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. 10, 1995
Filed:
Sep. 21, 1993
Toshiya Todoroki, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A data transmission system for transmitting data by way of encoding modulation has a transmitter including a convolutional encoder and a receiver including a Viterbi decoder. For the case when the bit rate is changed, the data transmission system employs the same modulator/demodulator, and effectively utilizes a frequency band which is unchanged. The transmitter includes a selector for periodically switching two output signals, one having a redundant bit produced from the convolutional encoder and the other having an information bit instead of a redundant bit, resulting in a variable encoding ratio. The Viterbi decoder decodes a designated signal from the convolutional encoder. The receiver also includes a circuit for reconstructing branch metrics only when a received symbol composed of only an information bit without a redundant bit is supplied, and circuits for regenerating a information bit which is added without depending on the encoding.