Blind equalizer and blind equalization processing method

A blind equalization and equalization technology, applied in the field of communication, can solve the problems of insufficient steady-state performance and slow convergence speed, and achieve the effect of improving the convergence speed and steady-state performance.

Inactive Publication Date: 2010-10-06
SHENZHEN UNIV +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the convergence speed of the DSE-CMA algorithm is relatively slow, and the steady-state performance is not good enough

Method used

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  • Blind equalizer and blind equalization processing method
  • Blind equalizer and blind equalization processing method

Examples

Experimental program
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Effect test

Embodiment 1

[0038] In the embodiment of the present invention, by using the steepest descent gradient algorithm, in order to minimize the error term of the first weight update module and maximize the logarithm of the local posterior probability density function adopted by the second weight update module, the update weight Value vector, and then according to the updated weight vector, the received signal vector is equalized and output, and a blind equalizer is realized.

[0039] figure 2 The structure of the blind equalizer provided by the embodiment of the present invention is shown, and only the parts related to the embodiment of the present invention are shown for convenience of description.

[0040] The blind equalizer can be used in a receiver of a wireless mobile communication system, and can be a software unit, a hardware unit or a combination of software and hardware running in these receivers, wherein:

[0041] The weight update unit 201, according to the steepest descent gradie...

Embodiment 2

[0071] In order to reduce the phase offset and further improve the convergence speed, as a preferred embodiment of the present invention, the first weight update module 2011 divides the CMA error term into two parts, the real part and the imaginary part, according to the steepest descent gradient algorithm, and then Adding a dithering random signal and performing a sign operation to form a new error term. In order to reduce the new error term and continuously update the first weight vector until convergence, the Dithered Signed-Error-Improved Constant Modulus Algorithm (Dithered Signed-Error- Modified Constant Modulus Algorithm, DSE-MCMA) algorithm updates the first weight vector, specifically, adopts the following iterative formula to update the first weight vector:

[0072] w c (n+1)=w c (n)+μ c ε(y n , d n )r * (n);

[0073] Among them, w c (n) represents the weight vector of the first weight update module 2011 at time n; μ c is the (positive) iterative step size of...

Embodiment 3

[0084] Figure 7 The implementation flow of the blind equalization processing method provided by the embodiment of the present invention is shown, and the details are as follows:

[0085] In step S701, the DSE-CMA algorithm is used to update the first weight vector;

[0086] In step S702, the maximum a posteriori probability theory is used as the judgment basis, and the steepest descent gradient algorithm is adopted to maximize the logarithmic value of the local a posteriori p.d.f., and update the second weight vector;

[0087] In step S703, merge the updated first weight vector and the second weight vector;

[0088] In step S704, according to the weight vector obtained after merging, the received signal vector is equalized and then output, and the received signal vector is equalized by the following formula:

[0089] y(n)=w(n) T r(n);

[0090] Among them, the superscript "T" indicates matrix transposition, w(n) is the weight vector obtained after merging in step S703, r(n...

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Abstract

The invention provides a blind equalizer and a blind equalization processing method, which are suitable for the field of communication. The blind equalizer comprises a weight updating unit and a wave filter, wherein the weight updating unit comprises a first weight updating module, a second weight updating module and a weight merging module. In the blind equalizer and the blind equalization processing method, a weight vector is updated by making the error items of the first weight updating module minimum and making the logarithmic value of a local posterior probability density function adopted by the second weight updating module maximum, and a received signal vector is output after the received signal vector is subjected to the equalization processing according to the updated weight vector, so the blind equalizer which can increase velocity of convergence and improve steady-state performance is implemented.

Description

technical field [0001] The invention belongs to the communication field, and in particular relates to a blind equalizer and a blind equalization processing method. Background technique [0002] Signal transmission in non-ideal channels will cause distortion. Equalization is a technique used to reduce distortion and compensate for signal loss. Since the blind equalization does not need to use the training sequence, it can improve the system bandwidth efficiency. In addition, for some communication systems, it is difficult to obtain a correct training sequence at the receiving end when the receiving end loses synchronization, etc. Blind equalization provides a practical means for such systems to eliminate the deleterious effects of the channel. [0003] Since the 1990s, the most researched and used blind equalization algorithm is the Constant Modulus Algorithm (CMA). CMA attempts to restore the constant envelope characteristics of some communication signals. By restoring th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L25/03
CPCH04L25/0307
Inventor 谢宁王晖胡恒云
Owner SHENZHEN UNIV
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