Baseband signal carrier recovery of a suppressed carrier modulation signal
US6707863B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1999 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | May 4, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3809
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A multidetector (40) circuit for use in a plurality of carrier recovery systems (10, 70) for recovery for a suppressed carrier modulated signal. The multidetector (40) receives demodulated, in-phase x and quadrature phase y components of a baseband signal (sn(t)) and generates output signals for use in a plurality of carrier recovery systems (10, 70). The multidetector (40) generates a lock detection signal that varies primarily in accordance with a lock signal x2y2 and a fourth-order amplitude detection signal (x2+y2)2 for use in either system. The multidetector particularly generates a phase error signal xy(x2−y2) for use in a Costas carrier recovery system (10). The multidetector also generates a second-order amplitude detection signal (x2+y2) for use in either system which can be used to adjust the amplitude of the incoming, modulated signal in order to control the loop gain of the carrier recovery phase locked loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.