Digital Amplitude-Phase Keying with M-Ary Alphabets

Author

Thomas, C. Melvil ; Weidner, Martin ; Durrani, S.H.

Author_Institution

TRW Systems, Inc., Redondo Beach, Calif., USA

Volume

22

Issue

2

fYear

1974

fDate

2/1/1974 12:00:00 AM

Firstpage

168

Lastpage

180

Abstract

Signal sets employing amplitude and phase keying (APK) with large alphabets conserve bandwidth and do not require as high a signal-to-noise ratio (SNR) as phase-shift keying (PSK). Twenty-nine empirically generated APK sets with $M$ -ary alphabet sizes from 4 to 128 are investigated to determine optimum designs. Selected sets are compared on the basis of a symbol-error-probability bound for both average and peak SNR. Results are presented in the form of symbol error curves. The degradation caused by nonlinearities in a typical TWT amplifier is examined. The effects of AM-AM and AM-PM distortion on APK are presented as a function of power backoff for single-carrier operation (when APK is at the greatest disadvantage compared with PSK). Modem implementation methods, including carrier phase reconstruction techniques, are discussed for basic APK designs.

Keywords

APK signals; Satellite communications; Bandwidth; Data communication; Degradation; Error probability; Intersymbol interference; Modems; Nonlinear distortion; Phase shift keying; Satellites; Signal design;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/TCOM.1974.1092165

Filename

1092165