Patent ID: 6539067
Filing Date: 2003-03-25
Classification: H04L

Abstract:
A method of estimating channel impulse response in a signal b transmitted over a channel in a communication system and received as a signal r, said method comprising the steps of:obtaining a priori knowledge about the transmitted signal b; using the transmitted signal and the a priori knowledge to formulate a cost function C as the expected value E{|râˆ’{circumflex over (r)}|2} of a distance between r and a reconstructed signal {circumflex over (r)}, wherein {circumflex over (r)} is obtained as the convolution Bh of a matrix B of bits bk of the transmitted signal b with a channel vector h, each transmitted bit bk has a log-likelihood ratio L(bk|r) which is conditioned on the received signal r, and each transmitted bit bk is estimated as tanhÂ½L(bk|r); and choosing, for the estimated channel impulse response, a value of h for which C has a minimum value when the expected value E{|râˆ’{circumflex over (r)}|2} is taken over the bits bk as conditioned on r.