Signal transmission method and device, apparatus, and storage medium

Abstract

The application discloses a signal transmission method, device, equipment and storage medium. The method comprises the following steps: a first communication device sends an excitation signal to a tag device; the excitation signal is obtained by modulating a pulse coded signal by using a carrier signal generated based on a differential synchronization signal; wherein the excitation signal is used for the tag device to generate a backscattering modulation signal and backscatter the backscattering modulation signal to a second communication device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, and in particular to a signal transmission method and device, equipment and a storage medium. BACKGROUND

[0002] At present, the basic working process of a radio frequency identification (RFID) system includes: an energizing signal transmitter in a passive transceiver sends an energizing signal to a tag device, the tag device modulates its own information onto the energizing signal by using backscatter communication technology and backscatters the signal to a reflection communication receiver in the passive transceiver, and the reflection communication receiver in the passive transceiver receives the reflection signal sent by the tag device and demodulates it, thereby realizing information transmission among the energizing signal transmitter, the tag device and the reflection communication receiver. The tag device needs to communicate with the transmission communication receiver at a long distance, and in the backscatter communication process, due to signal interference, the passive receiver may not be able to accurately recover the source coding signal, thereby reducing the anti-interference ability of the passive backscatter communication link. SUMMARY

[0003] Therefore, the embodiments of the present application aim to provide a signal transmission method, device, equipment and storage medium.

[0004] The technical scheme of the embodiments of the present application is implemented as follows:

[0005] The embodiments of the present application provide a signal transmission method applied to a first communication device, and the method includes:

[0006] sending an energizing signal to a tag device; the energizing signal is obtained by modulating a pulse coding signal by using a carrier signal generated based on a differential synchronization signal;

[0007] The energizing signal is used by the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to a second communication device.

[0008] In addition, according to at least one embodiment of the present application, the method further includes:

[0009] generating the pulse coding signal, a first carrier signal and the differential synchronization signal;

[0010] generating a second carrier signal based on the first carrier signal and the differential synchronization signal;

[0011] mixing the pulse coding signal and the second carrier signal to obtain a first mixed signal;

[0012] modulate the first mixed signal to obtain the excitation signal.

[0013] In addition, according to at least one embodiment of the present application, the tag device is an active tag device, and the sending of the excitation signal to the tag device comprises:

[0014] The excitation signal is sent to the active tag device.

[0015] In addition, according to at least one embodiment of the present application, the tag device is a passive tag device, and the sending of the excitation signal to the tag device comprises:

[0016] The excitation signal is sent to the passive tag device.

[0017] At least one embodiment of the present application provides a signal transmission method applied to a tag device; the method comprises:

[0018] receiving an excitation signal; the excitation signal is obtained by modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal by a first communication device;

[0019] The excitation signal is used by the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to a second communication device.

[0020] In addition, according to at least one embodiment of the present application, the method further comprises:

[0021] generating a backscatter modulation signal according to the excitation signal;

[0022] backscattering the backscatter modulation signal to a second communication device.

[0023] In addition, according to at least one embodiment of the present application, the tag device is an active tag device,

[0024] The generating of the backscatter modulation signal according to the excitation signal comprises:

[0025] demodulating the excitation signal to obtain a pulse coded signal;

[0026] determining whether the pulse coded signal meets a preset condition;

[0027] In a case where it is determined that the pulse coded signal meets the preset condition, source encoding is performed on first information of the active tag device to generate a source encoded signal;

[0028] According to the source encoded signal, a first source encoded signal and a second source encoded signal are generated;

[0029] The excitation signal is sampled according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and the excitation signal is sampled according to odd times of the symbol period of the excitation signal to obtain a second excitation signal;

[0030] The first source encoded signal is mixed with the first excitation signal to generate a first passive back link signal, and the second source encoded signal is mixed with the second excitation signal to generate a second passive back link signal;

[0031] The first passive back link signal and the second passive back link signal are XOR processed to obtain the backscatter modulation signal.

[0032] In addition, according to at least one embodiment of the present application, the first source encoded signal is mixed with the first excitation signal to generate a first passive back link signal, and the second source encoded signal is mixed with the second excitation signal to generate a second passive back link signal, comprising:

[0033] A clock division signal is generated according to a clock period of a clock signal generated by a local oscillator loop in the active tag device;

[0034] The first source encoded signal is mixed with the first excitation signal to generate a first passive back link signal by using the clock division signal, and the second source encoded signal is mixed with the second excitation signal to generate a second passive back link signal.

[0035] In addition, according to at least one embodiment of the present application, the tag device is a passive tag device,

[0036] The backscatter modulation signal is generated according to the excitation signal, comprising:

[0037] The excitation signal is demodulated to obtain a pulse encoded signal;

[0038] It is judged whether the pulse encoded signal meets a preset condition;

[0039] In a case where it is determined that the pulse encoded signal meets the preset condition, a second information of the passive tag device is source encoded to generate a source encoded signal;

[0040] The source encoded signal is used to generate a first source encoded signal and a second source encoded signal;

[0041] sample the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and sample the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal;

[0042] mix the first source coded signal with the first excitation signal to generate a first passive back link signal, and mix the second source coded signal with the second excitation signal to generate a second passive back link signal;

[0043] use the first passive back link signal and the second passive back link signal as the backscatter modulation signal.

[0044] In addition, according to at least one embodiment of the present application, the mixing the first source coded signal with the first excitation signal to generate a first passive back link signal, and mixing the second source coded signal with the second excitation signal to generate a second passive back link signal comprises:

[0045] generating a clock division signal according to a pulse interval period corresponding to the pulse coded signal;

[0046] mixing the first source coded signal with the first excitation signal to generate a first passive back link signal, and mixing the second source coded signal with the second excitation signal to generate a second passive back link signal by using the clock division signal.

[0047] In addition, according to at least one embodiment of the present application, the judging whether the pulse coded signal satisfies a preset condition comprises:

[0048] judging whether the pulse coded signal is a broadcast message or a system preset downlink dedicated message;

[0049] determining that the pulse coded signal satisfies the preset condition in a case where it is determined that the pulse coded signal is a broadcast message or a system preset downlink dedicated message.

[0050] At least one embodiment of the present application provides a signal transmission method, applied to a second communication device, and the method comprises:

[0051] receiving a backscatter modulation signal backscattered by a tag device;

[0052] The backscatter modulation signal is generated by the tag device based on an excitation signal transmitted by a first communication device, and the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal by the first communication device.

[0053] Further, according to at least one embodiment of the present application, the receiving backscatter modulated signal backscattered by the tag device comprises:

[0054] receiving a backscatter modulated signal backscattered by an active tag device;

[0055] wherein,

[0056] the backscatter modulated signal is source encoded by the active tag device on the first information of itself to generate a source encoded signal; according to the source encoded signal, a first source encoded signal and a second source encoded signal are generated; the excitation signal is sampled according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and the excitation signal is sampled according to odd times of the symbol period of the excitation signal to obtain a second excitation signal; the first source encoded signal is mixed with the first excitation signal to generate a first passive back link signal, and the second source encoded signal is mixed with the second excitation signal to generate a second passive back link signal; and the first passive back link signal and the second passive back link signal are XOR processed.

[0057] Further, according to at least one embodiment of the present application, the receiving backscatter modulated signal backscattered by the tag device comprises:

[0058] receiving a backscatter modulated signal backscattered by a passive tag device;

[0059] wherein,

[0060] the backscatter modulated signal comprises a first passive back link signal and a second passive back link signal; the first passive back link signal and the second passive back link signal are source encoded by the passive tag device on the second information of itself to generate a source encoded signal; according to the source encoded signal, a first source encoded signal and a second source encoded signal are generated; the excitation signal is sampled according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and the excitation signal is sampled according to odd times of the symbol period of the excitation signal to obtain a second excitation signal; the first source encoded signal is mixed with the first excitation signal, and the second source encoded signal is mixed with the second excitation signal.

[0061] Further, according to at least one embodiment of the present application, the method further comprises:

[0062] demodulating the backscatter modulated signal to obtain the source encoded signal.

[0063] At least one embodiment of the present application provides a signal transmission device, comprising:

[0064] The sending module is configured to send an excitation signal to the tag device, wherein the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal.

[0065] The excitation signal is used by the tag device to generate a backscatter modulated signal and backscatter the backscatter modulated signal to the second communication device.

[0066] At least one embodiment of the present application provides a signal transmission device, comprising:

[0067] The first receiving module is configured to receive an excitation signal, wherein the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal.

[0068] The excitation signal is used by the tag device to generate a backscatter modulated signal and backscatter the backscatter modulated signal to the second communication device.

[0069] At least one embodiment of the present application provides a signal transmission device, comprising:

[0070] The second receiving module is configured to receive a backscatter modulated signal backscattered by the tag device.

[0071] The backscatter modulated signal is generated by the tag device based on an excitation signal sent by the first communication device, wherein the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal.

[0072] At least one embodiment of the present application provides a first communication device, comprising a processor and a memory for storing a computer program capable of running on the processor,

[0073] The processor is configured to execute steps of the method of any one of the above first communication device sides when running the computer program.

[0074] At least one embodiment of the present application provides a tag device, comprising a processor and a memory for storing a computer program capable of running on the processor,

[0075] The processor is configured to execute steps of the method of any one of the above tag device sides when running the computer program.

[0076] At least one embodiment of the present application provides a second communication device, comprising a processor and a memory for storing a computer program capable of running on the processor,

[0077] The processor is configured to execute the computer program to implement the steps of any of the methods described above.

[0078] At least one embodiment of the present application provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the methods described above.

[0079] The signal transmission method, device, equipment and storage medium provided by the embodiments of the present application, the method comprises: a first communication device sends an excitation signal to a tag device; the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal; wherein the excitation signal is used for the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to a second communication device.

