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:
Nov. 12, 1985
Filed:
Sep. 16, 1983
Katsuhiro Nakamura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Disclosed is an error correction system in which part of the data bits of first multilevel input data is differentially encoded to form second data comprising the differentially encoded data bits and the remainder data bits and converting the bit patterns of the second data into third data in two-dimensional multilevel signal space according to a predetermined transfer function. A transparent error-correcting code is derived from each of the different phases of the third data and appended to each different phase to thereby form fourth data which is then modulated upon a carrier in two-dimensional multilevel signal space for transmission to a receiver where the signal is demodulated to recover the fourth data. The appended error-correcting code is separated from each different phase of the fourth data. An error which might exist in the received data is corrected by the separated error-correcting code in respect of each phase. The bit pattern of the error-corrected data is reconverted to recover the original second data. One of the phases of the second data is differentially decoded to recover the original first data.