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:
Jun. 24, 1986
Filed:
Apr. 14, 1983
George D Forney, Jr, Cambridge, MA (US);
Codex Corporation, Mansfield, MA (US);
Abstract
An improvement to a modulation system of the kind in which the encoder selects a codeword corresponding to a plurality of modulation signal points on the basis of a block of digital data, the available codewords for a given block being independent of the signal points corresponding to the codeword selected for any other block. In the improvement a constellation of available signals comprises groups with equal numbers of signals, and an encoder is arranged so that the group from which at least one signal point for a block is drawn depends on the group from which at least one other signal point for the block is drawn. In another aspect, the constellation includes inner signals and outer signals, one bit of data determines whether any of the signal points will be outer signals, and if so at least one other bit determines which will be an outer signal point.