A 2 Mbit/sec modem at 70 MHz based on the Tamed Frequency Modulation (TFM) principle
Abstract
A tamed frequency modulation (TFM) digital phase modulation method modem was designed and realized for satellite communication experiments. The method offers possibilities for bandwidth and power efficiency, and the use of nonlinear amplifiers, which makes it apt for satellite and mobile radio communication. Normal and coherent quadrature modulators are described. The carrier wave regain, necessary for coherent detection, is achieved with a heterodyne phase locked loop. Measured bit error rate as a function of the signal to noise ratio is given.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- May 1984
- Bibcode:
- 1984STIN...8631815V
- Keywords:
-
- Digital Spacecraft Television;
- Frequency Shift Keying;
- Modems;
- Phase Shift Keying;
- Bandwidth;
- Bit Error Rate;
- Carrier Waves;
- Heterodyning;
- Nyquist Frequencies;
- Phase Detectors;
- Phase Locked Systems;
- Power Amplifiers;
- Power Efficiency;
- Signal To Noise Ratios;
- Electronics and Electrical Engineering