Channel prediction in point-to-point MIMO-systems

The present paper introduces three sophisticated techniques to predict the channel transfer functions in frequency division duplex MIMO-systems. In frequency division duplex systems it is beneficial to have the knowledge of the uplink channel and the downlink channel at both sides of the point-to-point transmission link. However, the base station can only estimate the uplink channel based on the transmission of a-priori known training signals from the mobile station. Due to the frequency selective behavior of the mobile radio channel, the channel state information of the uplink channel and the channel state information of the downlink channel are different. One possibility to obtain the channel state information of the downlink channel in the base station is to feed back this information from the mobile station. Unfortunately, this feedback decreases the spectral efficiency. The presented techniques to obtain the channel state information of the downlink channel in the base station are based on the physical path parameters and are based on filtering the previously estimated channel state information. The performance of the investigated techniques is evaluated by means of measurement results.