Adaptive equalization in the discrete time, discrete frequency, and Hadamard domains

Abstract

The adaptive equalization is considered of digital data transmitted over discrete linear channels exhibiting intersymbol interference in addition to additive noise. The data format is binary baseband, and the simulated channel is a typical lowpass channel. Least mean square equalization is developed in the discrete sequence (i.e. Walsh or Hadamard) domain utilizing a gradient projection method. Error performance and mean square error convergence of the algorithm are subsequently investigated, and further compared with comparable simulations in the time and discrete frequency domains. The equalizer structure assumes a tapped delay line transversal filter configuration.