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

Abstract

The present application discloses a signal processing method, apparatus, electronic device and storage medium. The method includes: obtaining a signal to be processed and a 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 indication matrix corresponding to the second signal spectrum; and determining the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix. Embodiments of the present application provide a feasible technical means for accurately identifying a transmitter by using radio frequency fingerprint technology by extracting a large number of radio frequency fingerprint features in the time domain and frequency domain.

Description

Technical Field

[0001] This application relates to the field of Internet technologies, and in particular, to a signal processing method, apparatus, electronic device, and storage medium. Background Art

[0002] RF fingerprints originate from the differences in transmitter circuit designs and the manufacturing tolerances of hardware circuits during the production process. There are slight differences in device parameters even for different production batches or even within the same production batch. In addition, due to differences in component types, component layouts, and PCB traces, etc., the differences between transmitters designed by different manufacturers are even more significant.

[0003] RF fingerprints have uniqueness and are difficult to clone. This property of RF fingerprints can be used to identify wireless transmitters and also to authenticate the identity of transmitters to protect communication security. RF fingerprints are a kind of tiny signal distortion parasitic on the transmitted signal, and their generation mechanism is very complex and difficult to accurately model and characterize through a mathematical model. Therefore, it is also difficult to find a theoretically optimal RF fingerprint extraction method.

[0004] Since wireless transmitted signals usually reach the receiver through a wireless multipath channel, the transmitted signal and the multipath effect are in a convolutional relationship, and RF fingerprints are also in a convolutional relationship with the transmitted signal to a certain extent. Removing the multipath channel will inevitably damage the RF fingerprints. Therefore, the multipath effect greatly limits the accurate extraction of RF fingerprints. Summary of the Invention

[0005] Embodiments of this application provide a signal processing method, apparatus, electronic device, and storage medium.

[0006] On the one hand, embodiments of this application provide a signal processing method, which includes:

[0007] Obtain a signal to be processed and a reference signal; the signal to be processed includes RF fingerprint information and the reference signal;

[0008] 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;

[0009] 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;

[0010] Normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

[0011] Determine an indication matrix corresponding to the second signal spectrum;

[0012] Determine RF fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

[0013] In some possible embodiments, 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, including:

[0014] Windowing processing is performed on the signal to be processed and the reference signal respectively to obtain a first signal and a second signal;

[0015] Fourier transform is performed on the first signal and the second signal respectively to obtain a first signal spectrum and a second signal spectrum.

[0016] In some possible embodiments, obtaining the signal to be processed and the reference signal includes:

[0017] Obtaining a received signal from a receiving end; the received signal is obtained based on a transmitted signal transmitted by a transmitting end; the transmitted signal includes a reference signal and radio frequency fingerprint information;

[0018] Performing signal processing on the received signal to obtain the signal to be processed;

[0019] Obtaining the reference signal.

[0020] In some possible embodiments, performing signal processing on the received signal to obtain the signal to be processed includes:

[0021] Performing 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.

[0022] In some possible embodiments,

[0023] The signal to be processed is the signal of the preamble part;

[0024] The reference signal is the signal of the preamble part.

[0025] In some possible embodiments, the method further includes:

[0026] Displaying the radio frequency fingerprint information on a two-dimensional plane.

[0027] On the other hand, a signal processing device is provided, and the device includes:

[0028] 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;

[0029] 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;

[0030] 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;

[0031] A normalization processing module, configured to normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum;

[0032] An indication matrix determination module, configured to determine an indication matrix corresponding to the second signal spectrum;

[0033] An RF fingerprint information determination module, configured to determine RF fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

[0034] In some possible embodiments, a signal spectrum determination module is configured to:

[0035] Perform windowing processing on the signal to be processed and the reference signal respectively to obtain a first signal and a second signal;

[0036] Perform Fourier transform on the first signal and the second signal respectively to obtain a first signal spectrum and a second signal spectrum.

[0037] In some possible embodiments, a signal acquisition module is configured to:

[0038] Obtain a received signal from a receiving end; the received signal is obtained based on a transmitted signal transmitted by a transmitting end; the transmitted signal includes a reference signal and RF fingerprint information;

[0039] Perform signal processing on the received signal to obtain a signal to be processed;

[0040] Obtain a reference signal.

[0041] In some possible embodiments, a signal acquisition module is configured to:

[0042] 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 a signal to be processed.

[0043] In some possible embodiments,

[0044] The signal to be processed is a signal in a preamble part;

[0045] The reference signal is a signal in a preamble part.

