An automatically controlled predistorter for multilevel quadrature amplitude modulation
Abstract
In digital microwave transmission, the nonlinear characteristics in a high power amplifier, such as a TWT (traveling-wave tube), inhibit efficient output use. This note introduces a new predistorter control technique, and assesses the nonlinear compensation capability of a third-order predistorter incorporating this technique. Concerning 16-QAM (quadrature amplitude modulation), a 10 dB reduction in out-of-band emission and larger than 8 dB C/N improvement with respect to symbol error rate can be achieved at 3 dB TWT average output power backoff.
- Publication:
-
IEEE Transactions on Communications
- Pub Date:
- May 1983
- Bibcode:
- 1983ITCom..31..707N
- Keywords:
-
- Amplitude Modulation;
- Feedback Control;
- Microwave Transmission;
- Power Amplifiers;
- Signal Distortion;
- Traveling Wave Amplifiers;
- Carrier To Noise Ratios;
- Digital Systems;
- Error Analysis;
- Nonlinear Systems;
- Performance Prediction;
- Quadratures;
- Transmission Efficiency;
- Electronics and Electrical Engineering