WO2023155457A1

WO2023155457A1 - Signal processing method and apparatus, electronic device, and storage medium

Info

Publication number: WO2023155457A1
Application number: PCT/CN2022/125925
Authority: WO
Inventors: 俞佳宝; 胡爱群; 胡红星; 黄杰; 徐丹
Original assignee: 网络通信与安全紫金山实验室; 中汽创智科技有限公司
Priority date: 2022-02-18
Filing date: 2022-10-18
Publication date: 2023-08-24
Also published as: CN114584984A

Abstract

Disclosed in the present application are a signal processing method and apparatus, an electronic device, and a storage medium. The method comprises: obtaining a signal to be processed and a reference signal, wherein the signal to be processed comprises radio frequency fingerprint information and the reference signal; respectively performing time-frequency analysis on the signal to be processed and the reference signal to obtain a first signal spectrum and a second signal spectrum; determining a first time-varying power spectrum corresponding to the first signal spectrum and a second time-varying power spectrum corresponding to the second signal spectrum; normalizing the first time-varying power spectrum to obtain a normalized time-varying power spectrum; determining an indication matrix corresponding to the second signal spectrum; and determining the radio frequency fingerprint information on the basis of the normalized time-varying power spectrum and the indication matrix. According to embodiments of the present application, a large number of radio frequency fingerprint features of a time domain and a frequency domain are extracted to provide a feasible technical means for the high-precision recognition of a transmitter by using radio frequency fingerprint technology.

Description

A signal processing method, device, electronic equipment and storage medium

technical field

The present application relates to the technical field of the Internet, and in particular to a signal processing method, device, electronic equipment and storage medium.

Background technique

RF fingerprints originate from differences in transmitter circuit design and manufacturing tolerances of hardware circuits in the production process. There are subtle differences in device parameters in different production batches or even in the same production batch. In addition, due to differences in component types, component layouts, and PCB traces, the differences between transmitters designed by different manufacturers are even more significant.

Radio frequency fingerprints are unique and difficult to clone. This characteristic of radio frequency fingerprints can be used not only to identify wireless transmitters, but also to authenticate the transmitter's identity to protect communication security. RF fingerprint is a tiny signal distortion parasitic on the transmitted signal. Its generation mechanism is very complicated, and it is difficult to accurately model and represent it through mathematical models. Therefore, it is also difficult to find the theoretically optimal RF fingerprint extraction method.

Since the wireless transmission signal usually arrives at the receiver through the wireless multipath channel, the transmission signal and the multipath effect are in a convolutional relationship, and the RF fingerprint is also in a certain extent in a convolutional relationship with the transmission signal. To remove the multipath channel will inevitably damage the radio frequency. Fingerprints, therefore, multipath effects largely limit the precise extraction of RF fingerprints.

Contents of the invention

Embodiments of the present application provide a signal processing method, device, electronic equipment, and storage medium.

On the one hand, the embodiment of the present application provides a signal processing method, the method comprising:

Obtain the signal to be processed and the reference signal; the signal to be processed includes radio frequency fingerprint information and the reference signal;

performing time-frequency analysis on the signal to be processed and the reference signal respectively to obtain a first signal spectrum and a second signal spectrum;

determining a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum;

Normalizing the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

determining an indicator matrix corresponding to the second signal spectrum;

Radio frequency fingerprint information is determined based on the normalized time-varying power spectrum and the indicator matrix.

In some possible embodiments, time-frequency analysis is performed on the signal to be processed and the reference signal respectively to obtain the first signal spectrum and the second signal spectrum, including:

performing windowing processing on the signal to be processed and the reference signal respectively to obtain the first signal and the second signal;

Perform Fourier transform on the first signal and the second signal respectively to obtain the first signal spectrum and the second signal spectrum.

In some possible embodiments, obtaining the signal to be processed and the reference signal includes:

Obtain the received signal from the receiving end; the received signal is obtained based on the transmitted signal sent by the transmitting end; the transmitted signal includes reference signal and radio frequency fingerprint information;

Perform signal processing on the received signal to obtain the signal to be processed;

Get a reference signal.

In some possible embodiments, signal processing is performed on the received signal to obtain a signal to be processed, including:

Signal synchronization processing, carrier frequency offset estimation processing and residual frequency offset removal processing are performed on the received signal and the reference signal to obtain the signal to be processed.