[0080] The technical scheme provided by the embodiments of the present application is adopted, the first communication device modulates a pulse coded signal by a carrier signal generated based on a differential synchronization signal to obtain an excitation signal, and sends the excitation signal to a tag device. Subsequently, the tag device can use the excitation signal sent by the passive transmitter as a carrier signal to generate an approximate frequency shift keying signal with differential synchronization characteristics, i.e., a backscatter modulation signal, for the second communication device to recover the source coded signal. Since the approximate frequency shift keying signal with differential synchronization characteristics used by the tag device is not prone to serious distortion in the amplitude of the signal as the communication distance increases, and does not cause the backscatter signal sent by the tag device to the passive receiver to be misoperated, the second communication device can accurately recover the source coded signal, and the anti-interference capability of the passive backscatter communication link can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0081] Figure 1 is a schematic diagram of an RFID system in the related art;

[0082] Figure 2 is an implementation flowchart of the signal transmission method of the embodiments of the present application Figure 1 ;

[0083] Figure 3 is an implementation flowchart of the signal transmission method of the embodiments of the present application Figure 2 ;

[0084] Figure 4 is an implementation flowchart of the signal transmission method of the embodiments of the present application Figure 3 ;

[0085] Figure 5 is a system architecture schematic diagram of the signal transmission method of the embodiments of the present application;

[0086] Figure 6Ais a specific implementation flow diagram of the signal transmission method of the embodiment of the present application Figure 1 ;

[0087] Figure 6B is a frequency domain diagram of the first carrier signal of the embodiment of the present application

[0088] Figure 6C is a time domain diagram of the first carrier signal of the embodiment of the present application

[0089] Figure 7 is a specific implementation flow diagram of the signal transmission method of the embodiment of the present application Figure 2 ;

[0090] Figure 8 is a specific implementation flow diagram of the signal transmission method of the embodiment of the present application Figure 3 ;

[0091] Figure 9 is a component structure diagram of the signal transmission device of the embodiment of the present application Figure 1 ;

[0092] Figure 10 is a component structure diagram of the signal transmission device of the embodiment of the present application Figure 2 ;

[0093] Figure 11 is a component structure diagram of the signal transmission device of the embodiment of the present application Figure 3 ;

[0094] Figure 12 is a component structure diagram of the first communication device of the embodiment of the present application

[0095] Figure 13 is a component structure diagram of the tag device of the embodiment of the present application

[0096] Figure 14 is a component structure diagram of the second communication device of the embodiment of the present application DETAILED DESCRIPTION

[0097] Before the technical solutions of the embodiments of the present application are introduced, the related technologies are introduced.

[0098] Figure 1 is a diagram of the RFID system in the related technologies, such as Figure 1As shown, the basic working process is as follows: the excitation signal transmitter in the passive transceiver sends an excitation signal to the passive tag device, the passive tag device modulates its own information onto the excitation signal using backscatter communication technology and backscatters to the reflection communication receiver in the passive transceiver, the reflection communication receiver in the passive transceiver receives the reflection signal sent by the passive tag device and demodulates it, thereby realizing information transmission between the passive transceiver and the passive tag device. In order to save costs, a cellular network can be used to support passive or semi-passive Internet of Things applications. In this case, the cellular network needs to integrate passive or semi-passive Internet of Things technology.

[0099] Currently, the industry's research on the integration of passive Internet of Things and cellular networks is still in the demand research stage. From the current disclosed solutions, the main method is to attach a tag to the managed item, the receiver sends instructions to the exciter, the exciter forwards the instructions of the receiver to the tag device, and at the same time sends an excitation signal, the tag device receives the excitation signal and demodulates the instructions, and sends its own encoding and other information to the receiver through the antenna; the receiver receives the feedback signal sent by the tag device to realize command interaction and demodulate the encoded information.

[0100] Currently, in actual deployment scenarios, traditional RFID technology has limited communication distance and strong interference. Traditional ultra-high frequency RFID readers use a transceiver integrated full-duplex architecture to simultaneously transmit excitation signals and receive reflection signals, which causes strong system self-interference and inter-system mutual interference. In addition, the low receiving sensitivity of the tag device and the power limit of the RFID frequency band transmission result in limited coverage and a communication distance of less than 10m for traditional RFID technology, and a communication distance of less than 3m after integrating sensors. Therefore, in a split RFID system, in order to avoid the reflection signal sent by the tag device being misoperated due to the excessive communication distance in the actual deployment environment, the uplink and downlink channel adaptation capability of the transmission signal sent by the tag device needs to be improved.

[0101] How to improve the reception and anti-interference capability of the binary coding of the downlink relay link channel of the extremely low complexity passive tag to meet the needs of tag power conversion efficiency and decoding accuracy is a key challenge in the design of a split RFID system.

[0102] In addition, a low power wide area network (LPWAN) has the characteristics of "one long three low" (long distance, low power consumption, low cost, and low rate), and supports services with deeper coverage (20 dB), lower power consumption, and lower rate requirements. The LPWAN optimizes narrowband modulation technology (SS Chirp, UNB) and can obtain ultra-high receiving sensitivity (about 150 db) with low transmission power. Based on the SubG frequency band, the communication distance of the LPWAN technology can reach more than 15 km. Taking a lora signal as an example, the open area can cover 15-45 km, the suburb 15-22 km, and the urban area 3-8 km. However, for the downlink communication link of the passive tag of the split RFID system, there is no public passive technology and LPWA system fusion backscatter communication scheme to optimize the uplink and downlink performance of the passive tag.

[0103] Based on this, in the embodiments of the present application, the first communication device sends an excitation signal to the tag device; the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal; wherein the excitation signal is used for the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to the second communication device.

[0104] Referring to Figure 2 , Figure 2 is a flowchart of the implementation of the signal transmission method of the embodiments of the present application, applied to a first communication device, as shown in Figure 2 The method comprises the following steps:

[0105] Step 201: sending an excitation signal to the tag device; the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal; wherein the excitation signal is used for the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to the second communication device.

[0106] As an example, the tag device includes an active tag device and a passive tag device.

[0107] In some embodiments, the method further comprises:

[0108] generating the pulse coded signal, the first carrier signal, and the differential synchronization signal;

[0109] generating a second carrier signal based on the first carrier signal and the differential synchronization signal;

[0110] mixing the pulse coded signal and the second carrier signal to obtain a first mixed signal;

[0111] The first mixed signal is modulated to obtain the excitation signal.

[0112] As an example, the first communication device can source encode the original signal to generate a pulse encoded signal, wherein the original signal can be a signal formed by a string of binary bits.

[0113] Here, the source encoding method is not limited to: pulse width encoding (PIE, Pulse Interval Encoding), Manchester encoding, and a combination of the encoding methods.

[0114] As an example, the first carrier signal can include:

[0115] A narrowband modulation signal with high receiving sensitivity compatible with an LPWAN system, such as, but not limited to, a Lora signal, a Sigfox modulation signal, a ZETA signal, etc.

[0116] Or, a quadrature amplitude modulation signal compatible with a cellular system, such as, but not limited to, an NB-IoT, an LTE Cat.1 signal.

[0117] That is, a narrowband modulation signal with high receiving sensitivity compatible with an LPWAN system can be used as the first carrier signal, or a quadrature amplitude modulation signal compatible with a cellular system can be used as the first carrier signal.

[0118] It should be noted that the frequency domain characteristics of the first carrier signal can include: the starting positions of the waveforms in the odd symbol periods of the first carrier signal are fixed, and the starting positions are all at the same frequency offset position; the starting positions of the waveforms in the even symbol periods are also fixed, and the starting positions are all at the same frequency offset position.

[0119] It should be noted that the time domain characteristics of the first carrier signal can include: the frequencies of the waveforms in adjacent two symbol periods are different, such as, the waveform frequency of the first symbol period is a first frequency, and the waveform frequency of the second symbol period is a second frequency, the first frequency and the second frequency are different, and the two frequencies are transformed according to the period.

[0120] As an example, the differential synchronization signal can be a waveform sequence formed according to the values on the main diagonal line of a real number diagonal matrix, or a waveform sequence formed according to the values on the main diagonal line of a complex number diagonal matrix.

[0121] Here, the real number diagonal matrix can be a real number diagonal matrix in which real numbers 1 and -1 are alternately arranged on the k-order main diagonal line, and the complex number diagonal matrix can be a complex number diagonal matrix in which complex numbers i and -i are alternately arranged on the k-order main diagonal line.

[0122] Here, the differential synchronization signal can start with a real number 1 corresponding to a frequency waveform or start with a real number -1 corresponding to a frequency waveform, or can start with an imaginary number i corresponding to a frequency waveform or start with an imaginary number -i corresponding to a frequency waveform.

[0123] Here, the real number diagonal matrix with real numbers 1 and -1 alternating on the k-th main diagonal is represented by the following formula, and the specific formula is as follows:

[0124]

[0125] Where S1 represents the real number diagonal matrix with real numbers 1 and -1 alternating on the k-th main diagonal, and k is an integer greater than or equal to 2.

[0126] Here, the complex number diagonal matrix with imaginary numbers i and -i alternating on the k-th main diagonal is represented by the following formula, and the specific formula is as follows:

[0127]

[0128] Where S2 represents the complex number diagonal matrix with imaginary numbers i and -i alternating on the k-th main diagonal, and k is an integer greater than or equal to 2.

[0129] It should be noted that based on the first carrier signal and the differential synchronization signal, a second carrier signal with differential synchronization characteristics is generated, and the pulse coded signal is modulated using the second carrier signal. Compared with the traditional modulation method using a sinusoidal carrier signal, it helps to improve the link channel adaptation capability of the passive uplink and downlink carrier signal.

[0130] As an example, the mixing of the pulse coded signal and the second carrier signal can mean multiplying the pulse coded signal and the second carrier signal.

[0131] As an example, the modulation of the first mixed signal can mean amplitude modulation of the first mixed signal.

[0132] Here, the amplitude modulation method is not limited to double sideband amplitude modulation (DSB-ASK), single sideband amplitude modulation (SSB-ASK), and inverse amplitude modulation (PR-ASK).

[0133] In some embodiments, the tag device is an active tag device, and the method further comprises:

[0134] The excitation signal is transmitted to the active tag device.

[0135] In some embodiments, the tag device is a passive tag device, and the sending of the excitation signal to the tag device comprises:

[0136] The excitation signal is sent to the passive tag device.

