Backscatter communication method and system based on FSK (Frequency Shift Keying)

Abstract

The invention relates to the technical field of wireless communication, and discloses an FSK-based backscatter communication method and system, and the method comprises the steps: carrying out the analysis of an actual link budget, constructing an FSK backscatter communication model, and enabling the analysis to comprise the analysis of the factors of hardware insertion loss, non-ideal antenna gain, path loss index and noise floor; a link budget is calculated, communication parameters are set to complete the communication process of backscattering, and the communication process comprises FSK modulation, incoherent demodulation and self-adaptive matched filtering processing. According to the method, various factors in actual deployment are considered for modeling and verification of the low-power-consumption backscatter communication system, the reliability of the system is effectively improved, the power consumption of the system is reduced, the communication distance of the system is optimized through theoretical analysis and experimental verification, and the system is made to adapt to different communication environments and application requirements.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a FSK-based backscatter communication method and system. Background Art

[0002] Backscatter technology does not need to generate signals by itself but uses the surrounding environmental signals for wireless communication. Especially for distributed photovoltaic (PV) power generation systems, backscatter technology meets the real-time sensing needs and reduces deployment and maintenance costs.

[0003] However, the existing backscatter models fail to fully consider the impact of factors in actual deployment, such as hardware insertion loss, non-ideal antenna gain, path loss exponent, and noise floor, which greatly affect the system performance. Therefore, it is necessary to develop a backscatter communication model that takes these practical factors into account to improve the reliability of the model. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed. Therefore, the present invention provides a FSK-based backscatter communication method to solve the problem of backscattering, which fully considers the influence of factors such as hardware insertion loss, non-ideal antenna gain, path loss index and noise floor in actual deployment, and improves the reliability of the model.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a backscatter communication method based on FSK, comprising: analyzing an actual link budget and constructing an FSK backscatter communication model, wherein the analysis includes factor analysis of hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor;

[0008] Based on the FSK backscatter communication model, a link budget is calculated and communication parameters are set to complete a backscatter communication process, wherein the communication process includes FSK modulation, incoherent demodulation and adaptive matched filtering processing.

[0009] As a preferred solution of the FSK-based backscatter communication method of the present invention, the construction of the FSK backscatter communication model includes:

[0010] Perform the first stage of signal propagation. In response to the signal sent by the transmitter, the tag analyzes the initial attenuation of the signal before it reaches the tag after receiving it, and calculates the signal power reaching the internal circuit of the tag;

[0011] In response to the signal received by the tag, the second stage of signal propagation is carried out. Based on the wireless channel propagation distance, the signal is transmitted from the tag antenna to the receiver, and the insertion loss during the signal propagation process and the wireless channel propagation loss are analyzed to obtain the maximum communication distance.

[0012] As a preferred solution of the FSK-based backscatter communication method of the present invention, the analysis of the initial attenuation includes:

[0013] Assuming that the signal propagation distance in the first stage is d, according to the electromagnetic wave propagation attenuation algorithm, the calculation formula of the initial attenuation Loss1 is obtained, which is expressed as:

[0014]

[0015] Among them, λ represents the carrier wavelength, α1 represents the channel attenuation index of the first stage;

[0016] After the initial attenuation, the signal power P reaching the internal circuit of the tag In It is expressed as:

[0017] P In =P Tx +(G Tx +G Tag )+Loss1

[0018] Among them, P Tx Indicates the transmit power, G Tx represents the transmit antenna gain, G Tag Represents the tag antenna incident gain.

[0019] As a preferred solution of the FSK-based backscatter communication method of the present invention, the analysis of the insertion loss and the wireless channel propagation loss during signal propagation includes:

[0020] The wireless channel propagation loss Loss2 is expressed as:

[0021]

[0022] Among them, α2 represents the channel attenuation index of the second stage;

[0023] Based on the wireless channel propagation loss Loss2, the signal power P received by the receiver Rx It is expressed as:

[0024] PRx =P out +(G Tag +G Rx )+Loss2

[0025] Among them, P Out Represents the output power of the tag, G Rx represents the receiving antenna gain;

[0026] The insertion loss of the tag is the difference between the power received by the tag and the transmitted power, expressed as:

[0027] T Loss =P Out -P In

[0028] Assuming that the signal propagation distances in the first and second phases are equal, the signal power received by the receiver is expressed as:

[0029] P Rx =(P Tx +G Tx +Loss1+G Tag )+T Loss +(G Tag +Loss2+G Rx )

[0030] Among them, G Rx Indicates the receiving antenna gain.

