Reliability-weighted analog threshold decoder

摘要

Reliability weighting is provided in the input and/or feedback paths of an analog threshold decoder to achieve additional coding gain. Examples of the reliability weighting function for a bipolar signalling system (.+-.A volts), a receive voltage v and Gaussian noise having a variance &sgr;.sup.2 are R=tanh (vA/&sgr;.sup.2), R=tanh (1.6 v/A), and a linear transformation having voltage clamps at .+-.1 volt. In the latter case, the gain of the linear transformation in the feedback weighting function may be n times that of the input weighting function, where n is the number of estimates involves in the output.