[0137] In the embodiments of the present application, the following advantages are achieved:

[0138] (1) In the existing split RFID system, the tag device needs to communicate with a passive receiver such as a base station over a long distance. Due to signal interference, the amplitude shift keying signal used in the conventional method will be distorted seriously in the amplitude as the communication distance increases, resulting in the misoperation of the backscatter signal sent by the tag device to the passive receiver. Therefore, in the embodiments of the present application, the passive transmitter modulates the pulse coded signal with a carrier signal generated based on a differential synchronization signal with differential synchronization characteristics to obtain an excitation signal, and sends the excitation signal to the tag device. The tag device generates an approximate frequency shift keying signal with differential synchronization characteristics, i.e., a backscatter modulation signal, using the excitation signal sent by the passive transmitter as a carrier signal, for the passive receiver to recover a passive backscatter communication signal with correlation characteristics. Since the approximate frequency shift keying signal with differential synchronization characteristics used by the tag device is not easily distorted seriously in the amplitude as the communication distance increases, it will not result in the misoperation of the backscatter signal sent by the tag device to the passive receiver. That is, the receiving sensitivity and anti-interference capability of the passive backscatter communication link can be improved.

[0139] (2) A split RFID architecture integrated with an LPWA system in backscatter communication is proposed.

[0140] The split RFID architecture includes the first communication device, the tag device, and the second communication device. The first communication device can be a passive transmitter, which can be an exciter or an LPWA transceiver. The second communication device can be a passive receiver, which can be a reader or a base station.

[0141] (3) The circuit structure of the current tag device is simple, only supports simple envelope detection, and cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing. Therefore, in the embodiments of the present application, the tag device does not directly perform frequency shift keying modulation, but the passive receiver performs frequency shift keying modulation, so as to avoid the problem that the tag device cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing in the backscatter modulation in the related art.

[0142] For the passive tag device, it is difficult to provide a high-precision clock reference signal to realize frequency shift alignment by means of a simple circuit of the passive tag device. Through repeated sending and calculation of up-floating, the passive receiver receives repeated signals and performs bit decision to recover the original pulse signal.

[0143] Referring to Figure 3 , Figure 3 is a flowchart of an implementation of a signal transmission method according to an embodiment of the present application, which is applied to a tag device, as shown in Figure 3 The method comprises the following step 301.

[0144] Step 301: receiving an excitation signal; the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal by a first communication device; wherein the excitation signal is used for the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to a second communication device.

[0145] In some embodiments, the method further comprises:

[0146] generating a backscatter modulation signal according to the excitation signal;

[0147] backscattering the backscatter modulation signal to a second communication device.

[0148] In some embodiments, the tag device is an active tag device, and the generating a backscatter modulation signal according to the excitation signal comprises:

[0149] demodulating the excitation signal to obtain a pulse coded signal;

[0150] judging whether the pulse coded signal satisfies a preset condition;

[0151] in a case where it is determined that the pulse coded signal satisfies the preset condition, source encoding a first information of the active tag device to generate a source encoded signal;

[0152] generating a first source encoded signal and a second source encoded signal according to the source encoded signal;

[0153] sampling the excitation signal according to an even multiple of a symbol period of the excitation signal to obtain a first excitation signal, and sampling the excitation signal according to an odd multiple of the symbol period of the excitation signal to obtain a second excitation signal;

[0154] mixing the first source encoded signal with the first excitation signal to generate a first passive back link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back link signal;

[0155] The first passive back-link signal and the second passive back-link signal are XOR processed to obtain the backscatter modulation signal.

[0156] As an example, the active tag device receives the excitation signal through a down envelope detection circuit, demodulates the excitation signal to obtain a first mixed signal, and performs envelope detection processing on the first mixed signal to obtain a continuous pulse coded signal.

[0157] As an example, the first information of the active tag device can be identification information and other valid information of the active tag device.

[0158] As an example, the encoding mode of the first information is not limited to:

[0159] Polar (inner code) + Manchester (outer code) cascade encoding, that is, Manchester code modulation is superimposed on the basis of Polar encoding;

[0160] TBCC / Polar / FM0+repeated mode encoding, that is, TBCC / Polar / FM0 is repeatedly encoded;

[0161] Other encoding modes, such as Manchester code, Miller code, or FM0 code.

[0162] As an example, the active tag device can compare the voltage value of the waveform of the source coded signal with a first reference voltage, and after voltage comparison processing, if the voltage value of the waveform of the source coded signal is greater than the first reference voltage, it is judged as logic level 1, and the pulse signal corresponding to the logic level 1 is taken as the first source coded signal, wherein the amplitude of the pulse signal corresponding to the voltage value less than or equal to the first reference voltage in the waveform of the source coded signal is set to 0; compare the voltage value of the waveform of the source coded signal with a second reference voltage, and after voltage comparison processing, if the voltage of the waveform of the source coded signal is greater than the second reference voltage, it is judged as logic level 0, and the pulse signal corresponding to the logic level 0 is taken as the second source coded signal, wherein the amplitude of the pulse signal corresponding to the voltage value less than or equal to the second reference voltage in the waveform of the source coded signal is set to 0.

[0163] As an example, the active tag device samples the excitation signal according to even times of the symbol period of the excitation signal to obtain a first excitation signal, and samples the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal.

[0164] Here, the symbol period of the excitation signal can refer to the symbol period of the first carrier signal.

[0165] Here, the first excitation signal is denoted by g1(t1), where t1=2N×Δt; N=1, 2, 3,...M, M is an integer, and Δt is a symbol period of the first carrier signal.

[0166] Here, the second excitation signal is denoted by g2(t2), where t2=(2N+1)×Δt; N=1, 2, 3,...M, M is an integer, and Δt is a symbol period of the first carrier signal.

[0167] Wherein, t2-t1≥Δt.

[0168] As an example, here, the mixing of the first source encoded signal with the first excitation signal can refer to the multiplication of the first source encoded signal with the first excitation signal.

[0169] Here, the mixing of the second source encoded signal with the second excitation signal can refer to the multiplication of the second source encoded signal with the second excitation signal.

[0170] In some embodiments, the mixing of the first source encoded signal with the first excitation signal to generate a first passive backhaul signal, and the mixing of the second source encoded signal with the second excitation signal to generate a second passive backhaul signal, comprises:

[0171] Generating a clock division signal according to a clock period of a clock signal generated by a local oscillation loop in the active tag device;

[0172] Mixing the first source encoded signal with the first excitation signal to generate a first passive backhaul signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive backhaul signal, using the clock division signal.

[0173] In some embodiments, the tag device is a passive tag device,

[0174] The generating of the backscattering modulation signal according to the excitation signal comprises:

[0175] Demodulating the excitation signal to obtain a pulse encoded signal;

[0176] Determining whether the pulse encoded signal meets a preset condition;

[0177] In the case where it is determined that the pulse encoded signal meets the preset condition, source encoding a second information of the passive tag device to generate a source encoded signal;

[0178] generating a first source encoded signal and a second source encoded signal according to the source encoded signal;

[0179] sampling the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and sampling the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal;

[0180] mixing the first source encoded signal with the first excitation signal to generate a first passive back-link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back-link signal;

[0181] using the first passive back-link signal and the second passive back-link signal as the backscatter modulated signal.

[0182] As an example, the second information of the passive tag device can be identification information of the passive tag device, or other valid information.

[0183] It should be noted that the process of generating the first passive back-link signal and the second passive back-link signal by the passive tag device is similar to the process of generating the first passive back-link signal and the second passive back-link signal by the active tag device, and will not be repeated here.

[0184] As an example, the passive tag device can repeatedly send the first passive back-link signal to the second communication device, and repeatedly send the second passive back-link signal to the second communication device.

[0185] In some embodiments, the mixing the first source encoded signal with the first excitation signal to generate a first passive back-link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back-link signal, includes:

[0186] generating a clock division signal according to a pulse interval period corresponding to the pulse encoded signal;

[0187] mixing the first source encoded signal with the first excitation signal to generate a first passive back-link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back-link signal using the clock division signal.

[0188] As an example, here, the mixing the first source encoded signal with the first excitation signal can be multiplying the first source encoded signal with the first excitation signal.

[0189] Here, the mixing the second source coded signal with the second excitation signal can refer to multiplying the second source coded signal with the second excitation signal.

[0190] In some embodiments, the determining whether the pulse coded signal satisfies the preset condition comprises:

[0191] determining whether the pulse coded signal is a broadcast message or a system preset downlink dedicated message;

[0192] In a case where it is determined that the pulse coded signal is a broadcast message or a system preset downlink dedicated message, it is determined that the pulse coded signal satisfies the preset condition.

[0193] For example, it is determined whether a first specific bit in the pulse coded signal obtained by processing the excitation signal is same as a second specific bit in the broadcast message. If the specific bit in the pulse coded signal is same as the second specific bit in the broadcast message, it is determined that the pulse coded signal is a broadcast message issued by the passive transmitter, wherein the first specific bit can refer to at least one bit at a specific position in the pulse coded signal, such as the 3rd bit to the 4th bit, and the second specific bit can refer to at least one bit at a specific position in the broadcast message, such as the 5th bit to the 6th bit.

[0194] Alternatively, it is determined whether a first specific bit in the pulse coded signal obtained by processing the excitation signal is same as a third specific bit in the preset downlink dedicated message. If the first specific bit in the pulse coded signal is same as the third specific bit in the preset downlink dedicated message, it is determined that the pulse coded signal is the preset downlink dedicated message, wherein the third specific bit can refer to at least one bit at a specific position in the preset downlink dedicated message, such as the 3rd bit to the 4th bit.