[0046] In some possible embodiments, the apparatus further includes:

[0047] Display the RF fingerprint information on a two-dimensional plane.

[0048] On the other hand, an electronic device is provided, which includes a processor and a memory. At least one instruction or at least one program segment is stored in the memory, and the at least one instruction or at least one program segment is loaded and executed by the processor to perform any of the signal processing methods.

[0049] On the other hand, a computer-readable storage medium is provided, in which at least one instruction or at least one program segment is stored, and the at least one instruction or at least one program segment is loaded and executed by a processor to implement any one of the signal processing methods.

[0050] On the other hand, a computer program product is provided, the computer program product includes a computer program, the computer program is stored in a readable storage medium, and at least one processor of the computer device reads and executes the computer program, so that the computer device executes any one of the signal processing methods.

[0051] The signal processing method, device, electronic device and storage medium provided by the embodiments of the present application have the following technical effects:

[0052] Obtain a signal to be processed and a 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 a first signal spectrum and a second signal spectrum; 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; normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum; determine an indication matrix corresponding to the second signal spectrum; determine the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix. By extracting a large number of radio frequency fingerprint features in the time domain and frequency domain, the embodiments of the present application provide a feasible technical means for accurately identifying a transmitter using radio frequency fingerprint technology. Description of the Drawings

[0053] 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 required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0054] Figure 1 It is a schematic diagram of an application environment provided by an embodiment of the present application;

[0055] Figure 2 It is a schematic flowchart of a signal processing method provided by an embodiment of the present application;

[0056] Figure 3 It is a schematic diagram of a frame structure provided by an embodiment of the present application;

[0057] Figure 4 It is a schematic diagram of a signal spectrum provided by an embodiment of the present application;

[0058] Figure 5 It is a schematic diagram of a signal spectrum provided by an embodiment of the present application;

[0059] Figure 6 It is a schematic diagram of a time-varying power spectrum provided by an embodiment of the present application;

[0060] Figure 7 It is a schematic diagram of an effective time-frequency power spectrum provided by an embodiment of the present application;

[0061] Figure 8 It is a schematic structural diagram of a signal processing device provided by an embodiment of the present application;

[0062] Figure 9 It is a hardware structure block diagram of a server of a signal processing method provided by an embodiment of the present application. Detailed implementation manners

[0063] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0064] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order different from those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server including a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0065] Please refer to Figure 1 , Figure 1 It is a schematic diagram of an application environment provided by an embodiment of the present application. The schematic diagram includes a server 101 and a receiving end 102.

[0066] Specifically, the server 101 acquires a signal to be processed and a reference signal; performs 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; determines 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; normalizes the first time-varying power spectrum to obtain a normalized time-varying power spectrum; determines an indication matrix corresponding to the second signal spectrum; determines radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

[0067] The receiving end 102 may refer to a device including a receiver. Among them, the function of the receiver is opposite to that of the transmitter. The main function is to receive the signal in the channel, transform it into information in the same physical form as when it is transmitted, 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 information source from the disturbed signal to the greatest extent and reproduce the output of the information source as much as possible. A relatively common receiver is the satellite TV receiver.

[0068] In electronics, a transmitter or radio transmitter refers to a device that uses an antenna to transmit radio waves. The radio transmitter generates an alternating current, which acts on the antenna. The antenna generates radio waves and transmits them into space. In addition to its application in radio broadcasting, radio transmitters are also widely used in various devices that use radio for communication. Common applications include mobile phones, wireless local area networks, Bluetooth, wireless intercoms, and so on.

[0069] The following introduces a specific embodiment of a signal processing method of the present application. Figure 2 It is a schematic flowchart of a signal processing method provided by an embodiment of the present application. This specification provides the method operation steps such as in the embodiment or flowchart, but based on routine or non-creative labor, it may include more or fewer operation steps. The step order listed in the embodiment is only one way among the execution orders of numerous steps and does not represent the only execution order. When the actual system or server product executes, it can be executed in the order of the embodiment or the method shown in the drawings, or executed in parallel (for example, in an environment of parallel processors or multi-threaded processing). Specifically, as Figure 2 shown, the method may include:

[0070] 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.

[0071] In the embodiment of the present application, the server may obtain a received signal from the receiving end. Among them, the received signal is obtained through multi-path channel transmission based on the transmitted signal sent by the transmitting end. 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 the signal to be processed.

