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:
Mar. 07, 1995
Filed:
Dec. 15, 1993
Masaru Setoguchi, Fussa, JP;
Takashi Akutsu, Akishima, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
The lower significant n bits of a first differential value between adjacent sampled values of a sampled received signal are cut off to provide a second differential value, which is then subjected to adaptive quantization to thereby provide data compression. When this data is expanded, the second differential value decoded from the adaptive quantized value is sequentially accumulated by 2.sup.n times at a period corresponding to 1/2.sup.n of the sampling period of the received signal. As a result, a quantizing error (quantization noise) per sampling of the received signal is dispersed in 2.sup.n periods to thereby provide an improved acoustic S/N ratio. When the first differential value of the received signal is quantized, when the lower significant n bits of the first differential value are cut off, and when the resulting signal is subjected to adaptive quantization, the resulting respective quantizing errors are fed to corresponding values processed next. Thus, accumulation of the quantizing errors is prevented.