Generalised ENCAP-4/sup N/ digital modulation technique

Author

Gusmão, A. ; Esteves, N.

Author_Institution

Centro de Analise e Processamento de Sinais, Univ. Tecnica de Lisboa, Lisbon, Portugal

Volume

137

Issue

2

fYear

1990

fDate

4/1/1990 12:00:00 AM

Firstpage

78

Lastpage

84

Abstract

A class of encoding schemes for generating offset-QPSK-type signals is introduced. Each scheme supposes the specification of 4^N functions directly related to the eye-diagrams of the in-phase and quadrature signal components. The main features of the proposed modulation format are described, namely its connections with well known modulation formats. It is shown that the new signal design method provides a unified representation of all OQPSK-type (MSK-type) signals recommended so far (IJF-OQPSK, TFM, GMSK, XPSK, 12PM3X, etc.), and allows the generation of a large variety of new signals. The conditions under which a linear filter and a nonlinear amplifier preserve the proposed format are discussed. It is also pointed out that, in most practical situations, the encoding rules can be modified so as to allow the transmission of a nonlinearly amplified signal of the proposed class, having a variable envelope.<>

Keywords

band-pass filters; digital radio systems; encoding; minimum shift keying; phase shift keying; power amplifiers; MSK-type; digital radio systems; encoding schemes; eye-diagrams; generalised ENCAP-4/sup N/ digital modulation; in-phase signal components; linear filter; nonlinear amplifier; offset-QPSK-type signals; quadrature signal components; signal design method; variable envelope;

fLanguage

English

Journal_Title

Communications, Speech and Vision, IEE Proceedings I

Publisher

iet

ISSN

0956-3776

Type

jour

Filename

218052