ULTRA HIGH SPEED DATA MODEM.
Abstract
This report describes a study of the data modem techniques required to transmit 9,600 bits per second over a 3 KHz telephone line. Particular emphasis is placed on adaptive equalization of the channel at the receiver. A minimum rms error, correlation-type equalizer, is described and evaluated in a computer analysis. A breadboard model of the complete modem was built and tested over a schedule 4B telephone line. Error rates of 3 x 10 to the minus 4th power were achieved at 9,600 bits per second and signal-to-noise ratio of 30 db. Specific problem areas were discovered in regard to the synchronization of the receiver timing, the relationship of the signal sample timing to the channel pulse response, and internal noise. A less specific problem is the reduction in modem performance from that predicted by the analysis. Conclusions are that the modem is feasible but requires further development to correct problem areas and realize the full potential of the approach. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1967
- Accession Number
- AD0820802
Entities
People
- George K. Prentiss
- Harold G. Sullivan
Organizations
- Honeywell International, Inc.