Information sending method, receiving method, device, equipment and readable storage medium

Abstract

The application discloses an information sending method, a receiving method, a device, equipment and a readable storage medium, and belongs to the technical field of communication. The information sending method of the application comprises the following steps: a first device sends a first signal. The first signal comprises a first part and a second part. The first part occupies M first time units, the data in the M first time units are the same, the second part occupies M second time units, the data in the M second time units are the same, the data in the first time units are the same as or opposite to the data in the second time units, and the M is an integer greater than 2.

Description

Technical Field

[0001] This application belongs to the field of communication technology, specifically relating to an information transmission method, a receiving method, an apparatus, a device, and a readable storage medium. Background Technology

[0002] In bistatic backscatter communication systems, the received signal is a superposition of the useful backscattered signal and the co-frequency direct link interference signal, and the strength of the direct link interference signal may be much greater than that of the backscattered signal. Therefore, strong direct link interference cancellation is a technical prerequisite for achieving improved data rate, coverage, reliable transmission, and large-scale connectivity in backscatter communication. Existing direct link interference cancellation methods utilize the repetitive structure of the radio frequency signal in conjunction with the backscatter communication (BSC) baseband signal to demodulate the BSC modulated signal under strong direct link interference. However, the demodulation performance of this method is limited by factors such as the difference between the repetitive structure and the channel delay, the received signal-to-noise ratio, noise rise, and the decision threshold, resulting in poor demodulation performance. Summary of the Invention

[0003] This application provides an information sending method, receiving method, apparatus, device, and readable storage medium, which can solve the problem of poor demodulation performance of BSC modulated signals.

[0004] Firstly, a method for sending information is provided, including:

[0005] The first device sends a first signal, wherein the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units. M is an integer greater than 2.

[0006] Secondly, a method for sending information is provided, including:

[0007] The second device receives a first signal sent by the first device, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2;

[0008] The second device uses a second signal to perform backscatter modulation on the first signal to generate a third signal; wherein, the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part, the first sub-signal is used to modulate the first part to obtain the third part, the second sub-signal is used to modulate the second part to obtain the fourth part, and the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different between the polarity changes of data in every two adjacent first time units in the third part, and the second change being the same or different between the polarity changes of data in every two adjacent second time units in the fourth part;

[0009] The second device sends the third signal.

[0010] Thirdly, an information receiving method is provided, including:

[0011] The third device receives a third signal sent by the second device; the third signal includes a third part and a fourth part, the third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2; the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, the first change being different from the second change, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part;

[0012] The third device subtracts the data in every two adjacent first time units in the third part to obtain a first difference group, and subtracts the data in every two adjacent second time units in the fourth part to obtain a second difference group;

[0013] The third device determines a first correlation value of the difference between the data in every two adjacent first time units in the third part based on the first difference group, and determines a second correlation value of the difference between the data in every two adjacent second time units in the fourth part based on the second difference group.

[0014] The third device demodulates and obtains the bit information of the second signal based on the first correlation value and the second correlation value.

[0015] Fourthly, an information transmitting device is provided, applied to a first device, comprising:

[0016] A first transmitting module is used to transmit a first signal, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2.

[0017] Fifthly, an information transmitting device is provided, applied to a second device, comprising:

[0018] A first receiving module is configured to receive a first signal sent by a first device, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2;

[0019] A modulation module is used to backscatter and modulate the first signal using a second signal to generate a third signal; wherein the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part, the first sub-signal is used to modulate the first part to obtain the third part, the second sub-signal is used to modulate the second part to obtain the fourth part, and the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part;

[0020] The second transmitting module is used to transmit the third signal.

[0021] Sixthly, an information receiving device is provided, applied to a third device, comprising:

[0022] The second receiving module is used to receive a third signal sent by the second device; the third signal includes a third part and a fourth part, the third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2; the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part;

[0023] The processing module is used to subtract the data in every two adjacent first time units in the third part to obtain a first difference group, and to subtract the data in every two adjacent second time units in the fourth part to obtain a second difference group.

[0024] The determining module is configured to determine a first correlation value of the difference between the data in every two adjacent first time units in the third part based on the first difference group, and to determine a second correlation value of the difference between the data in every two adjacent first time units in the fourth part based on the second difference group.

[0025] The demodulation module is used to demodulate and obtain the bit information of the second signal based on the first correlation value and the second correlation value.

[0026] In a seventh aspect, a communication device is provided, including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect, or the method as described in the second aspect, or the method as described in the third aspect.

[0027] Eighthly, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or the method described in the second aspect, or the method described in the third aspect.

[0028] In a ninth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the steps of the method described in the first aspect, or the method described in the second aspect, or the method described in the third aspect.

[0029] In a tenth aspect, a computer program / program product is provided, the computer program / program product being stored in a storage medium, the computer program / program product being executed by at least one processor to implement the steps of the method as described in the first aspect, or the steps of the method as described in the second aspect, or the steps of the method as described in the third aspect.

[0030] Eleventhly, a communication system is provided, the communication system comprising at least two of a first device, a second device, and a third device, wherein the first device is configured to implement the steps of the method as described in the first aspect, the second device is configured to implement the steps of the method as described in the second aspect, and the third device is configured to implement the steps of the method as described in the third aspect.

[0031] In this embodiment of the application, by sending a first signal, in the scenario of backscatter communication, the repetitive time-domain structure of the first signal can be used, combined with the baseband signal waveform and modulation method of the BSC transmitting device, to eliminate strong direct link interference on the one hand, and reduce the demodulation complexity of the BSC modulation signal on the other hand, thereby improving the system performance of backscatter communication. Attached Figure Description

[0032] Figure 1A This is a block diagram of a monostatic backscatter communication system applicable to embodiments of this application;

[0033] Figure 1B This is a block diagram of a bistatic backscatter communication system applicable to embodiments of this application;

[0034] Figure 2 This is a flowchart of an information sending method provided in an embodiment of this application;

[0035] Figure 3 This is a schematic diagram of the structure of the first signal in an embodiment of this application;

[0036] Figure 4A and Figure 4B This is a schematic diagram of the distribution of the first signal in an embodiment of this application;

[0037] Figure 5 This is a flowchart of another information sending method provided in an embodiment of this application;

[0038] Figures 6A to 6D This is a schematic diagram of the baseband waveform in Example 1 of this application;

[0039] Figures 7A to 7H This is a schematic diagram of the baseband waveform in Example 2 of this application;

[0040] Figure 8 This is a flowchart of an information receiving method provided in an embodiment of this application;

[0041] Figure 9 This is a schematic diagram of the structure of an information transmission device provided in an embodiment of this application;

[0042] Figure 10 This is a schematic diagram of another information sending device provided in an embodiment of this application;

[0043] Figure 11 This is a schematic diagram of the structure of an information receiving device provided in an embodiment of this application;

[0044] Figure 12 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0046] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0047] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency Division Multiple Access (SC-FDMA), and other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used not only in the systems and radio technologies mentioned above, but also in other systems and radio technologies, such as New Radio (NR) systems, or 6th generation (6G) systems. th Generation 6G communication systems, etc.

[0048] To facilitate understanding of the embodiments of this application, the following will be described first.

[0049] Backscatter Communication (BSC) refers to a communication device that uses radio frequency signals from other devices or the environment to modulate its own information. It is a typical passive Internet of Things (IoT) device. The basic components and main functions of a backscatter communication transmitter include:

[0050] - Antenna unit: Used to receive radio frequency signals and control commands, and also to transmit modulated backscattered signals.

[0051] - Energy Harvesting Module or Power Supply Module: This module is used for radio frequency energy harvesting or other energy harvesting in the backscatter communication device, including but not limited to solar energy, kinetic energy, mechanical energy, and thermal energy. In addition to the energy harvesting module, it may also include a battery power supply module, in which case the backscatter communication device is a semi-passive device. The energy harvesting module or power supply module supplies power to all other modules in the device.

[0052] - Microcontrollers: including control baseband signal processing, energy storage or data scheduling status, switching, system synchronization, etc.

[0053] - Signal receiving module: Used to demodulate control commands or data sent by the backscatter communication receiver or other network nodes.

[0054] - Channel coding and modulation module: Performs channel coding and signal modulation under the control of the controller, and achieves modulation by selecting different load impedances through a selection switch under the control of the controller.

[0055] -Memory or sensing module: Used to store device identification ID information, location information, or sensing data, etc.

[0056] In addition to the typical components mentioned above, future backscatter communication transmitters can also integrate tunnel diode amplifier modules, low-noise amplifier modules, etc., to improve the receiver sensitivity and transmission power of the transmitter.

[0057] Optionally, the basic components and main functions of the backscatter communication receiver include:

[0058] - Antenna element: Used to receive modulated backscattered signals.

[0059] - Backscatter signal detection module: Used to detect the backscatter signal sent by the backscatter communication transmitter, including but not limited to ASK detection, PSK detection, FSK detection or QAM detection, etc.

[0060] - Demodulation and decoding module: Demodulates and decodes the detected signal to recover the original information stream.

