New multifrequency ternary signals: first period frequency response measurement

• Published in: IEEE transactions on instrumentation and measurement 1998-10, Vol.47 (5), p.1311-1315
• Main Authors: Henderson, I.A., McGhee, J.
• Format: Article
• Language: English
• Subjects: Binary sequences; Condition monitoring; Frequency estimation; Frequency response; Frequency shift keying; Signal design; Signal generators; Signal processing; System identification; Testing
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/19.746602

This paper introduces a new set of multifrequency ternary sequence (MTS) signals. They are MTS octave signals, which are designed by frequency shift keyed (FSK) modulation so that two separate parts of a frequency response are examined by one test signal. One of these signals is a new five-octave FSK MTS signal which is described by a total of 64 symbols. This is half the number of symbols required by the equivalent five-octave Van den Bos multifrequency binary sequence (MBS) signal. There are four, five, six, etc., octave FSK MTS in the set, all of which have one important advantage over an equivalent MBS signal. The switch-on transient is usually eliminated during the system identification of most systems by these signals. If it is not, the measurement code may be rearranged in an asymmetrical form to further minimize the switch-on transient during the first period of the signal. This means that two sets of accurate frequency estimates are obtained immediately after the first period of these novel signals. During this first period, when these signals are generated with a symmetrical code, a useful multifrequency measurement in the form of a data pattern may also be obtained. It may be used to condition monitor two separate parts of the frequency response of a system. The advantages of the five-octave FSK MTS test signal are illustrated with the aid of a recently developed data measurement toolbox using a simulated process with three lags.