Coexistence of Wi-Fi and heterogeneous small cell networks sharing unlicensed spectrum
Coexistence of Wi-Fi and heterogeneous small cell networks sharing unlicensed spectrum
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DOI：
10.1109/mcom.2015.7060498
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发表时间：
2015-02
影响因子：
11.2
通讯作者：
Haijun Zhang;Xiaoli Chu;Weisi Guo;Siyi Wang
中科院分区：
文献类型：
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作者：
Haijun Zhang;Xiaoli Chu;Weisi Guo;Siyi Wang
作为地面无线通信中的两个主要参与者，Wi-Fi系统和蜂窝网络具有不同的起源，并且在很大程度上分别演进。受指数增长的无线数据需求的推动，蜂窝网络正朝着异构和小小区网络架构演进，其中期望小小区提供非常高的容量。然而，由于蜂窝网络的许可频谱有限，通过网络致密化实现容量增长的任何努力都将面临严重的小区间干扰的挑战。有鉴于此，最近的标准化发展已经开始考虑蜂窝网络使用未授权频带的机会，包括当前由Wi-Fi、Zigbee和一些其他通信系统使用的2.4GHz和5GHz频带。在本文中，我们将探讨Wi-Fi和4G蜂窝网络共享未授权频谱的共存。我们介绍了一种网络架构，其中小型小区使用Wi-Fi系统在其中操作的相同的未授权频谱，而不影响Wi-Fi系统的性能。我们提出了一种无优先级的几乎空白子帧（ABS）方案来减轻小小区对Wi-Fi系统的同信道干扰，并提出了一种基于小小区估计附近Wi-Fi接入点的密度以促进它们在共享相同的未授权频谱的同时共存的干扰避免方案。仿真结果表明，所提出的网络架构和干扰避免方案可以在保持Wi-Fi系统服务质量的前提下，显著提高4G异构蜂窝网络的容量。
As two major players in terrestrial wireless communications, Wi-Fi systems and cellular networks have different origins and have largely evolved separately. Motivated by the exponentially increasing wireless data demand, cellular networks are evolving towards a heterogeneous and small cell network architecture, wherein small cells are expected to provide very high capacity. However, due to the limited licensed spectrum for cellular networks, any effort to achieve capacity growth through network densification will face the challenge of severe inter-cell interference. In view of this, recent standardization developments have started to consider the opportunities for cellular networks to use the unlicensed spectrum bands, including the 2.4 GHz and 5 GHz bands that are currently used by Wi-Fi, Zigbee and some other communication systems. In this article, we look into the coexistence of Wi-Fi and 4G cellular networks sharing the unlicensed spectrum. We introduce a network architecture where small cells use the same unlicensed spectrum that Wi-Fi systems operate in without affecting the performance of Wi-Fi systems. We present an almost blank subframe (ABS) scheme without priority to mitigate the co-channel interference from small cells to Wi-Fi systems, and propose an interference avoidance scheme based on small cells estimating the density of nearby Wi-Fi access points to facilitate their coexistence while sharing the same unlicensed spectrum. Simulation results show that the proposed network architecture and interference avoidance schemes can significantly increase the capacity of 4G heterogeneous cellular networks while maintaining the service quality of Wi-Fi systems.