[0061] Figure 1A This diagram illustrates a monostatic backscatter communication system (MBCSs) applicable to embodiments of this application. The MBCS system includes a BSC transmitter (e.g., a tag) and a reader. The reader contains an RF source and a BSC receiver. The RF source generates an RF signal to power the BSC transmitter / tag. The BSC transmitter backscatters the modulated RF signal, and the BSC receiver in the reader demodulates the signal upon receiving it. Because the RF signal transmitted from the BSC transmitter undergoes a double near-far effect due to signal attenuation during the round trip, the signal energy attenuation is significant. Therefore, MBCS systems are generally used for short-range backscatter communication, such as in traditional RFID applications.

[0062] Figure 1BThis diagram illustrates a bistatic backscatter communication system (BBCSs) applicable to embodiments of this application. Unlike monostatic backscatter communication systems (MBCSs), the RF source, BSC transmitter, and BSC receiver in a BBCS system are separate, thus avoiding the problem of significant round-trip signal attenuation. Furthermore, the performance of the BBCS communication system can be further improved by strategically placing the RF source. It is worth noting that environmental backscatter communication systems (ABCSs) are also a type of bistatic backscatter communication system, but unlike the dedicated signal source in a BBCS system, the RF source in an ABCS system can be an available environmental source, such as a TV tower, cellular base station, WiFi signal, or Bluetooth signal.

[0063] Unlike self-interference signals present in monostatic backscatter communication systems, bistatic backscatter communication systems experience direct link interference between the RF source and the BSC receiver. Furthermore, because this direct link interference may be a modulated signal, and the BSC receiver is generally unaware of the modulation characteristics of the direct link signal, canceling this direct link interference is far more complex.

[0064] To address the poor demodulation performance of current BSC modulated signals, this application's embodiments target backscatter communication. They utilize the repetitive time-domain structure of the carrier signal and the baseband signal waveform and modulation method of the BSC transmitting device to eliminate strong direct link interference / self-interference. Specifically, on one hand, the repetitive time-domain structure of the carrier signal is used to eliminate direct link interference / self-interference; on the other hand, the polarity change pattern between adjacent time units in the baseband signal is used to carry bit information. This allows the BSC receiving device to complete the demodulation of the modulated signal simply by determining the polarity between the modulated reference signal and the information signal, thereby improving the performance of the BSC demodulated signal under interference.

[0065] Optionally, the embodiments of this application can be applied to monostatic backscatter communication as well as bistatic backscatter communication. The following description mainly uses cross-link interference / direct-link interference under bistatic backscatter communication as an example, but it is not limited thereto.

[0066] The information sending method, receiving method, apparatus, device, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0067] Please see Figure 2 , Figure 2This is a flowchart of an information transmission method provided in an embodiment of this application. The method is applied to a first device, which is a radio frequency (RF) source, including but not limited to base stations, television towers, and other devices that transmit RF signals / carrier signals. Figure 2 As shown, the method includes the following steps:

[0068] Step 21: The first device sends the first signal.

[0069] In this embodiment, the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units, where M is an integer greater than 2. For the data in two time units to be opposite, it can be understood that the polarities of the data in the two time units are opposite. For example, the polarity of the data in one time unit is negative, and the polarity of the data in the other time unit is positive; or, the polarity of the data in one time unit is positive, and the polarity of the data in the other time unit is negative.

[0070] Optionally, the first time unit and the second time unit described above are time units of the same type, which may include any of the following: symbol, slot, subframe, frame, etc. For example, both the first time unit and the second time unit described above are slots, or both the first time unit and the second time unit described above are frames, or both the first time unit and the second time unit described above are symbols.

[0071] Optionally, the data length corresponding to the first time unit is N, and the data length corresponding to the second time unit is N, where N is a positive integer greater than a first threshold, and N can be random. The first threshold is a value related to channel delay, at least greater than the channel delay value, and can be set based on actual needs.

[0072] In some embodiments, the first signal described above is a signal used to provide a radio frequency carrier and / or radio frequency power, and may be referred to as a carrier signal, radio frequency signal, radio frequency carrier signal, etc., without limitation.

[0073] In some embodiments, the first part described above may be referred to as a reference block, such as a reference slot. The second part described above may be referred to as an information block, such as an information slot.

[0074] In some embodiments, the first signal described above can be represented as s(t), satisfying the following time-domain structure:

[0075]

[0076] Wherein, the value of m ranges from 0 to 2M; when 0≤m<M, it represents the corresponding first time unit, and when M≤m<2M, it represents the corresponding second time unit. The value of n ranges from 0 to N-1, representing a data sample value or data symbol in the first time unit / the second time unit. x(n) represents the nth data symbol or data sample value in the first time unit / the second time unit. c∈{1,-1} represents the polarity of the second part relative to the first part; for example, if c=1, the polarity of the data in the first time unit and the second time unit is the same, and if c=-1, the polarity of the data in the first time unit and the second time unit is opposite.

[0077] In some embodiments, taking that both the first time unit and the second time unit are slots, and M is equal to 4 as an example, the structure of the above-mentioned first signal may be as Figure 3 shown, wherein the first part includes 4 slots, the second part includes 4 slots, and the data length of each slot is N.

[0078] In this way, by transmitting the first signal, in the scenario of backscatter communication, the repeated time-domain structure of the first signal is utilized, in combination with the baseband signal waveform and modulation mode of the BSC transmitting device, on the one hand, the strong direct link interference is eliminated, and on the other hand, the demodulation complexity of the BSC modulated signal is reduced, thereby improving the system performance of backscatter communication.

[0079] Optionally, the data in the above-mentioned first time unit and second time unit may be: a non-random sequence or a random sequence.

[0080] For example, the data in the first time unit and the second time unit may be generated by using a non-random sequence or a random sequence. For example, the data in the first time unit and the second time unit may be a chaotic sequence generated according to a second-order Chebyshev polynomial function, and the chaotic sequence is a non-random sequence, which may be expressed as: x(n+1)=1-2x 2 (n). Wherein, the value of n ranges from 0 to N-1, representing the data position in the first time unit / the second time unit, and x(n) represents the nth data symbol or data sample value in the first time unit / the second time unit.

[0081] In this embodiment of the application, in order to perform noise smoothing, the first device may send P repeated first signals when sending the first signal, each of which is a basic signal. The P repeated first signals are distributed in a centralized or distributed manner, where P is an integer greater than or equal to 2. For a centralized manner, the P repeated first signals can be understood as being distributed together. For a distributed manner, the P repeated first signals can be understood as being distributed at intervals.

[0082] For example, when P repeated first signals are distributed in a centralized manner, it can be like this: Figure 4A As shown; or, when the P repeated first signals are distributed in a distributed manner, it can be as follows: Figure 4B As shown.

[0083] Please see Figure 5 , Figure 5 This is a flowchart illustrating an information transmission method provided in an embodiment of this application. The method is applied to a second device, which is a BSC transmitting device, including but not limited to tags, passive or semi-passive Internet of Things (IoT) devices, etc. Figure 5 As shown, the method includes the following steps:

[0084] Step 51: The second device receives the first signal sent by the first device.

[0085] In this embodiment, the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units, where M is an integer greater than 2. For the data in two time units to be opposite, it can be understood that the polarities of the data in the two time units are opposite. For example, the polarity of the data in one time unit is negative, and the polarity of the data in the other time unit is positive; or, the polarity of the data in one time unit is positive, and the polarity of the data in the other time unit is negative.

[0086] Optionally, the first time unit and the second time unit described above are time units of the same type, which may include any of the following: symbol, slot, subframe, frame, etc. For example, both the first time unit and the second time unit described above are slots, or both the first time unit and the second time unit described above are frames, or both the first time unit and the second time unit described above are symbols.

[0087] Optionally, the data length corresponding to the first time unit is N, and the data length corresponding to the second time unit is N, where N is a positive integer greater than a first threshold and can be random. The first threshold is a value related to channel delay and is at least greater than the channel delay value, and can be set based on actual needs.

[0088] It should be noted that when the second device receives the first signal s(t) sent by the first device, the signal received by the second device is the first signal s(t) transmitted from the first device to the second device via the channel h. st (t) The carrier signal after attenuation.

[0089] Step 52: The second device uses the second signal to perform backscatter modulation on the first signal to generate the third signal.

[0090] In this embodiment, the second signal is a baseband signal used to modulate the first signal. The first signal includes a first part and a second part, the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part. The first sub-signal corresponds to the first part and is used to modulate the first part to obtain the third part. The second sub-signal corresponds to the second part and is used to modulate the second part to obtain the fourth part. The third part occupies M first time units, and the fourth part occupies M second time units. After modulation, the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part. The first change and the second change are different. The first change is the similarity or difference between the polarity changes of data in every two adjacent first time units in the third part, and the second change is the similarity or difference between the polarity changes of data in every two adjacent second time units in the fourth part. For example, the first change is that the corresponding polarity changes are the same, and the second change is that the corresponding polarity changes are opposite; or, the first change is that the corresponding polarity changes are opposite, and the second change is that the corresponding polarity changes are the same.

[0091] Step 53: The second device sends a third signal.

[0092] For example, if the second device receives the first signal s(t) sent by the first device, then after estimating the channel delay and delay spread from the first device to the second device, and taking the channel delay and delay spread from the first device to the second device as the starting point, the generated third signal d(t) after modulation by the second signal (BSC baseband signal) can be expressed as:

[0093] d(t)=αb(t)*h st (t)*s(t)

[0094] Where α is the incident signal reflection coefficient in the second device (BSC transmitter), b(t) is the second signal (BSC baseband signal), and h st (t) represents the channel coefficient from the first device to the second device. That is, the second device transmits the BSC-modulated radio frequency signal through backscattering with a reflection coefficient α.

