Method and device for compensating the doppler effect for a digital signal receiver

A Doppler effect and receiver technology, applied in radio transmission systems, electrical components, transmission systems, etc., can solve the harmful problems of mobile reception, achieve the effect of improving tolerance and strengthening the effect of receivers

Inactive Publication Date: 2008-10-08
THOMSON LICENSING SA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Currently, the digital processing included in the COFDM demodulator circuit enables a greatly increased tolerance to the Doppler effect, but this phenomenon still exists and is detrimental to mobile reception

Method used

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  • Method and device for compensating the doppler effect for a digital signal receiver
  • Method and device for compensating the doppler effect for a digital signal receiver
  • Method and device for compensating the doppler effect for a digital signal receiver

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Embodiment Construction

[0023] The principle of the device or method according to the invention is based on the analysis of the Doppler phenomenon explained below:

[0024] If the signal received by the receiver's antenna 1 is affected by an echo - but not Doppler shifted, then the frequency is ω m And the echo of the OFDM modulated signal t with amplitude a has amplitude b and delay τ. The resulting signal seen by the receiver at time t is:

[0025] R = a sin ( ω m t ) + b sin ω m ( t + τ · · )

[0026] The amplitude of this signal is of the form:

[0027]

[0028] Amplitude is a function of carrier frequency, with a frequency having a maximum value of ω m τ...

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Abstract

The invention relates to a method of compensating the Doppler effect for a mobile receiver. This method consists in producing a phase- locked loop based on the signal to be demodulated to correct the frequency control of the tuner element and thus the drift due to the Doppler effect. The invention also relates to a receiver implementing this method.

Description

technical field [0001] The present invention relates to digital signal receivers, and in particular to a method for compensating for the Doppler effect and an associated apparatus for processing a received signal affected by distortion caused by the Doppler effect. It falls in particular within the scope of implementation of the emergency DVB-H (Digital Video Broadcasting Handheld) standard, the purpose of which is to allow reception of digital broadcast programmes from mobile diagnostics. Background technique [0002] Reception of digital television programmes in moving vehicles in urban, suburban or rural environments is technically possible but requires a powerful receiver in order to minimise the effects of propagation, especially Doppler effects due to speed, The speed causes frequency offsets on the channel. [0003] Two-channel or four-channel antenna diversity schemes are nevertheless effective methods to combat these phenomena that cause undesired interruptions in ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04B7/01
CPCH04B7/01
Inventor 让-卢克·罗伯特让-伊夫·勒娜奥尔让-弗朗索瓦·平托斯
Owner THOMSON LICENSING SA
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