Downlink and Uplink Decoupling in Two-Tier Heterogeneous Networks With Multi- Antenna Base Stations
Downlink and Uplink Decoupling in Two-Tier Heterogeneous Networks With Multi- Antenna Base Stations
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DOI：
10.1109/twc.2017.2665466
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发表时间：
2017-02
影响因子：
10.4
通讯作者：
M. Bacha;Yueping Wu;B. Clerckx
中科院分区：
文献类型：
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作者：
M. Bacha;Yueping Wu;B. Clerckx
为了提高未来蜂窝网络的上行链路性能，最近证明将下行链路（DL）和上行链路（UL）关联解耦的想法可以在覆盖范围和速率性能方面提供显着的增益。然而，所有工作都仅限于单输入单输出（SISO）网络。因此，为了研究多天线基站（BS）设置中DL和UL解耦提供的增益，我们研究了由多天线BS和单天线用户设备（UE）组成的两层异构网络。我们使用最大比组合（MRC）作为基站的线性接收器和随机几何工具，并推导出信号干扰比（SIR）覆盖概率和速率覆盖概率的易于处理的表达式。我们观察到，随着两层波束成形增益差异的增加，解耦关联相对于非解耦关联提供的 SIR 覆盖概率方面的增益会降低。我们进一步观察到，当两层天线数量不对称时，我们需要在解耦关联的顶部进一步偏向毫微微层，以平衡负载并获得最佳速率覆盖概率。
In order to improve the uplink performance of future cellular networks, the idea to decouple the downlink (DL) and uplink (UL) association has recently been shown to provide significant gain in terms of both coverage and rate performance. However, all the works are limited to a single input single output (SISO) network. Therefore, to study the gain provided by the DL and UL decoupling in multi-antenna base stations (BSs) setup, we study a two tier heterogeneous network consisting of multi-antenna BSs, and single antenna user equipments (UEs). We use maximal ratio combining (MRC) as a linear receiver at the BSs and tools from stochastic geometry, and we derive tractable expressions for both signal-to-interference ratio (SIR) coverage probability and rate coverage probability. We observe that as the disparity in the beamforming gain of both tiers increases, the gain in terms of SIR coverage probability provided by the decoupled association over non-decoupled association decreases. We further observe that when there is asymmetry in the number of antennas of both tiers, then we need further biasing toward femto-tier on the top of decoupled association to balance the load and get optimal rate coverage probability.