[0095] In this way, in the scenario of backscatter communication, the repetitive time-domain structure of the first signal can be used to eliminate direct link interference / self-interference, and the polarity change pattern between adjacent time units in the second signal can be used to carry bit information. This allows the BSC receiving device to complete the demodulation of the modulated signal simply by determining the polarity between the modulated reference signal and the information signal, thereby reducing the complexity of BSC modulated signal demodulation.

[0096] In this embodiment of the application, when obtaining the polarity change of data in every two adjacent first time units in the third part, the number M of first time units contained in the third part can be considered, and the parity of M can be taken into account to calculate the polarity change of data in the two adjacent first time units in sequence. When obtaining the polarity change of data in every two adjacent second time units in the fourth part, the number M of second time units contained in the fourth part can be considered, and the parity of M can be taken into account to calculate the polarity change of data in the two adjacent second time units in sequence, as long as the polarity change pattern between adjacent time units is used to carry bit information.

[0097] Optionally, when M equals 4, if the bit information of the second signal carried in the third signal is a first value, the first change is that the first polarity change is the same as the second polarity change, and the second change is that the third polarity change is opposite to the fourth polarity change; or, if the bit information of the second signal carried in the third signal is a second value, the first change is that the first polarity change is opposite to the second polarity change, and the second change is that the third polarity change is the same as the fourth polarity change. Wherein, the first polarity change is the polarity change from the data in the first first time unit to the data in the second first time unit in the third part, and the second polarity change is the polarity change from the data in the third first time unit to the data in the fourth first time unit in the third part; or, the first polarity change is the polarity change from the data in the second first time unit to the data in the first first time unit in the third part, and the second polarity change is the polarity change from the data in the fourth first time unit to the data in the third first time unit in the third part. The third polarity change is the polarity change of data from the first second time unit in the fourth part to the data from the second second time unit, and the fourth polarity change is the polarity change of data from the third second time unit in the fourth part to the data from the fourth second time unit; or, the third polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the first second time unit, and the fourth polarity change is the polarity change of data from the fourth second time unit in the fourth part to the data from the third second time unit.

[0098] Optionally, when M equals 3, if the bit information of the second signal carried in the third signal is a first value, the first change is that the fifth polarity change and the sixth polarity change are the same, and the second change is that the seventh polarity change and the eighth polarity change are opposite; or, if the bit information of the second signal carried in the third signal is a second value, the first change is that the fifth polarity change and the sixth polarity change are opposite, and the second change is that the seventh polarity change and the eighth polarity change are the same. Wherein, the fifth polarity change is the polarity change from the data in the first first time unit to the data in the second first time unit in the third part, and the sixth polarity change is the polarity change from the data in the second first time unit to the data in the third first time unit in the third part; or, the fifth polarity change is the polarity change from the data in the second first time unit to the data in the first first time unit in the third part, and the sixth polarity change is the polarity change from the data in the third first time unit to the data in the second first time unit in the third part. The seventh polarity change is the polarity change of data from the first second time unit in the fourth part to the data from the second second time unit; the eighth polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the third second time unit. Alternatively, the seventh polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the first second time unit; the eighth polarity change is the polarity change of data from the third second time unit in the fourth part to the data from the second second time unit.

[0099] Optionally, the first value is equal to 1 and the second value is equal to 0; or, the first value is equal to 0 and the second value is equal to 1. This setting of 0 and 1 simplifies the demodulation process of the modulated signal.

[0100] It should be noted that although the above embodiments are illustrated with M equal to 3 or 4 as an example, the embodiments of this application are not limited to this, and M can also take other values, such as M equal to 5, 6 or 8.

[0101] The modulation process in the embodiments of this application will be described below, taking the first and second time units as slots, with M equal to 4 or 3 as an example.

[0102] Example 1

[0103] In Example 1, the first part of the first signal contains 4 slots, the second part of the first signal contains 4 slots, that is, M equals 4, and the length of the first signal is 8 slots. Assume the second signal b(t) contains the first sub-signal b. R (mN+n) and the second sub-signal b D(mN+n), when 0≤m<M, it corresponds to the first sub-signal, and when M≤m<2M, it corresponds to the second sub-signal, where mod denotes the modulo operation symbol. The first sub-signal corresponds to the first part of the first signal, and is used to modulate said first part to obtain the third part of the third signal; the second sub-signal corresponds to the second part of the first signal, and is used to modulate said second part to obtain the fourth part of the third signal. The second signal b(t) may satisfy any of the following cases:

[0104] Case 1: If the second device transmits bit information B=1, that is, the bit information of the second signal is 1, then:

[0105]

[0106]

[0107] At this time, as Figure 6A shown, slot 1 to slot 2 in the first sub-signal changes from a low level to a high level, that is, the polarity change is positive, and slot 3 to slot 4 changes from a low level to a high level, that is, the polarity change is positive. The polarity change from slot 1 to slot 2 in the first sub-signal is the same as the polarity change from slot 3 to slot 4. Since the third part is obtained by modulation with the first sub-signal, the polarity change of the third part is the same as the polarity change of the first sub-signal. Therefore, the polarity change from slot 1 to slot 2 in the third part of the third signal is the same as the polarity change from slot 3 to slot 4. Slot 1 to slot 2 in the second sub-signal changes from a low level to a high level, that is, the polarity change is positive, and slot 3 to slot 4 changes from a high level to a low level, that is, the polarity change is negative. The polarity change from slot 1 to slot 2 in the second sub-signal is opposite to the polarity change from slot 3 to slot 4. Since the fourth part is obtained by modulation with the second sub-signal, the polarity change of the fourth part is the same as the polarity change of the second sub-signal. Therefore, the polarity change from slot 1 to slot 2 in the fourth part of the third signal is opposite to the polarity change from slot 3 to slot 4. That is, when the polarity changes corresponding to adjacent slots in the third part of the third signal are the same, and the polarity changes corresponding to adjacent slots in the fourth part of the third signal are opposite, the bit information carried in the corresponding third signal is 1.

[0108] And if the second device transmits bit information B=0, that is, the bit information of the second signal is 0, then:

[0109]

[0110]

[0111] At this time, as Figure 6A As shown, in the first sub-signal, slots 1 to 2 change from low to high level (positive polarity change), while slots 3 to 4 change from high to low level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 3 to 4. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from low to high (positive polarity), and slots 3 to 4 also change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 3 to 4. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 3 to 4. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0112] Scenario 2: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0113]

[0114]

[0115] At this time, as Figure 6BAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, and slots 3 to 4 change from high level to low level, i.e., the polarity change is negative. The polarity change of slots 1 to 2 in the first sub-signal is the same as that of slots 3 to 4. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity change of slots 1 to 2 in the third part of the third signal is the same as that of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from low to high (positive polarity), while slots 3 to 4 change from high to low (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 3 to 4. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 3 to 4. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0116] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0117]

[0118]

[0119] At this time, as Figure 6BAs shown, in the first sub-signal, slots 1 to 2 change from low to high level (positive polarity change), while slots 3 to 4 change from high to low level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 3 to 4. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), and slots 3 to 4 also change from high to low (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 3 to 4. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 3 to 4. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0120] Case 3: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0121]

[0122]

[0123] At this time, as Figure 6CAs shown, in the first sub-signal, slots 1 to 2 change from low to high level (i.e., the polarity change is negative), and slots 3 to 4 change from low to high level (i.e., the polarity change is negative). The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 3 to 4. Since the third part is modulated by the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), while slots 3 to 4 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 3 to 4. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 3 to 4. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0124] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0125]

[0126]

[0127] At this time, as Figure 6CAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, while slots 3 to 4 change from low level to high level, i.e., the polarity change is positive. The polarity change of slots 1 to 2 in the first sub-signal is opposite to that of slots 3 to 4. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity change of slots 1 to 2 in the third part of the third signal is opposite to that of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from low to high (positive polarity), and slots 3 to 4 also change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 3 to 4. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 3 to 4. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0128] Case 4: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0129]

[0130]

[0131] At this time, as Figure 6DAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, and slots 3 to 4 change from high level to low level, i.e., the polarity change is negative. The polarity change of slots 1 to 2 in the first sub-signal is the same as that of slots 3 to 4. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity change of slots 1 to 2 in the third part of the third signal is the same as that of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), while slots 3 to 4 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 3 to 4. Since the fourth part is modulated from the second sub-signal, its polarity changes are the same as those of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 3 to 4. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0132] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0133]

[0134]

[0135] At this time, as Figure 6DAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, while slots 3 to 4 change from low level to high level, i.e., the polarity change is positive. The polarity change of slots 1 to 2 in the first sub-signal is opposite to that of slots 3 to 4. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity change of slots 1 to 2 in the third part of the third signal is opposite to that of slots 3 to 4. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), and slots 3 to 4 also change from high to low (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 3 to 4. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 3 to 4. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0136] Similarly, in another implementation, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the bit information carried in the corresponding third signal is 1; and when the polarity changes of adjacent slots in the third part of the third signal are the same, and the polarity changes of adjacent slots in the fourth part of the third signal are opposite, the bit information carried in the corresponding third signal is 0. The specific modulation process is similar to the above process and will not be repeated here.

