Digital Pulse Position Modulation Communications System with Threshold Extension.
Abstract
A digital pulse position modulation (PPM) communications system with threshold extension including means in a radio receiver for achieving optimum coherent detection of a pulse position modulated communication signal comprising a coherent video detector coupled to the IF output of the radio receiver and a pulse repetition frequency loop locked to the detected video signals containing position modulation. The pulse repetition frequency loop includes a time discriminator, a filter, a voltage controlled oscillator, and a split gate generator providing a split gate not greater that the width of the applied video signal. The split gate is applied to the time discriminator resulting in the detected video signal being multipled by itself or coherently detected. A low pass filter is connected to the output of the discriminator to provide a demodulated communications analog or quasi-analog output signal such as a voice signal, transmitted to the receiver from a digitally coded PPM communications transmiter. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 16, 1984
- Accession Number
- ADD010757
Entities
People
- F. S. Gutleber
Organizations
- United States Department of the Navy