Method and system for compensation of a carrier frequency offset in an OFDM receiver
US8184523B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2001 |
| Grant date | May 22, 2012 |
| Priority date | — |
| Expiry date | Dec 15, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0067
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An Orthogonal Frequency Division Multiplexing (OFDM) receiver that employs N second-order phase-lock loops sharing a common integrator (where N is the number of pilots in the system). The N second order phase-lock loops track out independent pilot phase rotations to facilitate the constructive averaging of the pilots' phase information. At the same time, by sharing a common integrator, the OFDM receiver takes advantage of noise averaging over multiple pilots to obtain a cleaner frequency offset estimation. The OFDM receiver may also compensate for FFT window drift by calculating a phase difference between a selected pair of pilots and tracking the rate of change of the calculated phase difference over time. The calculated phase difference is used to control the position of an upstream FFT window after a predetermined phase difference threshold is exceeded. The tracked rate of change is used to continuously adjust the phase of downstream equalizer taps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.