CHANNEL ESTIMATION IN AN OFDM SYSTEM WITH HIGH DOPPLER SHIFT

摘要

A method of signal processing and a signal processor for a receiver for OFDM encoded digital signals. The OFDM encoded digital signals are transmitted as data symbol sub-carriers in several frequency channels. A subset of said sub carriers is in the form of pilot sub-carriers having a value known to the receiver. A first estimation of channel coefficients (H0) at said pilot sub-carriers is performed followed by cleaning of the estimated channel coefficients (H0) at the pilot sub-carriers. Then, a second estimation of channels coefficients (H1) is performed at the data symbol sub-carriers. The first estimation is performed by dividing received symbols (yp) at said pilot sub-carriers by the known pilot symbols (ap). the channel frequency response is supposed to vary linearly within one OFDM symbol. Therefore for each symbol and sub-band, a channel frequency response and its derivate are calculated or interpolated.