Backscatter communication method, device, and readable storage medium

Abstract

The application discloses a backscattering communication method, device and readable storage medium, and belongs to the technical field of communication. The method comprises the following steps: a first communication device determines a first signal according to first information; and sends the first signal to a second device; a second communication device determines a second signal according to second information; and differentially modulates the first signal in the amplitude dimension and / or the phase dimension according to the second signal to generate a third signal; a third communication device determines the signal modulation type and the signal modulation parameter of the second signal according to third information; and demodulates the bit information of the second signal from the third signal according to the signal modulation type and the signal modulation parameter of the second signal. The first signal comprises a first part and a second part, the first part occupies the length of a first time unit, the second part occupies the length of a second time unit, the length of the first time unit is the same as the length of the second time unit, and the data in the first time unit is the same as the data in the second time unit.

Description

Technical Field

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

[0002] The future 6th generation (6 th Generation 6G communication networks need to support massive Internet of Things (IoT) deployments, with the number of IoT devices reaching hundreds of billions. The connection density will be 10-100 times higher than 5G, reaching 10-100 devices / m². This massive number of IoT devices presents new challenges to cost and power consumption. Cellular networking, low cost, low power consumption, and even zero-power passive operation are the main trends in the future development of IoT devices. Limited by the transmission power of network nodes, two-way link attenuation, energy storage efficiency and capacity of energy storage circuits, the receiving sensitivity of backscatter communication devices, the gain of transceiver antennas, and the impact of signal interference, both forward and reverse coverage of backscatter communication face significant technical challenges. Adopting a bistatic architecture is one of the most effective ways to improve backscatter communication coverage, effectively avoiding the two-way signal attenuation problem in monostatic backscatter communication. By rationally placing the RF source and the backscatter communication receiver, and even deploying a dedicated RF source for RF power supply, the transmission coverage of backscatter communication can be effectively improved.

[0003] In backscatter communication systems, the received signal is a superposition of the useful backscatter signal and the same-frequency direct link interference signal or self-interference signal. The intensity of the self-interference signal and the direct link interference signal may be much greater than the intensity of the backscatter signal, which makes interference cancellation technology in backscatter communication quite difficult. Summary of the Invention

[0004] This application provides a backscatter communication method, device, and readable storage medium, which can solve the problem of difficulty in interference elimination in backscatter communication systems.

[0005] Firstly, a backscattering communication method is provided, including:

[0006] The first communication device determines the first signal based on the first information;

[0007] The first communication device sends the first signal to the second communication device;

[0008] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0009] Secondly, a backscattering communication method is provided, including:

[0010] The second communication device receives the first signal sent by the first communication device;

[0011] The second communication device determines the second signal based on the second information;

[0012] The second communication device modulates the first signal according to the second signal to generate a third signal;

[0013] The second communication device sends the third signal to the third communication device;

[0014] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing amplitude and / or phase dimension differential modulation on the first signal.

[0015] Thirdly, a backscattering communication method is provided, including:

[0016] The third communication device receives the third signal sent by the second communication device;

[0017] The third communication device determines the signal modulation type and signal modulation parameters of the second signal based on the third information;

[0018] The third communication device demodulates the bit information of the second signal modulation from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0019] The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0020] Fourthly, a backscatter communication method is provided, including one or more of the following:

[0021] The fourth communication device configures or instructs the first communication device with the first information;

[0022] The fourth communication device configures or instructs the second communication device with second information;

[0023] The fourth communication device configures or instructs the third communication device with third information;

[0024] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0025] Fifthly, a backscatter communication device is provided, comprising:

[0026] The first determining module is used to determine the first signal based on the first information;

[0027] The first transmitting module is used to transmit the first signal to the second communication device;

[0028] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0029] Sixthly, a backscatter communication device is provided, comprising:

[0030] The first receiving module is used to receive the first signal sent by the first communication device;

[0031] The second determining module is used to determine the second signal based on the second information;

[0032] A modulation module is used to perform backscatter modulation on the first signal based on the second signal to generate a third signal;

[0033] The second transmitting module is used to transmit the third signal to the third communication device;

[0034] The first signal comprises a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the backscatter communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

[0035] In a seventh aspect, a backscatter communication device is provided, comprising:

[0036] The second receiving module is used to receive the third signal sent by the second communication device;

[0037] The third determining module is used to determine the signal modulation type and signal modulation parameters of the second signal based on the third information.

