Transmitter predistortion circuit and method therefor
US7469491B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2004 |
| Grant date | Dec 30, 2008 |
| Priority date | — |
| Expiry date | Mar 1, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2614
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital communications transmitter (100) includes a digital linear-and-nonlinear predistortion section (200, 1800, 2800) to compensate for linear and nonlinear distortion introduced by transmitter-analog components (120). A direct-digital-downconversion section (300) generates a complex digital return-data stream (254) from the analog components (120) without introducing quadrature imbalance. A relatively low resolution exhibited by the return-data stream (254) is effectively increased through arithmetic processing. Distortion introduced by an analog-to-digital converter (304) may be compensated using a variety of adaptive techniques. Linear distortion is compensated using adaptive techniques with an equalizer (246) positioned in the forward-data stream (112). Nonlinear distortion is then compensated using adaptive techniques with a plurality of equalizers (226) that filter a plurality of orthogonal, higher-ordered-basis functions (214) generated from the forward-data stream (112). The filtered-basis functions are combined together and subtracted from the forward-data stream (112).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.