PPM decoder utilizing drop-out location information
US5615223A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Apr 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10009
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of and apparatus for decoding data from positive and negative pulses of an encoded pulse train, e.g. a NRZ pulse train for PPM encoding, wherein the recorded data is subject to drop-outs and drop-ins. Data bits are decoded from valid positive and negative pulses exceeding positive and negative peak pulse thresholds. Drop-outs are identified in the encoded pulse train as a function of read out positive and negative pulse magnitudes not exceeding positive and negative thresholds, and drop-out flags are provided in lieu of the respective positive and negative pulses. Decoded data bit signs are stored in memory locations, and drop-out flags are stored in memory locations in relation to the stored data bit signs such that the beginning and/or end of a drop-out in the encoded pulse train is indicated. Drop-out flags are also stored in response to the occurrence of two successive valid positive pulses or two successive valid negative pulses in the pulse train. Additionally, drop-out flags are stored in response to the time out of an interval between successive positive or negative pulses. The drop-out flag may also be stored in a memory location in relation to the preceding decod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.