[0072] In an alternative embodiment, the transmitting end may superimpose the reference signal and the radio frequency fingerprint information to obtain a transmitted signal, and then send the transmitted signal out, which is received by the receiving end to obtain the received signal.

[0073] Optionally, the server may obtain the reference signal.

[0074] In an optional embodiment, after the server obtains the received signal from the receiving end, it can use the acquired reference signal and the received signal for signal synchronization processing, carrier frequency offset estimation processing, and residual frequency offset removal processing, so as to obtain the signal to be processed.

[0075] Specifically, the server can use the reference signal and the received signal for complex correlation and differential processing to achieve signal synchronization and carrier frequency offset estimation. Subsequently, the residual frequency offset is removed from the synchronized signal to obtain the signal to be processed.

[0076] Optionally, the signal to be processed can be a signal with a length of N. Here, the length of N means that the signal to be processed contains N sub-signals.

[0077] Optionally, the reference signal can be the signal of the preamble part in the IEEE 802.11n communication system, and its frame structure is as Figure 3 shown. In this frame structure, it includes 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 preamble parts occupies 8 us. Assuming that the baseband signal is sampled at a sampling rate of 20 Msps, each short preamble (0.8 us) corresponds to 16 sampling points, each long preamble (3.2 us) corresponds to 64 sampling points, and the cyclic prefix G12 (1.6 us) corresponds to 32 sampling points. Thus, the entire preamble corresponds to 320 sampling points.

[0078] Since the received signal is obtained based on the transmitted signal, and the transmitted signal includes the reference signal (carrier) and radio frequency fingerprint information, therefore, the structure of the received signal can be consistent with the reference signal. In this way, the received signal can also be the signal of the preamble part. For example, specifically, it can be a signal with a length of N = 320.

[0079] However, in the actual process, the received signal can not only include the signal of the preamble part, but also include other signals. Here, only the signal of the preamble part is intercepted as an example for illustration, and other feasible embodiments of the present application are not limited.

[0080] The expression formula (1) of the signal to be processed is as follows:

[0081] Formula (1)

[0082] Among them, x(n) represents the transmitted signal containing radio frequency fingerprint information (specifically, the transmitted preamble signal), represents the linear convolution operation, represents the multipath channel, represents the additive noise, represents the length of the signal.

[0083] 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.

[0084] In an alternative embodiment, the server may perform time-frequency analysis on the signal to be processed and the reference signal respectively by using continuous wavelet transform to obtain a first signal spectrum corresponding to the signal to be processed and a second signal spectrum corresponding to the reference signal.

[0085] In another alternative embodiment, the server may perform time-frequency analysis on the signal to be processed and the reference signal by using short-time Fourier transform (STFT) to obtain a first signal spectrum corresponding to the signal to be processed and a second signal spectrum corresponding to the reference signal. The reason for using short-time Fourier transform is that: Fourier transform only reflects the characteristics of the signal in the frequency domain and cannot analyze the signal in the time domain. To relate the time domain and the frequency domain, the present application uses short-time Fourier transform. The short-time Fourier transform process is as follows: Multiply a window function with a finite time before performing Fourier transform on the signal, and assume that the non-stationary signal is stationary within a short time interval of the analysis window. By moving the window function on the time axis, the signal is analyzed segment by segment to obtain a set of local "spectrums" of the signal. And since the basic formula of short-time Fourier transform is Fourier transform, it is easier to understand and analyze.

[0086] In an alternative embodiment of performing time-frequency analysis on the signal to be processed and the reference signal by using short-time Fourier transform (STFT), the server may perform windowing processing on the signal to be processed and the reference signal respectively to obtain a first signal and a second signal.

[0087] Optionally, the server may perform windowing processing on each sub-signal in the signal to be processed and each sub-signal in the reference signal by using a window function.

[0088] Optionally, the window function may be a Hamming window, a Hanning window, a triangular window, a rectangular window, etc. Windowing is mainly to make the time-domain signal better meet the periodicity requirements of Fourier transform processing and reduce leakage.

[0089] Optionally, the server may select the window length M to be 64 based on the long pilot code sampling points 64, select the sliding interval R between adjacent windows to be 16 according to the short pilot code sampling points 16, and the signal overlap length between adjacent windows is 48. The above window length, sliding interval, and signal overlap length are only one embodiment, and in actual situations, they can be set based on actual requirements and experience.

[0090] In this way, the expression formula (2) of the m-th windowed signal to be processed can be obtained as follows:

[0091] Formula (2)

[0092] In this way, the expression formula (3) of the m-th windowed reference signal can be obtained as follows:

[0093] Formula (3)

[0094] Wherein, represents a window function, which can be a Hamming window; is the reference signal.

