The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 24, 1977
Filed:
Oct. 14, 1975
Yau-Chau Ching, Morganville, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
The idle-channel noise of a delta modulator is controlled by controlling the relative step size imbalance, 0. The instantaneous magnitude of the delta modulator output signal is converted to a multibit word and a second multibit word, representing a predetermined number, N, is subtracted therefrom. The dc component of the difference word is converted to analog form, amplified and inverted, and fed back to the delta modulator input stage. As a result, .theta. .apprxeq. -N. The delta modulated signal may be converted to a pulse-code modulated (PCM) signal using a digital integrator having a leak, .beta., in which case .theta. .apprxeq. -.beta.N. At the same time, the dc component of the PCM signal is advantageously reduced substantially to zero.