[0195] In the embodiments of the present application, the following advantages are provided:

[0196] (1) Considering that in the existing separated RFID system, the tag device needs to communicate with the passive receiver such as the base station at a long distance, and due to signal interference, the amplitude shift keying signal adopted by the traditional method will be seriously distorted in the amplitude with the increase of the communication distance in the backscattering communication process, resulting in that the backscattering signal sent by the tag device to the passive receiver is misoperated, therefore, in the embodiment of the present application, the passive transmitter modulates the pulse coded signal by using the carrier signal generated based on the differential synchronization signal with differential synchronization characteristics to obtain an excitation signal, and sends the excitation signal to the tag device, the tag device generates the approximate frequency shift keying signal with differential synchronization characteristics, i.e. the backscattering modulation signal, by using the excitation signal sent by the passive transmitter as the carrier signal, so that the passive backscattering communication signal with correlation characteristics can be recovered by the passive receiver, and since the approximate frequency shift keying signal with differential synchronization characteristics adopted by the tag device is not easy to be seriously distorted in the amplitude with the increase of the communication distance, it will not cause the backscattering signal sent by the tag device to the passive receiver to be misoperated, that is, the receiving sensitivity and the anti-interference ability of the passive backscattering communication link can be improved.

[0197] (2) A separated RFID architecture integrated with the LPWA system in the backscattering communication is provided.

[0198] The separated RFID architecture includes the first communication device, the tag device and the second communication device, wherein the first communication device can be a passive transmitter, specifically, the passive transmitter can be an exciter or an LPWA transceiver, and the second communication device can be a passive receiver, specifically, the passive receiver can be a reader or a base station.

[0199] (3) Considering that the circuit structure in the current tag device is simple and only supports simple envelope detection, and cannot directly generate the frequency shift keying signal and is difficult to perform frequency shifting processing, therefore, in the embodiment of the present application, the tag device does not directly perform frequency shift keying modulation, but the passive receiver performs frequency shift keying modulation, so as to avoid the problem that the tag device in the related art cannot directly generate the frequency shift keying signal and is difficult to perform frequency shifting processing in the backscattering modulation.

[0200] For the passive tag device, considering that the simple circuit of the passive tag device is difficult to provide a high-precision clock reference signal to realize frequency shift alignment, the passive receiver receives the repeated signal and performs bit decision to recover the original pulse signal by means of repeated sending and calculation of upward floating.

[0201] Referring to Figure 4 , Figure 4 is a flowchart of the implementation of the signal transmission method in the embodiment of the present application, and is applied to the second communication device, such as Figure 4As shown, the method comprises step 401:

[0202] Step 401: receiving a backscatter modulated signal backscattered by a tag device; wherein the backscatter modulated signal is generated by the tag device based on an excitation signal transmitted by a first communication device; the excitation signal is obtained by modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal.

[0203] In some embodiments, the receiving a backscatter modulated signal backscattered by a tag device comprises:

[0204] receiving a backscatter modulated signal backscattered by an active tag device;

[0205] wherein,

[0206] the backscatter modulated signal is generated by the active tag device by source encoding first information of itself to generate a source encoded signal; generating a first source encoded signal and a second source encoded signal according to the source encoded signal; sampling the excitation signal at even times of a symbol period of the excitation signal to obtain a first excitation signal, and sampling the excitation signal at odd times of the symbol period of the excitation signal to obtain a second excitation signal; mixing the first source encoded signal with the first excitation signal to generate a first passive back link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back link signal; and performing exclusive OR operation on the first passive back link signal and the second passive back link signal.

[0207] In some embodiments, the receiving a backscatter modulated signal backscattered by a tag device comprises:

[0208] receiving a backscatter modulated signal backscattered by a passive tag device;

[0209] wherein,

[0210] the backscatter modulated signal comprises a first passive back link signal and a second passive back link signal; the first passive back link signal and the second passive back link signal are generated by the passive tag device by source encoding second information of itself to generate a source encoded signal; generating a first source encoded signal and a second source encoded signal according to the source encoded signal; sampling the excitation signal at even times of a symbol period of the excitation signal to obtain a first excitation signal, and sampling the excitation signal at odd times of the symbol period of the excitation signal to obtain a second excitation signal; mixing the first source encoded signal with the first excitation signal, and mixing the second source encoded signal with the second excitation signal.

[0211] In some embodiments, the method further comprises:

[0212] demodulating the backscatter modulated signal to obtain the source encoded signal.

[0213] As an example, the second communication device demodulating the backscatter modulated signal transmitted by the active tag device can include: using timing synchronization and frequency offset estimation, demodulating the received backscatter modulated signal by frequency shift keying to recover the source encoded signal.

[0214] Here, in an actual scenario, if the received backscatter modulated signal contains interference, the passive receiver uses the diagonal matrix Sk to multiply the received first backscatter modulated signal to obtain a second uplink backscatter modulated signal, performs frequency offset estimation according to the symbol waveform of the second uplink backscatter modulated signal to recover the original first backscatter modulated signal, and then performs frequency shift keying modulation on the original first backscatter modulated signal to obtain the relevant pulse coded information.

[0215] As an example, the second communication device demodulating the backscatter modulated signal transmitted by the passive tag device can include: according to the repeatedly received backscatter modulated signal, recovering the pulse coded information by judging the bit positions one by one.

[0216] For example, for example, if N repeated bits are received, if (N+1) / N is greater than N / 2, it is determined that the bit position is logic 1 (logic 1), otherwise it is determined to be logic 0 (logic 0).

[0217] In the embodiments of the present application, the following advantages are provided:

[0218] (1) Considering that in the existing separated RFID system, the tag device needs to communicate with the passive receiver such as the base station at a long distance, and due to signal interference, the amplitude shift keying signal adopted by the traditional method is prone to serious distortion in the amplitude of the signal with the increase of the communication distance in the backscattering communication process, resulting in the misoperation of the backscattering signal sent by the tag device to the passive receiver, therefore, in the embodiment of the present application, the passive transmitter modulates the pulse coded signal by using the carrier signal generated based on the differential synchronization signal with differential synchronization characteristics to obtain the excitation signal, and sends the excitation signal to the tag device, and the tag device generates the approximate frequency shift keying signal with differential synchronization characteristics, that is, the backscattering modulation signal, by using the excitation signal sent by the passive transmitter as the carrier signal, for the passive receiver to recover the passive back communication signal with correlation characteristics, since the approximate frequency shift keying signal with differential synchronization characteristics adopted by the tag device is not prone to serious distortion in the amplitude of the signal with the increase of the communication distance, and will not cause the misoperation of the backscattering signal sent by the tag device to the passive receiver, that is, the receiving sensitivity and anti-interference ability of the passive back communication link can be improved.

[0219] (2) A separated RFID architecture integrated with an LPWA system in backscattering communication is provided.

[0220] The separated RFID architecture includes the first communication device, the tag device, and the second communication device; wherein the first communication device can be a passive transmitter, wherein the passive transmitter can be specifically an exciter or an LPWA transceiver; and the second communication device can be specifically a passive receiver, wherein the passive receiver can be specifically a reader or a base station.

[0221] (3) Considering that the circuit structure in the current tag device is simple, only supports simple envelope detection, and cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing, therefore, in the embodiment of the present application, the tag device does not directly perform frequency shift keying modulation, but the passive receiver performs frequency shift keying modulation, so as to avoid the problem that the tag device in the related art cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing in backscattering modulation.

[0222] For the passive tag device, considering that the simple circuit of the passive tag device is difficult to provide a high-precision clock reference signal to realize frequency shift alignment, the passive receiver receives the repeated signal and performs bit decision to recover the original pulse signal by means of repeated sending and calculation of upward floating.

[0223] Referring to Figure 5 , Figure 5 is a system architecture schematic diagram of the signal transmission method applied in the embodiment of the present application, as Figure 5The system comprises:

[0224] The first communication device is configured to send an excitation signal to the tag device, wherein the excitation signal is used to generate a backscatter modulated signal by the tag device and backscatter the backscatter modulated signal to the second communication device.

[0225] The tag device, specifically an active tag device and a passive tag device, is configured to receive the excitation signal, generate a backscatter modulated signal according to the excitation signal, and backscatter the backscatter modulated signal to the second communication device.

[0226] The second communication device is configured to receive the backscatter modulated signal backscattered by the tag device.

[0227] Here, the first communication device can be a passive transmitter, specifically an exciter or an LPWA transceiver.

[0228] Here, the second communication device can be a passive receiver, specifically a reader or a base station.

[0229] Here, the passive transmitter and the passive receiver constitute a passive transceiver.

[0230] Here, the system adopts a split forward link architecture and deploys the forward and reverse links in the passive receiver (e.g., a reader) and the passive transmitter (e.g., an exciter) respectively, thereby achieving link decoupling and expanding the coverage range of the RFID system. The synchronization and control interaction between the passive receiver (e.g., a reader) and the passive transmitter (e.g., an exciter) is carried through the management plane based on the wide-area coverage wireless technology. In the first case, the passive receiver (e.g., a reader) and the passive transmitter (e.g., an LPWA transceiver) are physically coupled, and the passive transceiver can also communicate with the base station directly through the cellular air interface. In the second case, the reader and the LPWA transceiver are separated and communicate with each other through wired or wireless communication. There can be multiple exciters, and the exciters interact with each other based on the neighbor discovery relationship of the networking topology (hierarchical and domain-based), and can realize the centralized scheduling of the base station according to the judgment order. The excitation link between the passive transmitter (e.g., an exciter) and the tag device realizes the simultaneous transmission of power and data to the tag.

[0231] The passive transmitter can generate a low-order modulation signal for wide-area Internet of Things, which is not limited to Lora signal, Sigfox modulation signal, NB-IoT signal, ZETA signal, and can also generate a modulation signal compatible with the cellular system, which is not limited to NB-IoT, LTE Cat.1, and other signals supporting quadrature amplitude modulation (QAM, Quadrature Amplitude Modulation) modulation.

[0232] Passive tag devices are subject to extremely simple circuit complexity structure, passive communication through backscattering communication, difficult to support crystal circuit and complex energy storage unit, only rely on the continuous pulse sent by the relay node to provide energy to the tag, to envelope detection mode to achieve relatively simple amplitude modulation.

[0233] Referring to Figure 6A , Figure 6A is a specific implementation flowchart of the signal transmission method of the embodiment of the present application, taking the first communication device as a passive transmitter for example, as shown in Figure 6A , the method comprises steps 601 to 606:

[0234] Step 601: The passive transmitter encodes the original signal as a source to generate a pulse coded signal.

[0235] Here, the original signal can be a signal formed by a binary bit string.