[0038] The demodulation module is used to demodulate the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0039] The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0040] Eighthly, a backscatter communication device is provided, comprising:

[0041] Configuration module, used for one or more of the following:

[0042] Configure or instruct the first communication device to provide first information;

[0043] Configure or instruct a second communication device to provide second information;

[0044] Configure or instruct third information to a third communication device;

[0045] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0046] A ninth aspect provides a communication device, the terminal 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, or the method as described in the fourth aspect.

[0047] In a tenth aspect, a communication device is provided, including a processor and a communication interface;

[0048] The processor is used by the first communication device to determine the first signal based on the first information;

[0049] The communication interface is used for the first communication device to send a first signal to the second device;

[0050] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0051] or,

[0052] The communication interface is used for the second communication device to receive the first signal sent by the first communication device;

[0053] The processor is used by the second communication device to determine the second signal based on the second information;

[0054] The processor is used by the second communication device to modulate the first signal according to the second signal to generate a third signal;

[0055] The communication interface is used for the second communication device to send the third signal to the third communication device;

[0056] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing amplitude and / or phase dimension differential modulation on the first signal.

[0057] or,

[0058] The communication interface is used for the third communication device to receive a third signal sent by the second communication device;

[0059] The processor is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal based on the third information.

[0060] The processor is used by the third communication device to demodulate the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0061] The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0062] or,

[0063] The communication interface is used for:

[0064] The fourth communication device configures or instructs the first communication device with the first information;

[0065] The fourth communication device configures or instructs the second communication device with second information;

[0066] The fourth communication device configures or instructs the third communication device with third information;

[0067] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0068] Eleventhly, a backscatter communication system is provided, comprising: a first communication device, a second communication device, a third communication device, and a fourth communication device, wherein the first communication device is configured to perform the steps of the backscatter communication method as described in the first aspect, the second communication device is configured to perform the steps of the backscatter communication method as described in the second aspect, the third communication device is configured to perform the steps of the backscatter communication method as described in the third aspect, and the fourth communication device is configured to perform the steps of the backscatter communication method as described in the fourth aspect.

[0069] In a twelfth aspect, 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 steps of the method described in the second aspect, or the steps of the method described in the third aspect, or the steps of the method described in the fourth aspect.

[0070] In a thirteenth 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 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, or the steps of the method as described in the fourth aspect.

[0071] In a fourteenth 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, or the steps of the method as described in the fourth aspect.

[0072] In this embodiment, the first signal emitted by the first communication device includes a first portion occupying the length of a first time unit and a second portion occupying the length of a second time unit. The data in the first time unit is the same as the data in the second time unit, i.e., the first signal has a repetitive time-domain structure. Subsequently, the second communication device performs amplitude and / or phase differential modulation on the first signal based on the second signal to obtain a third signal. The third communication device then demodulates the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal. In this way, on the one hand, the repetitive time-domain structure of the first signal is used to eliminate link interference; on the other hand, amplitude and / or phase differential modulation is used to improve the modulation and demodulation performance of the signal, or to improve the bandwidth utilization of the system and increase the baseband signal rate. Link interference elimination and modulation signal demodulation are completed through amplitude and / or phase differential modulation. Attached Figure Description

[0073] Figure 1a This is a schematic diagram of the structure of an existing backscatter communication transmitter;

[0074] Figure 1b This is a schematic diagram of the structure of an existing backscatter communication receiver;

[0075] Figure 2 This is a schematic diagram of the modulation circuit of an existing backscatter communication transmitter;

[0076] Figure 3 This is a schematic diagram of the structure of an existing monostatic backscatter communication system;

[0077] Figure 4 This is one of the structural schematic diagrams of an existing bistatic backscatter communication system;

[0078] Figure 5 This is the second schematic diagram of an existing bistatic backscatter communication system;

[0079] Figure 6 This is a schematic diagram of the BSC baseband signal of the source RF signal used for interference cancellation;

