Delta modulator with pseudo constant modulation level

Details Delta modulator with pseudo constant modulation level Delta modulator with pseudo constant modulation level

1996-05-23

1998-08-04

Gaffin, Jeffrey A.

Coded data generation or conversion

Analog to or from digital conversion

Differential encoder and/or decoder

375242, H03K 1300

Patent

active

057900620

ABSTRACT:
The present invention is directed to delta modulation in which the modulation level is optimized to improve overall system performance. A delta modulator in accordance with the invention includes a step size controller having a overload detector, a step size generator and a modulation level regulator. The overload detector monitors the output serial bit stream and produces a signal indicative of whether overload conditions are present. The step size generator produces steps of varying sizes in response to an input signal. The modulation level regulator monitors the signal output from the overload detector and outputs a modulated signal when the overload detector output has reached at least a certain threshold level. The modulation level regulator output is received at the step size generator input.

REFERENCES:
patent: 3815033 (1974-06-01), Tewksbury
patent: 3949299 (1976-04-01), Song
patent: 4025852 (1977-05-01), Ching
patent: 4123709 (1978-10-01), Dodds et al.
patent: 4151517 (1979-04-01), Kelley
patent: 4646322 (1987-02-01), Flanagin et al.
patent: 4654815 (1987-03-01), Marin et al.
patent: 5187482 (1993-02-01), Tiemann et al.
IEEE Catalogue No. 75 CHO 971-2 CSCB; vol. III Instit. of Electrical & Electronics Engineers, Inc. ICC75; Signal Processing in SLC-40, A 40 Channel Rural Subscriber Carrier.
The Bell System Technical Journal, vol. 49, Mar. 1970, No. 3; Adaptive Delta Modulation with a One-Bit Memory, by N.S. Jayant.
Motorola Communication Device Data, Article 1, pp. 4-17-4-20.
Motorola Communication Device Data, MC34115, pp. 2-402-2-416.
Motorola Semiconductor Technical Data, MC3417; MC3418; MC3517; MC3518, pp. 2-101-2-118.
Harris Semiconductor, HC-55564 Continuously Variable Slope Delta-Modulator (CVSD), pp. 8-147-8-152, 8-144-8-146, 10-204-10-213 (1993).
Linear and Adaptive Delta Modulation, by J.E. Abate, Proceedings of the IEEE, vol. 55, No. 3, Mar., 1967.
The Application of Delta Modulation to Analog-to-PCM Encoding by David J. Goodman, The Bell System Technical Journal, vol. 48, Feb. 1969, No. 2.
Delta Modulation Codec for Telephone Transmission and Switching Applications, by R.R. Laane and B.T. Murphy, The Bell System Technical Journal, Jul.-Aug., 1970.
On Delta Modulation by David Slepian; The Bell System Technical Journal, vol. 51, Dec., 1972, No. 10.
Slope Overload Noise in Linear Delta Modulators With Gaussian Inputs; by L.J. Greenstein, The Bell System Technical Journal; vol. 52, No. 3, Mar., 1973.
Digital Coding of Speech Waveforms: PCN, DPCM, and DM Quantizers, by Nuggehally S. Jayant, Proceedings of the IEEE, vol. 62, No. 5, May 1974.
Double-Loop Sigma-Delta Modulation with dc Input, by Ning He, Federico Kuhlmann, and Andres Buzo; IEEE Transactions on Communications, vol. 38, No. 4, Apr. 1990.
Adaptive Delta Modulation for Companded PCM Coding and Decoding, by Dan C. Song, IEEE Transactions on Communications, May 1977.
Time-Shared Codecs for Multichannel Delta Modulation and Differential PCM, by Frank S. Boxall, IEEE Transactions on Communications, vol. COM-23, No. 3, Mar. 1975.
Linear, Nonlinear, and Adaptive Delta Modulation, Hans R. Schindler, IEEE Transactions on Communications, vol. COM-22, No. 11, Nov. 1974.
Multipurpose Hardware for Digital Coding of Audio Signals, by James D. Johnston and Davis J. Goodman, IEEE Transactions on Communications, vol. COM-26, No. 11, Nov. 1978.
Adaptive Prediction for Speech Encoding by Jerry D. Gibson, IEEE ASSP Magazine, Jul. 1984.
Arithmetic Ternary Operations on Delta-Modulated Signals and Their Application in the Realization of Digital Filters by D. Zrilic, A. Mavretic and M. Freedman; IEEE Transactions on Acoustics, vol. ASSP-33, No. 3, Jun. 1985.
Embedded Delta Modulation by Ian James Wassell, David J. Goodman, and Raymond Steele, IEEE Transactions on Acoustics, vol. 36, No. 8, Aug. 1988.
A Discretely Adaptive Delta Modulation Codec by K. Niwa, A. Yukawa, and A. Tomozawa, IEEE Transactions on Communications, vol. COM-29, No. 2, Feb. 1981.
A Variable-Step-size Robust Delta Modulator by C. Song, J. Garodnick, and D. Schilling, IEEE Transactions on Communications, vol. COM-19, No. 6, Dec. 1971.
Nearly Instantaneous Companding for Nonuniformly Quantized PCM, by Donald Duttweiler, IEEE Transactions on Communications, vol. COM24, No. 8, Aug. 1976.
Variable Bandwidth Adaptive Delta Modulation, by J.O. Smith and J.B. Allen, The Bell System Technical Journal, vol. 60, No. 5, May-Jun. 1981.
A Delta Modulation Filter for Speech-Type Signals by Dimitrios P. Prezas and Joseph L. Locicero, IEEE Transactions on Communications, vol. COM28, No. 6, Jun. 1980.
A Low Delay 16 kb/s Speech Coder by Vasu Iyengar and Peter Kabal, IEEE Transactions on Signal Processing, vol. 39, No. 5, May, 1991.

Affiliated with

Also associated with

Rating

Delta modulator with pseudo constant modulation level does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Delta modulator with pseudo constant modulation level, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Delta modulator with pseudo constant modulation level will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1182132