[0137] In this way, the polarity changes of adjacent slots in the third / fourth part of the third signal can be used to carry bit information. Thus, the demodulation of the modulated signal can be completed simply by determining the polarity between the third and fourth parts of the modulated third signal, thereby reducing the complexity of BSC modulated signal demodulation.

[0138] Example 2

[0139] In Example 2, the first part of the first signal contains 3 slots, the second part of the first signal contains 3 slots, that is, M equals 3, and the length of the first signal is 6 slots. Assume the second signal b(t) contains the first sub-signal b. R(mN+n) and the second sub-signal b D (mN+n), when 0≤m<M, it corresponds to the first sub-signal, and when M≤m<2M, it corresponds to the second sub-signal, where mod denotes the modulo operator. The first sub-signal corresponds to the first part of the first signal, and is configured to modulate the first part to obtain the third part of the third signal. The second sub-signal corresponds to the second part of the first signal, and is configured to modulate the second part to obtain the fourth part of the third signal. The second signal b(t) may satisfy any of the following cases:

[0140] Case 1: If the second device transmits bit information B=1, that is, the bit information of the second signal is 1, then:

[0141]

[0142]

[0143] At this time, as Figure 7A shown, in the first sub-signal, slot 1 to slot 2 changes from a low level to level 0, that is, the polarity change is positive, and slot 2 to slot 3 changes from level 0 to a high level, that is, the polarity change is positive. The polarity change from slot 1 to slot 2 in the first sub-signal is the same as the polarity change from slot 2 to slot 3. Since the third part is obtained by modulation with the first sub-signal, the polarity change of the third part is the same as the polarity change of the first sub-signal. Therefore, the polarity change from slot 1 to slot 2 in the third part of the third signal is the same as the polarity change from slot 2 to slot 3. In the second sub-signal, slot 1 to slot 2 changes from a low level to a high level, that is, the polarity change is positive, and slot 2 to slot 3 changes from a high level to level 0, that is, the polarity change is negative. The polarity change from slot 1 to slot 2 in the second sub-signal is opposite to the polarity change from slot 2 to slot 3. Since the fourth part is obtained by modulation with the second sub-signal, the polarity change of the fourth part is the same as the polarity change of the second sub-signal. Therefore, the polarity change from slot 1 to slot 2 in the fourth part of the third signal is opposite to the polarity change from slot 2 to slot 3. That is, when the polarity changes corresponding to adjacent slots in the third part of the third signal are the same, and the polarity changes corresponding to adjacent slots in the fourth part of the third signal are opposite, the bit information carried in the corresponding third signal is 1.

[0144] However, if the second device transmits bit information B=0, that is, the bit information of the second signal is 0, then:

[0145]

[0146]

[0147] At this time, as Figure 7A As shown, in the first sub-signal, slots 1 to 2 change from low to high level (positive polarity change), while slots 2 to 3 change from high to 0 level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from low to low (positive polarity), and slots 2 to 3 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0148] Scenario 2: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0149]

[0150]

[0151] At this time, as Figure 7BAs shown, in the first sub-signal, slots 1 to 2 change from a high level to a low level, i.e., the polarity change is negative, and slots 2 to 3 change from a low level, i.e., the polarity change is negative. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from low to high (positive polarity), while slots 2 to 3 change from high to 0 (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0152] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0153]

[0154]

[0155] At this time, as Figure 7BAs shown, in the first sub-signal, slots 1 to 2 change from low to high level (positive polarity change), while slots 2 to 3 change from high to 0 level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low level (negative polarity), and slots 2 to 3 change from low to high level (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0156] Case 3: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0157]

[0158]

[0159] At this time, as Figure 7CAs shown, in the first sub-signal, slots 1 to 2 change from low level to level 0, i.e., the polarity change is positive, and slots 2 to 3 change from level 0 to high level, i.e., the polarity change is positive. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from a level of 0 to a high level (positive polarity change), while slots 2 to 3 change from a high level to a low level (negative polarity change). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0160] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0161]

[0162]

[0163] At this time, as Figure 7CAs shown, in the first sub-signal, slots 1 to 2 change from level 0 to high level (positive polarity change), while slots 2 to 3 change from high level to low level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from low to low (positive polarity), and slots 2 to 3 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0164] Case 4: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0165]

[0166]

[0167] At this time, as Figure 7DAs shown, in the first sub-signal, slots 1 to 2 change from a high level to a low level, i.e., the polarity change is negative, and slots 2 to 3 change from a low level, i.e., the polarity change is negative. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from a level of 0 to a high level (positive polarity change), while slots 2 to 3 change from a high level to a low level (negative polarity change). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0168] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0169]

[0170]

[0171] At this time, as Figure 7DAs shown, in the first sub-signal, slots 1 to 2 change from level 0 to high level (positive polarity change), while slots 2 to 3 change from high level to low level (negative polarity change). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low level (negative polarity), and slots 2 to 3 change from low to high level (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0172] Case 5: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0173]

[0174]

[0175] At this time, as Figure 7EAs shown, in the first sub-signal, slots 1 to 2 change from low level to level 0, i.e., the polarity change is positive, and slots 2 to 3 change from level 0 to high level, i.e., the polarity change is positive. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from a level of 0 to a low level (negative polarity), while slots 2 to 3 change from a low level to a high level (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0176] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0177]

[0178]

[0179] At this time, as Figure 7EAs shown, in the first sub-signal, slots 1 to 2 change from level 0 to low level (negative polarity), while slots 2 to 3 change from low level to high level (positive polarity). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from low to low (positive polarity), and slots 2 to 3 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part are opposite, and the polarity changes of adjacent slots in the fourth part are the same, the corresponding bit information carried in the third signal is 0.

[0180] Case 6: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0181]

[0182]

[0183] At this time, as Figure 7FAs shown, in the first sub-signal, slots 1 to 2 change from a high level to a low level, i.e., the polarity change is negative, and slots 2 to 3 change from a low level, i.e., the polarity change is negative. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from a level of 0 to a low level (negative polarity), while slots 2 to 3 change from a low level to a high level (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0184] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0185]

[0186]

[0187] At this time, as Figure 7FAs shown, in the first sub-signal, slots 1 to 2 change from level 0 to low level (negative polarity), while slots 2 to 3 change from low level to high level (positive polarity). The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is modulated by the first sub-signal, the polarity changes of the third part are the same as those of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low level (negative polarity), and slots 2 to 3 change from low to high level (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0188] Case 7: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0189]

[0190]

[0191] At this time, as Figure 7GAs shown, in the first sub-signal, slots 1 to 2 change from low level to level 0, i.e., the polarity change is positive, and slots 2 to 3 change from level 0 to high level, i.e., the polarity change is positive. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), while slots 2 to 3 change from low to 0 (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0192] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0193]

[0194]

[0195] At this time, as Figure 7GAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, while slots 2 to 3 change from low level to level 0, i.e., the polarity change is positive. The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from low to low (positive polarity), and slots 2 to 3 change from low to high (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated by the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0196] Case 8: If the second device sends bit information B=1, that is, the bit information of the second signal is 1, then:

[0197]

[0198]

[0199] At this time, as Figure 7HAs shown, in the first sub-signal, slots 1 to 2 change from a high level to a low level, i.e., the polarity change is negative, and slots 2 to 3 change from a low level, i.e., the polarity change is negative. The polarity changes of slots 1 to 2 in the first sub-signal are the same as those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are the same as those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low (negative polarity), while slots 2 to 3 change from low to 0 (positive polarity). The polarity changes of slots 1 to 2 in the second sub-signal are opposite to those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are opposite to those of slots 2 to 3. In other words, when adjacent slots in the third part of the third signal have the same polarity change, and adjacent slots in the fourth part of the third signal have opposite polarity changes, the corresponding bit information carried in the third signal is 1.

[0200] If the second device sends bit information B=0, that is, the bit information of the second signal is 0, then:

[0201]

[0202]

[0203] At this time, as Figure 7HAs shown, in the first sub-signal, slots 1 to 2 change from high level to low level, i.e., the polarity change is negative, while slots 2 to 3 change from low level to level 0, i.e., the polarity change is positive. The polarity changes of slots 1 to 2 in the first sub-signal are opposite to those of slots 2 to 3. Since the third part is obtained by modulating the first sub-signal, the polarity change of the third part is the same as that of the first sub-signal. Therefore, the polarity changes of slots 1 to 2 in the third part of the third signal are opposite to those of slots 2 to 3. In the second sub-signal, slots 1 to 2 change from high to low level (negative polarity), and slots 2 to 3 change from low to high level (negative polarity). The polarity changes of slots 1 to 2 in the second sub-signal are the same as those of slots 2 to 3. Since the fourth part is modulated from the second sub-signal, its polarity change is the same as that of the second sub-signal. Therefore, the polarity changes of slots 1 to 2 in the fourth part of the third signal are the same as those of slots 2 to 3. In other words, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the corresponding bit information carried in the third signal is 0.

