We present a reciprocity calibration method for dual-antenna repeaters in wireless networks. The method uses bi-directional measurements between two network nodes, A and B, where for each bi-directional measurement, the repeaters are configured in different states. The nodes A and B could be two access points in a distributed MIMO system, or they could be a base station and a mobile user terminal, for example. From the calibration measurements, the differences between the repeaters' forward and reverse gains are estimated. The repeaters are then (re-)configured to compensate for these differences such that the repeaters appear, transparently to the network, as reciprocal components of the propagation environment, enabling reciprocity-based beamforming in the network.

翻译：我们提出了一种适用于无线网络中双天线中继器的互易校准方法。该方法利用两个网络节点A和B之间的双向测量，其中每次双向测量时，中继器配置在不同状态。节点A和B可以是分布式MIMO系统中的两个接入点，也可以是基站和移动用户终端等。通过校准测量，可以估计出中继器正向与反向增益之间的差异。随后，对中继器进行（重新）配置以补偿这些差异，从而使中继器在网络上表现为传播环境中的互易组件，进而实现基于互易性的网络波束赋形。