In-service measurement of transmitter nonlinearities
US6275523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Nov 3, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B17/18
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A system for in-service nonlinearity measurements measures such nonlinearities by way of comparing received linear error-corrected unfiltered signal samples with re-generated reference signal samples to calculate magnitude and phase nonlinear error values. Linear distortion is removed from the received signal samples in order to truly characterize nonlinear behavior of the transmitter. The linear error-corrected received signal samples are generated without applying the receiver shaping filtering. Reference signal samples are re-generated from estimated transmitted symbols from the unfiltered linear error-corrected received signal samples. The transmitted symbols are estimated using a multi-region slicer which dynamically estimates constellation decision levels from the unfiltered signal samples. A weighted, least-square based polynomial regression is performed on magnitude and phase nonlinear error values to estimate magnitude and phase nonlinear error functions while suppressing the impact of other non-systematic distortions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.