In some possible embodiments,

The signal to be processed is a signal of the preamble part;

The reference signal is a signal of the preamble part.

In some possible embodiments, the method also includes:

Display radio frequency fingerprint information on a two-dimensional plane.

Another aspect provides a signal processing device, the device comprising:

The signal acquisition module is used to acquire the signal to be processed and the reference signal; the signal to be processed includes radio frequency fingerprint information and the reference signal;

The signal spectrum determination module is used to perform time-frequency analysis on the signal to be processed and the reference signal respectively to obtain the first signal spectrum and the second signal spectrum;

A power spectrum determination module, configured to determine a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum;

A normalization processing module is used to normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

An indication matrix determination module, configured to determine an indication matrix corresponding to the second signal spectrum;

The radio frequency fingerprint information determination module is used to determine the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indicator matrix.

In some possible embodiments, the signal spectrum determination module is configured to:

In some possible embodiments, the signal acquisition module is configured to:

Get a reference signal.

In some possible embodiments, the signal acquisition module is configured to:

In some possible embodiments,

The signal to be processed is a signal of the preamble part;

The reference signal is a signal of the preamble part.

In some possible embodiments, the device also includes:

Display radio frequency fingerprint information on a two-dimensional plane.

Another aspect provides an electronic device. The electronic device includes a processor and a memory. At least one instruction or at least one program is stored in the memory. The at least one instruction or at least one program is loaded by the processor and executes any signal processing method.

Another aspect provides a computer-readable storage medium, where at least one instruction or at least one program is stored, and the at least one instruction or at least one program is loaded and executed by a processor to implement any signal processing method.

Another aspect provides a computer program product, the computer program product includes a computer program, the computer program is stored in a readable storage medium, at least one processor of the computer device reads and executes the computer program from the readable storage medium, so that the computer device A signal-handling method that executes either.

The input signal processing method, device, electronic equipment, and storage medium provided in the embodiments of the present application have the following technical effects:

Obtain the signal to be processed and the reference signal; the signal to be processed includes radio frequency fingerprint information and the reference signal; perform time-frequency analysis on the signal to be processed and the reference signal respectively to obtain the first signal spectrum and the second signal spectrum; determine the first signal spectrum corresponding to the first signal spectrum A time-varying power spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum; normalizing the first time-varying power spectrum to obtain a normalized time-varying power spectrum; determining an indicator matrix corresponding to the second signal spectrum ; Determine the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indicator matrix. The embodiment of the present application extracts a large number of radio frequency fingerprint features in the time domain and frequency domain, so as to provide a feasible technical means for using the radio frequency fingerprint technology to identify transmitters with high precision.

Description of drawings

In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the appended The drawings are only some embodiments of the present application, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic diagram of an application environment provided by an embodiment of the present application;

FIG. 2 is a schematic flowchart of a signal processing method provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of a frame structure provided by an embodiment of the present application;

Fig. 4 is a schematic diagram of a signal spectrum provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a signal spectrum provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of a time-varying power spectrum provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of an effective time-frequency power spectrum provided by an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a signal processing device provided by an embodiment of the present application;

FIG. 9 is a block diagram of a hardware structure of a server of a signal processing method provided by an embodiment of the present application.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in the present application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present application.

It should be noted that the terms "first" and "second" in the description and claims of the present application and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or server comprising a series of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of an application environment provided by an embodiment of the present application, and the schematic diagram includes a server 101 and a receiving end 102 .

Specifically, the server 101 acquires the signal to be processed and the reference signal; performs time-frequency analysis on the signal to be processed and the reference signal respectively to obtain the first signal spectrum and the second signal spectrum; determines the first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum; normalizing the first time-varying power spectrum to obtain a normalized time-varying power spectrum; determining an indicator matrix corresponding to the second signal spectrum; The variable power spectrum and indicator matrix determine the radio frequency fingerprint information.

The receiver 102 may refer to a device including a receiver. Among them, the role of the receiver is opposite to that of the transmitter, mainly to receive the signal in the channel, transform it into information in the same physical form as when it was sent, and then transmit it to the destination, that is, to complete the so-called decoding process. The basic requirement of the receiver is to be able to extract the information output by the source from the interfered signal to the greatest extent, and to reproduce the output of the source as much as possible. The most common receiver is a satellite TV receiver.

