Phase-encoded data signal demodulator
US4302845A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1980 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Feb 7, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0331
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A demodulator is described for demodulating phase-encoded data signals transmitted on a noisy communication channel, such as, for example, radio communication channels of a radio communication system. The demodulator includes a digital phase-locked loop for phase-locking to the mid-bit transitions of the phase-encoded data signal, which, in the preferred embodiment is encoded according to the well known Manchester coding format, and further includes demodulating circuitry for sampling the phase-encoded data signal a predetermind number of times, weighting the samples according to predetermined weighting factors, totalizing the weighted samples for each bit interval and comparing the totalized samples to a predetermined threshold value for ascertaining the logical state of each bit of the phase-encoded data signal. For example, if the magnitude of the totalized samples is greater than or equal to the threshold value, a logical one state may be provided for the decoded data signal, and, if the magnitude of the totalized samples is less than the threshold value, a logical zero state may be provided for the decoded data signal. In preferred embodiments of the present invention, the wei…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.