Method for correcting errors from a jamming signal in a frequency hopped spread spectrum communication system
US5793795A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Dec 4, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/10
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A selective call communication system (10) has a selective call device (100) for transmitting a frequency hopped spread spectrum signal (320) encoded as Reed Solomon code words and modulated as a four-level frequency shift keying (4FSK) signal. A base site transceiver (156) receives the signal on a plurality of narrow band channels. A digital signal processor (DSP)(152) performs a fast fourier transform on the signal to generate frequency samples. The DSP (152) has a comparator (342) that compares an 4FSK symbol to a predetermined threshold, a determinator (344), in response to the comparator (342), determines when there is an interference signal jamming the narrow band channel, an erasure marker (346) marks a position in the Reed Solomon symbol determined to be jammed as an erasure and an error correcting code (348) corrects errors in the Reed Solomon code words marked with erasures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.