J. O. Coleman

TITLE:

Modeling Finite-Memory Nonlinearity in Unit DAC Elements, Binary Storage Channels, and BPSK Data Channels

AUTHORS:

J. O. Coleman

ABSTRACT:

Spectral shaping of quantization noise can allow a few (or one) oversampled D/A converters restricted to two output levels, unit DAC elements, to replace high-resolution converters. In high-resolution or high-speed settings however, even the performance of systems with only two output levels can be limited by conversion-circuit nonlinearities that introduce quantization-noise intermodulation products into the signal band through nonlinear intersymbol interference (ISI). Nonlinear ISI also affects the communication and magnetic storage of data. Here a simple but very general model structure for such binary-in, analog-out nonlinearities is proposed. Curiously, its structure is that of a convolutional coder whose output bits are separately LTI filtered before being finally summed to form the analog output. The largest-energy filter responses have natural interpretations if this convolutional code is chosen carefully. One such code is presented here.

DOWNLOADABLE PREPRINT:

PDF (205 Kbytes),

STATUS:

Presented to the 17th European Conf. on Circuit Theory and Design (an IEEE conference), Cork, Ireland, Aug 29 - Sep 1, 2005.

DATE OF ENTRY:

March 2005. Updated May 2005 and September 2005.