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Front processor for data receiver and nonlinear distortion equalizing method

A nonlinear distortion and receiver technology, applied in digital transmission systems, demodulation of modulated electromagnetic waves, multi-frequency code systems, etc., can solve problems such as no one has proposed

Inactive Publication Date: 2002-11-20
INTERDIGITAL PATENT HLDG INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, no one has proposed a method for compensating the nonlinear distortion in the complex signal at the receiving end

Method used

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  • Front processor for data receiver and nonlinear distortion equalizing method
  • Front processor for data receiver and nonlinear distortion equalizing method
  • Front processor for data receiver and nonlinear distortion equalizing method

Examples

Experimental program
Comparison scheme
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Embodiment 1

[0124] A front-end processor used in Embodiment 1 according to the present invention will be described below with reference to the drawings. image 3 is a block diagram showing the overall structure of the front-end processor 100 for the data receiver according to the present embodiment. A front-end processor for a data receiver is formed to include a nonlinear distortion equalizer 101, a quasi-synchronous detector 108, and a carrier recovery circuit. In each of the block diagrams shown below, thick solid lines indicate the flow of complex signals (vector information), and solid lines thinner than thick solid lines indicate the flow of scalar information.

[0125] image 3 The nonlinear distortion equalizer 101 has a complex signal converter 102 for nonlinear distortion equalization, a root-raised cosine filter 103, an error estimator (ERR EST) 104, and a coefficient estimator 105 for nonlinear distortion equalization. The complex signal converter 102 for nonlinear distortio...

Embodiment 2

[0181] A front-end processor for a data receiver according to Embodiment 2 of the present invention will be described below with reference to the drawings. Figure 11 is to show the front-end processor 200 used for the data receiver according to the present embodiment. A front-end processor 200 for a data receiver includes a quasi-synchronous detector 108 and a nonlinear distortion equalizer 201 . The nonlinear distortion equalizer 201 according to the present embodiment differs from the nonlinear distortion equalizer 101 of Embodiment 1 in the coefficient estimator 202 for nonlinear distortion equalization. The non-linear distortion equalizer 201 is characterized by the image 3 The carrier recovery circuit 111 of the preceding stage of the nonlinear distortion equalizer 101 is provided in the subsequent stage of the root raised cosine filter 103 of the nonlinear distortion equalizer 201 . quasi-synchronous detector 108 with image 3 shown in the same, and every other bloc...

Embodiment 3

[0213] Next, a front-end processor for a data receiver according to Embodiment 3 of the present invention will be described with reference to the drawings. Figure 15 To show the structure of a front-end processor 300 used for the data receiver according to this embodiment. The front-end processor 300 for the data receiver includes a quasi-synchronous detector 108 , a carrier recovery circuit 111 and a nonlinear distortion equalizer 301 . This nonlinear distortion equalizer 301 is different from the nonlinear distortion equalizer 101 of Embodiment 1 in the structure of the coefficient estimator 302 for nonlinear distortion equalization. In this nonlinear distortion equalizer 301 , a complex signal converter 303 for linear distortion equalization is added to the subsequent stage of the root raised cosine filter 103 . The complex signal converter 303 for linear distortion equalization is abbreviated as "COMP SIG CONV2" in the drawings. The coefficient estimator 304 for linear ...

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Abstract

An OFDM baseband signal subjected to synchronous carrier modulation or differential carrier modulation is input to a complex signal converter for nonlinear distortion equalization, thereby converting according to the Nth order function conversion characteristic (N>1). Non-linear distortions in the OFDM baseband signal are then compensated for. At this time, use the following equation as a conversion equation y(n)=x(n)+∑am(n)xm(n)(m>1), where the input signal, output signal and The coefficients of the mth order distortion equalization are x(n), y(n) and am(n) respectively.

Description

field of invention [0001] The present invention relates to techniques for eliminating nonlinear distortion occurring in digital transmissions such as satellite broadcasting, terrestrial broadcasting, and coaxial cable broadcasting. Background technique [0002] In recent years, digitization of television broadcasting has rapidly progressed in coaxial cable, satellite, and terrestrial media in Japan as well as in Western countries. In Japan, regular BS digital broadcasting started in December 2000. In addition, regular terrestrial digital broadcasting is expected to start in cities in 2003. [0003] In BS broadcasting, the transmission distance exceeds tens of thousands of kilometers. Therefore, amplifiers in transponders in broadcasting satellites have little compensation and operate in regions of high amplification factor. Therefore, the radio waves sent from the transmitting station receive nonlinear distortion, and are sent from the broadcasting satellite to the receiv...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04N7/015H04L27/26H04L27/38
CPCH04L27/2647H04L27/38H04N7/015
Inventor 大内干博神野一平加藤久也
Owner INTERDIGITAL PATENT HLDG INC