Data compression using a nested hierachy of fixed phrase length static and dynamic dictionaries
US7982636B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2009 |
| Grant date | Jul 19, 2011 |
| Priority date | — |
| Expiry date | Sep 23, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/3088
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention describes lossless data compression/decompression methods and systems. A random access memory (RAM) operates as a static dictionary and includes commonly used strings/symbols/phrases/words. An input buffer operates as a dynamic dictionary and includes input strings/phrases/symbols/words. A set-associative cache memory operates as a hash table, and includes pointers pointing to the commonly used strings/symbols/phrases/words in the static dictionary and/or pointing to one or more of the input strings/phrases/symbols/words in the dynamic dictionary. Alternatively, the set-associative cache memory combines the dynamic dictionary, the static dictionary and the hash table. When encountering a symbol/phrase/string/word in the static or dynamic dictionary in an input stream, a compressor logic or module places a pointer pointing to the symbol/phrase/string/word at a current location on the output stream. The hash table may include phrases/symbols/strings/words and/or pointers pointing to phrases/symbols/strings/words.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.