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A Constant Modulus Blind Equalization Method Based on the Amplitude of APSK Modulated Signal

A modulation signal and blind equalization technology, which is applied in the field of constant modulus blind equalization based on the APSK modulation signal amplitude, can solve the problems that the constellation point amplitude does not have I and Q path separation, and the performance of intersymbol interference is inferior, achieving low implementation complexity degree, improved inter-symbol interference performance, and easy-to-implement effects

Active Publication Date: 2017-08-29
BEIJING RES INST OF TELEMETRY +1
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  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, for APSK modulation, which is often used in broadband satellite communications, the constellation point amplitude does not have the characteristics of QAM modulation's I and Q path separation, and the intersymbol interference performance of the MMA algorithm after equalization is worse than that of the CMA algorithm.

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  • A Constant Modulus Blind Equalization Method Based on the Amplitude of APSK Modulated Signal
  • A Constant Modulus Blind Equalization Method Based on the Amplitude of APSK Modulated Signal
  • A Constant Modulus Blind Equalization Method Based on the Amplitude of APSK Modulated Signal

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Embodiment Construction

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation examples.

[0042] Such as figure 1 Shown is the schematic diagram of the constant modulus blind equalization method based on the APSK modulation signal amplitude of the present invention. First, the filter coefficient W(n) whose initialization length is L is W 0 (n), to obtain y(n) after filtering the input signal X(n) with length L. Then, take the difference between y(n) and the objective function of each constellation ring to get |y(n)| 2 -R k , and get ||y(n)| 2 -R k |The corresponding k value when taking the minimum value, e(n)=e k (n), and the error function e(n) is obtained accordingly. Finally, update the filter coefficient W(n) with the error e(n), and input a new received signal, and then enter the next iteration. The specific implementation method is as follows:

[0043] Step (1), Set 2 M In the first-order APSK mod...

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Abstract

The invention relates to a constant-modulus blind equalization method based on an APSK (amplitude phase shift keying) modulation signal amplitude value. The method comprises the steps of firstly initializing a filter coefficient W(n) with the length of L into W0(n), filtering an input signal X(n) with the length of L to obtain y(n), then subtracting y(n) and a target function of each constellation ring to obtain |y(n)|2-Rk, calculating a k value corresponding to a minimum value of the ||y(n)|2-Rk| so as to obtain an error function e(n), finally updating the filter coefficient W(n) through the error e(n), inputting a new receiving signal, and stepping into the next iteration. According to the constant-modulus blind equalization method, the signal intersymbol interference performance after converging by an equalizer of an Amplitude Phase Shift Keying (APSK) modulation system receiver is improved, and the signal quality is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of digital wireless communication transmission, and relates to a constant modulus blind equalization method of an amplitude-phase shift keying modulation signal in a satellite mobile communication system, in particular to a constant modulus blind equalization method based on the amplitude of an APSK modulation signal. Background technique [0002] In the broadband satellite communication system, in addition to the noise of the transmission channel, the channels experienced by the signal also include ground station equipment and power amplifiers on the satellite. Nonlinear phase responses exist to varying degrees in band-pass filters, transmitters and other communication devices in satellite communication systems. The impact of these nonlinear responses on the amplitude phase shift keying (APSK) modulation method commonly used in broadband satellite communications cannot be ignored. Intersymbol interference (...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L25/03H04L27/22
Inventor 闫朝星周三文卢满宏
Owner BEIJING RES INST OF TELEMETRY