[0095] Optionally, the server performs Fourier transforms on the first signal and the second signal respectively to obtain a first signal spectrum and a second signal spectrum.

[0096] Specifically, the server can perform Fourier transforms on each sub-signal in the windowed first signal and each sub-signal in the windowed second signal to obtain a first signal spectrum and a second signal spectrum.

[0097] Continuing with the m-th sub-signal as an example, the server can perform an N = 64-point Fourier transform on the windowed m-th signal and to obtain the signal spectra and , and the specific formulas are as follows:

[0098] Formula (4)

[0099] Formula (5)

[0100] Then, after the server performs Fourier transforms on all the windowed sub-signals, a first signal spectrum and a second signal spectrum can be obtained. Among them, the formula for the first signal spectrum is:

[0101] Formula (6)

[0102] Among them, the formula for the second signal spectrum is:

[0103] Formula (7)

[0104] Wherein, , represents the floor function.

[0105] By performing time-frequency analysis on the received baseband signal through short-time Fourier transform, time-domain and frequency-domain features are extracted simultaneously as RF fingerprint information. In this way, the Figure 4 shown first signal spectrum corresponding to the signal to be processed collected at the preset position by the receiving end can be obtained, and the Figure 5The second signal spectrum corresponding to the reference signal shown. As can be seen by comparing the two figures, due to the influence of radio frequency fingerprint information and the wireless channel (including the multipath channel 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, due to the superposition of the characteristics of radio frequency fingerprint information, the signal to be processed is significantly different from the ideal standard reference information. Specifically, as Figure 4 , the darker part has a weaker power.

[0106] S205: 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.

[0107] In the embodiments of the present application, the server can calculate 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 based on the first signal spectrum and the second signal spectrum.

[0108] Optionally, the first time-varying power spectrum and the second time-varying power spectrum can be calculated respectively according to the following formulas, as follows:

[0109] Formula (8)

[0110] Formula (9)

[0111] Wherein, Formula (10)

[0112] Wherein, Formula (11)

[0113] Formula (12)

[0114] Wherein, Formula (13)

[0115] S207: Normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum.

[0116] In the embodiments of the present application, the server can normalize the first time-varying power spectrum to obtain a channel-independent normalized time-varying power spectrum. The specific formula is:

[0117] Formula (14)

[0118] As can be seen from the above formula (14), 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 retained. Moreover, the influence of noise can be eliminated through the summation part in the denominator. As Figure 6The normalized time-varying power spectrum corresponding to the signal to be processed collected by the receiving end at the preset position in this embodiment is shown .

[0119] S209: Determine the indication matrix corresponding to the second signal spectrum.

[0120] In the embodiments of the present application, there are signals at not all frequency points, and the signal-to-noise ratios at different frequency points are different. As can be seen from the above Figure 6 , since the power fluctuations of some frequency points vary greatly with time and are easily affected by channel noise, and division is more affected by noise and will further amplify the fluctuations, resulting in unstable fingerprints at 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 calculate the indication matrix to obtain the effective time-frequency power spectrum.

[0121] In the embodiments of the present application, the server obtains an indication matrix of size according to the second time-varying power spectrum , and this indication matrix represents the effective time-frequency points occupied by the reference signal (relatively ideal transmitted signal). The matrix elements are composed of 0 and 1. Among them, the element in the k-th row and m-th column is defined as follows: , where Th represents the preset effective time-frequency discrimination threshold. In this embodiment, this threshold is set to one-tenth of the mean value of the time-varying power spectrum of the ideal signal.

[0122] Formula (15)

[0123] where Th represents the preset effective time-frequency discrimination threshold. In this embodiment, this threshold is set to one-tenth of the mean value of the time-varying power spectrum of the ideal signal.

[0124] S211: Determine the RF fingerprint information based on the normalized time-varying power spectrum and the indication matrix.

[0125] In the embodiments of the present application, the server can calculate the Hadamard product of the normalized time-varying power spectrum and the indication matrix , and use the obtained effective time-frequency power spectrum as the RF fingerprint information , and the formula is as follows:

[0126] Formula (16)

[0127] where represents element-by-element multiplication of the matrices.

[0128] By performing time-frequency analysis on the received baseband signal through short-time Fourier transform, time-domain and frequency-domain features are extracted as RF fingerprint information. The influence of multipath effects is eliminated through channel-independent normalization, and time-frequency features vulnerable to channel noise interference are removed using the indication matrix, improving the robustness of the RF fingerprint.