[0031] As a preferred solution of the FSK-based backscatter communication method of the present invention, the obtaining of the maximum communication distance includes:

[0032] Assume the noise floor is P n , the signal-to-noise ratio threshold required for successful demodulation is S, when P Rx >P n +S, stable communication can be maintained. Rx =P n +S indicates the theoretical critical communication distance of the tag;

[0033] The signal power P received by the receiver Rx The distance-related items included in are Loss1 and Loss2, and the following formula can be obtained, expressed as:

[0034] Loss1+Loss2=P n +S-(P Tx +G Tx +G Tag +T Loss +G Tag +G Rx )

[0035] Get the maximum communication distance d max , expressed as:

[0036]

[0037] As a preferred solution of the FSK-based backscatter communication method described in the present invention, the FSK modulation includes:

[0038] The transmitter sends a single carrier, and the backscatter tag works within the bandwidth B. The incident excitation signal is modulated by switching the RF switch. When the operating bandwidth is defined as B and the carrier frequency is f0, the backscatter signals are located at f L =f0-B / 2 and f H =f0+B / 2, the tag modulated signal c(t) is expressed as:

[0039] c(t)=a(t)cos(2πf L t)+(1-a(t))cos(2πf H t)

[0040] Where a(t) represents a square wave with a period of T;

[0041] The backscattered signal based on FSK modulation, that is, the signal received by the receiver is expressed as:

[0042]

[0043] Among them, f s represents the introduced frequency offset, f c represents the system frequency offset, and n(t) represents additive white Gaussian noise.

[0044] As a preferred solution of the FSK-based backscatter communication method described in the present invention, the incoherent demodulation and adaptive matched filtering processing include:

[0045] After FSK modulation, the signal is demodulated incoherently, and the signal is transferred from the RF band to the baseband to eliminate the frequency offset f s , the signal f(t) is expressed as:

[0046]

[0047] After acquiring the baseband signal, different baseband signals are extracted, and the orthogonal components of the baseband signals are passed through a pair of matched filters in parallel to obtain envelope detection signals of different frequencies;

[0048] Each baseband signal is passed through a low-pass filter to obtain an absolute value, the cutoff frequency of the filter is matched with the carrier frequency, and then the FSK low-frequency component and high-frequency component signals are combined and processed to obtain a bipolar waveform signal, which is then decoded to extract the sampling rate information corresponding to the maximum correlation peak amplitude.

[0049] In a second aspect, the present invention provides a FSK-based backscatter communication system, comprising:

[0050] A construction module is used to analyze the actual link budget and construct an FSK backscatter communication model, wherein the analysis includes hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor factor analysis;

[0051] The communication module is used to calculate the link budget based on the FSK backscatter communication model and set communication parameters to complete the backscatter communication process, which includes FSK modulation, incoherent demodulation and adaptive matched filtering processing.

[0052] In a third aspect, the present invention provides an electronic device, comprising:

[0053] Memory and processor;

[0054] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the FSK-based backscatter communication method are implemented.

[0055] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the FSK-based backscatter communication method.

[0056] Compared with the prior art, the present invention has the following beneficial effects: the present invention takes into account various factors in actual deployment to model and verify the low-power backscatter communication system, effectively improves the reliability of the system and reduces the system power consumption. Through theoretical analysis and experimental verification, the communication distance of the system is optimized to adapt to different communication environments and application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0058] Figure 1The figure is a schematic diagram of the overall process of the FSK-based backscatter communication method according to an embodiment of the present invention;

[0059] Figure 2 A schematic diagram of an FSK backscatter communication model of an FSK-based backscatter communication method according to an embodiment of the present invention;

[0060] Figure 3 A schematic diagram of non-coherent demodulation of a FSK-based backscatter communication method according to an embodiment of the present invention;

[0061] Figure 4 The present invention is a schematic diagram of a model verification process of an FSK-based backscatter communication method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0063] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0064] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0065] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0066] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] Reference Figure 1-Figure 4 , is an embodiment of the present invention, and provides a FSK-based backscatter communication method, such as Figure 1 As shown, including:

[0069] S100, such as Figure 2 , 4 As shown, the actual link budget is analyzed, and the FSK backscatter communication model is constructed. The analysis includes factors such as hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor.

