Correlative phase modulation for fixed satellite services, volume 1 (phase 1)
Abstract
The feasibility of correlative phase modulation (CPM) for fixed satellite services was studied. With CPM for the Earth station transmitter a saturated amplifier can be used and there is no need for any transmitter RF filtering. A binary scheme (tamed frequency modulation or a raised cosine shaping) and a quaternary scheme (correlative phase shift keying or a raised cosine shaping), both with modulation index 0.5 are discussed. The binary scheme offers a bandwidth efficiency approaching 1.4 bits/sec/Hz, (satellite) power efficiency similar to QPSK and a simple implementation with a QPSK-like receiver. The quaternary scheme offers a slightly lower bandwidth efficiency (satellite) power efficiency 2 dB better than for QPSK, but requires a more complex implementation, while the maximum bitrate is limited to 8 Mb/sec with today's technology and to 25 Mb/sec in the near future.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1983
- Bibcode:
- 1983STIN...8417465M
- Keywords:
-
- Correlators;
- Phase Modulation;
- Phase Shift Keying;
- Spacecraft Communication;
- Bandwidth;
- Digital Systems;
- Feasibility Analysis;
- Power Efficiency;
- Time Division Multiple Access;
- Communications and Radar