[0236] Here, the source encoding mode is not limited to: pulse width encoding (PIE, Pulse Interval Encoding), Manchester encoding (Manchester encoding), and the combination of the encoding mode.

[0237] Step 602: The excitation signal transmitter unit of the passive transmitter generates a first carrier signal, which is used as the carrier signal of the pulse coded signal.

[0238] Here, the first carrier signal can include:

[0239] A narrowband modulated signal with high receiving sensitivity compatible with a low power wide area network (LPWAN, Low Power Wide Area Network) system, for example, but not limited to Lora signal, Sigfox modulated signal, ZETA signal, etc.

[0240] Or, a quadrature amplitude modulation signal compatible with a cellular system, for example, but not limited to NB-IoT, LTE Cat.1 signal.

[0241] That is, the narrowband modulated signal with high receiving sensitivity compatible with the LPWAN system can be used as the first carrier signal, or the quadrature amplitude modulation signal compatible with the cellular system can be used as the first carrier signal.

[0242] Figure 6B is a frequency domain diagram of the first carrier signal of the embodiment of the present application, as Figure 6BAs shown, the starting position of the waveform in the odd symbol period of the first carrier signal is fixed, and the starting positions are all at the same frequency offset position, and the starting position of the waveform in the even symbol period of the first carrier signal is also fixed, and the starting positions are all at the same frequency offset position.

[0243] Figure 6C is a time domain schematic diagram of the first carrier signal of the embodiment of the present application, as Figure 6C As shown, the frequencies of the waveforms in adjacent two symbol periods are different, for example, the waveform frequency of the first symbol period is a first frequency, the waveform frequency of the second symbol period is a second frequency, the first frequency and the second frequency are different, and the two frequencies are transformed in a period.

[0244] Step 603: The passive transmitter generates a differential synchronization signal.

[0245] Here, the differential synchronization signal can refer to a waveform sequence formed according to the values on the main diagonal of a real diagonal matrix, or a waveform sequence formed according to the values on the main diagonal of a complex diagonal matrix.

[0246] Here, the real diagonal matrix can refer to a real diagonal matrix in which real numbers 1 and -1 are staggered on the main diagonal of order k, and the complex diagonal matrix can refer to a complex diagonal matrix in which imaginary numbers i and -i are staggered on the main diagonal of order k.

[0247] Here, the differential synchronization signal can start with a waveform corresponding to a real number 1 or start with a waveform corresponding to a real number -1, or can start with a waveform corresponding to an imaginary number i or start with a waveform corresponding to an imaginary number -i.

[0248] Here, the real diagonal matrix in which real numbers 1 and -1 are staggered on the main diagonal of order k is represented by formula (1), and specifically as follows:

[0249]

[0250] wherein S1 represents a real diagonal matrix in which real numbers 1 and -1 are staggered on the main diagonal of order k, and k is an integer greater than or equal to 2.

[0251] Here, the complex diagonal matrix in which imaginary numbers i and -i are staggered on the main diagonal of order k is represented by formula (2), and specifically as follows:

[0252]

[0253] wherein S2 represents a complex diagonal matrix in which imaginary numbers i and -i are staggered on the main diagonal of order k, and k is an integer greater than or equal to 2.

[0254] Step 604: The passive transmitter generates a second carrier signal based on the first carrier signal and the differential synchronization signal.

[0255] Here, the first carrier signal to be transmitted is multiplied by the differential synchronization signal to generate the second carrier signal.

[0256] Here, the second carrier signal is expressed by formula (3) as follows:

[0257]

[0258] wherein Y(Δt) represents the second carrier signal, S is a differential synchronization signal generated by using a real number diagonal matrix or a complex number diagonal matrix of k order, X(kΔt) represents the first carrier signal, k is an integer from 0 to n, n is an integer greater than or equal to 1, and Δt is a symbol period of the first carrier signal. The waveform after multiplication, i.e., the second carrier signal, is a differential phase modulation signal with a symbol period Δt of the first carrier signal as a time interval and with autocorrelation.

[0259] Step 605: The passive transmitter mixes the locally generated pulse coded signal to be transmitted with the second carrier signal to obtain a first mixed signal, and then modulates the amplitude of the first mixed signal to generate an excitation signal.

[0260] Here, the amplitude modulation mode is not limited to double sideband amplitude modulation (DSB-ASK), single sideband amplitude modulation (SSB-ASK), or phase reversal amplitude modulation (PR-ASK).

[0261] Step 606: The passive transmitter transmits the excitation signal to the tag device.

[0262] Here, the passive transmitter can transmit the excitation signal to an active tag device, or can also transmit the excitation signal to a passive tag device.

[0263] In this example, the following advantages are achieved:

[0264] (1) Considering that in the existing separated RFID system, the tag device needs to communicate with the passive receiver such as the base station at a long distance, and due to signal interference, the amplitude shift keying signal adopted by the conventional method is prone to serious distortion in the amplitude of the signal with the increase of the communication distance in the backscattering communication process, resulting in the misoperation of the backscattering signal sent by the tag device to the passive receiver, therefore, in the embodiment of the application, the passive transmitter generates an excitation signal based on the differential synchronization signal with differential synchronization characteristics, and sends the excitation signal to the tag device, the tag device generates an approximate frequency shift keying signal with differential synchronization characteristics, that is, a backscattering modulation signal, using the excitation signal sent by the passive transmitter as a carrier signal, for the passive receiver to recover the passive backscattering signal with autocorrelation characteristics, since the approximate frequency shift keying signal with differential synchronization characteristics adopted by the tag device is not prone to serious distortion in the amplitude of the signal with the increase of the communication distance, it will not cause the misoperation of the backscattering signal sent by the tag device to the passive receiver, that is, the anti-interference ability of the passive backscattering communication link can be improved.

[0265] (2) Considering that the circuit structure in the current tag device is simple, only supports simple envelope detection, cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing, therefore, in the embodiment of the application, the tag device does not directly perform frequency shift keying modulation, but the passive receiver performs frequency shift keying modulation, so as to avoid the problem of the tag device in the related art that cannot directly generate a frequency shift keying signal and is difficult to perform frequency shifting processing in backscattering modulation.

[0266] Referring to Figure 7 , Figure 7 is a specific implementation flowchart of the signal transmission method of the embodiment of the application, taking the first communication device as the passive transmitter, the tag device as the active tag device and the second communication device as the passive receiver, as shown in Figure 7 , the method comprises steps 701 to 710:

[0267] Step 701: The active tag device receives the excitation signal sent by the passive transmitter.

[0268] Here, the active tag device receives the excitation signal sent by the passive transmitter through the downlink envelope detection circuit, demodulates the excitation signal to obtain a first mixed signal, and performs envelope detection processing on the first mixed signal to obtain a continuous pulse code signal.

[0269] Step 702: The active tag device determines whether the pulse coded signal obtained by processing the excitation signal is a broadcast message or a system preset downlink dedicated message (such as a query instruction and other request instructions), and in the case where it is determined that the pulse coded signal is a broadcast message or a system preset downlink dedicated message, the first information (such as the identification information of the active tag device and other valid information) of the active tag device is source coded to generate an uplink source coded signal.

[0270] Here, it is determined whether the first specific bit in the pulse coded signal obtained by processing the excitation signal is the same as the second specific bit in the broadcast message, and if the specific bit in the pulse coded signal is the same as the second specific bit in the broadcast message issued by the passive transmitter, it is determined that the pulse coded signal is the broadcast message issued by the passive transmitter, wherein the first specific bit can refer to at least one bit at a specific position in the pulse coded signal, such as the 3rd bit to the 4th bit, and the second specific bit can refer to at least one bit at a specific position in the broadcast message, such as the 5th bit to the 6th bit.

[0271] Alternatively, it is determined whether the first specific bit in the pulse coded signal obtained by processing the excitation signal is the same as the third bit in the preset downlink dedicated message, and if the first specific bit in the pulse coded signal is the same as the third specific bit in the preset downlink dedicated message, it is determined that the pulse coded signal is the preset downlink dedicated message, wherein the third specific bit can refer to at least one bit at a specific position in the preset downlink dedicated message, such as the 3rd bit to the 4th bit.

[0272] Here, the encoding mode of the first information is not limited to:

[0273] Polar (inner code) + Manchester (outer code) cascade encoding, i.e. superimposing Manchester code modulation on the basis of Polar encoding;

[0274] TBCC / Polar / FM0+repeated mode encoding;

[0275] Other encoding modes, such as Manchester code, Miller code or FM0 code, etc.

[0276] Step 703: The active tag device compares the voltage value of the waveform of the source coded signal with the first reference voltage, and after voltage comparison processing, if the voltage value of the waveform of the source coded signal is greater than the first reference voltage, it is judged as logic level 1, and the pulse signal corresponding to logic level 1 (logic 1) is taken as the first source coded signal, denoted by s(t), wherein the amplitude of the pulse signal corresponding to the first reference voltage is set to 0 in the waveform of the source coded signal; the voltage value of the waveform of the source coded signal is compared with the second reference voltage, and after voltage comparison processing, if the voltage of the waveform of the source coded signal is greater than the second reference voltage, it is judged as logic level 0, and the pulse signal corresponding to logic level 0 (logic 0) is taken as the second source coded signal, denoted by s(t), wherein the amplitude of the pulse signal corresponding to the second reference voltage is set to 0 in the waveform of the source coded signal.

[0277] Step 704: The active tag device generates a higher precision clock auxiliary signal, i.e. a clock division signal, according to the clock period of the clock signal generated by the local oscillation loop.

[0278] Step 705: The active tag device samples the excitation signal according to even times of the symbol period of the excitation signal to obtain a first excitation signal, and samples the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal.

[0279] Here, the symbol period of the excitation signal can refer to the symbol period of the first carrier signal.

[0280] Here, the first excitation signal is denoted by g1(t1), wherein t1=2N×Δt; N=1, 2, 3,... M, M is an integer, and△t is the symbol period of the first carrier signal.

[0281] Here, the second excitation signal is denoted by g2(t2), wherein t2=(2N+1)×△t; N=1, 2, 3,... M, M is an integer, and△t is the symbol period of the first carrier signal.

[0282] Wherein, t2-t1≥△t.

