US 5,396,239 A · Data and forward error control coding techniques for digital signals

Abstract

Input values are data encoded for improved signal characteristics (e.g., limited maximum run length and limited cumulative DC-offset) so as to form "data codewords," and then a number of the data codewords, collectively referred to as a block, are error protection encoded, preferably using a conventional linear and systematic forward error control ("FEC") code, to yield an FEC code block. Preferably, an FEC code block is formed by generating a number of check bits or FEC bits equal to the number of data codewords in the block, and then concatenating one FEC bit and its binary complement with each data codeword, so that one FEC bit and its complement is interposed between each successive codeword.

Claims23

Dependent claims

An encoder, comprising:

A) sequence encoding means for encoding each of a plurality of bit sequences of a digital signal into a plurality of first codewords, each first codeword being characterized by a maximum run length below a pre-selected limit, and a cumulative DC-offset below a pre-selected limit, and
B) protection encoding means coupled to said sequence encoding means for receiving the first codewords therefrom and generating a plurality of error protection symbols from the first codewords.

A communication system comprising:

A) a transmitter section including:
(1) an encoder comprising
a. protection encoding means for receiving a plurality of bit sequences of a digital signal, and generating a plurality of error protection symbols from said bit sequences,
b. complement-forming means coupled to said protection encoding means for forming a binary complement for each of said error protection symbols, and
c. block-forming means coupled to said protection encoding means and said complement-forming means for forming a plurality of first blocks, each of said first blocks having a bit length and comprising a plurality of said bit sequences, said error protection symbols generated from said bit sequences, and said complements corresponding to said error protection symbols, such that each of said data words has a boundary disposed adjacent to a boundary of at least one other of said data words, said boundaries of adjacent data words having therebetween an error protection pair of symbols comprising one of said error protection symbols and the corresponding complement thereto,
(2) a transmitter for sending a communication signal including said first blocks over a channel;
and
B) a receiver section including:
(1) a receiver for receiving said communication signal, and thereby receiving said first blocks,
(2) framer means responsive to said error protection symbol pairs for determining said boundaries of said data words within said first blocks, thereby identifying said data words and said error protection symbols;
and
(3) protection decoding means coupled to said framer means for using said error protection symbols to detect any errors in said data words.

9 more elements

Dependencies are inferred from the claim text.

Data and forward error control coding techniques for digital signals

Life of this patent

Data and forward error control coding techniques for digital signals

Life of this patent

Abstract

Claims23