[0080] Figure 7 This is one of the flowcharts of the backscatter communication method provided in the embodiments of this application;

[0081] Figure 8a This is one of the structural schematics of the first signal provided in the embodiments of this application;

[0082] Figure 8b This is a second schematic diagram of the structure of the first signal provided in the embodiments of this application;

[0083] Figure 9This is a second schematic flowchart of the backscatter communication method provided in the embodiments of this application;

[0084] Figure 10 This is the third flowchart illustrating the backscatter communication method provided in the embodiments of this application;

[0085] Figure 11 This is the fourth flowchart illustrating the backscatter communication method provided in the embodiments of this application;

[0086] Figure 12a This is one of the structural schematic diagrams of the backscatter communication device provided in the embodiments of this application;

[0087] Figure 12b This is a second schematic diagram of the backscatter communication device provided in the embodiments of this application;

[0088] Figure 12c This is the third schematic diagram of the backscatter communication device provided in the embodiments of this application;

[0089] Figure 12d This is the fourth schematic diagram of the backscatter communication device provided in the embodiments of this application;

[0090] Figure 13 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application; Detailed Implementation

[0091] 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.

[0092] 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.

[0093] 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 in the systems and radio technologies mentioned above, as well as in other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and NR terminology is used in most of the following description; however, these technologies can also be applied to applications beyond NR systems, such as 6th Generation (6G) communication systems.

[0094] To better understand the technical solution of this application, the following content will be introduced first:

[0095] Backscatter Communication (BSC)

[0096] Backscatter communication refers to the use of radio frequency signals from other devices or the environment to modulate signals and transmit information. It is a typical passive Internet of Things (IoT) device. Figure 1a As a backscatter communication transmitter, its basic components and main functions include:

[0097] Antenna element 101: used to receive radio frequency signals and control commands, and also to transmit modulated backscattered signals.

[0098] Energy harvesting module or power supply module 102: 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, a battery power supply module may also be included. The energy harvesting module or power supply module supplies power to all other modules in the device.

[0099] Microcontroller 103: Includes control of baseband signal processing, energy storage or data scheduling status, switching, system synchronization, etc.

[0100] Signal receiving module 104: Used to receive control commands or data, etc.

[0101] Channel coding and modulation module 105: Performs channel coding and signal modulation under the control of the microcontroller, and achieves modulation by selecting different load impedances through a selection switch under the control of the microcontroller;

[0102] Memory or sensing module 106: Used to store device ID information, location information, or sensing data, etc.

[0103] In addition to the typical components mentioned above, the backscatter communication transmitter can also integrate a low-power amplifier module to improve the receiver sensitivity and transmit power.

[0104] Figure 1b As a backscatter communication receiver, the backscatter communication receiver in a traditional Radio Frequency Identification (RFID) system is the reader. Its basic components and main functions include:

[0105] Antenna element 111: Used to receive modulated backscattered signals.

[0106] Backscatter signal detection module 112: This module is used to detect the backscatter signal transmitted by the transmitter, including Amplitude Shift Keying (ASK) detection, Phase Shift Keying (PSK) detection, Frequency Shift Keying (FSK) detection, or Quadrature Amplitude Modulation (QAM) detection.

[0107] Demodulation and decoding module 113: Demodulates and decodes the detected signal to recover the original information stream.

[0108] Its modulation circuit is as follows Figure 2 As shown, backscatter communication devices control the reflection coefficient Γ of the circuit by adjusting its internal impedance, thereby changing the amplitude, frequency, and phase of the incident signal to achieve signal modulation. The signal reflection coefficient can be characterized as:

[0109]

[0110] Where Z0 is the characteristic impedance of the antenna, Z1 is the load impedance, j represents a complex number, and θ TThis represents the phase. Assume the incident signal is S. in (t), then the output signal is Therefore, by reasonably controlling the reflection coefficient, corresponding amplitude modulation, frequency modulation, or phase modulation can be achieved. Based on this, backscatter communication devices can be tags in traditional Radio Frequency Identification (RFID) or passive / semi-passive Internet of Things (IoT) devices. For convenience, they are collectively referred to here as BSC devices.

