Method and digital receiver for receiving orthogonal frequency-division multiplexed signals
US5946292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1997 |
| Grant date | Aug 31, 1999 |
| Priority date | — |
| Expiry date | Aug 4, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2679
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital receiver uses a local oscillator to down-convert an orthogonal frequency-division multiplexed signal that has been modulated by differential phase-shift keying, and performs further processing to obtain a differentially demodulated array of phase values. According to a first aspect of the invention, the digital receiver detects a carrier offset, applies a corresponding phase correction to the values in the array, then shifts the entire array by an amount corresponding to the carrier offset. As a result, the local oscillator need be tuned only in a frequency range equal to the subcarrier spacing. According to a second aspect of the invention, the local oscillator is tuned within a range equal to the subcarrier spacing multiplied by a certain integer, the array is shifted by a multiple of this integer, and the phase correction is eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.