In electronics, a transmitter or radio transmitter refers to a device that uses an antenna to send radio waves. A radio transmitter produces an alternating current that acts on the antenna. The antenna generates radio waves and sends them into space. In addition to applications in radio broadcasting, radio transmitters are also widely used in various devices that use radio to communicate. Common applications include mobile phones, wireless local area networks, Bluetooth, wireless walkie-talkies and so on.

The following describes a specific embodiment of a signal processing method of the present application. FIG. 2 is a schematic flow chart of a signal processing method provided in the embodiment of the present application. Or uninventive labor may include more or fewer operational steps. The sequence of steps enumerated in the embodiments is only one of the execution sequences of many steps, and does not represent the only execution sequence. When an actual system or server product is executed, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (for example, in a parallel processor or multi-thread processing environment). Specifically as shown in Figure 2, the method may include:

S201: Obtain a signal to be processed and a reference signal, where the signal to be processed includes radio frequency fingerprint information and the reference signal.

In the embodiment of the present application, the server may obtain the received signal from the receiving end. Wherein, the received signal is obtained based on the transmitted signal sent by the transmitting end through multi-path channel transmission, and the transmitted signal may include a reference signal and radio frequency fingerprint information. Subsequently, the server may perform signal processing on the received signal to obtain a signal to be processed.

In an optional embodiment, the transmitting end may superimpose the reference signal and the radio frequency fingerprint information to obtain a transmitting signal, and then send the transmitting signal, and receive it at the receiving end to obtain a receiving signal.

Optionally, the server may obtain the reference signal.

In an optional embodiment, after the server obtains the received signal from the receiving end, it can use the obtained reference signal and the received signal to perform signal synchronization processing, carrier frequency offset estimation processing and residual frequency offset removal processing, so as to obtain Handle signals.

Specifically, the server can use the reference signal and the received signal to perform complex correlation and difference processing, so as to realize signal synchronization and carrier frequency offset estimation. Then the residual frequency offset is removed from the synchronized signal to obtain the signal to be processed.

Optionally, the signal to be processed may be a signal with a length of N, where the length of N means that the signal to be processed includes N sub-signals.

Optionally, the reference signal may be a signal of the preamble part in the IEEE 802.11n communication system, and its frame structure is shown in FIG. 3 . In this frame structure, it contains a short preamble part composed of 10 short preambles t1, t2, ..., t10, and a long preamble part composed of two long preambles T1, T2 and a cyclic prefix G12 , each of the two guide codes occupies 8us. Assuming that the baseband signal is sampled at a sampling rate of 20Msps, each short preamble (0.8us) corresponds to 16 sampling points, each long preamble (3.2us) corresponds to 64 sampling points, and the cyclic prefix G12 (1.6us) corresponds to 32 sampling points sampling points, thus the entire preamble corresponds to 320 sampling points.

Since the received signal is obtained based on the transmitted signal, and the transmitted signal includes a reference signal (carrier) and radio frequency fingerprint information, the structure of the received signal can be consistent with that of the reference signal. In this way, the received signal may also be a signal of the preamble part, for example, specifically, it may be a signal whose length is N=320.

However, in an actual process, the received signal may include not only the signal of the preamble part, but also other signals. Here, the signal of the preamble part is intercepted as an example for illustration, and other feasible embodiments of the present application are not limited.

The expression formula (1) of the signal to be processed is as follows:

y(n)=x(n)*h(n)+ε(n), n=0, 1, ..., N _y-1 ... formula (1)

Among them, x(n) represents the transmitted signal containing RF fingerprint information (specifically the transmitted preamble signal), * represents the linear convolution operation, h(n) represents the multipath channel, ε(n) represents the additive noise, N _y - 1 represents the length of the signal.

S203: Perform time-frequency analysis on the signal to be processed and the reference signal respectively to obtain a first signal spectrum and a second signal spectrum.

In an optional embodiment, the server may use continuous wavelet transform to perform time-frequency analysis on the signal to be processed and the reference signal respectively, to obtain the first signal spectrum corresponding to the signal to be processed and the second signal spectrum corresponding to the reference signal.

