REFIM: A Practical Interference Management in Heterogeneous Wireless Access Networks
REFIM: A Practical Interference Management in Heterogeneous Wireless Access Networks
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DOI：
10.1109/jsac.2011.110613
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发表时间：
2011-05
影响因子：
16.4
通讯作者：
K. Son;Soohwan Lee;Yung Yi;S. Chong
中科院分区：
文献类型：
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作者：
K. Son;Soohwan Lee;Yung Yi;S. Chong
由于无线蜂窝网络对容量的需求不断增加，微微小区和毫微微小区等小小区越来越多地获得空间重用收益，因此不同大小的小区有望以复杂的方式共存。在这种异构性的环境中，干扰管理(IM)的作用变得更加重要，但技术挑战也随之增加，因为遭受邻近小区严重干扰的小区边缘用户数量自然会增加。为了克服现有静态和动态IM算法的低性能和/或高复杂度，我们提出了一种新的低复杂度的全分布式IM方案，称为REFIM(Reference Based Interference Management)，用于异质多小区网络的下行链路。我们首先描述了一个一般的优化问题，结果证明该问题需要难以处理的计算复杂性才能实现全局最优。在REFIM中，为了具有低计算和信令开销的实用解决方案，这对于低成本的小小区解决方案(如毫微微小区)至关重要，我们基于参考用户的概念将其分解为每个BS(基站)问题，并在时间和空间上减少回程的反馈开销。我们通过在不同配置下的大量模拟来评估REFIM，包括来自BSS实际部署的场景。仿真结果表明，与未采用IM的方案相比，REFIM在提高小区边缘用户吞吐量的同时，整体性能提高了10%~107%。这相当于现有集中式IM算法(MC-IIWF)的95%左右的性能，该算法已知接近最优，但由于其令人望而却步的复杂性而难以在实践中实现。我们还指出，只要干扰管理得当，频谱共享策略的性能优于最佳频谱分割策略，后者的子信道数量在宏蜂窝和毫微微小区之间进行了优化分配。
Due to the increasing demand of capacity in wireless cellular networks, the small cells such as pico and femto cells are becoming more popular to enjoy a spatial reuse gain, and thus cells with different sizes are expected to coexist in a complex manner. In such a heterogeneous environment, the role of interference management (IM) becomes of more importance, but technical challenges also increase, since the number of cell-edge users, suffering from severe interference from the neighboring cells, will naturally grow. In order to overcome low performance and/or high complexity of existing static and other dynamic IM algorithms, we propose a novel low-complex and fully distributed IM scheme, called REFIM (REFerence based Interference Management), in the downlink of heterogeneous multi-cell networks. We first formulate a general optimization problem that turns out to require intractable computation complexity for global optimality. To have a practical solution with low computational and signaling overhead, which is crucial for low-cost small-cell solutions, e.g., femto cells, in REFIM, we decompose it into per-BS (base station) problems based on the notion of reference user and reduce feedback overhead over backhauls both temporally and spatially. We evaluate REFIM through extensive simulations under various configurations, including the scenarios from a real deployment of BSs. We show that, compared to the schemes without IM, REFIM can yield more than 40% throughput improvement of cell-edge users while increasing the overall performance by 10~107%. This is equal to about 95% performance of the existing centralized IM algorithm (MC-IIWF) that is known to be near-optimal but hard to implement in practice due to prohibitive complexity. We also present that as long as interference is managed well, the spectrum sharing policy can outperform the best spectrum splitting policy where the number of subchannels is optimally divided between macro and femto cells.