Synchronizer for frequency hopping receiver
US4023103A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1976 |
| Grant date | May 10, 1977 |
| Priority date | — |
| Expiry date | Jan 26, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04K1/003
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A receiver of a fast frequency hopping (FFH) system is synchronized with a ending transmitter in three phases from a starting condition where the frequency hopping local signal leads the received signal prior to synchronization. During the first phase, the difference frequency of a frequency hopping received signal and the frequency hopping local signal is monitored for IF during each FFH period. The FFH periods are grouped; when there is IF during all the periods of a group, the first phase terminates; however, until this condition is met, the local frequency is set back one FFH period for each group of periods. Then in the next phase, the IF in the two halves of each FFH period is compared to ascertain whether more of the leading half or more of the trailing half of each FFH period has the IF and the phase of the local signal is adjusted until the phase difference between the frequency hopping local signal and the frequency hopping received signal is less than a predetermined minor fraction of an FFH period. Then in the following phase, two additional local signals, the same as, the one local signal but phase advanced and phase retarded, respectively, by the same minor fraction o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.