In another optional embodiment, the server can use short-time Fourier transform (short-time Fourier transform, STFT) to perform time-frequency analysis on the signal to be processed and the reference signal to obtain the first signal spectrum corresponding to the signal to be processed A second signal spectrum corresponding to the reference signal. The short-time Fourier transform is used because the Fourier transform only reflects the characteristics of the signal in the frequency domain, and cannot analyze the signal in the time domain. In order to relate the time domain and the frequency domain, this application uses a short-time Fourier transform. The short-time Fourier transform process is: multiply a time-limited window function before the signal is Fourier transformed, and assume that the non-stationary signal is stable within the short time interval of the analysis window, and pass the window function on the time axis Moving, the signal is analyzed segment by segment to obtain a set of local "spectrums" of the signal. And because the short-time Fourier transform is basically the Fourier transform, it is easier to understand and analyze.

In an optional embodiment of using short-time Fourier transform (STFT) to perform time-frequency analysis on the signal to be processed and the reference signal, the server may perform windowing processing on the signal to be processed and the reference signal respectively to obtain the first signal and the reference signal second signal.

Optionally, the server may use a window function to respectively perform windowing processing on each sub-signal in the signal to be processed and each sub-signal in the reference signal.

Optionally, the window function can be Hamming window, Hanning window, triangular window, rectangular window and so on. The main purpose of windowing is to make the time-domain signal better meet the periodic requirements of Fourier transform processing and reduce leakage.

Optionally, the server can select the length M of the window to be 64 based on the number of long preamble sampling points of 64, and select the sliding interval R between adjacent windows to be 16 according to the number of short preamble sampling points of 16, and the signals between adjacent windows overlap The length is 48. The above-mentioned window length, sliding interval, and signal overlap length are just an example, and may be set based on actual requirements and experience in actual situations.

In this way, the expression formula (2) of the mth windowed signal to be processed can be obtained, as follows:

y _m (n) = y (n + mR) ω (n), n = 0, 1, ..., M-1 ... formula (2)

In this way, the expression formula (3) of the m-th windowed reference signal can be obtained, as follows:

s _m (n) = s (n + mR) ω (n), n = 0, 1, ..., M-1 ... formula (3)

Wherein, ω(n) represents a window function, which may be a Hamming window; s(n) is a reference signal.

Optionally, the server respectively performs Fourier transform on the first signal and the second signal to obtain the first signal spectrum and the second signal spectrum.

Specifically, the server may perform Fourier transform on each sub-signal in the windowed first signal and each sub-signal in the windowed second signal to obtain the first signal spectrum and the second signal spectrum.

Continuing to take the m-th sub-signal as an example, the server can perform N=64-point Fourier transform on the m-th signal y _m (n) and s _m (n) after windowing to obtain the signal spectrum Y _m (k) and S _m (k), the specific formula is as follows:

Then, after the server performs Fourier transform on all windowed sub-signals, the first signal spectrum and the second signal spectrum can be obtained, wherein the formula of the first signal spectrum is:

Y(k)=[Y ₀ (k), Y ₁ (k), Y ₂ (k), ..., Y _F-1 (k)]...Formula (6)

Wherein, the formula of the second signal spectrum is:

S(k)=[S ₀ (k), S ₁ (k), S ₂ (k), ..., S _F-1 (k)]...Formula (7)

in,

represents the floor function.

The time-frequency analysis of the received baseband signal is carried out by short-time Fourier transform, and the time-domain and frequency-domain features are extracted as the RF fingerprint information. In this way, the first signal spectrum corresponding to the signal to be processed collected by the receiving end at the preset position shown in FIG. 4 and the second signal spectrum corresponding to the reference signal shown in FIG. 5 can be obtained. It can be seen from the comparison of the two figures that due to the influence of radio frequency fingerprint information and wireless channels (including multipath channels and channel noise), there are significant differences between the signal spectrum of the signal to be processed and the signal spectrum of the corresponding reference signal, that is to say , the signal to be processed is significantly different from the ideal standard reference information due to the superposition of the characteristics of the radio frequency fingerprint information. Specifically, as shown in FIG. 4 , the part with a darker color is a part with relatively weak power.

S205: Determine a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum.