[0204] Similarly, in another implementation, when the polarity changes of adjacent slots in the third part of the third signal are opposite, and the polarity changes of adjacent slots in the fourth part of the third signal are the same, the bit information carried in the corresponding modulated signal is 1; and when the polarity changes of adjacent slots in the third part of the third signal are the same, and the polarity changes of adjacent slots in the fourth part of the third signal are opposite, the bit information carried in the corresponding modulated signal is 0. The specific modulation process is similar to the above process and will not be repeated here.

[0205] In this way, the polarity changes of adjacent slots in the third / fourth part of the third signal can be used to carry bit information. Thus, the demodulation of the modulated signal can be completed simply by determining the polarity between the third and fourth parts of the modulated third signal, thereby reducing the complexity of BSC modulated signal demodulation.

[0206] Please see Figure 8 , Figure 8This is a flowchart illustrating an information receiving method provided in an embodiment of this application. The method is applied to a third device, which is a BSC receiving device, including but not limited to a reader / writer. It should be noted that when this embodiment is applied to monostatic backscatter communication, the third device and the first device are physically identical and integrated together. However, when this embodiment is applied to bistatic backscatter communication, the third device and the first device are different devices. Figure 8 As shown, the information receiving method includes the following steps:

[0207] Step 81: The third device receives the third signal sent by the second device.

[0208] In this embodiment, the third signal is the signal modulated by the second signal (baseband signal) of the second device after the first signal is received. The third signal includes a third part and a fourth part. The third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2. The bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part. The first change and the second change are different. The first change refers to the similarity or difference between the polarity changes of data in every two adjacent first time units in the third part, and the second change refers to the similarity or difference between the polarity changes of data in every two adjacent second time units in the fourth part. For example, the first change may be that the corresponding polarity changes are the same, and the second change may be that the corresponding polarity changes are opposite; or, the first change may be that the corresponding polarity changes are opposite, and the second change may be that the corresponding polarity changes are the same.

[0209] Optionally, the first time unit and the second time unit described above are time units of the same type, which may include any of the following: symbol, slot, subframe, frame, etc. For example, both the first time unit and the second time unit described above are slots, or both the first time unit and the second time unit described above are frames, or both the first time unit and the second time unit described above are symbols.

[0210] Optionally, the data length corresponding to the first time unit is N, and the data length corresponding to the second time unit is N, where N is a positive integer greater than a first threshold and can be random. The first threshold is a value related to channel delay and is at least greater than the channel delay value, and can be set based on actual needs.

[0211] For example, suppose the first signal transmitted by the first device (i.e., the radio frequency source) is s(t), and the channel from the first device to the second device (i.e., the BSC transmitting device) is h. st(t), the second signal modulated by the second device is b(t), and the channel from the first device to the third device (i.e., the BSC receiving device) is h. sr (t), the channel from the second device to the third device is h. tr If y(t) is a reflection coefficient and α is the reflection coefficient, then the received signal y(t) of the third device can be expressed as:

[0212] y(t)=αs(t-τ2)b(t)h st h tr +h sr s(t-τ1)+w(t)

[0213] Among them, the first term αs(t-τ2)b(t)h st h tr The useful backscattered signal is sent from the second device, the second term h. sr s(t-τ1) is the direct link interference signal sent from the first device, w(t) is the Gaussian noise part, τ1 and τ2 are the multipath delays of the direct link and the backscatter cascaded link, respectively, and τ2>τ1. The received signal delay of the third device can be defined as τ=max{τ1,τ2}.

[0214] Furthermore, after symbol synchronization and starting with the cascaded channel delay, the received signal y(t) can be transformed as follows:

[0215] y(t)=h sr (t)*s(t)+h tr (t)*αb(t)·h st (t)*s(t)+w(t)

[0216] =(h sr (t)+h tr (t)*αb(t)·h st (t))*s(t)+w(t)

[0217] Step 82: The third device subtracts the data in every two adjacent first time units in the third part to obtain the first difference group, and subtracts the data in every two adjacent second time units in the fourth part to obtain the second difference group.

[0218] Step 83: The third device determines the first correlation value of the difference between the data in every two adjacent first time units in the third part according to the first difference group, and determines the second correlation value of the difference between the data in every two adjacent second time units in the fourth part according to the second difference group.

[0219] In this embodiment, the aforementioned first correlation value can characterize the similarity or polarity change similarity of the differences between data in every two adjacent first time units in the third part, and can be obtained by performing correlation calculations on the differences between data in every two adjacent first time units in the first difference group. The aforementioned second correlation value can characterize the similarity or polarity change similarity of the differences between data in every two adjacent second time units in the fourth part, and can be obtained by performing correlation calculations on the differences between data in every two adjacent first time units in the second difference group. That is, step 83 may include: the third device performing correlation calculations on the differences between data in every two adjacent first time units in the first difference group to obtain the first correlation value, and performing correlation calculations on the differences between data in every two adjacent second time units in the second difference group to obtain the second correlation value. The correlation calculations include, but are not limited to, multiplication and summation.

[0220] Step 84: The third device demodulates and obtains the bit information of the second signal based on the first correlation value and the second correlation value.

[0221] In this way, when the third device receives the third signal sent by the second device, it also receives the first signal sent by the first device. At this time, the first signal is a direct link interference signal. The data in adjacent time units in the first part of the first signal are completely identical, and the data in adjacent time units in the second part of the first signal are completely identical. Moreover, the repetitive structure of the signal is still maintained after passing through the channel. Therefore, by subtracting the data in every two adjacent first time units in the third part of the third signal and subtracting the data in every two adjacent second time units in the fourth part of the third signal, the direct link interference signal can be eliminated. As for the modulated third signal (i.e., the backscattered signal), since the bit information of the second signal carried in the third signal is represented by the first change in the third part and the second change in the fourth part, by determining the first correlation value of the corresponding difference in the third part and the second correlation value of the corresponding difference in the fourth part, and combining the modulation rule, demodulation can be performed based on the determined correlation value. Therefore, when performing demodulation, there is no need to construct a specific decision threshold, and it is not limited by the effective repetitive structure length and the influence of channel environment such as received SNR. Thus, the demodulation complexity of the third device can be greatly reduced, and the system performance of backscatter communication can be improved.

[0222] In this embodiment of the application, the difference between the data in every two adjacent first time units in the third part of the third signal can be calculated according to the modulation rule to obtain a first difference group, and the difference between the data in every two adjacent second time units in the fourth part of the third signal can be calculated to obtain a second difference group. Optionally, when M equals 4, the first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the fourth first time unit and the data in the third first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the third first time unit and the data in the fourth first time unit in the third part. The second difference group includes: the difference between the data in the second second time unit and the data in the first second time unit in the fourth part, and the difference between the data in the fourth second time unit and the data in the third second time unit in the fourth part; or, the second difference group includes: the difference between the data in the first second time unit and the data in the second second time unit in the fourth part, and the difference between the data in the third first time unit and the data in the fourth first time unit in the fourth part.

[0223] Optionally, when M equals 3, the first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the third first time unit and the data in the second first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the second first time unit and the data in the third first time unit in the third part. The second difference group includes: the difference between the data in the second second time unit and the data in the first second time unit in the fourth part, and the difference between the data in the third second time unit and the data in the second second time unit in the fourth part; or, the second difference group includes: the difference between the data in the first second time unit and the data in the second second time unit in the fourth part, and the difference between the data in the second second time unit and the data in the third second time unit in the fourth part.

[0224] In this embodiment of the application, in order to perform noise smoothing, the second device can send P third signals, where P is an integer greater than 2. In this case, after obtaining the first difference group and the second difference group, the differences included in the P first difference groups corresponding to the P third signals can be averaged (this averaging can be understood as averaging the corresponding differences of the P third parts) to obtain the first average difference group, and the differences included in the P second difference groups corresponding to the P third signals can be averaged (this averaging can be understood as averaging the corresponding differences of the P fourth parts) to obtain the second average difference group; then, based on the first average difference group, a first correlation value of the difference of the data in every two adjacent first time units in the third part is determined, and based on the second average difference group, a second correlation value of the difference of the data in every two adjacent second time units in the fourth part is determined.

[0225] Optionally, after obtaining the first average difference group and the second average difference group, the third device can perform correlation calculations on the average differences contained in the first average difference group to obtain a first correlation value, and perform correlation calculations on the average differences contained in the second average difference group to obtain a second correlation value. The correlation calculations include, but are not limited to, multiplication and summation.

[0226] In this embodiment, since the bit information of the second signal carried in the third signal is characterized by the first change of the third part and the second change of the fourth part, and the first change is different from the second change, the first change is the similarity or difference between the polarity changes of data in every two adjacent first time units in the third part, and the second change is the similarity or difference between the polarity changes of data in every two adjacent second time units in the fourth part. Therefore, the similarity of the polarity changes of data in every two adjacent first time units in the third part is different from the similarity of the polarity changes of data in every two adjacent second time units in the fourth part. Therefore, based on the relative magnitude comparison of the second correlation value of the fourth part based on the first correlation value of the third part, the bit information of the second signal can be demodulated.

[0227] Optionally, the above-mentioned method of obtaining the bit information of the second signal by demodulation based on the first correlation value and the second correlation value may include: the third device determining the bit information of the second signal as the first value when the first correlation value is greater than or equal to the second correlation value, or determining the bit information of the second signal as the second value when the first correlation value is less than the second correlation value, according to preset modulation and demodulation rules.

