Title :
A new method of television signal deghosting
Author :
Abreu, E. ; Mitra, S.K. ; Marchesani, R.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
Abstract :
A multipath channel in television broadcasting can result in overlaid images (ghosts) or distorted noisy images on the display and is a major problem to be overcome. We propose a method to equalize the multipath distortion for the case of digital transmission and nonminimum phase channels. The method employs noncausal allpass recursive filters operating in reversed time followed by a decision feedback equalizer (DFE). It does not require the computation of zeros of the channel impulse response, and the channel noise level is not enhanced. The equalized impulse response is such that, in most cases, the first nonnegligible sample has the largest magnitude, as appropriate for DFE decoders. Computer simulation results verifying the proposed approach are included
Keywords :
all-pass filters; decision feedback equalisers; decoding; digital communication; digital television; filtering theory; multipath channels; recursive filters; television broadcasting; television interference; transient response; video coding; DFE; DFE decoders; PSK; TV display; channel impulse response; channel noise level; computer simulation results; decision feedback equalizer; digital transmission channels; distorted noisy images; equalized impulse response; multipath channel; multipath distortion equalisation; noncausal allpass recursive filters; nonminimum phase channels; overlaid images; reversed time; television broadcasting; television signal deghosting; video coding; Computer displays; Computer simulation; Decision feedback equalizers; Decoding; Finite impulse response filter; Multipath channels; Noise level; Phase distortion; TV broadcasting; Transfer functions;
Conference_Titel :
Image Processing, 1994. Proceedings. ICIP-94., IEEE International Conference
Conference_Location :
Austin, TX
Print_ISBN :
0-8186-6952-7
DOI :
10.1109/ICIP.1994.413320