In this embodiment of the present application, the server may calculate based on the first signal spectrum and the second signal spectrum to obtain a first time-varying power spectrum corresponding to the first signal spectrum and a second time-varying power spectrum corresponding to the second signal spectrum.

Optionally, the first time-varying power spectrum P _Y (k) and the second time-varying power spectrum _PS (k) can be calculated respectively according to the following formula, as follows:

P _Y (k)＝[|Y ₀ (k)| ² ，|Y ₁ (k)| ² ，|Y ₂ (k)| ² ，…，|Y _F-1 (k)| ² ]… Formula (8)

P _S (k)＝[|S ₀ (k)| ² ，|S ₁ (k)| ² ，|S ₂ (k)| ² ，…，|S _F-1 (k)| ² ]… Formula (9)

Among them, |Y _m (k)| ² ＝|X _m (k)| ² |H(k)| ² ...... formula (10)

in,

Among them, x _m (n)=x(n+mR)ω(n), n=0, 1,..., M-1...Formula (13)

S207: Normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum.

In the embodiment of the present application, the server can normalize the first time-varying power spectrum P _Y (k) to obtain a channel-independent normalized time-varying power spectrum, and the specific formula is:

It can be seen from the above formula (14) that by dividing by the average power spectrum, the influence of the channel is effectively eliminated, that is, the multipath effect can be eliminated, and a large number of radio frequency fingerprint features are preserved. Also, the noise effect can be eliminated by the summation part of the denominator part. As shown in FIG. 6 , the normalized time-varying power spectrum G _Y corresponding to the signal to be processed collected at the preset position by the receiving end in this embodiment is shown.

S209: Determine an indicator matrix corresponding to the second signal spectrum.

In the embodiment of the present application, not all frequency points have signals, and signal-to-noise ratios at different frequency points are different. It can be seen from Figure 6 above that some frequency points are susceptible to interference from channel noise because the power of some frequency points fluctuates greatly with time, and the division method is relatively affected by noise, which will further amplify the fluctuation, resulting in unstable fingerprints of some time-frequency points. Therefore, to select the part with relatively large power according to the power of the reference signal (ideal signal), it is necessary to obtain an effective time-frequency power spectrum by calculating an indicator matrix.

In the embodiment of the present application, the server obtains an indication matrix Φ with a size of N×F (64×17) according to the second time-varying power spectrum P _S (k), and the indication matrix expresses the occupancy of reference signals (ideal transmission signals). The effective time-frequency points of , the matrix elements are composed of 0 and 1, where the elements of row k and column m are defined as follows:

Wherein, Th represents a preset effective time-frequency discrimination threshold, and in this embodiment, the threshold is set to one-tenth of the average value of the time-varying power spectrum of an ideal signal.

S211: Determine radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

In the embodiment of the present application, the server can calculate the Hadamard product of the normalized time-varying power spectrum G _Y and the indicator matrix Φ, and use the obtained effective time-frequency power spectrum G _Φ as the radio frequency fingerprint information RFF, the formula is as follows:

RFF＝G _Φ ＝G _Y ⊙Φ...Formula (16)

Among them, ⊙ represents matrix multiplication point by point.

The time-frequency analysis of the received baseband signal is carried out by short-time Fourier transform, and the time-domain and frequency-domain features are extracted as the radio frequency fingerprint information. The time-frequency characteristics, which are easily disturbed by channel noise, improve the robustness of RF fingerprints.

Optionally, after the server obtains the radio frequency fingerprint information, it may plot the radio frequency fingerprint information, that is, the effective time-frequency power spectrum, on a two-dimensional plane in the form of a chromaticity diagram, that is, form a visualized radio frequency fingerprint. This method can display the details of radio frequency fingerprints from two dimensions of time and frequency, and has a large amount of characteristic information, which is convenient for observation and comparison.

FIG. 7 shows the effective time-frequency power spectrum corresponding to the signal to be processed collected by the receiving end at a preset position in this embodiment.

