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:
Jan. 19, 1999
Filed:
Nov. 29, 1996
Takatoshi Sugiyama, Yokohama, JP;
Masahiro Umehira, Yokohama, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A digital transmission apparatus is provided, by which the amount of transmission delay and circuit miniaturization can be realized in the case of using an FEC method together with a differential coding method. In the digital transmission apparatus, a digital signal to be transmitted is serial-to-parallel-converted into parallel n-channel signals; each signal is FEC-encoded and encoded signals are then differentially encoded; and a carrier is modulated by the parallel n-channel differentially-encoded signals to be transmitted as a 2.sup.n multi-level modulated signal. The signal is detected at the receiving side and parallel n-channel demodulated and decoded signals are output; FEC decoding is performed; and the parallel n-channel digital signals after FEC decoding is parallel-to-serial-converted. When block coding is used as an FEC method, parallel n-channel digital signals to be transmitted are respectively processed by block-encoding of the same logic; the parallel n-channel signals after encoding are differentially encoded; and a carrier is modulated by the parallel n-channel differentially-encoded signals to be transmitted as a 2.sup.n multi-level modulated signal. At the receiving side, parallel n-channel signals after detection are stored; syndrome data for detecting an error bit position for each signal is calculated; and based on the syndrome data, time-series detection of each error bit position is performed so as to correct the errors included in the stored signals.