Method of estimating fading in a pilot channel

摘要

A method of estimating fading of a modulated signal transmitted through a pilot channel using a digital filter 20 is disclosed herein. The signal is divided into frames each of a plurality of symbols Yi and the method comprises the step of deriving a moving average of the symbols received in each frame, of the form 1 $x_n=\left(\left(n-1\right)/n\right)x_{n-1}+1/Rn\left(\sum _{i=R\left(n-1\right)+1}^{Rn}{y}_i\right)$ where xn is the moving average of the symbols so far received for the frame, xn-1 is a previously calculated moving average, R is the number of received symbols since the previous average was calculated and n is the number of averages calculated per frame, each average providing a fading estimate for the frame.