Patent ID: 9537625
Date: 2017-01-03
CPC Classifications: H04B,H04L,H04W

Claim:
1. A method for calibrating data transmitted by coordinated Access Points (APs), comprising: a base station obtaining an uplink channel frequency-domain response and a downlink channel frequency-domain response between a first AP and a second AP which participate in coordination; the base station dividing the uplink channel frequency-domain response by the downlink channel frequency-domain response to obtain an uplink-downlink channel response difference between the first AP and the second AP; and the base station calibrating the data transmitted by the first AP and the second AP in coordination according to the uplink-downlink channel response difference; wherein the step of the base station obtaining the uplink channel frequency-domain response and the downlink channel frequency-domain response between the first AP and the second AP which participate in coordination comprises: the base station obtaining a channel frequency-domain response calculated by the second AP at a time t1 according to a calibration sequence received from the first AP, and using the channel frequency-domain response as the downlink channel frequency-domain response between the first AP and the second AP; the base station obtaining a channel frequency-domain response calculated by the first AP at a time t2 according to a calibration sequence received from the second AP, and using the channel frequency-domain response as the uplink channel frequency-domain response between the first AP and the second AP; when the first AP and the second AP have not performed self-calibration of their own set of antennas, if the obtained downlink channel frequency-domain response is calculated by the second AP at the time t1 according to the calibration sequence transmitted by the first AP via an antenna Ant(j) and received by the second AP via an antenna Ant(i), the base station obtaining the uplink channel frequency-domain response calculated by the first AP at the time t2 according to the calibration sequence transmitted by the second AP via the antenna Ant(i) and received by the first AP via the antenna Ant(j), and when the first AP and the second AP have performed self-calibration of their own set of antennas, if the obtained downlink channel frequency-domain response is calculated by the second AP at the time t1 according to the calibration sequence transmitted by the first AP via an antenna Ant(j) and received by the second AP via an antenna Ant(i), the base station obtaining the uplink channel frequency-domain response calculated by the first AP at the time t2 according to the calibration sequence transmitted by the second AP via an antenna Ant(j′) and received by the first AP via an antenna Ant(i′); wherein iε[0,N−1], i′ε[0,N−1], jε[0,N−1], j′ε[0,N−1], the time t1 is different from the time t2, and N is a number of antennas of the coordinated AP.