Apparatus for encoding and decoding binary data in a modified zero modulation data code
US3995264A · kind A · utility
28Cited by
2References
8Claims
0Family size
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Key dates
| Filing date | Nov 1, 1974 |
| Grant date | Nov 30, 1976 |
| Priority date | — |
| Expiry date | Nov 1, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/4025
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for processing data employs a modification of a zero modulation code. The zero modulation code has a waveform that is symmetrical about a zero signal level within narrow defined limits. Each data digit, 1 or 0, is encoded into two NRZI digits. A relaxed run length limitation allows use of a (d,k) code of (1,4), where (d) is the minimum number of 0 digits between 1 digits and (k) is the maximum number of 0 digits between 1 digits, without violating the frequency and charge constraints. Only five charge states and only one bit lookahead is needed in order to encode data in the (1,4) code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.