Equalization for partial-response systems

Abstract

The design of the equalization devices for a binary partial-response class-IV (PR-IV) system is discussed. A method is presented for the optimization of the analog filter, the sample-timing phase, and the digital filter, with the object of achieving minimum mean-squared error (MSE) between the FIR filter output signal and a PR-IV reference signal. For a given channel characteristic and fixed timing phase, the pole and zero locations of the analog filter and the coefficients of the digital filter are jointly optimized by using the conjugate gradient algorithm of R. Fletcher and M.J.D. Powell (1963). The joint optimum of the filter parameters and the timing phase is found by computing the minimum MSE as a function of timing phase. The minimum of this function defines the optimum phase, and the corresponding parameters the optimum filters.