THEORETICAL DISCUSSION OF DIPHASE TRANSMISSION
Abstract
The problem of sending many communication channels over a single cable for relatively great distances has long been one of the primary problems in military communications. A theoretical evaluation is permitted of a digital modulation approach that can be used to greatly improve PCM transmission over Cable, CX-4245. The present cable transmission system consists of attended repeater points every 40 miles with unattended repeater points every mile. These repeaters must carry out total pulse regeneration for signals at a pulse rate of 2.304 megabits per second. The present modulation approach, which is used to send PCM over a cable, is called dipulse and has a variety of deficiencies associated with its realized system. Some of these include accumulation of timing jitter, relative sensitivity to noise, and expense of the unattended repeaters. The use of diphase modulation is proposed in place of dipulse with no change in repeater spacing or pulse transmission frequency. A differential diphase repeater was subjected to extensive theoretical analysis. Dipulse and diphase systems were compared with respect to their power density spectrum, detectability, and tolerance to noise and timing extraction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1963
- Accession Number
- AD0421519
Entities
People
- L. U. Dworkin
Organizations
- United States Army Communications-Electronics Command