[0283] Step 706: The active tag device mixes the first source coded signal with the first excitation signal according to the pulse interval period indicated by the clock division signal to generate a first passive backlink signal to be transmitted.

[0284] Here, the mixing the first source encoded signal with the first excitation signal can refer to multiplying the first source encoded signal with the first excitation signal.

[0285] Step 707: The active tag device mixes the second source encoded signal with the second excitation signal to generate a second passive back-link signal to be sent.

[0286] Here, the mixing the second source encoded signal with the second excitation signal can refer to multiplying the second source encoded signal with the second excitation signal.

[0287] Step 708: The active tag device XORs the sent first passive back-link signal and the second passive back-link signal to generate a back-scattering modulation signal to be sent.

[0288] Step 709: The active tag device sends the back-scattering modulation signal to a passive receiver (such as a reader or a base station).

[0289] Step 710: The passive receiver (such as a reader or a base station) recovers the source encoded signal by timing synchronization and frequency offset estimation after frequency shift keying demodulation of the received back-scattering modulation signal.

[0290] Here, in an actual scenario, if the received back-scattering modulation signal contains interference, the passive receiver uses a diagonal matrix Sk to multiply the received first back-scattering modulation signal to obtain a second uplink back-scattering modulation signal, performs frequency offset estimation according to the symbol waveform of the second uplink back-scattering modulation signal to recover the original first back-scattering modulation signal, and then performs frequency shift keying modulation on the original first back-scattering modulation signal to obtain the relevant pulse coded information.

[0291] Referring to Figure 8 , Figure 8 is a specific implementation flowchart of the signal transmission method of the embodiment of the present application, taking a first communication device as a passive transmitter, a tag device as an active tag device, and a second communication device as a passive receiver, as shown in Figure 8 , the method comprises steps 801 to 810:

[0292] Step 801: The passive tag device receives an excitation signal sent by the passive transmitter.

[0293] Here, the passive tag device receives the excitation signal sent by the passive transmitter through a downlink envelope detection circuit, demodulates the excitation signal to obtain a first mixed signal, and performs envelope detection processing on the first mixed signal to obtain a continuous pulse coded signal.

[0294] Step 802: The passive tag device determines whether the pulse coded signal obtained by processing the excitation signal is a broadcast message or a system preset downlink dedicated message (such as a request for inventory query instruction and other request instructions), and in a case where it is determined that the pulse coded signal is a broadcast message or a system preset downlink dedicated message, source encodes second information (such as identification information and other valid information) of the passive tag device to generate an uplink source coded signal.

[0295] Here, it is determined whether a first specific bit in the pulse coded signal obtained by processing the excitation signal is the same as a second specific bit in the broadcast message, and if the specific bit in the pulse coded signal is the same as the second specific bit in the broadcast message, it is determined that the pulse coded signal is a broadcast message, wherein the first specific bit can be at least one bit at a specific position in the pulse coded signal, such as the 3rd bit to the 4th bit, and the second specific bit can be at least one bit at a specific position in the broadcast message, such as the 5th bit to the 6th bit.

[0296] Alternatively, it is determined whether a first specific bit in the pulse coded signal obtained by processing the excitation signal is the same as a third specific bit in the preset downlink dedicated message, and if the first specific bit in the pulse coded signal is the same as the third specific bit in the preset downlink dedicated message, it is determined that the pulse coded signal is a preset downlink dedicated message, wherein the third specific bit can be at least one bit at a specific position in the preset downlink dedicated message, such as the 3rd bit to the 4th bit.

[0297] Here, the encoding mode of the second information is not limited to:

[0298] a TBCC / Polar / FM0+ repetition mode;

[0299] other encoding modes, such as Manchester code, Miller code, or FM0 code, etc.

[0300] Step 803: The passive tag device compares the voltage value of the waveform of the source coded signal with the first reference voltage, and after voltage comparison processing, if the voltage value of the waveform of the source coded signal is greater than the first reference voltage, it is judged as logic level 1, and the pulse signal corresponding to logic level 1 (logic 1) is taken as the first source coded signal, denoted as s(t), wherein the amplitude of the pulse signal corresponding to the first reference voltage is set to 0 in the waveform of the source coded signal; the voltage value of the waveform of the source coded signal is compared with the second reference voltage, and after voltage comparison processing, if the voltage of the waveform of the source coded signal is greater than the second reference voltage, it is judged as logic level 0, and the pulse signal corresponding to logic level 0 (logic 0) is taken as the second source coded signal, denoted as s(t), wherein the amplitude of the pulse signal corresponding to the second reference voltage is set to 0 in the waveform of the source coded signal.

[0301] Step 804: The passive tag device performs clock frequency division according to the pulse interval period of the extracted pulse coded signal (for example, the pulse interval period of PIE coding is 2 Tari, and Tari is the standard length of coding corresponding to 0 in PIE coding) to provide a clock auxiliary signal, that is, a clock frequency division signal.

[0302] Step 805: The active tag device samples the excitation signal according to an even multiple of the symbol period of the excitation signal to obtain a first excitation signal, and samples the excitation signal according to an odd multiple of the symbol period of the excitation signal to obtain a second excitation signal.

[0303] Here, the symbol period of the excitation signal can refer to the symbol period of the first carrier signal.

[0304] Here, the first excitation signal is denoted as g1(t1), wherein t1=2N×Δt; N=1, 2, 3,... M, M is an integer, and△t is the symbol period of the first carrier signal.

[0305] Here, the second excitation signal is denoted as g2(t2), wherein t2=(2N+1)×△t; N=1, 2, 3,... M, M is an integer, and△t is the symbol period of the first carrier signal.

[0306] Wherein, t2-t1≥△t.

[0307] Step 806: The passive tag device mixes the first source coded signal s(t) of the uplink with the first excitation signal according to the pulse interval period indicated by the clock frequency division signal to generate a first passive backlink signal to be transmitted.

[0308] Step 807: The passive tag device repeatedly sends the first passive back-link signal to a passive receiver (such as a reader or base station).

[0309] Step 808: The passive tag device mixes the uplink second source encoded signal with the second excitation signal according to the pulse interval period indicated by the clock division signal, to generate a passive back-link signal to be sent, i.e., a second passive back-link signal.

[0310] Step 809: The passive tag device repeatedly sends the second passive back-link signal to a passive receiver (such as a reader or base station).

[0311] Step 810: The passive transceiver (such as a reader or base station) recovers the source encoded signal from the repeatedly received uplink backscatter modulated signal, i.e., the first passive back-link signal and the second passive back-link signal.

[0312] Specifically, the source encoded signal is recovered by bit-by-bit decision from the repeatedly received uplink backscatter modulated signal, for example, if (N+1) / N is greater than N / 2, the bit is determined to be logic 1, otherwise, it is determined to be logic 0.

[0313] To implement the signal transmission method of the embodiments of the present application, the embodiments of the present application further provide a signal transmission device arranged in a first communication device. Figure 9 is a structural diagram of the signal transmission device of the embodiments of the present application, as shown in the figure, the device comprises: Figure 9

[0314] The sending module 91 is configured to send an excitation signal to a tag device; the excitation signal is obtained by modulating a pulse encoded signal by a carrier signal generated based on a differential synchronization signal.

[0315] The excitation signal is used by the tag device to generate a backscatter modulated signal and backscatter the backscatter modulated signal to a second communication device.

[0316] In some embodiments, the device is further configured to:

[0317] generate the pulse encoded signal, a first carrier signal, and the differential synchronization signal;

[0318] generate a second carrier signal based on the first carrier signal and the differential synchronization signal;

[0319] mix the pulse encoded signal with the second carrier signal to obtain a first mixed signal; ​​

[0320] modulating the first mixed signal to obtain the excitation signal.

[0321] In some embodiments, the tag device is an active tag device, and the sending module 91 is further configured to:

[0322] sending the excitation signal to the active tag device.

[0323] In some embodiments, the tag device is a passive tag device, and the sending module 91 is further configured to send the excitation signal to the passive tag device.

[0324] In actual application, the sending module 91 can be implemented by a communication interface in a signal transmission device.

[0325] It should be noted that: the signal transmission device provided in the above embodiments is used for signal transmission, and the above-mentioned division of each program module is only used as an example for illustration. In actual application, the above-mentioned processing can be completed by different program modules according to needs, that is, the internal structure of the device is divided into different program modules to complete all or part of the above-mentioned processing. In addition, the signal transmission device and the signal transmission method provided in the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be repeated here.

[0326] To implement the signal transmission method of the embodiments of the present application, the embodiments of the present application further provide a signal transmission device arranged in a tag device. Figure 10 is a schematic diagram of the composition structure of the signal transmission device of the embodiments of the present application, as shown in Figure 10 The device comprises:

[0327] A first receiving module 101 is configured to receive an excitation signal; the excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal by a first communication device;

[0328] The excitation signal is used for the tag device to generate a backscatter modulation signal and backscatter the backscatter modulation signal to a second communication device.

[0329] In some embodiments, the device is further configured to:

[0330] generate a backscatter modulation signal according to the excitation signal;

[0331] backscatter the backscatter modulation signal to the second communication device.

[0332] In some embodiments, the tag device is an active tag device, and the device is further configured to:

[0333] demodulate the excitation signal to obtain a pulse coded signal;

[0334] determine whether the pulse coded signal satisfies a preset condition;

[0335] in a case where it is determined that the pulse coded signal satisfies the preset condition, source encode first information of the active tag device to generate a source encoded signal;

[0336] generate a first source encoded signal and a second source encoded signal according to the source encoded signal;

[0337] sample the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and sample the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal;

[0338] mix the first source encoded signal with the first excitation signal to generate a first passive back-link signal, and mix the second source encoded signal with the second excitation signal to generate a second passive back-link signal;

[0339] perform exclusive OR operation on the first passive back-link signal and the second passive back-link signal to obtain the backscatter modulated signal.

[0340] In some embodiments, the apparatus is further configured to:

[0341] generate a clock division signal according to a clock period of a clock signal generated by a local oscillator loop in the active tag device;

[0342] mix the first source encoded signal with the first excitation signal to generate the first passive back-link signal using the clock division signal, and mix the second source encoded signal with the second excitation signal to generate the second passive back-link signal using the clock division signal.

