Equalizer and feedback equalization method

An equalizer and addition technology, which is applied in the baseband system, shaping network in transmitter/receiver, digital transmission system, etc., can solve the problem that the optimal value of the channel is far away, the process is time-consuming, and it is not suitable for application and constant forgetting Factors and other issues to achieve the effect of reducing the amount of calculation, fast speed, and improving the convergence speed

Inactive Publication Date: 2016-05-04
THE THIRD RES INST OF CHINA ELECTRONICS TECH GRP CORP
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AI Technical Summary

Problems solved by technology

For the equalized time-varying frequency selection fading channel, the disadvantages are: 1) the process is time-consuming, and the value searched by the algorithm may be far from the optimal value of the channel; 2) when the optimal fading rate of the channel is not a constant, the optimal Invariant forgetting factor

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  • Equalizer and feedback equalization method
  • Equalizer and feedback equalization method
  • Equalizer and feedback equalization method

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Embodiment approach

[0199] According to an embodiment of the present invention, the tap coefficient determination includes:

[0200] Get initial tap coefficients and initial autocorrelation matrix;

[0201] Utilize the output y(n) (observation signal sequence) of the feedback filter, the current filter coefficient w(n-1) of the feedback filter and the number of iterations to update the intermediate variable;

[0202] Determine the updated forgetting factor according to the number of iterations;

[0203] Determine the updated autocorrelation matrix according to the updated forgetting factor, intermediate variable and initial autocorrelation matrix;

[0204] Determine the prior error according to the intermediate variable, the autocorrelation matrix, and the current filter coefficient w(n-1);

[0205] Determine the gain vector according to the current autocorrelation matrix inverse matrix P(n-1), the updated intermediate variable, and the updated forgetting factor;

[0206] Update the autocorrel...

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Abstract

The invention discloses an equalizer, which comprises a feed-forward filter, a first adder, a feedback filter, a second adder and a filter tap coefficient determination unit, wherein the feed-forward filter carried out feed-forward filtering on an underwater acoustic communication training sequence; the first adder adds the underwater acoustic communication training sequence subjected to feed-forward filtering and an output of the feedback filter together and outputs an adding result to the feedback filter; the second adder adds the output of the first adder and an expected output d(n) of the equalizer together; and the filter tap coefficient determination unit determines tap coefficients of the feed-forward filter and the feedback filter according to the output of the second adder. According to the equalizer and the feedback equalization method, a channel model is simplified, the calculated amount for design of the equalizer is reduced and the rate of convergence of an algorithm is improved, so that the algorithm can be converged at a smaller convergence residual, the computational complex is reduced and the equalization performance is improved.

Description

technical field [0001] The invention belongs to the field of underwater acoustic communication, and in particular relates to a feedback equalization method with low computational complexity. Background technique [0002] Multipath transmission means that a sound source signal arrives at the receiving end through different paths from different directions, which causes random fluctuations in the amplitude of the received signal and time delay expansion of the signal. The multi-channel transmission of the shallow sea acoustic channel is mainly caused by the multiple reflections of the sea surface and the seabed, and the climatic structure of the sound velocity gradient in the sea. Channel equalization technology refers to an anti-drop measure adopted to improve the transmission characteristics of a communication system in a fading channel, mainly to eliminate or weaken the intersymbol interference (ISI) problem caused by multipath transmission during broadband communication. ...

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Application Information

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IPC IPC(8): H04L25/03
CPCH04L25/03878
Inventor 尹航张学磊董雷刘德铸铁煜石建飞
Owner THE THIRD RES INST OF CHINA ELECTRONICS TECH GRP CORP
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