Patent ID: 8271042
Filing Date: 2012-09-18
Classification: H04B

Abstract:
1. A method of calibrating system frequency responses for joint antenna processing in a multi-antenna wireless communication system that comprises three or more time-reuse groups, each time-reuse group including two or more antennas that are each connected to a corresponding transmit-receive RF chain, the method comprising: during a first time interval, transmitting a pilot signal from at least those antennas in a first time-reuse group, and receiving the pilot signals at antennas in one or more other time-reuse groups, wherein, during the first time interval, transmitting a pilot signal from at least those antennas belonging to a first time-reuse group comprises using a different transmit frequency, different channelization code, or both, for each of two or more subsets of the antennas belonging to the first time-reuse group; during a second time interval, transmitting a pilot signal from at least those antennas in a second time-reuse group, and receiving the pilot signals at antennas in one or more other time-reuse groups, wherein during the second time interval, transmitting a pilot signal from at least those antennas belonging to a second time-reuse group comprises using a different transmit frequency, different channelization code, or both, for each of two or more subsets of the antennas belonging to the second time-reuse group; during a third time interval, transmitting a pilot signal from at least those antennas in a third time-reuse group, and receiving the pilot signals at antennas in one or more other time-reuse groups, wherein during the third time interval, transmitting a pilot signal from at least those antennas belonging to a third time-reuse group comprises using a different transmit frequency, different channelization code, or both, for each of two or more subsets of the antennas belonging to the third time-reuse group; and calculating an RF-chain calibration factor for each of one or more of the antennas, based on the received pilot signals, each calibration factor accounting for a frequency response difference between the RF chain of the corresponding antenna and the RF chain of another one of the antennas.