[0070] Preferably, constructing the FSK backscatter communication model includes:

[0071] Perform the first stage of signal propagation, i.e., signal propagation from the transmitter to the backscattering tag. In response to the signal sent by the transmitter, the tag receives the signal and analyzes the initial attenuation of the signal before it reaches the tag, and calculates the signal power reaching the internal circuit of the tag;

[0072] In response to the signal received by the tag, the second stage of signal propagation is carried out. Based on the wireless channel propagation distance, the signal is transmitted from the tag antenna to the receiver, and the insertion loss during the signal propagation process and the wireless channel propagation loss are analyzed to obtain the maximum communication distance.

[0073] It should be noted that this embodiment proposes an FSK backscatter communication model that includes factors such as hardware insertion loss, non-ideal antenna gain, path loss index and noise floor. The model takes into account the impact of changes in antenna gain and path loss index on communication distance, and introduces hardware insertion loss as an important parameter for system design. Through comprehensive consideration of these parameters, the model can more accurately predict the effectiveness and range of backscatter communication under different deployment conditions.

[0074] Specifically, the link budget analysis of the backscatter communication process can be divided into two stages. The first stage involves the signal propagation from the transmitter to the backscatter tag. The transmitter is equipped with an omnidirectional antenna and sends out a signal. The signal undergoes initial attenuation before reaching the tag. The tag's omnidirectional antenna receives the signal, which is then reflected by the tag's internal circuit and transmitted through the antenna port.

[0075] Preferably, the analysis of initial decay includes:

[0076] Assuming that the signal propagation distance in the first stage is d, according to the electromagnetic wave propagation attenuation algorithm, the calculation formula of the initial attenuation Loss1 is obtained, which is expressed as:

[0077]

[0078] Where λ represents the carrier wavelength and α1 represents the channel attenuation index of the first stage, which is equal to 2 in free space propagation. However, the actual channel attenuation index is usually greater than 2 due to factors such as air dust scattering and ground reflection of electromagnetic waves in the real environment.

[0079] After the initial attenuation, the signal power P reaching the internal circuit of the tag In It is expressed as:

[0080] P In =P Tx +(G Tx +G Tag )+Loss1

[0081] Among them, P Tx Indicates the transmit power, G Tx represents the transmit antenna gain, G Tag Represents the tag antenna incident gain.

[0082] Specifically, the second stage of propagation involves the signal being transmitted from the tag antenna, propagating a distance d through the wireless channel, and being received by the receiver's omnidirectional antenna, a process that includes an insertion loss T Loss And the wireless channel propagation loss L0ss2 is similar to the attenuation in the first stage propagation process.

[0083] Preferably, analyzing the insertion loss and wireless channel propagation loss during signal propagation includes:

[0084] The wireless channel propagation loss Loss2 is expressed as:

[0085]

[0086] Among them, α2 represents the channel attenuation index of the second stage;

[0087] Based on the wireless channel propagation loss Loss2, assuming that the tag output power is P Out , and considering that the tag uses a single antenna, the gain is expressed as G Tag , used for receiving and transmitting, therefore, the signal power P received by the receiver Rx It is expressed as:

[0088] P Rx =P Out +(G Tag +G Rx )+Loss2

[0089] Among them, P Out Represents the output power of the tag, G Rx represents the receiving antenna gain;

[0090] The insertion loss of the tag is the difference between the power received by the tag and the transmitted power, expressed as:

[0091] T Loss =P Out -P In

[0092] Assuming that the signal propagation distances in the first and second phases are equal, the signal power received by the receiver is expressed as:

[0093] P Rx =(P Tx +G Tx +Loss1+G Tag )+T Loss +(G Tag +Loss2+G Rx )

[0094] Among them, G Rx Indicates the receiving antenna gain.

[0095] Preferably, let the noise floor be P n , the signal-to-noise ratio threshold required for successful demodulation is S, when P Rx >P n +S, stable communication can be maintained. Rx =P n+S indicates the theoretical critical communication distance of the tag;

[0096] The signal power P received by the receiver Rx The distance-related items included in are Loss1 and Loss2, and the following formula can be obtained, expressed as:

[0097] Loss1+Loss2=P n +S-(P Tx +G Tx +G Tag +T Loss +G Tag +G Rx )

[0098] Get the maximum communication distance d max , expressed as:

[0099]

[0100] S200, based on the FSK backscatter communication model, calculate the link budget and set the communication parameters to complete the backscatter communication process, the communication process includes FSK modulation, incoherent demodulation and adaptive matched filter processing.