To sum up, the radio frequency fingerprint extraction method based on short-time Fourier transform time-frequency analysis proposed in the embodiment of the present application, through a baseband signal (that is, a received signal received by the receiving end that contains radio frequency fingerprint information and a reference signal) A series of operations, including short-time Fourier transform, time-varying power spectrum calculation, channel-independent normalization, indicator matrix, time-varying power spectrum division, etc., can effectively remove the influence of channel additive noise and multipath effect, and then extract A large number of radio frequency fingerprint features in time domain and frequency domain can provide technical means for high-precision identification of transmitters using radio frequency fingerprint technology. The invention has low complexity, is easy to implement, and is applicable to various wireless communication systems, especially broadband wireless communication systems.

The embodiment of the present application also provides a signal processing device. FIG. 8 is a schematic structural diagram of a signal processing device provided in the embodiment of the present application. As shown in FIG. 8 , the device includes a signal acquisition module 801 and a signal spectrum determination module 802 , a signal spectrum determination module 803, a normalization processing module 804, an indication matrix determination module 805 and a radio frequency fingerprint information determination module 806,

Signal acquiring module 801, is used for acquiring signal to be processed and reference signal; Signal to be processed comprises radio frequency fingerprint information and reference signal;

A signal spectrum determination module 802, configured to perform time-frequency analysis on the signal to be processed and the reference signal respectively to obtain a first signal spectrum and a second signal spectrum;

A signal spectrum determining module 803, configured to determine a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum;

A normalization processing module 804, configured to normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

An indication matrix determination module 805, configured to determine an indication matrix corresponding to the second signal spectrum;

The radio frequency fingerprint information determination module 806 is configured to determine radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

In some possible embodiments, the signal acquisition module is configured to:

Get a reference signal.

In some possible embodiments, the signal acquisition module is configured to:

In some possible embodiments,

The signal to be processed is a signal of the preamble part;

The reference signal is a signal of the preamble part.

In some possible embodiments, the device also includes:

Display radio frequency fingerprint information on a two-dimensional plane.

The device and method embodiments in the embodiments of the present application are based on the same application concept.

The method embodiments provided in the embodiments of the present application may be executed in computer terminals, servers or similar computing devices. Taking running on a server as an example, FIG. 9 is a block diagram of a hardware structure of a server of a signal processing method provided by an embodiment of the present application. As shown in Figure 9, the server 900 may have relatively large differences due to different configurations or performances, and may include one or more central processing units (Central Processing Units, CPU) 910 (the processor 910 may include but not limited to microprocessor MCU or programmable logic device FPGA, etc.), memory 930 for storing data, one or more storage media 920 for storing application programs 923 or data 922 (for example, one or more mass storage devices). Wherein, the memory 930 and the storage medium 920 may be temporary storage or persistent storage. The program stored in the storage medium 920 may include one or more modules, and each module may include a series of instructions to operate on the server. Furthermore, the central processing unit 910 may be configured to communicate with the storage medium 920 , and execute a series of instruction operations in the storage medium 920 on the server 900 . The server 900 can also include one or more power supplies 960, one or more wired or wireless network interfaces 950, one or more input and output interfaces 940, and/or, one or more operating systems 921, such as Windows Server™, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

The input-output interface 940 can be used to receive or send data via a network. The specific example of the above network may include a wireless network provided by the communication provider of the server 900 . In one example, the input and output interface 940 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the input and output interface 940 may be a radio frequency (Radio Frequency, RF) module, which is used to communicate with the Internet in a wireless manner.

Those of ordinary skill in the art can understand that the structure shown in FIG. 9 is only a schematic diagram, which does not limit the structure of the above-mentioned electronic device. For example, server 900 may also include more or fewer components than shown in FIG. 9 , or have a different configuration than that shown in FIG. 9 .

Embodiments of the present application also provide a computer storage medium, which can be set in a server to store at least one instruction, at least one segment of program, and code related to a signal processing method in the method embodiment A set or an instruction set, the at least one instruction, the at least one section of program, the code set or the instruction set are loaded and executed by the processor to implement the above-mentioned signal processing method.

Optionally, in this embodiment, the foregoing storage medium may be located in at least one network server among multiple network servers of the computer network. Optionally, in this embodiment, the above-mentioned storage medium may include but not limited to: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk Various media that can store program codes such as discs or optical discs.

