阅读说明：本技术 一种采用维纳滤波进行信号解调的方法及装置 (Method and device for signal demodulation by adopting wiener filtering ) 是由 熊军 曹柯 郭晓峰 于 2020-03-10 设计创作，主要内容包括：本申请公开一种采用维纳滤波进行信号解调的方法及装置。所述方法包括：将导频的调制信号去除,得到信道信息；对信道信息连续N个点进行叠加,叠加后的信号进行矩阵组合,完成信道求逆得到频率和初始相位；提取业务信号,完成业务信号的解扩；提取每一个业务信号的相位进行维纳滤波处理,对业务信号的相位进行预测,修正业务信号的相位最后正确解调出信号。能够利用前后信号的相关性完成信号的解调,能够更好的估计出信号的相位,从而能够更好的解调出信号信息,相比现有技术信号解调更准确,而且根据输入的邻近信号进行频偏估计实时调整,能够最好的适应频偏的变动。(The application discloses a method and a device for signal demodulation by adopting wiener filtering. The method comprises the following steps: removing the pilot frequency modulation signal to obtain channel information; superposing N continuous points of channel information, performing matrix combination on the superposed signals, and completing channel inversion to obtain frequency and an initial phase; extracting service signals and finishing de-spreading of the service signals; and extracting the phase of each service signal to carry out wiener filtering processing, predicting the phase of the service signal, correcting the phase of the service signal and finally correctly demodulating the signal. The method can complete the demodulation of the signal by utilizing the correlation of the front signal and the rear signal, can better estimate the phase of the signal, and can better demodulate signal information.)

1. A method for signal demodulation using wiener filtering, comprising:

removing the pilot frequency modulation signal to obtain channel information;

superposing N continuous points of channel information, performing matrix combination on the superposed signals, and completing channel inversion to obtain frequency and an initial phase;

extracting service signals and finishing de-spreading of the service signals;

and extracting the phase of each service signal to carry out wiener filtering processing, predicting the phase of the service signal, correcting the phase of the service signal and finally correctly demodulating the signal.

2. The method of claim 1, wherein N successive points of channel information are superimposed, and the superimposed signals are matrix-combined to complete channel inversion to obtain a frequency and an initial phase, and the method comprises the following substeps:

superposing N continuous points of the channel information to obtain a superposed numerical value;

performing phase solving on the superposed numerical value to obtain a phase angle _ pre, and adjusting the phase angle _ pre;

and forming a matrix according to the adjusted phases to obtain an initial frequency and an initial phase.

3. The method of claim 2, wherein the phase angle _ pre is adjusted by subtracting 2PI if the current phase is larger than PI and adding 2PI if the current signal and the previous signal are smaller than PI.

4. The method as claimed in claim 1, wherein the method for demodulating signals by wiener filtering comprises the following steps:

obtaining the initial frequency and phase through the synchronization head, thereby obtaining the phase of the service signal needing initial calibration, and calibrating the phase of the subsequent service signal;

the phase of each service signal input per se is obtained, and then the new predicted phase is obtained through wiener filtering;

performing phase correction on a signal input later by using the new predicted phase, thereby outputting a phase-corrected signal;

and demodulating the TS _ symNum service data to obtain a final signal.

5. The method of claim 4, wherein the step of demodulating the TS _ symNum traffic data to obtain a final signal comprises the following sub-steps:

acquiring a previously predicted phase;

calculating the phase of the current input signal;

carrying out normalization processing on the current phase direction and recording;

extracting Syn _ num symbol time stamps adjacent to a current signal k;

performing matrix inversion according to the timestamp and the adjacent normalized input signal phase combination, and solving frequency variation and the current initial phase by using wiener filtering processing;

calculating according to the frequency variation and the initial phase to obtain the current phase variation condition;

the predicted phase modifies the current signal phase.

6. An apparatus for signal demodulation using wiener filtering, comprising:

the pilot frequency modulation information processing module is used for removing the modulation signal of the pilot frequency to obtain channel information;

the frequency and initial phase calculation module is used for superposing N continuous points of channel information, performing matrix combination on the superposed signals and completing channel inversion to obtain frequency and initial phase;

the service signal de-spreading module is used for extracting the service signal and finishing de-spreading of the service signal;

and the wiener filtering processing module is used for extracting the phase of each service signal to carry out wiener filtering processing, predicting the phase of the service signal, correcting the phase of the service signal and finally correctly demodulating the signal.

