Method of determining levels at given frequencies of a VF signal

Details Method of determining levels at given frequencies of a VF signal Method of determining levels at given frequencies of a VF signal

1992-09-18

1994-10-04

Dwyer, James L.

Telephonic communications

Supervisory or control line signaling

Signal receiver

379283, 36472409, G06F 1531, H04M 300

Patent

active

053533445

ABSTRACT:
A dialing receiver (1) for determining multifrequency dialing signals on an incoming signal in a telecommunication switching system, including a sampling circuit (4) for taking N values of the incoming signal at a given sampling rate, where N is a positive integer; a zero value generator circuit (6) for supplementing at the given sampling rate the N samples with M successive zero values so as to yield N+M values, where M is a positive integer; a discrete Fourier transformation circuit (7) for performing a discrete Fourier transform (DFT) of said N+M values in accordance with the Goertzel algorithm; and a result evaluating circuit (8) for directly evaluating the results of the DFT processing of the N+M values without interpolation so as to determine the identity of the multifrequency dialing signals.

REFERENCES:
patent: 3875347 (1975-04-01), Alaily
patent: 4460806 (1984-07-01), Canniff et al.
patent: 5119322 (1992-06-01), Stroobach
patent: 5163050 (1992-11-01), Cromack
patent: 5214693 (1993-05-01), Chujo
ADSP-2100 Family Applications Handbook, vol. 2, 6-22 to 6-25 Analog Devices Inc.
Goertzel G.: "An Algorithm For the Evaluation of Finite Trigonometric Series," American Mathematics Monthly, vol. 5, 1958.
Digital Signal Processing Applications with the TMS320 Family: pp. 552-555.
Verdun F. R., Giancaspro C., Marshall A. G., "Effects of Noise on the `Exact` Interpolation of Fast Fourier Transform Spectra", Applied Spectroscopy, vol. 42, No. 5, 1985 pp. 715-717.
"Digital MF Receiver Using Discrete Fourier Transform", Ivan Koval and George Gera, IEEE vol. Com-21, No. 12, Dec. 1973, pp. 1331-1335.
"Digital Integrated Circuit SM301-A4 with Special Filter for Processing Inband Dual-Tone Switching Signals," K. D. Rother and F. V. Sichart, pp. 256-260 Seimens Forsch.-u.Entwickl.-Ber. Bd. 8 (1979) Nr. 5, Springer-Verlag 1978.
International Conference on Acoustics, Speech and Signal Processing, bd 2, 23, Mai 1989, Glasgow, Scotland Seiten 1334-1137, XP90308 S. L. Gay et al. `Algorithms for Mutlti-Channel DTMF detection for the WE DSP32 family` *das ganz Dokument*.
EDN Bd. 30, Nr 6, 1985, Bostonm, Mass.-USA, Seiten 205-220 P. Mock `Add DTMF generation and Decoding to DSP-uP Designs` *das ganz Document*.

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