[0111] Monostatic Backscatter Communication System (MBCS) and Signal Self-Interference

[0112] like Figure 3 The diagram illustrates a Monostatic Backscatter Communication System (MBCS), a typical example of a traditional RFID system. This system includes a Base Station Controller (BSC) transmitter (e.g., a Tag) and a reader. The reader contains an RF source and a BSC receiver. The RF source generates a radio frequency signal to power the BSC transmitter / Tag. The BSC transmitter backscatters the modulated RF signal, and the BSC receiver in the reader receives and demodulates this backscattered signal. Because the RF source and BSC receiver are in the same device, such as the reader in this example, it is called a monostatic backscatter communication system. In MBCS systems, the RF signal transmitted from the BSC transmitter undergoes a double near-far effect due to signal attenuation during the round trip, resulting in significant signal energy attenuation. Therefore, MBCS systems are generally used for short-range backscatter communication, such as in traditional RFID applications.

[0113] In monostatic backscatter communication, the RF source and backscatter communication receiver transmit RF carriers to provide energy and target carriers for the backscatter communication equipment, while also receiving the useful signals transmitted by the backscatter communication equipment. This full-duplex working mechanism leads to carrier leakage at the receiver front end. When the RF source and backscatter communication receiver (reader) is working, the receiving antenna will simultaneously receive the useful signal of the same frequency and the self-interference signal caused by carrier leakage, and the signal strength of the self-interference signal is much greater than that of the received useful backscatter signal. Specifically, there are three factors that cause the self-interference signal of carrier leakage: (1) the limited isolation between the transmitter and receiver causes the transmitter carrier to leak to the receiving front end; (2) the mismatch of the reader antenna causes the carrier signal to be reflected to the receiving front end; (3) the reflection of the carrier signal by the environment enters the receiving antenna again. Therefore, in order to reduce the signal self-interference caused by carrier leakage, the reader's transmitting and receiving channels can be isolated in the reader structure, such as using a dual-antenna structure with separate transmitting and receiving antennas; using a multi-port circulator; using a coupler, etc. For carrier leakage that has already been detected, carrier cancellation technology or self-interference cancellation technology can be used to eliminate the carrier leakage, thereby improving the receiver's sensitivity.

[0114] Bistatic Backscatter Communication Systems (BBCSs) and Direct Link Interference

[0115] Unlike the MBCS system, the RF source, BSC transmitter, and BSC receiver are separate in the BBCS system, such as... Figure 4 The diagram shows a schematic of a BBCS system. Therefore, BBCS avoids the problem of large round-trip signal attenuation. Furthermore, the performance of the BBCS communication system can be further improved by appropriately placing the RF source. It is worth noting that ambient backscatter communication (ABCS) is also a type of bistatic backscatter communication, but unlike the dedicated signal source in a BBCS system, the RF source in an ABCS system can be any available ambient RF source, such as a TV tower, cellular base station, WiFi signal, or Bluetooth signal.

[0116] Unlike the self-interference signal present in monostatic backscatter communication, bistatic backscatter communication systems suffer from direct link interference or cross-link interference between the RF source and the backscatter communication receiver. Furthermore, because this direct link interference may be a modulated signal, and the backscatter communication receiver is generally unaware of the modulation characteristics of the direct link signal, canceling direct link interference presents a greater challenge. The following explanation of existing interference cancellation techniques uses direct link interference cancellation as an example.

[0117] Assuming the radio frequency carrier signal transmitted by the radio frequency source is s(t), the channel from the radio frequency source to the BSC transmitting device is h1, the baseband signal used by the BSC transmitting device to modulate the radio frequency carrier signal s(t) is b(t), and the channels from the radio frequency source to the BSC receiving device and from the BSC transmitting device to the BSC receiving device are h3 and h2 respectively, then the received signal of the BSC receiving device is:

[0118] y(t)=h3(t)*s(t)+h2(t)*α·b(t)*h1(t)*s(t)+w(t)=(h3(t)+h2(t)*αb(t)·h1(t))*s(t)+w(n);

[0119] Where h2(t)*α·b(t)*h1(t)*s(t) is the backscattered signal, h3(t)*s(t) is the direct link or cross-link interference signal, w(n) is Gaussian noise, * is time-domain convolution, and α is the reflection coefficient. Since the backscattered signal and the direct link interference signal are transmitted simultaneously at the same frequency, and since the signal power of the direct link interference signal is usually much greater than that of the backscattered signal, the direct link interference signal has a significant impact on the demodulated effective baseband signal b(t).