[0343] In some embodiments, the tag device is a passive tag device, and the apparatus is further configured to:

[0344] demodulate the excitation signal to obtain a pulse coded signal;

[0345] determine whether the pulse coded signal satisfies a preset condition;

[0346] in a case where it is determined that the pulse coded signal satisfies the preset condition, source encode second information of the passive tag device to generate a source encoded signal;

[0347] generate a first source encoded signal and a second source encoded signal according to the source encoded signal;

[0348] sample the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and sample the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal;

[0349] mix the first source coded signal with the first excitation signal to generate a first passive reverse link signal, and mix the second source coded signal with the second excitation signal to generate a second passive reverse link signal;

[0350] use the first passive reverse link signal and the second passive reverse link signal as the backscatter modulation signal.

[0351] In some embodiments, the apparatus is further configured to:

[0352] generate a clock division signal according to a pulse interval period corresponding to the pulse coded signal;

[0353] mix the first source coded signal with the first excitation signal to generate a first passive reverse link signal using the clock division signal, and mix the second source coded signal with the second excitation signal to generate a second passive reverse link signal using the clock division signal.

[0354] In some embodiments, the apparatus is further configured to:

[0355] determine whether the pulse coded signal is a broadcast message or a system preset downlink dedicated message;

[0356] determine that the pulse coded signal meets a preset condition if it is determined that the pulse coded signal is a broadcast message or a system preset downlink dedicated message.

[0357] In actual application, the first receiving module 101 can be implemented by a communication interface in a signal transmission apparatus.

[0358] It should be noted that the signal transmission apparatus provided in the above embodiments is only used for example to illustrate the division of the above program modules, and in actual application, the above processes can be completed by different program modules according to needs, that is, the internal structure of the apparatus is divided into different program modules to complete all or part of the above processes. In addition, the signal transmission apparatus and the signal transmission method provided in the above embodiments belong to the same concept, and the specific implementation process is described in the method embodiments, which will not be repeated here.

[0359] To implement the signal transmission method provided in the embodiments of the present application, the embodiments of the present application further provide a signal transmission apparatus arranged in a second communication device.Figure 11 is a schematic diagram of a signal transmission device according to an embodiment of the present application, as shown, the device comprises: Figure 11

[0360] a second receiving module 111, configured to receive a backscatter modulated signal backscattered by a tag device;

[0361] wherein the backscatter modulated signal is generated by the tag device based on an excitation signal transmitted by a first communication device; the excitation signal is obtained by modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal.

[0362] In some embodiments, the second receiving module 111 is configured to:

[0363] receive a backscatter modulated signal backscattered by an active tag device;

[0364] wherein,

[0365] the backscatter modulated signal is generated by the active tag device by source encoding first information of the active tag device to generate a source encoded signal, generating a first source encoded signal and a second source encoded signal according to the source encoded signal, sampling the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal and sampling the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal, mixing the first source encoded signal with the first excitation signal to generate a first passive back link signal and mixing the second source encoded signal with the second excitation signal to generate a second passive back link signal, and performing exclusive OR operation on the first passive back link signal and the second passive back link signal.

[0366] In some embodiments, the second receiving module 111 is configured to:

[0367] receive a backscatter modulated signal backscattered by a passive tag device;

[0368] wherein,

[0369] ​The backscatter modulation signal comprises a first passive back link signal and a second passive back link signal; the first passive back link signal and the second passive back link signal are source encoded by the passive tag device to the second information of itself to generate a source encoded signal; the first source encoded signal and the second source encoded signal are generated according to the source encoded signal; the first excitation signal is obtained by sampling the excitation signal according to even times of a symbol period of the excitation signal, and the second excitation signal is obtained by sampling the excitation signal according to odd times of the symbol period of the excitation signal; the first source encoded signal is mixed with the first excitation signal, and the second source encoded signal is mixed with the second excitation signal.

[0370] In some embodiments, the apparatus is further configured to:

[0371] The backscatter modulation signal is demodulated to obtain the source encoded signal.

[0372] In actual application, the second receiving module 111 can be implemented by a communication interface in a signal transmission apparatus.

[0373] It should be noted that: the signal transmission apparatus provided in the above embodiments is used for signal transmission, and only the division of the above program modules is used for example. In actual application, the above processing can be completed by different program modules according to needs, that is, the internal structure of the apparatus is divided into different program modules to complete all or part of the above processing. In addition, the signal transmission apparatus and the signal transmission method provided in the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiments, which will not be repeated here.

[0374] The embodiment of the present application further provides a first communication device, as shown in the following table: Figure 12 The first communication device comprises:

[0375] The first communication interface 121 is capable of information interaction with other first communication devices;

[0376] The first processor 122 is connected with the first communication interface 121, and is used for running a computer program to execute the method provided in one or more technical solutions of the first communication device. The computer program is stored in the first memory 123.

[0377] It should be noted that the specific processing process of the first processor 122 and the first communication interface 121 is detailed in the method embodiments, which will not be repeated here.

[0378] Of course, in actual applications, the various components in the first communication device 120 are coupled together through a bus system 124. It can be understood that the bus system 124 is used to realize the connection communication between the components. The bus system 124 includes not only a data bus, but also a power supply bus, a control bus, and a status signal bus. However, for the purpose of clear illustration, all the buses are marked as the bus system 124 in the following description. Figure 12

[0379] The first memory 123 in the embodiment of the present application is used to store various types of data to support the operation of the first communication device 120. Examples of the data include any computer programs used for operating on the first communication device 120.

[0380] The method disclosed in the embodiment of the present application can be applied to or implemented by the first processor 122. The first processor 122 can be an integrated circuit chip with the processing capability of signals. In the implementation process, each step of the above method can be completed by the integrated logic circuit of hardware or the instruction in the form of software in the first processor 122. The first processor 122 described above can be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The first processor 122 can implement or execute the disclosed methods, steps, and logic block diagrams in the embodiment of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiment of the present application, the hardware decoding processor can be directly embodied to execute the completion, or the combination of hardware and software modules in the decoding processor can be executed to complete. The software module can be located in the storage medium, which is located in the first memory 123. The first processor 122 reads the information in the first memory 123 and combines the hardware to complete the steps of the above method.

[0381] The embodiment of the present application further provides a tag device, as shown in Figure 13 The tag device comprises:

[0382] A second communication interface 131 capable of information interaction with other first communication devices;

[0383] A second processor 132 connected with the second communication interface 131, used for running a computer program to execute the method provided by one or more technical solutions of the tag device. The computer program is stored in the second memory 133.

[0384] It should be noted that the specific processing process of the second processor 132 and the second communication interface 131 is described in the method embodiment, which will not be repeated here.​

[0385] Of course, in actual applications, the various components in the tag device 130 are coupled together through the bus system 134. It can be understood that the bus system 134 is used to realize the connection communication between the components. The bus system 134 includes not only a data bus, but also a power supply bus, a control bus and a status signal bus. However, for the purpose of clear illustration, all the buses are marked as the bus system 134 in the following description. Figure 13

[0386] The second memory 133 in the embodiment of the present application is used to store various types of data to support the operation of the tag device 130. Examples of the data include any computer programs used for the operation on the tag device 130.

[0387] The method disclosed in the above embodiment of the present application can be applied to or implemented by the second processor 132. The second processor 132 can be an integrated circuit chip with the processing capability of signals. In the implementation process, each step of the above method can be completed by the integrated logic circuit of hardware or the instruction in the form of software in the second processor 132. The second processor 132 disclosed above can be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The second processor 132 can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiments of the present application, the execution can be directly completed by the hardware decoding processor or by the combination of hardware and software modules in the decoding processor. The software module can be located in the storage medium, which is located in the second memory 133. The second processor 132 reads the information in the second memory 133 and combines the hardware to complete the steps of the above method.

[0388] The embodiment of the present application further provides a second communication device, as shown in the following: Figure 14 The second communication device comprises:

[0389] A third communication interface 141, which is capable of information interaction with other devices;

[0390] A third processor 142, which is connected with the third communication interface 141 and is used to execute the method provided by one or more technical solutions of the second communication device when running a computer program. The computer program is stored in the third memory 143.

[0391] ​It should be noted that the specific processing process of the third processor 142 and the third communication interface 141 is detailed in the method embodiment, which will not be repeated here.

[0392] Of course, in actual application, various components in the second communication device 140 are coupled together through the bus system 144. It can be understood that the bus system 144 is used to realize the connection communication between the components. In addition to including a data bus, the bus system 144 also includes a power bus, a control bus and a status signal bus. However, in order to clearly illustrate, all kinds of buses are marked as the bus system 144 in the Figure 14

[0393] The third storage 143 in the embodiment of the present application is used to store various types of data to support the operation of the second communication device 140. Examples of these data include: any computer programs used to operate on the second communication device 140.

[0394] The method disclosed in the above embodiment of the present application can be applied to the third processor 142 or implemented by the third processor 142. The third processor 142 can be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above method can be completed by the integrated logic circuit of hardware or the instruction in the form of software in the third processor 142. The third processor 142 mentioned above can be a general-purpose processor, a digital data processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The third processor 142 can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiments of the present application, the hardware decoding processor can be directly embodied to execute the completion, or the hardware and software modules in the decoding processor are combined to execute the completion. The software module can be located in the storage medium, which is located in the third storage 143, and the third processor 142 reads the information in the third storage 143, and combines the hardware to complete the steps of the above method.

[0395] ​In the exemplary embodiments, the first communication device 120, the tag device 130, the second communication device 140 can be implemented by one or more Application Specific Integrated Circuits (ASICs), DSPs, Programmable Logic Devices (PLDs), Complex Programmable Logic Devices (CPLDs), Field-Programmable Gate Arrays (FPGAs), general-purpose processors, controllers, Micro Controller Units (MCUs), Microprocessors, or other electronic elements for performing the aforementioned methods.

