Optimal filtering and upconversion in OFDM systems
US6657950B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1999 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Feb 19, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03414
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Systems and methods for converting a baseband OFDM signal to an IF signal while minimizing lengthening of the impulse response duration experienced by the OFDM signal. A conversion technique according to the present invention provides sufficient filtering to limit the effects of spurious frequency domain components caused by transitions between successive OFDM bursts. In one embodiment, the filtering is provided by a combination of a finite impulse response (FIR) filter having non-linear phase characteristics and a cyclic convolution filter. Conversion from the frequency domain into the time domain, upsampling, and cyclic filtering may be combined into one operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.