Heterogeneous Cellular Networks with Flexible Cell Association: A Comprehensive Downlink SINR Analysis
Heterogeneous Cellular Networks with Flexible Cell Association: A Comprehensive Downlink SINR Analysis
复制标题
DOI：
10.1109/twc.2012.081612.111361
复制
发表时间：
2012-10-01
影响因子：
10.4
通讯作者：
Andrews, Jeffrey G.
中科院分区：
文献类型：
--
作者：
Jo, Han-Shin;Sang, Young Jin;Andrews, Jeffrey G.
在本文中，我们开发了一个易于处理的框架，用于具有灵活单元关联策略的下行异构蜂窝网络（HCNs）的SINR分析。HCN被建模为多层蜂窝网络，其中每层的基站（BSs）是随机分布的，并且具有特定的发射功率、路径损耗指数、空间密度和允许移动用户的偏差。例如，与macrocell相比，piccell通常具有更低的发射功率，更高的路径损耗指数（更低的天线），更高的空间密度（每个macrocell有许多piccell），并且具有正偏置，因此macrocell用户被积极鼓励使用负载更轻的piccell。在本文中，我们隐式地假设所有基站都有满队列；未来的工作应该放松这一点。对于该模型，我们推导出全网或某一层典型用户的中断概率，即下行SINR累积分布函数。结果对所有sinr都是准确的，并且在一些貌似合理的特殊情况下，它们的表达式承认相当简单的封闭形式。我们还推导出典型用户的平均遍历率和最小平均用户吞吐量—每层中一个单元支持的平均用户吞吐量中的最小值。我们观察到，在具有无偏倚细胞关联（无偏倚）的干扰限制的满载HCN中，BSs或层的数量都不会改变中断概率或平均遍历率，并观察偏倚如何改变各种指标。
In this paper we develop a tractable framework for SINR analysis in downlink heterogeneous cellular networks (HCNs) with flexible cell association policies. The HCN is modeled as a multi-tier cellular network where each tier's base stations (BSs) are randomly located and have a particular transmit power, path loss exponent, spatial density, and bias towards admitting mobile users. For example, as compared to macrocells, picocells would usually have lower transmit power, higher path loss exponent (lower antennas), higher spatial density (many picocells per macrocell), and a positive bias so that macrocell users are actively encouraged to use the more lightly loaded picocells. In the present paper we implicitly assume all base stations have full queues; future work should relax this. For this model, we derive the outage probability of a typical user in the whole network or a certain tier, which is equivalently the downlink SINR cumulative distribution function. The results are accurate for all SINRs, and their expressions admit quite simple closed-forms in some plausible special cases. We also derive the average ergodic rate of the typical user, and the minimum average user throughput - the smallest value among the average user throughputs supported by one cell in each tier. We observe that neither the number of BSs or tiers changes the outage probability or average ergodic rate in an interference-limited full-loaded HCN with unbiased cell association (no biasing), and observe how biasing alters the various metrics.