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:
Oct. 31, 1989
Filed:
Dec. 28, 1987
Michio Shimada, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
For use in decoding received code symbols corresponding to original code symbols consisting of original information symbols and original redundancy symbols and comprising a sequential decode controller (45) responsive to the received code symbols for producing a sequence of presumed information symbols corresponding to the respective original information symbols, an encoder replica (46, 47) responsive to the presumed information symbols for producing presumed code symbols consisting of the presumed information symbols and presumed redundancy symbols corresponding to the respective original redundancy symbols, and a likelihood calculator (48) for calculating likelihoods which the presumed code symbols have relative to the respective received code symbols, a decoder comprises a position counter (61) for counting position counts for the respective presumed information symbols in the sequence and a modifier (81) for giving a predetermined value, such as zero, to the likelihoods calculated for the respective presumed redundancy symbols until the position counts reach a predetermined count after initialization of the position counter. The position counter is initialized on dealing with buffer overflow of at least one buffer used in the decoder, such as a buffer (41, 43) for the received code symbols. Preferably, the predetermined count is equal to the number of presumed information symbols held at a time in the encoder replica for use in producing each presumed redundancy symbol.