Time prediction of non flat fading channels

In this paper three different techniques to predict the channel transfer functions of non flat fading channels in multiple antenna systems are investigated. The prediction is done into time direction. In time division duplex systems, it is beneficial to have the full channel state information. A receiver can achieve the channel state information for one certain time instant based on the reception of a-priori known training signals. This estimated channel state information can be outdated when receiving signals at another time instant or especially when transmitting a signal back to the previously transmitter at another time instant. One possibility to cope with the problem of outdated channel state information is to retransmit a-priori known training signals in order to update the channel state information but this decreases the spectral efficiency. This paper shows techniques to perform the prediction based on the estimation of the physical path parameters of the electromagnetic waves and based on filtering the outdated channel state information. The performance of the presented techniques is evaluated by means of measurement results.