From a physical layer aspect, those techniques feature high frequency and power efficiency, and are able to adapt to changing environments and services, will win in the long run.

在物理层技术层面上，具有高频谱效率和功率效率，并能适应环境和业务变化的技术成为研究的热点。

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Now the low frequency noise has been paid more attention in modern city. It can run with long distance and penetrate through wall into human ears.

现代城市中的低频噪声已越来越引起人们的重视，低频噪声能够长距离奔袭和穿墙透壁直入人耳。

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