System and method for generating many ones codes with hamming distance after precoding
US6084535A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1997 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Jan 30, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/31
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system comprises an encoder, a precoder, a PRML channel, a detector, and a decoder. An input signal is received by the encoder. The encoder generates a code string by adding one or more bits and outputs the code string to the precoder. The encoder applies encoding such that the code string after passing through the precoder has a Hamming distance greater than one to eliminate error events with a small distance at the output of the PRML channel. The present invention also provides codes that after precoding have Hamming distance of 2 and 0 mod 3 number of ones. These codes when used over a PRML channel in an interleaved manner preclude +/-( . . . 010-10 . . . ) error events and error events +/-( . . . 01000-10 . . . ). The code string also has a predetermined minimum number of ones at the output of the PRML channel to help derive a clock from the input signal. The encoder provides a "systematic" encoding scheme in which for many code strings the encoded bits are the same as the input bits used to generate the encoded bits. This systematic approach of the present invention provides an encoder that is easy to implement because a majority of the bits directly "feed through" and non-t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.