[0228] Optionally, the first value is equal to 1 and the second value is equal to 0; or, the first value is equal to 0 and the second value is equal to 1. In this way, by means of the setting of 0 and 1, the demodulation process of the modulated signal can be simplified.

[0229] In the following, the demodulation process in the embodiments of the present application is described by taking that both the first time unit and the second time unit are slots, and M is equal to 4 or 3 as an example.

[0230] Example 3

[0231] In this Example 3, the first part of the first signal includes 4 slots, and the second part of the first signal includes 4 slots, that is, M is equal to 4, and the length of the first signal is 8 slots, which corresponds to Example 1 in the above description of the modulation process. After completing synchronization, the third device obtains the received signal y(t). Thereafter, taking every 8 slots as a basic time slot block unit, the first 4 slots are the third part modulated with the BSC baseband signal, and the last 4 slots are the fourth part modulated with the BSC baseband signal. The two adjacent even and odd slots in the third part and the fourth part are respectively subtracted to obtain a first difference group and a second difference group.

[0232] For example, the second slot in the third part may be subtracted by the first slot, and the fourth slot in the third part may be subtracted by the third slot to obtain the first difference group; and the second slot in the fourth part may be subtracted by the first slot, and the fourth slot in the fourth part may be subtracted by the third slot to obtain the second difference group.

[0233] For example, the difference calculated in the third part / the fourth part may be expressed as follows:

[0234] z(mN+n)=y((m+1)N+n)-y(mN+n)

[0235] =αs(mN+n)(b((m+1)N+n)-b(mN+n))h st h tr +w((m+1)N+n)-w(mN+n)

[0236] Wherein, τ2≤n≤N+τ1-1, mod(m,4)=even, 0≤m<M. z(mN+n) represents the difference between the nth data symbol in the (m+1)th slot and the mth slot. It can be obtained from the above expression: since the data s(t) of two adjacent slots are completely identical, the direct link interference term is eliminated; however, the power of the noise term of the received signal is also raised, and the noise power becomes twice as much as before.

[0237] Optionally, if the radio frequency source (i.e., the first device) transmits P repeated first signals, then these P repeated first signals can be used for noise smoothing. That is, the differences contained in the calculated first difference group are averaged at positions to obtain a first average difference group, and the differences contained in the calculated second difference group are averaged at positions to obtain a second average difference group, as follows:

[0238] If the P repeated first signals are lumped together, then:

[0239] If the P repeated first signals are distributed, then:

[0240] Where Q is the length of a data slot in the distributed structure, and the data slots are time slot blocks of the radio frequency source used for other functions.

[0241] Optionally, after obtaining the first and second average difference groups, the average of the differences obtained from two adjacent even and odd slots within the third part can be calculated. Relevant value C R And calculate the average of the differences between two adjacent even and odd slots in Part 4. Relevant value C D ,as follows:

[0242]

[0243]

[0244] Where τ1 and τ2 are the multipath delays of the direct link and the backscatter cascaded link, respectively, and τ2>τ1.

[0245] Furthermore, by combining modulation and demodulation rules, it is possible to determine the appropriate modulation and demodulation rules based on C. R With C D The relative magnitude comparison shows the bit information B of the demodulated BSC baseband signal (i.e., the second signal), for example:

[0246]

[0247] Specifically, in Example 1 above, since the polarity changes of adjacent slots in the third part are the same when B=1, and the polarity changes of adjacent slots in the fourth part are opposite, the similarity of polarity changes between adjacent slots in the third part is greater than that between adjacent slots in the fourth part. That is, the correlation value C corresponding to the third part is... R Greater than the relevant value C corresponding to Part 4 D Therefore, during demodulation, if CR ≥C D Therefore, we can determine that the information bit B of the second signal is 1. Since the polarity changes of adjacent slots in the third part are opposite when B = 0, and the polarity changes of adjacent slots in the fourth part are the same, the similarity of polarity changes between adjacent slots in the third part is less than that between adjacent slots in the fourth part. That is, the correlation value C corresponding to the third part is... R Less than the relevant value C corresponding to Part 4 D Therefore, during demodulation, if C R <C D Then it can be determined that the information bit B of the second signal is 0.

[0248] Example 4

[0249] In this Example 4, the first part of the first signal contains 3 slots, and the second part of the first signal contains 3 slots, i.e., M equals 3. The length of the first signal is 6 slots, corresponding to Example 2 described above when explaining the modulation process. After synchronization, the third device obtains the received signal y(t). Then, taking 6 slots as a basic time slot block unit, the first 3 slots are the third part of the modulated BSC baseband signal, and the last 3 slots are the fourth part of the modulated BSC baseband signal. The first difference group and the second difference group are obtained by subtracting the two adjacent slots in the third part and the fourth part, respectively.

[0250] For example, the first difference group can be obtained by subtracting the first slot from the second slot in the third part, and by subtracting the second slot from the third slot in the third part; and the second difference group can be obtained by subtracting the first slot from the second slot in the fourth part, and by subtracting the second slot from the third slot in the fourth part.

[0251] For example, the difference calculated from the third signal can be represented as follows:

[0252] z((m-1)N+n)=y(mN+n)-y((m-1)N+n)

[0253] =αs((m-1)N+n)(b(mN+n)-b((m-1)N+n))h st h tr +w(mN+n)-w((m-1)N+n)

[0254] z(mN+n)=y((m+1)N+n)-y(mN+n)

[0255] =αs(mN+n)(b((m+1)N+n)-b(mN+n))hst h tr +w((m+1)N+n)-w(mN+n)

[0256] where τ2≤n≤N+τ1-1, mod(m,3)=odd, 0≤m<M. z(mN+n) represents the difference value of the nth data symbol in the (m+1)-th slot and the m-th slot. It can be derived from the above expression that since the data s(t) of two adjacent slots are completely identical, the direct link interference term is eliminated; however, this also causes the power of the noise term of the received signal to rise, and the noise power becomes twice as large as before.

[0257] Optionally, if the radio frequency source (i.e., the first device) transmits P repeated first signals, the P repeated first signals may be used for noise smoothing, that is, performing bitwise averaging on the difference values included in the calculated first difference set to obtain a first average difference set, and performing bitwise averaging on the difference values included in the calculated second difference set to obtain a second average difference set, as follows:

[0258] If the P repeated first signals are centralized, then:

[0259] If the P repeated first signals are distributed, then:

[0260] where Q is the length of one data slot in the distributed structure, and the Data slots are time slot blocks of the radio frequency source for other functions.

[0261] Optionally, after the first average difference set and the second average difference set are obtained, the average value of the two difference values obtained from two adjacent slots in the third part may be calculated the correlation value C R , and the average value of the two difference values obtained from two adjacent slots in the fourth part is calculated the correlation value C D , as follows:

[0262]

[0263]

[0264] where τ1 and τ2 are the multipath time delays of the direct link and the backscatter cascaded link respectively, and τ2>τ1.

[0265] Further, in combination with the modulation rule, according to C R and C DThe relative magnitude comparison shows the bit information B of the demodulated BSC baseband signal (i.e., the second signal), for example:

[0266]

[0267] Specifically, in Example 2 above, since the polarity changes of adjacent slots in the third part are the same when B=1, and the polarity changes of adjacent slots in the fourth part are opposite, the similarity of polarity changes between adjacent slots in the third part is greater than that between adjacent slots in the fourth part. That is, the correlation value C corresponding to the third part is... R Greater than the relevant value C corresponding to Part 4 D Therefore, during demodulation, if C R ≥C D Therefore, we can determine that the information bit B of the second signal is 1. Since the polarity changes of adjacent slots in the third part are opposite when B = 0, and the polarity changes of adjacent slots in the fourth part are the same, the similarity of polarity changes between adjacent slots in the third part is less than the similarity of polarity changes between adjacent slots in the fourth part. That is, the correlation value C corresponding to the third part is... R Less than the relevant value C corresponding to Part 4 D Therefore, during demodulation, if C R <C D Then it can be determined that the information bit B of the second signal is 0.

[0268] The information sending method provided in this application can be executed by an information sending device. This application uses an information sending device executing the information sending method as an example to illustrate the information sending device provided in this application.

[0269] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of an information transmission device provided in an embodiment of this application. The device is applied to a first device, which is a radio frequency (RF) source, including but not limited to base stations, television towers, and other devices that transmit RF signals / carrier signals. Figure 9 As shown, the information transmitting device 90 includes:

[0270] The first transmitting module 91 is used to transmit a first signal, wherein the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units. M is an integer greater than 2.

[0271] Optionally, the first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

[0272] Optionally, the data in the first time unit and the second time unit are either non-random sequences or random sequences.

[0273] Optionally, the first transmitting module 91 is further configured to: transmit P repeated first signals, wherein the P repeated first signals are distributed in a centralized manner or in a distributed manner, and P is an integer greater than or equal to 2.

[0274] Optionally, the data length corresponding to the first time unit is N, the data length corresponding to the second time unit is N, and N is a positive integer greater than the first threshold.

