Patent ID: 6687288
Filing Date: 2004-02-03
Classification: H04B,H04L

Abstract:
A method of NEXT cancellation in a modem pool having a plurality of modems, where each modem has at least one FIR filter, each FIR filter for filtering signals from a transmitting one of said modems, each modem transmitting a signal having a plurality of contiguous signal blocks, the method comprising:providing a frequency response vector per FIR filter; for each corresponding one of said transmitting signal blocks for each of said modems: adapting the length of said signal block to equal the length of said frequency response vector; transforming said adapted signal block into the frequency domain, thereby generating a frequency-domain signal vector; for each of said modems and its at least one FIR filter; multiplying said frequency response vector of said FIR filter by a corresponding one of said frequency-domain signal vectors, thereby generating a filtered frequency-domain signal vector; adding said filtered frequency-domain signal vectors, thereby generating a combined filtered frequency-domain signal vector; transforming said combined filtered frequency-domain signal vector into the time domain, thereby generating a combined filtered time-domain signal vector; adapting the length of said combined filtered time-domain signal vector; and subtracting said adapted combined filtered time-domain signal vector from a received signal block generally corresponding in time to said transmitted signal block, thereby resulting in a received signal block from which NEXT has been at least partially cancelled.