Digital signal coding/decoding apparatus, digital signal coding apparatus, and digital signal decoding apparatus
US5381143A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1993 |
| Grant date | Jan 10, 1995 |
| Priority date | — |
| Expiry date | Sep 8, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B14/046
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A digital signal processing system comprising a compressor, an expander and a scale-down circuit. The compressor includes non-block frequency analyzer that frequency analyzes the digital input digital signal, without dividing it into block, to provide a frequency range signal in each of plural frequency ranges. A block frequency analyzer divides the frequency range signals into blocks and performs a block frequency analysis of each block of the frequency range signals to provide a block of spectral coefficients. A quantizer quantizes the block of spectral coefficients from the block frequency analyzer to provide a block of a compressed signal. The expander includes a block frequency synthesizer that performs a block frequency synthesis to transform, from the frequency domain to the time domain, the spectral coefficients in each of the frequency ranges in each block of the compressed signal to provide, in each of the frequency ranges, a block of a reproduced frequency range signal. A non-block frequency synthesizer synthesizes the reproduced frequency range signals, without dividing them into blocks, to provide the digital output signal. Finally, the system includes a scale-down cir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.