[0101] It should be noted that the present invention uses FSK modulation to encode information onto the backscattered signal to achieve reliable data transmission, and adopts a non-coherent demodulation scheme that includes an adaptive bit rate matching filter to allow retrieval of specific tag information.

[0102] Specifically, the transmitter is equipped with a single antenna and sends a single carrier s(t) = cos(2πf0t) as excitation, where f0 is the carrier frequency. The backscatter tag works within the bandwidth B and modulates the incident excitation signal by switching the radio frequency (RF) switch. In order to avoid interference on the direct path from the transmitter to the receiver, the frequency of the reflected signal is offset from the original excitation frequency. Therefore, the signal y(t) received by the receiver can be expressed as:

[0103]

[0104] Where c(t) is the signal modulated by the tag, x(t) is the signal transmitted through the backward channel, and f s represents the introduced frequency offset, f c is the system frequency offset, and n(t) represents additive white Gaussian noise.

[0105] Preferably, FSK modulation includes:

[0106] The transmitter sends a single carrier, and the backscatter tag works within the bandwidth B. The incident excitation signal is modulated by switching the RF switch. When the operating bandwidth is defined as B and the carrier frequency is f0, the backscatter signals are located at f L =f0-B / 2 and f H =f0+B / 2, the tag modulated signal c(t) is expressed as:

[0107] c(t)=a(t)cos(2πf L t)+(1-a(t))cos(2πf H t)

[0108] Where a(t) represents a square wave with a period of T;

[0109] The backscattered signal based on FSK modulation, that is, the signal received by the receiver is expressed as:

[0110]

[0111] Among them, f s represents the introduced frequency offset, f c represents the system frequency offset, and n(t) represents additive white Gaussian noise.

[0112] Preferably, the incoherent demodulation and adaptive matched filtering processing include:

[0113] After FSK modulation, the signal is demodulated non-coherently, and the signal is transferred from the RF band to the baseband to eliminate the frequency offset f s , the signal f(t) is expressed as:

[0114]

[0115] After acquiring the baseband signal, different baseband signals are extracted, and the orthogonal components of the baseband signals are passed through a pair of matched filters in parallel to obtain envelope detection signals of different frequencies;

[0116] like Figure 3 As shown, each baseband signal takes an absolute value through a low-pass filter, the cutoff frequency of the filter matches the carrier frequency, and then the FSK low-frequency component and high-frequency component signals are combined and processed to obtain a bipolar waveform signal, which is then decoded to extract the sampling rate information corresponding to the maximum correlation peak amplitude.

[0117] Exemplarily, after acquiring the baseband signal, its orthogonal components are passed through a pair of matched filters in parallel, and then envelope detection signals of different frequencies are obtained. It should be noted that the frequency offset fc is significantly smaller than the bit rate 1 / T, and for the convenience of analysis, the noise is not considered. Four different baseband signals are extracted as follows:

[0118]

[0119] Each signal is then passed through a low-pass filter whose cutoff frequencies match the baseband carrier frequency f0 after taking its absolute value, and then summed according to the following combination:

[0120] I-channel signal of FSK low frequency component Q signal with FSK low frequency component Add; similarly, the I signal of the FSK high frequency component Q signal with FSK low frequency component Addition;

[0121] The bipolar waveform signal obtained by subtracting the last two square sums is:

[0122] v(t)=(g i2 (t) 2 +g q2 (t) 2 )-(g i1 (t) 2 +g q1 (t) 2 )=2a(t)-1

[0123] It should be noted that the above process eliminates the system frequency offset f c , a bipolar waveform v(t) is obtained, which is then decoded to extract the embedded information.

[0124] Adaptive matched filtering, under the premise of known tag preamble sequence, simultaneously changes the duration of the FIR filter coefficient sequence and the sampling frequency of decoding. In the related operations performed by decoding, the sampling rate corresponding to the maximum correlation peak amplitude is extracted. This optimally identified sampling frequency directly corresponds to the bit rate of the target tag.

[0125] It should be noted that the present invention adopts a non-coherent demodulation scheme and no longer relies on restoring the precise carrier phase for demodulation, thereby simplifying the design complexity of the system. In addition, an adaptive bit rate matching filter is integrated, which can automatically adjust the transmission rate according to the communication environment to ensure the best communication quality, demonstrating the low energy consumption characteristics of the present invention and its potential in practical applications.