[0120] Direct link interference cancellation methods

[0121] The simplest demodulation method at the receiver is to treat direct link interference as noise and use hard decision demodulation. However, the demodulation performance of this algorithm is greatly degraded by the presence of interference terms. To effectively eliminate strong direct link interference from radio frequency (RF) sources, the receiver can effectively eliminate strong direct link interference by combining the time-domain and frequency-domain structure characteristics of the RF carrier signal with the backscattered baseband signal design. Considering the Orthogonal Frequency Division Multiplexing (OFDM) signal waveform widely used in LTE and NR systems, researchers have utilized the characteristic of a cyclic prefix (CP) time-domain repetition structure in OFDM signals. By jointly designing a differential baseband modulation signal in the backscattered communication device, strong direct link interference can be effectively eliminated without exceeding the CP length. In addition to utilizing the repetition structure in the OFDM time domain, interference cancellation can also be achieved using guard bands in the OFDM frequency domain. This is done by shifting the equivalent frequency of the baseband signal to different guard bands for signal modulation. The same design concept can also be extended to unmodulated single sine wave RF signals, etc. The following uses a single sine wave as the radio frequency carrier signal to illustrate the main process of eliminating direct link interference in bistatic backscatter communication.

[0122] like Figure 5As shown, assuming the radio frequency signal transmitted by the radio frequency source is a single-frequency sine wave signal, it can be represented as:

[0123]

[0124] Among them, P s T s , φ s This indicates the power, period, and initial phase of the radio frequency signal. Assume the BSC transmitter modulates the received radio frequency signal and generates a backscattered signal:

[0125] x(t) = αb(t)s(t);

[0126] Where α represents the reflection coefficient and b(t) represents the modulated baseband signal.

[0127] The signals received by the BSC receiver include:

[0128] y(t)=h3s(t)+h1h2x(t)+w(t);

[0129] in, The noise is Gaussian. Since the communication distance between the two base stations is short, the time delay between signals s(t) and x(t) can be ignored; therefore, the received signal can be simplified to:

[0130] y(t)=[h3+h1h2αb(t)]s(t)+w(t);

[0131] The first term in the above formula represents the direct link interference signal, and the second term represents the useful backscattered signal. Due to the attenuation of the two-way channel, the power of the direct link interference signal will be much greater than that of the backscattered signal, and since they use the same radio frequency signal, they are still co-frequency signals.

[0132] To effectively eliminate the effects of direct link interference, the RF signal and the BSC baseband signal can be jointly designed. Figure 6 The BSC baseband signal is the source RF signal used for interference cancellation.

[0133] By adjusting the symbol period T of the BSC modulated signal b With respect to the period T of the carrier frequency signal s And satisfy:

[0134] T b =2KT s ,K∈N + ;

[0135] Additionally, the backscatter communication baseband signal can be defined using Miller encoding; that is, if the transmitted bit B = 0, the baseband signal is:

[0136] b(t) = 0, 0 ≤ t ≤ T b ;

[0137] When bit B = 1 is transmitted, the baseband signal is:

[0138]

[0139] Reader with T b The received signal is sampled at a sampling rate of / N. Based on the Miller code signal structure, the second half T of the received signal is used. b The periodic signal minus the first half of T b A periodic signal is used to obtain a differential signal:

[0140]

[0141] According to T b =2KT s Based on the relationship and Miller's properties, cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0142]

[0143] in As can be seen from the above formula, due to the repetitive time-domain structure of the source signal and the use of Miller coding for the BSC baseband signal, the direct link interference term is effectively eliminated. Furthermore, this method is a non-coherent detection method, and therefore there are no issues such as carrier frequency offset (CFO).

[0144] The backscatter communication method provided in this application will be described in detail below with reference to the accompanying drawings, through some embodiments and application scenarios.

