Method and device in a telecommunication system

A control system and control device technology, applied in the transmission system, multi-carrier system, modulated carrier system, etc., can solve the problems of reducing the bandwidth or speed of the control system, the inconvenience of normal operation interruption, etc., and achieve the reduction of boundary requirements and ensure stability , the effect of wide bandwidth

Inactive Publication Date: 2004-09-22
TELEFON AB LM ERICSSON (PUBL)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This disruption to normal operation is inconvenient if the operation of the majority of the system - such as a feed-forward linearizer - is not acceptable
Additionally, this modification will reduce the potential bandwidth or speed of the control system

Method used

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  • Method and device in a telecommunication system
  • Method and device in a telecommunication system
  • Method and device in a telecommunication system

Examples

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no. 1 example

[0048] Figure 1 illustrates a feedforward linearizer according to one embodiment of the invention. According to a first embodiment of the invention, the linearizer comprises three controllers 16 , 26 , 38 .

[0049] The controller according to the first embodiment of the invention controls the quadrature gain and phase adjuster (QGPA). Note that a detector scheme, such as a complex Cartesian correlator or a pilot recovery and quadrature down conversion circuit, is required to generate the Cartesian error signal before the control means 16,26,38. There are three QGPAs in the illustrated linearizer.

[0050] In the following description, similar or identical features in different embodiments will be denoted by the same reference numerals. In some cases, however, features operating in a similar manner have different reference numbers, for example control means 16, 26, 38 denote similar control means in different positions of the feedforward linearizer according to FIG.

[0051...

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PUM

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Abstract

According to the invention, a Cartesian control means (16) comprising a phase rotator (50) and a phase adjuster (52) is provided. With a method and a device according to the invention, a system is provided that is unconditionally stable with respect to non-phase alignment, regardless of input power changes, temperature and component ageing. No certain conditions need to be placed upon the control system to ensure stability, i.e. the system is non-obtrusive and requires no off-line calibration. The inclusion of the phase rotator (50) and phase adjustment techniques into the Cartesian control system makes this possible.

Description

technical field [0001] The present invention relates to Cartesian control systems. Background technique [0002] In telecommunication systems, especially in RF applications, efficient methods of linearization are required to minimize intermodulation, one reason being distortions produced by nonlinearities in power amplifiers. [0003] In wideband systems, there are two approaches to dealing with amplifier distortion: predistortion and feedforward. Predistortion means reversibly mimicking the distortion introduced by the main amplifier and supplied to the input of the amplifier, thereby producing a constant that is completely ideally equal to power independent. [0004] The feedforward technique basically consists of two steps. The first step is to extract the distortion introduced by the main amplifier on the signal to be amplified. This is called extracting the error signal. The second step is to invert and time-align this error signal into the output of the feedforward...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H03C3/08H03D7/16H03F1/32H03F1/34H04L27/20H04L27/36
CPCH03F2201/3231H03F1/3282H03F1/3247H03D7/168H03F1/34H04L27/368H03F1/345H03F1/3229H03C3/08H03F2200/57H03F1/3294
Inventor S·A·莱约恩杰姆M·布里法
Owner TELEFON AB LM ERICSSON (PUBL)
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