Experimental study of a modulation scheme for embedding data in DSB-AM

Author

Lockhart, G.B. ; Bayes, T. ; Mehdi, A.A.A. ; Al-Jalili, Y.O.

Author_Institution

Leeds Univ., UK

fYear

1988

Firstpage

310

Lastpage

313

Abstract

Methods of embedding data in conventional DSB-AM signals are of interest in a number of applications including radiodata services for HF sound broadcasting. The data signals carry information which can be used by specially equipped receivers for various display and control functions such as automatic retuning when the transmission frequency is changed. In the case of DSB-AM, frequency modulation of the carrier in addition to the usual envelope modulation can provide a data channel but unless the data rate is very small the modulated signal is likely to exceed its allocated bandwidth. Zero-synchronous modulation (ZSM) is a spectrally-efficient combined AM/FM scheme proposed by Lockhart and Al-Jalili (1982) which permits data to be embedded in DSB-AM without significantly increasing the bandwidth or distorting the envelope. An experimental transmitter/receiver system constructed to study the practical performance of ZSM is described and some results presented.<>

Keywords

amplitude modulation; data communication systems; radio broadcasting; radio systems; AM/FM scheme; DSB-AM signals; HF sound broadcasting; automatic retuning; bandwidth; carrier; data channel; data rate; data signals; envelope modulation; frequency modulation; radiodata services; transmitter/receiver system; zero-synchronous modulation; Amplitude modulation; Data communication; Radio broadcasting;

fLanguage

English

Publisher

iet

Conference_Titel

HF Radio Systems and Techniques, 1988., Fourth International Conference on

Conference_Location

London, UK

Print_ISBN

0-85296-358-0

Type

conf

Filename

7043