OFDM channel estimation method for eliminating noise combined with wavelet transformed domain

A wavelet transform and channel estimation technology, applied in multiplexing communications, electrical components, orthogonal multiplexing systems, etc., to solve problems such as receiver performance degradation

Inactive Publication Date: 2008-08-20
BEIJING SAMSUNG TELECOM R&D CENT +1
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  • Application Information

AI Technical Summary

Problems solved by technology

As we know, due to noise, inter-subcarrier interference and linear interpolation, errors will be introduced in our final interpolated channel frequency response values, and these errors will cause performance degradation of OFDM (Orthogonal Frequency Division Multiplexing) receivers

Method used

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  • OFDM channel estimation method for eliminating noise combined with wavelet transformed domain
  • OFDM channel estimation method for eliminating noise combined with wavelet transformed domain
  • OFDM channel estimation method for eliminating noise combined with wavelet transformed domain

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Embodiment

[0067] The actual DRM (Digital Radio Globalization) broadcast channel is a double-fading channel with both frequency selectivity caused by multipath and time selectivity caused by Doppler spread or frequency shift. Among them, the multipath propagation is mainly caused by the reflection of the ionosphere at different heights. The maximum delay spread of the channel can reach several milliseconds. The Doppler spread and frequency shift are mainly caused by the spectral characteristics of the ionospheric reflection and the movement of the receiver. . Taking mid-latitude regions as an example, the maximum delay spread can reach 6ms, and the Doppler spread can reach 5Hz. Typically, the typical values ​​of delay spread and Doppler spread are 2ms and 1Hz, which are the parameter values ​​of channel model 4 we use.

[0068] Based on the principle of proceeding from reality, we have investigated the situation of channel model 3 and channel model 4 in the DRM (Digital Radio Globalizat...

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Abstract

The invention discloses an OFDM channel estimation method by combining wavelet transform domain denoise method, comprising the following steps of: extracting the information on a pilot subcarrier, calculating the channel frequency response where the pilot subcarrier is; carrying out interpretation to the channel frequency response in the direction of time according to the calculated channel frequency response on the location of the pilot; the channel frequency response of the interpretation on the direction of time is removed noise and interference; carrying out the interpretation on the direction of frequency to the channel frequency response removed noise and interference on the direction of frequency channel. Because the noise, interference between subcarriers and linear interpolation can bring errors into the channel frequency response obtained by the interpretation, the errors can reduce the performance of the OFDM(Orthogonal frequency-division multiplexing) receiver. The method based on the wavelet transform domain is adopted to reduce the errors in the channel frequency response, increase the accuracy of the estimated value of the channel, and reduce the error rate of receiving system.

Description

technical field [0001] The present invention relates to a radio broadcasting system, in particular to an OFDM (orthogonal frequency division multiplexing) channel estimation method combined with wavelet transform domain denoising. Background technique [0002] DRM (Digital Radio Globalization) is the only universal non-proprietary digital radio broadcasting system for the shortwave, mediumwave and longwave AM broadcasting bands. Under the same coverage conditions, the power of the DRM (Digital Radio Globalization) transmitter is 6-9dB lower than that of the traditional analog transmitter, and the same-adjacent frequency protection rate of digital broadcasting is lower than that of analog broadcasting, and the ability to resist multipath interference is strong. It is convenient for mobile reception; the sound quality can reach the quality of CD (CD) or FM stereo; it can provide additional data and multimedia information; compared with DAB (Digital Audio Broadcasting), its rec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04J11/00
Inventor 潘立军魏立军
Owner BEIJING SAMSUNG TELECOM R&D CENT
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