A fast adaptive equalizer structure for voiceband communication link

A new equalizer structure that speeds up the convergence rate of the decision feedback equalizer (DFE) is presented. It consists of a prefilter, a feedforward filter and an error prediction filter. The prefilter shapes the spectral density of the received data in order to reduce the eigenvalue spread. The feedforward filter equalizes the channel distortion. The error prediction filter cancels intersymbol interference and suppresses colored noise. Simulation results showing that the structure converges two to three times faster than the conventional DFE and has lower mean square error are reported. The DFE is well suited for equalizing slowly time-varying channels with moderate signal-to-noise ratio and for multipoint data transmission