OFDM receiver includes digital filter

摘要

An orthogonal frequency division multiplex (OFDM) system, e.g. for a telephone subscriber twisted pair loop, includes a transmitter for generating sets of time division samples in respective channels corresponding to an input data sequence comprising a series of bits, and a receiver coupled to the transmitter via the transmission path. The receiver incorporates a time variant digital filter 35 having a plurality of elements one for each said channel, and Fourier transform means 352 for recovering the data stream from the outputs of said filter elements. The time variant digital filter comprises a set of wavelet filters one for each transmission channel and whose tap weights are determined so as to provide specific interference rejection.