Time reversal is a physical principle well known for its deterministic focusing effect. Recently discovered statistical effects show that the time reversal focusing spot is not a point but has a Bessel power distribution. This finding offers accurate and reliable speed estimation indoors, where multipaths are abundant, with mostly nonline-of-sight (NLOS) conditions, and enable various indoor applications, such as wireless sensing and tracking. No known techniques can thrive in such scenarios. In essence, time reversal is an effective tool that embraces multipaths as virtual sensors with hundreds of thousands of degrees of freedom for our utilization.

中文翻译：

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时间反转的统计原理[观点]

时间反转是一种以其确定性聚焦效应而闻名的物理原理。最近发现的统计效应表明，时间反转聚焦点不是一个点，而是具有贝塞尔幂分布。这一发现提供了准确可靠的室内速度估计，室内多路径丰富，且大多是非视距 (NLOS) 条件，并支持各种室内应用，例如无线传感和跟踪。没有任何已知的技术可以在这种情况下发挥作用。从本质上讲，时间反转是一种有效的工具，它将多路径作为虚拟传感器，具有数十万个自由度供我们使用。