[0126] The present invention takes into account various factors in actual deployment to model and verify the low-power backscatter communication system, effectively improves the reliability of the system and reduces the system power consumption. Through theoretical analysis and experimental verification, the communication distance of the system is optimized to adapt to different communication environments and application requirements.

[0127] The above is a schematic scheme of a backscatter communication method based on FSK in this embodiment. It should be noted that the technical scheme of the backscatter communication system based on FSK and the technical scheme of the backscatter communication method based on FSK above belong to the same concept, and the details of the technical scheme of the backscatter communication system based on FSK in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the backscatter communication method based on FSK above.

[0128] The FSK-based backscatter communication system in this embodiment includes:

[0129] A construction module is used to construct an FSK backscatter communication model by analyzing the actual link budget, including hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor factors;

[0130] The communication module is used to set communication parameters based on the FSK backscatter communication model through link budget calculation to complete the backscatter communication process, which includes FSK modulation, incoherent demodulation and adaptive matched filtering processing.

[0131] Specifically, the communication module includes a modulation module and a demodulation module.

[0132] Modulation module, used for FSK modulation, the transmitter sends a single carrier, the backscatter tag works within bandwidth B, and modulates the incident excitation signal by switching the RF switch. When the operating bandwidth is defined as B and the carrier frequency is f0, the backscatter signals are located at f L =f0-B / 2 and f H =f0+B / 2, the tag modulated signal c(t) is expressed as:

[0133] c(t)=a(t)cos(2πf L t)+(1-a(t))cos(2πf H t)

[0134] Where a(t) represents a square wave with a period of T;

[0135] The backscattered signal based on FSK modulation, that is, the signal received by the receiver is expressed as:

[0136]

[0137] Among them, f s represents the introduced frequency offset, f c represents the system frequency offset, and n(t) represents additive white Gaussian noise.

[0138] Demodulation module, including down-conversion module, FIR filter module, low-pass filter module and decoding module;

[0139] First, the signal is transferred from the RF band to the baseband through a down-conversion module to eliminate the frequency offset f s , the signal is:

[0140]

[0141] After acquiring the baseband signal, its orthogonal components are passed through a pair of matched FIR filters in parallel, and then envelope detection signals of different frequencies are obtained;

[0142] Then each signal passes through a low-pass filter, and after taking the absolute value, the cutoff frequencies of these filters match the baseband carrier frequency f0, and then the signals of the FSK low-frequency component and high-frequency component are combined and processed to obtain a bipolar waveform signal;

[0143] The bipolar waveform signal is then sent to the decoding module to extract the embedded information.

[0144] Under the premise of knowing the tag leading sequence, the duration of the coefficient sequence of the FIR filter and the sampling rate of the decoding module are changed simultaneously. In the correlation operation performed by the decoding module, the sampling rate corresponding to the maximum correlation peak amplitude is extracted. This optimally identified sampling frequency directly corresponds to the bit rate of the target tag.

[0145] Specifically, the device in the system of the present invention includes a transmitter responsible for generating an excitation signal, a single antenna tag that uses a radio frequency (RF) switch to perform signal modulation, and a receiver specifically responsible for signal demodulation.

[0146] This embodiment further provides an electronic device, which is applicable to the case of FSK-based backscatter communication, including:

[0147] Memory and processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the FSK-based backscatter communication method proposed in the above embodiment.

[0148] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the FSK-based backscatter communication method proposed in the above embodiment is implemented.

[0149] The storage medium proposed in this embodiment and the method for implementing FSK-based backscatter communication proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0150] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0151] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A backscatter communication method based on FSK, characterized in that: include: Analyze the actual link budget and build an FSK backscatter communication model, including hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor factor analysis; Based on the FSK backscatter communication model, a link budget is calculated and communication parameters are set to complete a backscatter communication process, wherein the communication process includes FSK modulation, incoherent demodulation and adaptive matched filtering processing.

2. The FSK-based backscatter communication method according to claim 1, characterized in that: Described constructing FSK backscatter communication model comprises: Perform the first stage of signal propagation. In response to the signal sent by the transmitter, the tag analyzes the initial attenuation of the signal before it reaches the tag after receiving it, and calculates the signal power reaching the internal circuit of the tag; In response to the signal received by the tag, the second stage of signal propagation is carried out. Based on the wireless channel propagation distance, the signal is transmitted from the tag antenna to the receiver, and the insertion loss during the signal propagation process and the wireless channel propagation loss are analyzed to obtain the maximum communication distance.

