Distortion compensation apparatus and distortion compensation method
US6657493B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2002 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Apr 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/3294
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A distortion compensation apparatus returns a part of an amplified output signal of a power amplifier amplifying a transmission signal, reads a distortion compensation signal from a distortion compensation table, multiplies the transmission signal with the distortion compensation signal thereof, and inputs the signal to the power amplifier. The distortion compensation signal corresponding to a signal calculated based on an error signal that is a difference between the transmission signal and the amplified output signal, the distortion compensation signal from the distortion compensation table and the step size parameter, and to a power of the transmission signal. The distortion compensation apparatus comprises a &mgr; control part including a fast Fourier transformation part that obtains a spectrum of the amplified output signal, a calculation part that calculates an adjacent channel leakage power ratio based on the spectrum, and a &mgr; adjusting part that varies the step size parameter by comparing the calculated adjacent leakage power ratio with a threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.