DocumentCode :
1055394
Title :
Impact of a New TWTA Linearizer Upon QPSK/TDMA Transmission Performance
Author :
Satoh, Gunkichi ; Mizuno, Toshio
Author_Institution :
Kokusai Denshin Denwa Company, Tokyo, Japan
Volume :
1
Issue :
1
fYear :
1983
fDate :
1/1/1983 12:00:00 AM
Firstpage :
39
Lastpage :
45
Abstract :
In transmitting a band-limited PSK/TDMA signal via satellite, the signal is distorted due to the nonlinearities of an earth station HPA and a satellite TWTA. To reduce the impairments due to these nonlinearities, a new TWTA linearizer, called a soft-limiter type linearizer (SL-LRZ), has been developed. The overall amplitude characteristic of a TWTA associated with an SL-LRZ is linear up to saturation and has a constant envelope beyond saturation. As to the AM/PM conversion characteristic, it has almost zero phase shift, irrespective of the operating point. The TWTA with SL-LRZ gives better bit error rate (BER) performance and less out-of-band emission (OBE) compared to cases where TWTA is operated by itself or with a conventional linearizer. In this paper, the impact of the new TWTA linearizer upon the transmission performance of a QPSK/TDMA signal is described. The transmission performance over a nonlinear satellite channel has been evaluated experimentally using a 120 Mbit/s QPSK modem and an INTELSAT V channel simulator.
Keywords :
Amplifier distortion; Phase-shift keying; Satellite communication, onboard systems; TDMA (time-division multiple-access); Time-division multiple-access; Traveling wave amplifiers; Degradation; Filters; High power amplifiers; Modems; Nonlinear distortion; Phase shift keying; Quadrature phase shift keying; Satellite ground stations; Shape; Time division multiple access;
fLanguage :
English
Journal_Title :
Selected Areas in Communications, IEEE Journal on
Publisher :
ieee
ISSN :
0733-8716
Type :
jour
DOI :
10.1109/JSAC.1983.1145900
Filename :
1145900
Link To Document :
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