[0129] Optionally, after the server obtains the RF fingerprint information, the RF fingerprint information, that is, the effective time-frequency power spectrum, can be plotted on a two-dimensional plane in the form of a chromaticity diagram, that is, a visual RF fingerprint is formed. In this way, the details of the RF fingerprint can be displayed from two dimensions of time and frequency, and there are a large number of characteristic information, which is convenient for observation and comparison.

[0130] Figure 7 The effective time-frequency power spectrum corresponding to the signal to be processed collected by the receiving end at the preset position in this embodiment is shown.

[0131] In summary, the RF fingerprint extraction method based on short-time Fourier transform time-frequency analysis proposed in the embodiment of the present application performs a series of operations on the baseband signal (that is, the received signal containing RF fingerprint information and reference signal received by the receiving end), including short-time Fourier transform, time-varying power spectrum calculation, channel-independent normalization, indicator matrix, time-varying power spectrum division, etc., effectively removing the influence of channel additive noise and multipath effects, and then extracting a large number of RF fingerprint features in the time domain and frequency domain, which can provide a technical means for accurately identifying the transmitter using RF fingerprint technology. The present invention has low complexity, is easy to implement, and is applicable to various wireless communication systems, especially broadband wireless communication systems.

[0132] The embodiment of the present application also provides a signal processing device. Figure 8 It is a schematic structural diagram of a signal processing device provided by the embodiment of the present application. As Figure 8 shown, the device includes a signal acquisition module 801, a signal spectrum determination module 802, a signal spectrum determination module 803, a normalization processing module 804, an indicator matrix determination module 805, and an RF fingerprint information determination module 806.

[0133] The signal acquisition module 801 is used to acquire a signal to be processed and a reference signal; the signal to be processed includes RF fingerprint information and a reference signal.

[0134] The signal spectrum determination module 802 is used 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.

[0135] The signal spectrum determination module 803 is used 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.

[0136] The normalization processing module 804 is used to normalize the first time-varying power spectrum to obtain a normalized time-varying power spectrum.

[0137] The indicator matrix determination module 805 is used to determine an indicator matrix corresponding to the second signal spectrum.

[0138] 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.

[0139] In some possible embodiments, the signal spectrum determination module is configured to:

[0140] Perform windowing processing on the signal to be processed and the reference signal respectively to obtain a first signal and a second signal;

[0141] Perform Fourier transform on the first signal and the second signal respectively to obtain a first signal spectrum and a second signal spectrum.

[0142] In some possible embodiments, the signal acquisition module is configured to:

[0143] Obtain a 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 a reference signal and radio frequency fingerprint information;

[0144] Perform signal processing on the received signal to obtain a signal to be processed;

[0145] Obtain a reference signal.

[0146] In some possible embodiments, the signal acquisition module is configured to:

[0147] 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 a signal to be processed.

[0148] In some possible embodiments,

[0149] The signal to be processed is the signal of the preamble part;

[0150] The reference signal is the signal of the preamble part.

[0151] In some possible embodiments, the apparatus further includes:

[0152] Display the radio frequency fingerprint information on a two-dimensional plane.

[0153] The apparatus and the method embodiments in the embodiments of the present application are based on the same application concept.

[0154] The method embodiments provided by the embodiments of the present application can be executed on a computer terminal, a server, or a similar computing device. Taking running on a server as an example, Figure 9 It is a hardware structure block diagram of a server for a signal processing method provided by the embodiments of the present application. As Figure 9As shown, the server 900 can vary significantly due to differences in configuration or performance, and may include one or more central processing units (CPUs) 910 (the processor 910 may include, but is not limited to, processing devices such as a microprocessor MCU or a field-programmable gate array FPGA), a memory 930 for storing data, and one or more storage media 920 (such as one or more mass storage devices) for storing application programs 923 or data 922. Among them, the memory 930 and the storage medium 920 can be transient 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 instruction operations on the server. Further, the central processor 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 may also include one or more power supplies 960, one or more wired or wireless network interfaces 950, one or more input / output interfaces 940, and / or one or more operating systems 921, such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, and so on.