It can be seen from the above embodiments of the signal processing method, device or storage medium provided by the present application that in the present application, the signal to be processed and the reference signal are obtained; and the signal to be processed and the reference signal are respectively subjected to time-frequency analysis to obtain the first signal spectrum and the second signal spectrum. Two signal spectra; determine the first time-varying power spectrum corresponding to the first signal spectrum, and the second time-varying power spectrum corresponding to the second signal spectrum; normalize the first time-varying power spectrum to obtain normalized time-varying power spectrum; determining an indication matrix corresponding to the second signal spectrum; determining radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix. The embodiment of the present application extracts a large number of radio frequency fingerprint features in the time domain and frequency domain, so as to provide a feasible technical means for using the radio frequency fingerprint technology to identify transmitters with high precision.

It should be noted that: the order of the above-mentioned embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. And the above describes the specific embodiments of this specification. Other implementations are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Multitasking and parallel processing are also possible or may be advantageous in certain embodiments.

Each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the difference from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, please refer to part of the description of the method embodiment.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above embodiments can be completed by hardware, and can also be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned The storage medium mentioned may be a read-only memory, a magnetic disk or an optical disk, and the like.

The above descriptions are only preferred embodiments of the application, and are not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection of the application. within range.

Claims

A signal processing method, characterized in that the method comprises:

Obtain a signal to be processed and a reference signal; the signal to be processed includes radio frequency fingerprint information and the reference signal;

respectively performing time-frequency analysis on the signal to be processed and the reference signal to obtain a first signal spectrum and a second signal spectrum;

determining a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum;

normalizing the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

determining an indicator matrix corresponding to the second signal spectrum;

The radio frequency fingerprint information is determined based on the normalized time-varying power spectrum and the indication matrix.
The method according to claim 1, wherein the time-frequency analysis is performed on the signal to be processed and the reference signal respectively to obtain a first signal spectrum and a second signal spectrum, comprising:

performing windowing processing on the signal to be processed and the reference signal respectively to obtain a first signal and a second signal;

performing Fourier transform on the first signal and the second signal respectively to obtain the first signal spectrum and the second signal spectrum.
The method according to claim 1, wherein said obtaining the signal to be processed and the reference signal comprises:

Acquiring a received signal from a receiving end; the received signal is obtained based on a transmitted signal sent by a transmitting end; the transmitted signal includes the reference signal and the radio frequency fingerprint information;

performing signal processing on the received signal to obtain the signal to be processed;

Acquire the reference signal.
The method according to claim 3, wherein said performing signal processing on said received signal to obtain said signal to be processed comprises:

Perform signal synchronization processing, carrier frequency offset estimation processing, and residual frequency offset removal processing on the received signal and the reference signal to obtain the signal to be processed.
The method according to claim 4, characterized in that,

The signal to be processed is a signal of the preamble part;

The reference signal is a signal of the preamble part.
The method according to claim 1, further comprising:

The radio frequency fingerprint information is displayed on a two-dimensional plane.
A signal processing device, characterized in that the device comprises:

A signal acquisition module, configured to acquire a signal to be processed and a reference signal; the signal to be processed includes radio frequency fingerprint information and the reference signal;

a signal spectrum determination module, configured to perform time-frequency analysis on the signal to be processed and the reference signal respectively to obtain a first signal spectrum and a second signal spectrum;

A power spectrum determination module, configured to determine a first time-varying power spectrum corresponding to the first signal spectrum, and a second time-varying power spectrum corresponding to the second signal spectrum;

A normalization processing module, configured to normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

an indication matrix determination module, configured to determine an indication matrix corresponding to the second signal spectrum;

A radio frequency fingerprint information determination module, configured to determine the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix.
An electronic device, characterized in that the electronic device includes a processor and a memory, at least one instruction or at least one section of program is stored in the memory, and the at least one instruction or the at least one section of program is loaded by the processor And execute the signal processing method as described in any one of claims 1-6.
A computer-readable storage medium, characterized in that at least one instruction or at least one section of program is stored in the computer storage medium, and the at least one instruction or at least one section of program is loaded and executed by a processor to implement the claims 1- 6. Any one of the above signal processing methods.
A computer program product, characterized in that the computer program product includes a computer program, the computer program is stored in a readable storage medium, and at least one processor of a computer device reads and executes the computer program from the readable storage medium The computer program, so that the computer device executes the signal processing method according to any one of claims 1 to 6.