7. The apparatus for signal demodulation using wiener filtering of claim 6, wherein the frequency and initial phase calculation module is specifically configured to: superposing N continuous points of the channel information to obtain a superposed numerical value; performing phase solving on the superposed numerical value to obtain a phase angle _ pre, and adjusting the phase angle _ pre; and forming a matrix according to the adjusted phases to obtain an initial frequency and an initial phase.

8. The apparatus of claim 7, wherein the frequency and initial phase calculation module obtains an initial frequency and an initial phase according to the adjusted phase composition matrix, and is specifically configured to adjust the phase angle _ pre by subtracting 2PI if the current phase is larger than PI, and adding 2PI if the current signal and the previous signal are smaller than PI.

9. The apparatus for signal demodulation by wiener filtering according to claim 6, wherein the wiener filtering processing module is specifically configured to obtain an initial frequency and a phase obtained by a synchronization header, so as to obtain a phase of a service signal that needs to be initially calibrated, and calibrate a subsequent phase of the service signal; the phase of each service signal input per se is obtained, and then the new predicted phase is obtained through wiener filtering; performing phase correction on a signal input later by using the new predicted phase, thereby outputting a phase-corrected signal; and demodulating the TS _ symNum service data to obtain a final signal.

10. The apparatus for demodulating signals using wiener filtering according to claim 9, wherein the wiener filtering processing module demodulates TS _ symNum service data to obtain a final signal, and is specifically configured to: acquiring a previously predicted phase; calculating the phase of the current input signal; carrying out normalization processing on the current phase direction and recording; extracting Syn _ num symbol time stamps adjacent to a current signal k; performing matrix inversion according to the timestamp and the adjacent normalized input signal phase combination, and solving frequency variation and the current initial phase by using wiener filtering processing; calculating according to the frequency variation and the initial phase to obtain the current phase variation condition; the predicted phase modifies the current signal phase.

Technical Field

The present application relates to the field of channel communication technologies, and in particular, to a method and an apparatus for signal demodulation using wiener filtering.

Background

Spread Spectrum Communication (Spread Spectrum Communication) is called Spread Spectrum Communication for short, and is characterized in that the bandwidth used for transmitting information is far larger than the bandwidth of the information. The spread spectrum communication technology uses spread spectrum coding to perform spread spectrum modulation at a transmitting end and uses related demodulation technology to receive information at a receiving end, and the process makes the communication technology have a plurality of excellent characteristics. Spread spectrum communication technology is an information transmission mode, and the frequency bandwidth occupied by signals is far larger than the minimum bandwidth necessary for the transmitted information; the frequency band is spread by an independent code sequence, and the spreading is realized by a coding and modulation method and is independent of the information data; at the receiving end, the same code is used for carrying out related synchronous receiving, despreading and recovering the transmitted information data.

In burst spread communication, the spreading SP ratio is generally relatively large, for example, the spreading ratio SP is 128, and in this case, the SNR is relatively low before signal despreading, so that channel estimation is often inaccurate, and therefore, a single carrier frequency domain equalization or a single carrier time domain equalization apparatus cannot be generally used. The scheme of the application is provided for solving the problem of correct demodulation of a single carrier signal under low SNR.

Disclosure of Invention

The application provides a method for demodulating signals by adopting wiener filtering, which comprises the following steps:

removing the pilot frequency modulation signal to obtain channel information;

superposing N continuous points of channel information, performing matrix combination on the superposed signals, and completing channel inversion to obtain frequency and an initial phase;

extracting service signals and finishing de-spreading of the service signals;

and extracting the phase of each service signal to carry out wiener filtering processing, predicting the phase of the service signal, correcting the phase of the service signal and finally correctly demodulating the signal.

The method for demodulating signals by using wiener filtering as described above, wherein N consecutive points of channel information are superimposed, and the superimposed signals are subjected to matrix combination to complete channel inversion to obtain a frequency and an initial phase, specifically including the following substeps:

superposing N continuous points of the channel information to obtain a superposed numerical value;

performing phase solving on the superposed numerical value to obtain a phase angle _ pre, and adjusting the phase angle _ pre;

and forming a matrix according to the adjusted phases to obtain an initial frequency and an initial phase.

The method for demodulating a signal by wiener filtering as described above, wherein the phase angle _ pre is adjusted, specifically, 2PI is subtracted if the current phase is greater than PI, and 2PI is added if the current signal and the previous signal are less than PI.

