Digital radio having improved modulation and detection processes
US5857003A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1995 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Dec 14, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2272
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
There is provided a detection process for a digital radio which receives a multistate baseband signal comprising removing the low frequency information content of the baseband signal and subsequently restoring the low frequency information content to provide a conditioned baseband signal for detection so as to provide automatic frequency control for the radio on a manner avoiding loss of the low frequency information content of the baseband signal. This is accomplished by removing the low frequency information content of the baseband signal by high pass filtering to provide a filtered baseband signal, decoding the filtered baseband signal to provide decoded information signals in digital form, converting the decoded digital information signals to analog information signals, low pass filtering the analog information signals to recover the low frequency information content and adding the low pass filtered analog signal to the baseband signal to provide a conditioned baseband signal for detection wherein the conditioned baseband signal contains the low frequency information content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.