Frequency selective predistortion in a linear transmitter
US5867065A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 7, 1997 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | May 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2201/3233
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A system for linearly transmitting an amplified output signal using predistortion is disclosed. The system uses a straight inverse modeling scheme to more easily and accurately determine the inverse of the distortion caused by a power amplifier of a RF transmitter. The direct inverse modeling scheme of the present invention indexes the LUT using the modulated input signals instead of the potentially noisier output signals, which helps to increase the accuracy of the predistortion. The predistorter system stores complex coefficients in the LUT, which are then used as the tap weights of a digital filter implementing the predistorter. Finally, the trainer uses a modified version of the power amplifier output signal. The modified power amplifier output signal has the in-band distortion removed from the power amplifier output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.