Channel calibration for a time division duplexed communication system

摘要

Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

主权项

1. A method for calibrating downlink and uplink channels in a wireless communication system, comprising:
obtaining an estimate of a downlink channel response; obtaining an estimate of an uplink channel response; determining first and second sets of correction factors based on the estimates of the downlink and uplink channel responses; and calibrating the downlink channel and uplink channel based on the first and second sets of correction factors and a scaling value to form a calibrated downlink channel and a calibrated uplink channel, wherein the scaling value is indicative of an average difference between the estimate of the downlink channel response and the estimate of the uplink channel response.