[0275] The information sending device 90 provided in this application embodiment can achieve... Figure 2 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0276] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of an information transmission device provided in an embodiment of this application. The device is applied to a second device, which is a BSC transmission device, including but not limited to tags, passive or semi-passive IoT devices, etc. Figure 10 As shown, the information transmitting device 100 includes:

[0277] The first receiving module 101 is used to receive a first signal sent by the first device, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2;

[0278] Modulation module 102 is used to backscatter modulate the first signal using a second signal to generate a third signal; wherein the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part, the first sub-signal is used to modulate the first part to obtain the third part, the second sub-signal is used to modulate the second part to obtain the fourth part, and the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part;

[0279] The second transmitting module 103 is used to transmit the third signal.

[0280] Optionally, the first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

[0281] Optionally, when M equals 4, if the bit information is a first value, the first change is that the first polarity change and the second polarity change are the same, and the second change is that the third polarity change and the fourth polarity change are opposite; or, if the bit information is a second value, the first change is that the first polarity change and the second polarity change are opposite, and the second change is that the third polarity change and the fourth polarity change are the same.

[0282] Wherein, the first polarity change is the polarity change of data from the first first time unit to the second first time unit in the third part, and the second polarity change is the polarity change of data from the third first time unit to the fourth first time unit in the third part; or, the first polarity change is the polarity change of data from the second first time unit to the first first time unit in the third part, and the second polarity change is the polarity change of data from the fourth first time unit to the third first time unit in the third part;

[0283] The third polarity change is the polarity change of data from the first second time unit to the second second time unit in the fourth part, and the fourth polarity change is the polarity change of data from the third second time unit to the fourth second time unit in the fourth part; or, the third polarity change is the polarity change of data from the second second time unit to the first second time unit in the fourth part, and the fourth polarity change is the polarity change of data from the fourth second time unit to the third second time unit in the fourth part.

[0284] Optionally, when M equals 3, if the bit information is a first value, the first change is that the fifth polarity change and the sixth polarity change are the same, and the second change is that the seventh polarity change and the eighth polarity change are opposite; or, if the bit information is a second value, the first change is that the fifth polarity change and the sixth polarity change are opposite, and the second change is that the seventh polarity change and the eighth polarity change are the same.

[0285] Wherein, the fifth polarity change is the polarity change of data from the first first time unit in the third part to the data from the second first time unit, and the sixth polarity change is the polarity change of data from the second first time unit in the third part to the data from the third first time unit; or, the fifth polarity change is the polarity change of data from the second first time unit in the third part to the data from the first first time unit, and the sixth polarity change is the polarity change of data from the third first time unit in the third part to the data from the second first time unit.

[0286] The seventh polarity change is the polarity change of data from the first second time unit in the fourth part to the data from the second second time unit, and the eighth polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the third second time unit; or, the seventh polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the first second time unit, and the eighth polarity change is the polarity change of data from the third second time unit in the fourth part to the data from the second second time unit.

[0287] Optionally, the first value is equal to 1 and the second value is equal to 0; or, the first value is equal to 0 and the second value is equal to 1.

[0288] Optionally, the data length corresponding to the first time unit is N, the data length corresponding to the second time unit is N, and N is a positive integer greater than the first threshold.

[0289] The information sending device 100 provided in this application embodiment can achieve... Figure 5 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0290] Please see Figure 11 , Figure 11 This is a schematic diagram of the structure of an information receiving device provided in an embodiment of this application. This device is applied to a third device, which is a BSC receiving device, including but not limited to a reader / writer. Figure 11 As shown, the information receiving device 110 includes:

[0291] The second receiving module 111 is used to receive a third signal sent by the second device; the third signal includes a third part and a fourth part, the third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2; the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part;

[0292] The processing module 112 is used to subtract the data in every two adjacent first time units in the third part to obtain a first difference group, and to subtract the data in every two adjacent second time units in the fourth part to obtain a second difference group.

[0293] The determining module 113 is configured to determine, based on the first difference group, a first correlation value of the difference between the data in every two adjacent first time units in the third part, and based on the second difference group, a second correlation value of the difference between the data in every two adjacent second time units in the fourth part.

[0294] The demodulation module 114 is used to demodulate and obtain the bit information of the second signal based on the first correlation value and the second correlation value.

[0295] Optionally, the first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

[0296] Optionally, when M equals 4, the first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the fourth first time unit and the data in the third first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the third first time unit and the data in the fourth first time unit in the third part.

[0297] The second difference group includes: the difference between the data in the second second time unit of the fourth part and the data in the first second time unit, and the difference between the data in the fourth second time unit of the fourth part and the data in the third second time unit; or, the second difference group includes: the difference between the data in the first second time unit of the fourth part and the data in the second second time unit, and the difference between the data in the third first time unit of the fourth part and the data in the fourth first time unit.

[0298] Optionally, when M equals 3, the first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the third first time unit and the data in the second first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the second first time unit and the data in the third first time unit in the third part.

[0299] The second difference group includes: the difference between the data in the second second time unit of the fourth part and the data in the first second time unit, and the difference between the data in the third second time unit of the fourth part and the data in the second second time unit; or, the second difference group includes: the difference between the data in the first second time unit of the fourth part and the data in the second second time unit, and the difference between the data in the second second time unit of the fourth part and the data in the third second time unit.

[0300] Optionally, the third signal includes P basic signals, each basic signal including the third part and the fourth part, where P is an integer greater than or equal to 2;

[0301] The processing module 112 is further configured to: perform positional averaging on the differences included in the first difference group of the P basic signals to obtain a first average difference group, and perform positional averaging on the differences included in the second difference group of the P basic signals to obtain a second average difference group.

[0302] The determining module 113 is further configured to: determine the first correlation value based on the first average difference group, and determine the second correlation value based on the second average difference group.

[0303] Optionally, the determining module 113 is further configured to: perform correlation calculation on the difference between the data in every two adjacent first time units in the first difference group to obtain the first correlation value, and perform correlation calculation on the difference between the data in every two adjacent second time units in the second difference group to obtain the second correlation value.

[0304] Optionally, the demodulation module 114 is further configured to: determine the bit information of the second signal as a first value when the first correlation value is greater than or equal to the second correlation value, or determine the bit information of the second signal as a second value when the first correlation value is less than the second correlation value, according to a preset modulation rule.

[0305] Optionally, the first value is equal to 1 and the second value is equal to 0; or, the first value is equal to 0 and the second value is equal to 1.

[0306] The information receiving device 110 provided in this application embodiment can achieve... Figure 8 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0307] Optional, such as Figure 12 As shown, this application embodiment also provides a communication device 120, including a processor 121 and a memory 122. The memory 122 stores a program or instructions that can be executed on the processor 121. For example, when the communication device 120 is a first device, the program or instructions executed by the processor 121 implement the above-mentioned... Figure 2 The various steps of the information transmission method embodiment shown can achieve the same technical effect. When the communication device 120 is a second device, the above-described procedure or instruction is implemented when executed by the processor 121. Figure 5 The various steps of the information transmission method embodiment shown can achieve the same technical effect. When the communication device 120 is a third device, the program or instructions executed by the processor 121 implement the above. Figure 8 The steps of the information receiving method embodiment shown are the same and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0308] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described information sending method embodiments or the various processes of the above-described information receiving method embodiments, and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0309] The processor is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0310] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described information sending method embodiment or the various processes of the above-described information receiving method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0311] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0312] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described information sending method embodiment or the various processes of the above-described information receiving method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0313] This application embodiment also provides a communication system, which includes at least two of a first device, a second device, and a third device, wherein the first device can be used to implement the above. Figure 2 The second device can be used to implement the steps of the information transmission method described above. Figure 5 The third device can be used to implement the steps of the information transmission method described above. Figure 8 The steps of the information receiving method are described.

[0314] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0315] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0316] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for sending information, characterized in that, include: A first device transmits a first signal, wherein the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2. The first signal is used to generate a third signal, which is obtained by backscattering the first signal using a second signal. The second signal includes a first sub-signal and a second sub-signal. The third signal includes a third part and a fourth part. The first sub-signal is used to modulate the first part to obtain the third part, and the second sub-signal is used to modulate the second part to obtain the fourth part. The bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part. The first change and the second change are different. The first change is the same or different polarity change between the data in every two adjacent first time units in the third part, and the second change is the same or different polarity change between the data in every two adjacent second time units in the fourth part.

2. The method according to claim 1, characterized in that, The first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

3. The method according to claim 1 or 2, characterized in that, The data in the first time unit and the data in the second time unit are either non-random sequences or random sequences.

4. The method according to claim 1 or 2, characterized in that, Sending the first signal includes: The first device sends P repeated first signals, wherein the P repeated first signals are distributed in a centralized or distributed manner, and P is an integer greater than or equal to 2.

5. The method according to claim 1, characterized in that, The data length corresponding to the first time unit is N, and the data length corresponding to the second time unit is N, where N is a positive integer greater than the first threshold.

6. A method for sending information, characterized in that, include: The second device receives a first signal sent by the first device, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2; The second device uses a second signal to perform backscatter modulation on the first signal to generate a third signal; wherein, the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part, the first sub-signal is used to modulate the first part to obtain the third part, the second sub-signal is used to modulate the second part to obtain the fourth part, and the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different between the polarity changes of data in every two adjacent first time units in the third part, and the second change being the same or different between the polarity changes of data in every two adjacent second time units in the fourth part; The second device sends the third signal.