3. The FSK-based backscatter communication method according to claim 2, characterized in that: The analysis of the initial decay includes: Assuming that the signal propagation distance in the first stage is d, according to the electromagnetic wave propagation attenuation algorithm, the calculation formula of the initial attenuation Loss1 is obtained, which is expressed as: Among them, λ represents the carrier wavelength, α1 represents the channel attenuation index of the first stage; After the initial attenuation, the signal power P reaching the internal circuit of the tag In It is expressed as: P In =PT x +(GT x +G Tag )+Loss1 Among them, P Tx Indicates the transmit power, G Tx represents the transmit antenna gain, G Tag Represents the tag antenna incident gain.

4. The FSK-based backscatter communication method according to claim 3, characterized in that: The analysis of the insertion loss during signal propagation and the wireless channel propagation loss includes: The wireless channel propagation loss Loss2 is expressed as: Among them, α2 represents the channel attenuation index of the second stage; Based on the wireless channel propagation loss Loss2, the signal power P received by the receiver Rx It is expressed as: P Rx =P Out +(G Tag +G Rx )+Loss2 Among them, P Out Represents the output power of the tag, G Rx represents the receiving antenna gain; The insertion loss of the tag is the difference between the power received by the tag and the transmitted power, expressed as: T Loss =P out -P In Assuming that the signal propagation distances in the first and second phases are equal, the signal power received by the receiver is expressed as: P Rx =(P Tx +G Tx +Loss1+G Tag )+T Loss +(G Tag +Loss2+G Rx ) Among them, G Rx Indicates the receive antenna gain.

5. The FSK-based backscatter communication method according to claim 4, characterized in that: The obtaining of the maximum communication distance comprises: Assume the noise floor is P n , the signal-to-noise ratio threshold required for successful demodulation is S, when P Rx >P n +S, stable communication can be maintained. Rx =P n +S indicates the theoretical critical communication distance of the tag; The signal power P received by the receiver Rx The distance-related items included in are Loss1 and Loss2, and the following formula can be obtained, expressed as: Loss1+Loss2=P n +S-(P Tx +G Tx +G Tag +T Loss +G Tag +G Rx ) Get the maximum communication distance d max , expressed as:

6. The FSK-based backscatter communication method according to claim 1 or 5, characterized in that: The FSK modulation includes: The transmitter sends a single carrier, and the backscatter tag works within the bandwidth B. The incident excitation signal is modulated by switching the RF switch. When the operating bandwidth is defined as B and the carrier frequency is f0, the backscatter signals are located at f L =f0-B / 2 and f H =f0+B / 2, the tag modulated signal c(t) is expressed as: c(t)=a(t)cos(2πf L t)+(1-a(t))cos(2πf H t) Where a(t) represents a square wave with a period of T; The backscattered signal based on FSK modulation, that is, the signal received by the receiver is expressed as: Among them, f s represents the introduced frequency offset, f c represents the system frequency offset, and n(t) represents additive white Gaussian noise.

7. The FSK-based backscatter communication method according to claim 6, characterized in that: The incoherent demodulation and adaptive matched filtering processing include: After FSK modulation, the signal is demodulated incoherently, and the signal is transferred from the RF band to the baseband to eliminate the frequency offset f s , the signal f(t) is expressed as: After acquiring the baseband signal, different baseband signals are extracted, and the orthogonal components of the baseband signals are passed through a pair of matched filters in parallel to obtain envelope detection signals of different frequencies; Each baseband signal is passed through a low-pass filter to obtain an absolute value, the cutoff frequency of the filter is matched with the carrier frequency, and then the FSK low-frequency component and high-frequency component signals are combined and processed to obtain a bipolar waveform signal, which is then decoded to extract the sampling rate information corresponding to the maximum correlation peak amplitude.

8. A FSK-based backscatter communication system, characterized in that: include, A construction module is used to construct an FSK backscatter communication model by analyzing an actual link budget, wherein the analysis includes hardware insertion loss, non-ideal antenna gain, path loss index, and noise floor factor analysis; The communication module is used to set communication parameters based on the FSK backscatter communication model through link budget calculation to complete the backscatter communication process, wherein the communication process includes FSK modulation, incoherent demodulation and adaptive matched filtering processing.

9. An electronic device, characterized in that: include: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the FSK-based backscatter communication method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: It stores computer executable instructions, which, when executed by a processor, implement the steps of the FSK-based backscatter communication method described in any one of claims 1 to 7.

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