Data receiver including hybrid decision feedback equalizer

A decision feedback encoder comprising:

• an analog to digital converter for converting an input signal into digital signals representing decision levels;
• a digital processing circuit responsive to said digital signals from the converter to provide a succession of symbol values;
• means for storing digital values of coefficients;
• digital to analog converters for converting said coefficients into corresponding analog values;
• and
• analog circuit means for forming a sum of the products of each of said symbol values with a respective one of said analog values to provide a feedback signal for the reduction of inter-symbol interference in said input signal.

A decision feedback encoder comprising:

• an analog to digital converter for converting an input signal into digital signals representing decision levels;
• a first digital processing circuit responsive to signals from the converter to provide a succession of symbol values;
• shift register means for storing a succession of said symbol values;
• means for storing a set of digital coefficients;
• a second digital processing circuit responsive to said symbol values to compute new values for said coefficients, said means for storing being coupled to said second digital processing circuit to store said new values for said digital coefficients;
• digital to analog converters for converting said digital coefficients into corresponding analog values;
• analog circuit means for forming a plurality of analog products, each product being the product of a respective symbol value and a respective one of said analog values;
• and
• analog circuit means for combining said products and for offsetting said input signal in accordance with the sum of said products to reduce inter-symbol interference in said input signal.

A system for providing a measure of inter-symbol interference related to data patterns, the system comprising:

• a decision feedback encoder for receiving encoded signals, the encoder comprising,
• an analog-to-digital converter for converting an input signal into digital signals, said digital signals representing decision levels;
• a signal processing circuit for processing said digital signals to produce a succession of symbol values and a set of coefficients;
• digital-to-analog converters for converting said coefficients into corresponding analog values;
• and
• analog circuit means for forming a sum of products of each of said symbol values with a respective one of said analog values to provide a feedback signal to reduce inter-symbol interference in said input signal.

A method for providing a measure of inter-symbol interference related to data patterns, the method comprising:

• receiving encoded signals using a decision feedback equalizer;
• converting an input signal into digital signals, said digital signals representing decision levels;
• processing said digital signals to produce a succession of symbol values and a set of coefficients;
• converting said coefficients into corresponding analog values;
• and
• forming a sum of products of each of said symbol values with a respective one of said analog values to provide a feedback signal to reduce inter-symbol interference in said input signal.