[0155] The input / output interface 940 can be used to receive or send data via a network. Specific examples of the above network may include a wireless network provided by the communication provider of the server 900. In one example, the input / output interface 940 includes a network interface controller (NIC), which can be connected to other network devices through a base station and thus communicate with the Internet. In one example, the input / output interface 940 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0156] Those of ordinary skill in the art can understand that Figure 9 the structure shown is only schematic and does not limit the structure of the above electronic device. For example, the server 900 may also include more or fewer components than Figure 9 shown in Figure 9 or have a different configuration from

[0157] Embodiments of the present application also provide a computer storage medium, which can be disposed in the server to store at least one instruction, at least one program, a code set or an instruction set related to implementing a signal processing method in the method embodiments. The at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the above signal processing method.

[0158] Optionally, in this embodiment, the above storage medium may be located in at least one of multiple network servers of a computer network. Optionally, in this embodiment, the above storage medium may include, but is not limited to: various media that can store program codes such as USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs.

[0159] On the other hand, an electronic device is provided. The electronic device includes a processor and a memory. At least one instruction or at least one segment of program is stored in the memory, and the at least one instruction or at least one segment of program is loaded and executed by the processor to perform any one of the signal processing methods.

[0160] On the other hand, a computer program product is provided. 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, so that the computer device performs any one of the signal processing methods.

[0161] As can be seen from the embodiments of the signal processing method, device, or storage medium provided by the present application above, in the present application, a signal to be processed and a reference signal are obtained; time-frequency analysis is respectively performed on the signal to be processed and the reference signal to obtain a first signal spectrum and a second signal spectrum; 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 are determined; the first time-varying power spectrum is normalized to obtain a normalized time-varying power spectrum; an indication matrix corresponding to the second signal spectrum is determined; and radio frequency fingerprint information is determined based on the normalized time-varying power spectrum and the indication matrix. The embodiments of the present application provide a feasible technical means for accurately identifying a transmitter by extracting a large number of radio frequency fingerprint features in the time domain and frequency domain.

[0162] It should be noted that: the above sequence of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the specific embodiments of this specification have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be executed in a different order than in the embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0163] Each embodiment in this specification is described in a progressive manner. For the identical or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and reference can be made to the relevant parts of the method embodiments for the relevant content.

[0164] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware, or can be completed by instructing the relevant hardware through a program. The program can be stored in a computer-readable storage medium, and the above-mentioned storage medium can be a read-only memory, a magnetic disk, an optical disk, or the like.

[0165] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. A signal processing method, characterized in that, The method includes: Obtaining a signal to be processed and a 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 indication matrix corresponding to the second signal spectrum; Determining the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix; The indication matrix represents valid time-frequency points occupied by the reference signal; The determining the radio frequency fingerprint information based on the normalized time-varying power spectrum and the indication matrix includes: Calculating the Hadamard product of the normalized time-varying power spectrum and the indication matrix, using the obtained Hadamard product as the valid time-frequency power spectrum, and using the valid time-frequency power spectrum as the radio frequency fingerprint information.

2. The method according to claim 1, wherein The 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 includes: 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.

3. The method according to claim 1, characterized in that, The obtaining the signal to be processed and the reference signal includes: Obtaining a received signal from a receiving end; the received signal is obtained based on a transmitted signal transmitted 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; Obtaining the reference signal.

4. The method according to claim 3, wherein The performing signal processing on the received signal to obtain the signal to be processed includes: Performing 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.

5. The method according to claim 4, wherein The signal to be processed is a signal of a preamble part; The reference signal is a signal of a preamble part.

6. The method according to claim 1, wherein The method further includes: Displaying the radio frequency fingerprint information on a two-dimensional plane.

7. A signal processing device, characterized in that, The apparatus includes: A signal acquisition module, configured to obtain 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; The indication matrix represents valid time-frequency points occupied by the reference signal; Determining the RF fingerprint information based on the normalized time-varying power spectrum and the indication matrix includes: Calculating the Hadamard product of the normalized time-varying power spectrum and the indication matrix, taking the obtained Hadamard product as the effective time-frequency power spectrum, and using the effective time-frequency power spectrum as the RF fingerprint information.

8. An electronic device, characterized in that, The electronic device includes a processor and a memory. At least one instruction or at least one program segment is stored in the memory, and the at least one instruction or the at least one program segment is loaded and executed by the processor to perform the signal processing method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, At least one instruction or at least one program segment is stored in the computer-readable storage medium, and the at least one instruction or the at least one program segment is loaded and executed by a processor to implement the signal processing method according to any one of claims 1-6.

10. 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. At least one processor of the computer device reads and executes the computer program, so that the computer device performs the signal processing method according to any one of claims 1 to 6.

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