Minimization of Channel Impulse Noise using Digital Smear Filter

The paper describes a digital smear-desmear technique (SDT) based on polyphase multilevel sequences of unlimited length with good autocorrelation properties. A design procedure for digital implementation of SDT is defined and sequences with power efficiency higher than 50% are generated. These sequences are applied to the design of digital smear/desmear filters and combined with uncoded and coded ITU-T V.150.1 communication systems. The impulse noise is modeled as a sequence of Poisson arriving delta functions with gaussian amplitudes. The impulse noise parameters are computed from experimental data. Simulation results shows that the SDT filter design method yields a significant improvement in bit error rates for both systems subject to impulse noise, relative to systems with no SDT. The technique also completely removes the error floor caused by impulse noise.