A predictive adaptive delta modulator

A method is surveyed for telephone communication using a predictive adaptive delta modulator. This method is based on an estimation of the input waveform and an encoding of the signal into a digital sequence. The Kalman Filter does this estimation to filter out some of the noise, thus increasing the fidelity of the output to the original signal. The adaptive delta modulator does the encoding and allows the digital output to be reconstructed by a decoder which is identical to the feedback portion of the encoder. In implementing the adaptive delta modulator, a bi-state quantizer and tri-state quantizer are presented for comparison. Since the grannular region difficulties can be eliminated by the tri-state quantizer, the tri-state quantizer ADM provides a better stability. The present design also consists of a predictor which is based on the theory of a Taylor series expansion in order to match the overload rate whenever the signal slope becomes too sharp. The results indicate that the present design is suitable for implementation when the incoming messages are highly correlated-implying rapid signal sampling.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1977

Author dc:creator

• Ju, Yuh-tai

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/64043

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/64043