IF DBPSK modems design for command link and telemetry systems
Abstract
The modular system of a 70-MHz IF differential binary phase shift keying (DBPSK) modem is described together with the design procedure and consideration of the modem with Costas loop. A design example is presented, and the implementation of this design is described. Also evaluated is the modem's bit error rate performance. The false lock of Costas loops caused by arm filter distortion of the data can be a problem during loop acquisition; to avoid this problem, Cahn's (1977) method for frequency acquisition improvement, which requires no additional circuitry, was employed.
- Publication:
-
ITC/USA/'86; Proceedings of the International Telemetering Conference
- Pub Date:
- 1986
- Bibcode:
- 1986isa..conf..551H
- Keywords:
-
- Bit Error Rate;
- Modems;
- Parallel Processing (Computers);
- Phase Shift Keying;
- Systems Engineering;
- Telemetry;
- Automatic Gain Control;
- Bandpass Filters;
- Bit Synchronization;
- Crystal Oscillators;
- Hardware;
- Voltage Controlled Oscillators;
- Communications and Radar