UNBLOCK：移动毫米波器件的低复杂度瞬态阻塞恢复
UNBLOCK: Low Complexity Transient Blockage Recovery for Mobile mm-Wave Devices
摘要：
定向无线电波束用于毫米波段以对抗高路径损耗。毫米波段还遭受来自干墙、木材、玻璃、混凝土等的高穿透损耗，还有人体。因此，当移动用户移动时，移动设备和基站（BS）之间的视线（LoS）路径可能被插入路径中的物体阻挡，导致链路丢失。失去链接的手机需要通过初始访问重新获得新用户，这一过程可能需要一秒钟，从而导致应用程序中断。UNBLOCK是一种协议，允许移动设备从瞬时阻塞中恢复，例如由人手或另一个人走进路径线或物体造成的其他暂时阻塞，这些阻塞通常在$100$ ms的量级内消失，而不必经历重新获取。UNBLOCK基于在办公室类型环境中的广泛实验，该实验已经表明，虽然LoS路径被阻塞，但通常存在非LoS路径，即，通过散射体的反射路径，损耗在LoS路径的大约$10$ dB内。UNBLOCK主动保留这样的NLoS路径，以在发生阻塞时使用，通常没有任何警告。UNBLOCK使用此NLoS路径来保持与BS的时间同步，直到阻塞消失，并搜索更好的NLoS路径（如果可用）。当瞬时阻塞消失时，它在已经由BS调度用于与移动台通信的时期处重新建立LoS通信。
英文摘要：
Directional radio beams are used in the mm-Wave band to combat the high path loss. The mm-Wave band also suffers from high penetration losses from drywall, wood, glass, concrete, etc., and also the human body. Hence, as a mobile user moves, the Line of Sight (LoS) path between the mobile and the Base Station (BS) can be blocked by objects interposed in the path, causing loss of the link. A mobile with a lost link will need to be re-acquired as a new user by initial access, a process that can take up to a second, causing disruptions to applications. UNBLOCK is a protocol that allows a mobile to recover from transient blockages, such as those caused by a human hand or another human walking into the line of path or other temporary occlusions by objects, which typically disappear within the order of $100$ ms, without having to go through re-acquisition. UNBLOCK is based on extensive experimentation in office type environments which has shown that while a LoS path is blocked, there typically exists a Non-LoS path, i.e., a reflected path through scatterers, with a loss within about $10$ dB of the LoS path. UNBLOCK proactively keeps such a NLoS path in reserve, to be used when blockage happens, typically without any warning. UNBLOCK uses this NLoS path to maintain time-synchronization with the BS until the blockage disappears, as well as to search for a better NLoS path if available. When the transient blockage disappears, it reestablishes LoS communication at the epochs that have been scheduled by the BS for communication with the mobile.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
