Carrier recovery systems for arbitrarily mapped APK signals
Abstract
This paper introduces new carrier recovery techniques for general amplitude-phase keying (APK) modulation signals. The APK's include not only normal QAM but also arbitrarily mapped APK's, including an unsymmetrical APK. Difficulty in phase error detection due to signal mapping complexity, undesirable stable-lock point existence, and the contradiction between a fast acquisition and an accurate steady state performance can be overcome. For that purpose, an acquisition mode and a steady-state mode are used. Furthermore, read-only memories (ROM) are used for recognizing various system states. Random sampling controlled PLL noise performance and acquisition mode carrier recovery circuit pull-in performance with hysteresis property was obtained.
- Publication:
-
IEEE Transactions on Communications
- Pub Date:
- October 1982
- Bibcode:
- 1982ITCom..30.2385M
- Keywords:
-
- Amplitude Modulation;
- Carrier Frequencies;
- Phase Error;
- Phase Shift Keying;
- Signal Processing;
- Tracking Problem;
- Hysteresis;
- Performance Prediction;
- Phase Error;
- Random Sampling;
- Steady State;
- Task Complexity;
- Electronics and Electrical Engineering