Replacing unencoded PCM/PSK with convolutional encoded PCM/PSK
Abstract
The ideal relationships for a class of convolutional encoded PSK links are described, and pitfalls to avoid when applying these techniques are noted. Rate 1/2 constraint length 7 convolutionally encoded PCM/QPSK techniques are shown to offer significant Bit Error Probability versus Signal to Noise Performance improvements as compared to unencoded PCM/BPSK, without requiring increase in system bandwidth. Test results are used to demonstrate the critical effects of degradation in modem signal to noise performance. The fundamentals of BPSK/QPSK modulation are discussed, and it is shown how convolutional encoding/decoding affects such systems considerations as bandwidth, Signal to Noise threshold, and Bit Error Probability, as well as carrier and bit clock stability.
- Publication:
-
International Telemetering Conference
- Pub Date:
- 1975
- Bibcode:
- 1975isa..conf..432L
- Keywords:
-
- Data Transmission;
- Error Correcting Codes;
- Phase Shift Keying;
- Pulse Code Modulation;
- Signal To Noise Ratios;
- Transmission Efficiency;
- Bandwidth;
- Error Analysis;
- Modems;
- Performance Prediction;
- Probability Theory;
- Space Communications, Spacecraft Communications, Command and Tracking