7. The method according to claim 6, characterized in that, The first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

8. The method according to claim 6 or 7, characterized in that, When M equals 4 If the bit information is a first value, the first change is that the first polarity change and the second polarity change are the same, and the second change is that the third polarity change and the fourth polarity change are opposite; or, if the bit information is a second value, the first change is that the first polarity change and the second polarity change are opposite, and the second change is that the third polarity change and the fourth polarity change are the same. Wherein, the first polarity change is the polarity change of data from the first first time unit to the second first time unit in the third part, and the second polarity change is the polarity change of data from the third first time unit to the fourth first time unit in the third part; or, the first polarity change is the polarity change of data from the second first time unit to the first first time unit in the third part, and the second polarity change is the polarity change of data from the fourth first time unit to the third first time unit in the third part; The third polarity change is the polarity change of data from the first second time unit to the second second time unit in the fourth part, and the fourth polarity change is the polarity change of data from the third second time unit to the fourth second time unit in the fourth part; or, the third polarity change is the polarity change of data from the second second time unit to the first second time unit in the fourth part, and the fourth polarity change is the polarity change of data from the fourth second time unit to the third second time unit in the fourth part.

9. The method according to claim 6 or 7, characterized in that, When M equals 3 If the bit information is a first value, the first change is that the fifth polarity change and the sixth polarity change are the same, and the second change is that the seventh polarity change and the eighth polarity change are opposite; or, if the bit information is a second value, the first change is that the fifth polarity change and the sixth polarity change are opposite, and the second change is that the seventh polarity change and the eighth polarity change are the same. Wherein, the fifth polarity change is the polarity change of data from the first first time unit in the third part to the data from the second first time unit, and the sixth polarity change is the polarity change of data from the second first time unit in the third part to the data from the third first time unit; or, the fifth polarity change is the polarity change of data from the second first time unit in the third part to the data from the first first time unit, and the sixth polarity change is the polarity change of data from the third first time unit in the third part to the data from the second first time unit. The seventh polarity change is the polarity change of data from the first second time unit in the fourth part to the data from the second second time unit, and the eighth polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the third second time unit; or, the seventh polarity change is the polarity change of data from the second second time unit in the fourth part to the data from the first second time unit, and the eighth polarity change is the polarity change of data from the third second time unit in the fourth part to the data from the second second time unit.

10. The method according to claim 8, characterized in that, The first value is equal to 1, and the second value is equal to 0; or, the first value is equal to 0, and the second value is equal to 1.

11. The method according to claim 6 or 7, characterized in that, The data length corresponding to the first time unit is N, and the data length corresponding to the second time unit is N, where N is a positive integer greater than the first threshold.

12. An information receiving method, characterized in that, include: The third device receives a third signal sent by the second device; the third signal includes a third part and a fourth part, the third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2; the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, the first change being different from the second change, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part; The third device subtracts the data in every two adjacent first time units in the third part to obtain a first difference group, and subtracts the data in every two adjacent second time units in the fourth part to obtain a second difference group; The third device determines a first correlation value of the difference between the data in every two adjacent first time units in the third part based on the first difference group, and determines a second correlation value of the difference between the data in every two adjacent second time units in the fourth part based on the second difference group. The third device demodulates the bit information of the second signal based on the first correlation value and the second correlation value.

13. The method according to claim 12, characterized in that, The first time unit and the second time unit are time units of the same type, including any one of the following: symbol, time slot, subframe, frame.

14. The method according to claim 12 or 13, characterized in that, When M equals 4 The first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the fourth first time unit and the data in the third first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the third first time unit and the data in the fourth first time unit in the third part; The second difference group includes: the difference between the data in the second second time unit and the data in the first second time unit in the fourth part, and the difference between the data in the fourth second time unit and the data in the third second time unit in the fourth part; or, the second difference group includes: the difference between the data in the first second time unit and the data in the second second time unit in the fourth part, and the difference between the data in the third first time unit and the data in the fourth first time unit in the fourth part.

15. The method according to claim 12 or 13, characterized in that, When M equals 3 The first difference group includes: the difference between the data in the second first time unit and the data in the first first time unit in the third part, and the difference between the data in the third first time unit and the data in the second first time unit in the third part; or, the first difference group includes: the difference between the data in the first first time unit and the data in the second first time unit in the third part, and the difference between the data in the second first time unit and the data in the third first time unit in the third part; The second difference group includes: the difference between the data in the second second time unit and the data in the first second time unit in the fourth part, and the difference between the data in the third second time unit and the data in the second second time unit in the fourth part; or, the second difference group includes: the difference between the data in the first second time unit and the data in the second second time unit in the fourth part, and the difference between the data in the second second time unit and the data in the third second time unit in the fourth part.

16. The method according to claim 12, characterized in that, If the second device sends P third signals, where P is an integer greater than or equal to 2; after subtracting the data in every two adjacent first time units in the third part to obtain a first difference group, and subtracting the data in every two adjacent second time units in the fourth part to obtain a second difference group, the method further includes: The third device performs a positional average of the differences included in the P first difference groups corresponding to the P third signals to obtain a first average difference group, and performs a positional average of the differences included in the P second difference groups corresponding to the P third signals to obtain a second average difference group. The step of determining a first correlation value for the difference between data in every two adjacent first time units in the third part based on the first difference group, and determining a second correlation value for the difference between data in every two adjacent second time units in the fourth part based on the second difference group, includes: The third device determines the first correlation value based on the first average difference group and determines the second correlation value based on the second average difference group.

17. The method according to claim 12, characterized in that, The step of determining the first correlation value of the third part based on the first difference group, and determining the second correlation value of the fourth part based on the second difference group, includes: The third device performs correlation calculations on the differences between data in every two adjacent first time units in the first difference group to obtain the first correlation value, and performs correlation calculations on the differences between data in every two adjacent second time units in the second difference group to obtain the second correlation value.

18. The method according to claim 12 or 13, characterized in that, The step of demodulating and obtaining the bit information of the second signal based on the first correlation value and the second correlation value includes: The third device determines the bit information of the second signal as a first value when the first correlation value is greater than or equal to the second correlation value, or determines the bit information of the second signal as a second value when the first correlation value is less than the second correlation value, according to a preset modulation rule.

19. The method according to claim 18, characterized in that, The first value is equal to 1, and the second value is equal to 0; or, the first value is equal to 0, and the second value is equal to 1.

20. An information transmitting device, characterized in that, include: A first transmitting module is used to transmit a first signal, wherein the first signal includes a first part and a second part. The first part occupies M first time units, and the data in the M first time units is the same. The second part occupies M second time units, and the data in the M second time units is the same. The data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2. The first signal is used to generate a third signal, which is obtained by backscattering the first signal using a second signal. The second signal includes a first sub-signal and a second sub-signal. The third signal includes a third part and a fourth part. The first sub-signal is used to modulate the first part to obtain the third part, and the second sub-signal is used to modulate the second part to obtain the fourth part. The bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part. The first change and the second change are different. The first change is the same or different polarity change between the data in every two adjacent first time units in the third part, and the second change is the same or different polarity change between the data in every two adjacent second time units in the fourth part.

21. An information transmitting device, characterized in that, include: A first receiving module is configured to receive a first signal sent by a first device, wherein the first signal includes a first part and a second part, the first part occupies M first time units, and the data in the M first time units is the same, the second part occupies M second time units, and the data in the M second time units is the same, the data in the first time units is the same as or opposite to the data in the second time units, and M is an integer greater than 2; A modulation module is used to backscatter and modulate the first signal using a second signal to generate a third signal; wherein the second signal includes a first sub-signal and a second sub-signal, and the third signal includes a third part and a fourth part, the first sub-signal is used to modulate the first part to obtain the third part, the second sub-signal is used to modulate the second part to obtain the fourth part, and the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part; The second transmitting module is used to transmit the third signal.

22. An information receiving device, characterized in that, include: The second receiving module is used to receive a third signal sent by the second device; the third signal includes a third part and a fourth part, the third part occupies M first time units, and the fourth part occupies M second time units, where M is an integer greater than 2; the bit information of the second signal carried in the third signal is characterized by a first change in the third part and a second change in the fourth part, wherein the first change and the second change are different, the first change being the same or different polarity change between every two adjacent first time units in the third part, and the second change being the same or different polarity change between every two adjacent second time units in the fourth part; The processing module is used to subtract the data in every two adjacent first time units in the third part to obtain a first difference group, and to subtract the data in every two adjacent second time units in the fourth part to obtain a second difference group. The determining module is configured to determine a first correlation value of the difference between data in every two adjacent first time units in the third part based on the first difference group, and to determine a second correlation value of the difference between data in every two adjacent second time units in the fourth part based on the second difference group. The demodulation module is used to demodulate and obtain the bit information of the second signal based on the first correlation value and the second correlation value.

23. A communication device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the information transmission method as described in any one of claims 1 to 5, or the steps of the information transmission method as described in any one of claims 6 to 11, or the steps of the information reception method as described in any one of claims 12 to 19.

24. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the information transmission method as described in any one of claims 1 to 5, or the steps of the information transmission method as described in any one of claims 6 to 11, or the steps of the information reception method as described in any one of claims 12 to 19.

Images