Method and apparatus for estimating PSK modulated signals
US5590158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 1995 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | Oct 11, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An in-phase component and a quadrature component of a digitized input DQPSK modulated signal are provided from interpolation filters, respectively. An instantaneous amplitude and an instantaneous phase of the input signal for each symbol clock are detected from the in-phase and quadrature components and are fed to adders. At the same time, that one of symbols "0, 0," "0, 1," "1, 0" and "1, 1" which corresponds to the instantaneous phase is detected by a symbol detector. An ideal reference signal generating part generates an ideal amplitude component and an ideal phase component corresponding to the detected symbol and provides them to a parameter calculating part. In an I-Q origin offset detecting part, an I-Q origin offset is calculated on the basis of the relationship between a triangle formed by the current detected vector corresponding to an ideal symbol and a vector detected one symbol clock before and a triangle formed by the said two vectors. An amplitude and a phase corresponding to the calculated I-Q origin offset are provided to the adders, respectively, and are corrected with respect to the detected instantaneous amplitude and phase, thereafter being fed to the parameter…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.