US Navy begins shift to digital telemetry
Abstract
The processing of the transistor-transistor-logic-compatible binary input for the new telemetry binary digital transmitters used by the U.S. Navy is discussed. The deglitching, voltage buffering, voltage offsetting, and low-pass filtering are addressed. The digital transmitter combines premodulation processing and modulation, eliminating the need for an external box. The problems involved in the introduction of encryption to a digital telemetry system are briefly discussed. Spectral responses for a test circuit with variable bit rates and two outputs are shown; for a digital transmitter, these signals are symmetrical with respect to the channel center. The center frequency is taken as the average of the steady-state one and zero conditions, and deviation symmetry is guaranteed. Comparisons with analog devices are made throughout.
- Publication:
-
Microwaves
- Pub Date:
- March 1983
- Bibcode:
- 1983MicWa..22...90R
- Keywords:
-
- Binary Codes;
- Digital Systems;
- Radio Telemetry;
- Radio Transmitters;
- Signal Processing;
- Ttl Integrated Circuits;
- Ultrahigh Frequencies;
- Analog Circuits;
- Channel Capacity;
- Data Transmission;
- Steady State;
- Transmission Efficiency;
- Communications and Radar