Process of selectively protecting information bits against transmission errors
US5850403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 12, 1996 |
| Grant date | Dec 15, 1998 |
| Priority date | — |
| Expiry date | Nov 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/63
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Based on the sequence of the information bits to be transmitted, the coder forms a second sequence of bits c.sub.n, which includes a redundant subset. A differential coding of the form d.sub.n =c.sub.n .sym.d.sub.f(n) with f(n)<n produces a third sequence of bits d.sub.n. The signal sent represents the bits of the third sequence in a specified order. Having obtained likelihood data r.sub.n associated with the bits d.sub.n, the receiver calculates estimates of the bits c.sub.n of the redundant subset as a function of the sign of r.sub.n .multidot.r.sub.f(n). By exploiting the redundancy, the receiver can detect the bits c.sub.n of the subset having erroneous estimates, and rectify the sign of the less reliable of the two associated likelihood data items r.sub.n and r.sub.f(n). The other bits c.sub.n ' of the second sequence then benefit from additional protection if there is at least one bit c.sub.n of the redundant subset such that n'=f(n) or f(n')=n or f(n).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.