Simultaneous transmission opportunities for LTE-LAA smallcells coexisting with WiFi in unlicensed spectrum
Simultaneous transmission opportunities for LTE-LAA smallcells coexisting with WiFi in unlicensed spectrum
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DOI：
10.1109/icc.2016.7511073
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发表时间：
2016-05
期刊：
影响因子：
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通讯作者：
Long Li;A. Jafari;Xiaoli Chu;Jie Zhang
中科院分区：
文献类型：
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作者：
Long Li;A. Jafari;Xiaoli Chu;Jie Zhang
基于非授权频谱的LTE许可辅助接入（LTE- laa）由于其诱人的数据流量分流潜力而备受关注。然而，LTE和WiFi技术共存于同一个未经许可的频段需要仔细设计，以避免它们之间的严重干扰。在本文中，我们提出了一种共存方案，为LTE-LAA小蜂窝和WiFi设备同时传输创造机会。我们将多信号分类（MUSIC）到达方向（DOA）估计与零转向技术相结合，以避免LTE-LAA和WiFi传输之间的冲突。我们假设LTE-LAA小型小区配备了最新的802.11接收器，用于监控WiFi传输并捕获同步传输时间。通过仿真对该方案在避免碰撞和信道占用时间比方面的性能进行了评价。结果表明，通过DOA估计和零指向，LTE-LAA小小区可以与附近的WiFi设备同时传输，不会对其造成明显干扰。因此，LTE-LAA小蜂窝可以获得更多的信道接入机会和更长的信道占用时间，同时对共存的WiFi网络“不可见”。
LTE License-Assisted Access (LTE-LAA) in unlicensed spectrum has drawn a lot of attention due to its appealing data traffic offloading potential. However, the coexistence of LTE and WiFi technologies in the same unlicensed bands needs careful design to avoid severe interference between them. In this paper, we propose a coexistence scheme to create opportunities for LTE-LAA small cells and WiFi devices to transmit simultaneously. We combine Multiple Signal Classification (MUSIC) direction of arrival (DOA) estimation with null steering techniques to avoid collisions between LTE-LAA and WiFi transmissions. We assume that the LTE-LAA small cells are equipped with the latest 802.11 receivers for monitoring WiFi transmissions and for capturing simultaneous transmission timing. The performance of the proposed scheme in terms of collision avoidance and channel occupancy time ratio is evaluated via simulations. The results show that with DOA estimation and null steering, LTE-LAA small cells can transmit simultaneously with nearby WiFi devices without causing significant interference to them. As a result, LTE-LAA small cells can gain much more channel access opportunities and longer channel occupancy time while being “invisible” to coexisting WiFi networks.