Receiver unit in radio communication system
US4633484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1984 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Nov 23, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3818
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A receiver unit in a radio communication system in which a transmitter unit outputs transmission data, modulated in accordance with a multilevel QAM method and containing a leakage carrier by addition of a DC offset signal to either one of the quadrature components forming the transmission data, to the receiver unit through a transmission line, including: means for receiving the transmission data; means for branching a signal received at the transmission data receiving means into first and second signal components forming the multilevel QAM data, each including the leakage carrier having a phase difference of .pi./2 radian; first channel means for demodulating the first branched signal component and including a first synchronous detection circuit and a first discriminator; second channel means for demodulating the second branched signal component and including a second synchronous detection circuit and a second discriminator; and means for recovering the carrier including a control circuit, for cancelling a noise component contained in the output signal from either one of the first and second synchronous detection circuits and for providing only a DC component representing a phase …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.