The method for demodulating a signal by using wiener filtering as described above, wherein the method comprises the following sub-steps of extracting a phase of each service signal, then performing wiener filtering, finally predicting the phase of the service signal, correcting the phase of the service signal, and finally correctly demodulating the signal:

obtaining the initial frequency and phase through the synchronization head, thereby obtaining the phase of the service signal needing initial calibration, and calibrating the phase of the subsequent service signal;

the phase of each service signal input per se is obtained, and then the new predicted phase is obtained through wiener filtering;

performing phase correction on a signal input later by using the new predicted phase, thereby outputting a phase-corrected signal;

and demodulating the TS _ symNum service data to obtain a final signal.

The method for demodulating a signal by using wiener filtering as described above, where the TS _ symNum service data is demodulated to demodulate a final signal, specifically includes the following substeps:

acquiring a previously predicted phase;

calculating the phase of the current input signal;

carrying out normalization processing on the current phase direction and recording;

extracting Syn _ num symbol time stamps adjacent to a current signal k;

performing matrix inversion according to the timestamp and the adjacent normalized input signal phase combination, and solving frequency variation and the current initial phase by using wiener filtering processing;

calculating according to the frequency variation and the initial phase to obtain the current phase variation condition;

the predicted phase modifies the current signal phase.

The present application further provides a device for signal demodulation using wiener filtering, comprising:

the pilot frequency modulation information processing module is used for removing the modulation signal of the pilot frequency to obtain channel information;

the frequency and initial phase calculation module is used for superposing N continuous points of channel information, performing matrix combination on the superposed signals and completing channel inversion to obtain frequency and initial phase;

the service signal de-spreading module is used for extracting the service signal and finishing de-spreading of the service signal;

and the wiener filtering processing module is used for extracting the phase of each service signal to carry out wiener filtering processing, predicting the phase of the service signal, correcting the phase of the service signal and finally correctly demodulating the signal.

The apparatus for demodulating a signal using wiener filtering as described above, wherein the frequency and initial phase calculating module is specifically configured to: superposing N continuous points of the channel information to obtain a superposed numerical value; performing phase solving on the superposed numerical value to obtain a phase angle _ pre, and adjusting the phase angle _ pre; and forming a matrix according to the adjusted phases to obtain an initial frequency and an initial phase.

The apparatus for demodulating a signal by wiener filtering as described above, wherein in the frequency and initial phase calculation module, an initial frequency and an initial phase are obtained according to a matrix formed by adjusted phases, and specifically, the initial frequency and the initial phase are used to adjust a phase angle _ pre, specifically, 2PI is subtracted if a current phase is larger than PI, and 2PI is added if the current signal and a previous signal are smaller than PI.

The apparatus for demodulating a signal by using wiener filtering as described above, wherein the wiener filtering processing module is specifically configured to obtain an initial frequency and a phase obtained by a synchronization header, thereby obtaining a phase of a service signal that needs initial calibration, and calibrating a subsequent phase of the service signal; the phase of each service signal input per se is obtained, and then the new predicted phase is obtained through wiener filtering; performing phase correction on a signal input later by using the new predicted phase, thereby outputting a phase-corrected signal; and demodulating the TS _ symNum service data to obtain a final signal.

The apparatus for demodulating a signal by using wiener filtering as described above, wherein in the wiener filtering processing module, the TS _ symNum service data is demodulated to demodulate a final signal, and the apparatus is specifically configured to: acquiring a previously predicted phase; calculating the phase of the current input signal; carrying out normalization processing on the current phase direction and recording; extracting Syn _ num symbol time stamps adjacent to a current signal k; performing matrix inversion according to the timestamp and the adjacent normalized input signal phase combination, and solving frequency variation and the current initial phase by using wiener filtering processing; calculating according to the frequency variation and the initial phase to obtain the current phase variation condition; the predicted phase modifies the current signal phase.

The beneficial effect that this application realized is as follows: by adopting the method, the demodulation of the signal can be completed by utilizing the correlation of the front signal and the rear signal, and the phase of the signal can be better estimated, so that the signal information can be better demodulated. Because the frequency offset changes violently under the high-speed moving high local oscillator, the method is difficult to adapt according to the existing algorithm, and the method carries out frequency offset estimation real-time adjustment according to the input adjacent signals, so that the method can adapt to the change of the frequency offset best.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to the drawings.

Fig. 1 is a schematic frame structure diagram of a burst spread spectrum communication system according to an embodiment of the present application;

fig. 2 is a flowchart of a method for demodulating a signal by wiener filtering according to an embodiment of the present application;

FIG. 3 shows the simulation of P after the input signal direction normalization_k(0) The radian size of the phase (cal _ phase (k + 8)) is compared with a phase (cal _ phase (k + 8)) curve output by the wiener filter;

fig. 4 shows a comparison of signal constellations before and after the wiener filtered output.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.