expected, that small and moderate shadowing has a negative impact on regular networks as it increases the mean interference factor. However, as pointed out in the seminal paper [16], this impact can be largely reduced if the serving BS is chosen as the one which offers the smallest path-loss. Revisiting the model studied in this latter paper, we obtain a perhaps more surprising result saying that in large irregular (Poisson) networks the shadowing does not impact at all the interference factor, whose mean can be evaluated explicitly in a simple expression depending only on the path-loss exponent. Moreover, in small and moderate size networks, a very strong variability of the shadowing can be even beneficial in both hexagonal and Poisson networks.