[0396] It can be understood that the memory (the first memory 123, the second memory 133, and the third memory 143) of the embodiments of the present application can be a volatile memory or a non-volatile memory, and can also include both volatile and non-volatile memories. The non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a ferromagnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM). The magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM can be used, such as a static random access memory (SRAM), a synchronous static random access memory (SSRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a sync link dynamic random access memory (SLDRAM), and a direct rambus random access memory (DRRAM).The memory described in the embodiments of the present application is intended to include, but not limited to, these and any other suitable types of memory.

[0397] In the example embodiments, the embodiments of the present application also provide a storage medium, i.e. a computer storage medium, specifically a computer readable storage medium, such as a memory storing a computer program, which can be executed by the first processor 122 of the first communication device 120 to complete the steps of the aforementioned first communication device side method. The computer readable storage medium can be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM, etc.

[0398] It should be noted that "first", "second", etc. are used to distinguish similar objects, and do not necessarily mean a specific order or sequence.

[0399] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0400] The above is only a preferred embodiment of the present application, and is not intended to limit the protection scope of the present application.

Claims

1. A signal transmission method, characterized by, The method is applied to a first communication device, and comprises: sending an excitation signal to a tag device; the excitation signal is obtained by modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal; wherein the excitation signal is used by the tag device to generate a backscatter modulated signal and backscatter the backscatter modulated signal to a second communication device; the method further comprises: generating the pulse coded signal, a first carrier signal, and the differential synchronization signal; generating a second carrier signal based on the first carrier signal and the differential synchronization signal; mixing the pulse coded signal with the second carrier signal to obtain a first mixed signal; modulating the first mixed signal to obtain the excitation signal.

2. The method of claim 1, wherein, The tag device is an active tag device, and the sending of the excitation signal to the tag device comprises: sending the excitation signal to the active tag device.

3. The method of claim 1, wherein, The tag device is a passive tag device, and the sending of the excitation signal to the tag device comprises: sending the excitation signal to the passive tag device.

4. A signal transmission method characterized by, The method is applied to a tag device, and comprises: receiving an excitation signal; the excitation signal is obtained by a first communication device modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal, the pulse coded signal, a first carrier signal, and the differential synchronization signal are generated by the first communication device, a second carrier signal is generated based on the first carrier signal and the differential synchronization signal, the pulse coded signal is mixed with the second carrier signal to obtain a first mixed signal, and the first mixed signal is modulated to obtain the excitation signal; wherein the excitation signal is used by the tag device to generate a backscatter modulated signal and backscatter the backscatter modulated signal to a second communication device.

5. The method of claim 4, wherein, The method further comprises: generating a backscatter modulated signal according to the excitation signal; backscattering the backscatter modulated signal to a second communication device.

6. The method of claim 5, wherein, The tag device is an active tag device, The generation of the backscatter modulated signal according to the excitation signal comprises: demodulating the excitation signal to obtain a pulse coded signal; determining whether the pulse coded signal meets a preset condition; in a case where it is determined that the pulse coded signal meets the preset condition, source encoding a first information of the active tag device to generate a source encoded signal; generating a first source encoded signal and a second source encoded signal according to the source encoded signal; sampling the excitation signal according to even times of a symbol period of the excitation signal to obtain a first excitation signal, and sampling the excitation signal according to odd times of the symbol period of the excitation signal to obtain a second excitation signal; mixing the first source encoded signal with the first excitation signal to generate a first passive back link signal, and mixing the second source encoded signal with the second excitation signal to generate a second passive back link signal; performing exclusive OR processing on the first passive back link signal and the second passive back link signal to obtain the backscatter modulated signal.

7. The method of claim 6, wherein the mixing the first source encoded signal with the first excitation signal to generate a first passive backhaul signal and the mixing the second source encoded signal with the second excitation signal to generate a second passive backhaul signal comprises: generating a clock division signal according to a clock period of a clock signal generated by a local oscillator in the active tag device; and mixing the first source encoded signal with the first excitation signal to generate the first passive backhaul signal and the mixing the second source encoded signal with the second excitation signal to generate the second passive backhaul signal using the clock division signal. The tag device is a passive tag device, The generating the backscatter modulated signal according to the excitation signal comprises: demodulating the excitation signal to obtain a pulse encoded signal; 8. The method of claim 5, wherein, determining whether the pulse encoded signal satisfies a preset condition; source encoding second information of the passive tag device to generate a source encoded signal in a case where it is determined that the pulse encoded signal satisfies the preset condition; generating a first source encoded signal and a second source encoded signal according to the source encoded signal; sampling the excitation signal according to an even multiple of a symbol period of the excitation signal to obtain a first excitation signal and sampling the excitation signal according to an odd multiple of the symbol period of the excitation signal to obtain a second excitation signal; mixing the first source encoded signal with the first excitation signal to generate a first passive backhaul signal and mixing the second source encoded signal with the second excitation signal to generate a second passive backhaul signal; The first passive backhaul signal and the second passive backhaul signal are both used as the backscatter modulated signal.

9. The method of claim 8, wherein the mixing the first source encoded signal with the first excitation signal to generate a first passive backhaul signal and the mixing the second source encoded signal with the second excitation signal to generate a second passive backhaul signal comprises: generating a clock division signal according to a pulse interval period corresponding to the pulse encoded signal; and mixing the first source encoded signal with the first excitation signal to generate the first passive backhaul signal and the mixing the second source encoded signal with the second excitation signal to generate the second passive backhaul signal using the clock division signal.

10. The method of claim 6 or 8, wherein the determining whether the pulse encoded signal satisfies a preset condition comprises: determining whether the pulse encoded signal is a broadcast message or a system preset downlink dedicated message; and determining that the pulse encoded signal satisfies the preset condition in a case where it is determined that the pulse encoded signal is the broadcast message or the system preset downlink dedicated message. The method is applied to a second communication device, and the method comprises: receiving a backscatter modulated signal backscattered by a tag device; ​ ​ ​ ​ ​ ​ ​ ​ 11. A signal transmission method, characterized by, ​ ​ The reverse modulation signal is generated by the tag device based on an excitation signal sent by the first communication device; the excitation signal is obtained by modulating a pulse coded signal with a carrier signal generated based on a differential synchronization signal, the pulse coded signal, the first carrier signal and the differential synchronization signal are generated by the first communication device, the second carrier signal is generated based on the first carrier signal and the differential synchronization signal, the first mixed signal is obtained by mixing the pulse coded signal and the second carrier signal, and the excitation signal is obtained by modulating the first mixed signal.

12. The method of claim 11, wherein the receiving the backscatter modulation signal backscattered by the tag device comprises: receiving the backscatter modulation signal backscattered by an active tag device; wherein the backscatter modulation signal is generated by the active tag device by source encoding first information of the active tag device to generate a source encoded signal, generating a first source encoded signal and a second source encoded signal based on the source encoded signal, sampling the excitation signal at even multiples of a symbol period of the excitation signal to obtain a first excitation signal and sampling the excitation signal at odd multiples of the symbol period of the excitation signal to obtain a second excitation signal, mixing the first source encoded signal with the first excitation signal to generate a first passive back link signal and mixing the second source encoded signal with the second excitation signal to generate a second passive back link signal, and performing an exclusive OR operation on the first passive back link signal and the second passive back link signal.

13. The method of claim 11, wherein the receiving the backscatter modulation signal backscattered by the tag device comprises: receiving the backscatter modulation signal backscattered by a passive tag device; wherein the backscatter modulation signal comprises a first passive back link signal and a second passive back link signal, the first passive back link signal and the second passive back link signal are generated by the passive tag device by source encoding second information of the passive tag device to generate a source encoded signal, generating a first source encoded signal and a second source encoded signal based on the source encoded signal, sampling the excitation signal at even multiples of a symbol period of the excitation signal to obtain a first excitation signal and sampling the excitation signal at odd multiples of the symbol period of the excitation signal to obtain a second excitation signal, and mixing the first source encoded signal with the first excitation signal and mixing the second source encoded signal with the second excitation signal. The method further comprises: demodulating the backscatter modulation signal to obtain the source encoded signal. comprising: a sending module configured to send an excitation signal to a tag device; 14. The method according to any one of claims 11 to 13, characterized in that, ​ ​ 15. A signal transmission device, characterized by comprising: ​ ​ The excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal, the pulse coded signal, a first carrier signal and the differential synchronization signal being generated by the first communication device, a second carrier signal being generated based on the first carrier signal and the differential synchronization signal, the pulse coded signal being mixed with the second carrier signal to obtain a first mixed signal, and the first mixed signal being modulated to obtain the excitation signal. The excitation signal is used by the tag device to generate a backscatter modulated signal, and the backscatter modulated signal is backscattered to the second communication device.

16. A signal transmission device, characterized by The method comprises: The first receiving module is configured to receive an excitation signal. The excitation signal is obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal, the pulse coded signal, a first carrier signal and the differential synchronization signal being generated by the first communication device, a second carrier signal being generated based on the first carrier signal and the differential synchronization signal, the pulse coded signal being mixed with the second carrier signal to obtain a first mixed signal, and the first mixed signal being modulated to obtain the excitation signal. The excitation signal is used by the tag device to generate a backscatter modulated signal, and the backscatter modulated signal is backscattered to the second communication device.

17. A signal transmission device, characterized by The method comprises: The second receiving module is configured to receive a backscatter modulated signal backscattered by the tag device. The backscatter modulated signal is generated by the tag device based on an excitation signal transmitted by the first communication device, the excitation signal being obtained by modulating a pulse coded signal by a carrier signal generated based on a differential synchronization signal, the pulse coded signal, a first carrier signal and the differential synchronization signal being generated by the first communication device, a second carrier signal being generated based on the first carrier signal and the differential synchronization signal, the pulse coded signal being mixed with the second carrier signal to obtain a first mixed signal, and the first mixed signal being modulated to obtain the excitation signal.

18. A first communication device, characterized by The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 3, or the steps of the method of any one of claims 4 to 10, or the steps of the method of any one of claims 11 to 14. The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 3, or the steps of the method of any one of claims 4 to 10, or the steps of the method of any one of claims 11 to 14.

19. A labeling apparatus characterized by comprising: ​ ​ 20. A second communication device, characterized by ​ ​ 21. A computer readable storage medium having stored thereon a computer program, characterized in that, ​

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