[0145] See Figure 7 This application provides a backscatter communication method. The execution subject of the method is a first communication device. In some application scenarios, the first communication device can be a radio frequency source in a BSC system, used to provide a radio frequency carrier signal to the BSC transmitter.

[0146] The method includes:

[0147] Step 701: The first communication device determines the first signal based on the first information;

[0148] Step 702: The first communication device sends a first signal to the second communication device;

[0149] The aforementioned second communication device can specifically be a BSC transmitter in a BSC system. Correspondingly, the first communication device sending a first signal to the second communication device is equivalent to the radio frequency source providing a radio frequency signal to the BSC transmitter. Specifically, the first signal can also be referred to as a radio frequency signal, a carrier signal, or a radio frequency carrier signal.

[0150] The aforementioned first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0151] In this embodiment, the first signal emitted by the first communication device includes a first portion occupying the length of a first time unit and a second portion occupying the length of a second time unit. The data in the first time unit is the same as the data in the second time unit, that is, the first signal has a repeating time-domain structure. In this way, the repeating time-domain structure of the first signal is used to eliminate link interference.

[0152] It is understood that the specific categories of time units, such as the first time unit and the second time unit frame, subframe, time slot, sub-time slot, symbol, symbol set, etc., are not limited in the embodiments of this application.

[0153] In one specific implementation, the first information is used to indicate the signal type and signal parameters of the first signal;

[0154] The signal type of the first signal includes any one of the following:

[0155] The first signal type includes a first part and a second part;

[0156] The second signal type includes a first part, a second part and a third part, with the third part located between the first part and the second part, and the third part occupying the length of a third time unit;

[0157] The first signal type and the second signal type mentioned above correspond to two signal formats of the first signal, respectively. Specifically, the first signal type mentioned above can be called centralized, and the first signal type mentioned above can be called distributed.

[0158] See Figure 8a and Figure 8b Taking time unit category as slot as an example, Figure 8a The structure of the centralized first signal is shown. Figure 8b The structure of the distributed first signal is shown;

[0159] See details Figure 8aThe radio frequency source transmits a radio frequency signal s(t) that satisfies the following:

[0160] s(t) includes two time slot blocks (slot1 and slot2) with identical polarity and data. Each pair of time slot blocks is lumped together to form a basic time slot block. The data length in each time slot is N, and the period length is T. s And it is random.

[0161]

[0162] Where m represents the m-th slot in the radio frequency signal, and x(n) represents random data of length n;

[0163] See details Figure 8b The radio frequency source transmits a carrier signal s(t):

[0164] s(t) includes two time slots (slot1 and slot2) with identical polarity and data. Each pair of time slots is distributed, with an interval of Q slots or a duration of T between them. a Other data units:

[0165]

[0166] Optionally, the data in each time slot can be a non-random or random sequence generated according to preset rules.

[0167] When the signal type of the first signal is a first signal type, the signal parameters of the first signal include any one of the following:

[0168] (1) The length of the first time unit; that is, the signal parameters of the first signal include the above-mentioned T. s ;

[0169] (2) The length of the second time unit; that is, the signal parameters of the first signal include the above-mentioned T. s ;

[0170] (3) The sum of the lengths of the first time unit and the second time unit; that is, the signal parameters of the first signal include 2T. s ;

[0171] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0172] (1) The length of the first time unit and the length of the third time unit; that is, the signal parameters of the first signal include the above T. s and T a .

[0173] (2) The length of the second time unit and the length of the third time unit; that is, the signal parameters of the first signal include the above T. s and T a (The length of both the first and second time units is T) s ).

[0174] (3) The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit; that is, the signal parameters of the first signal include the above T. s and T s +T a .

[0175] (4) The length of the first time unit, and the sum of the lengths of the second and third time units; that is, the signal parameters of the first signal include the above T. s and T s +T a .

[0176] (5) The length of the second time unit, and the sum of the lengths of the first and third time units; that is, the signal parameters of the first signal include the above-mentioned T. s and T s +T a .

[0177] (6) The length of the second time unit, and the sum of the lengths of the second and third time units. That is, the signal parameters of the first signal include the aforementioned T... s and T s +T a .

[0178] The signal format of the first signal and the length of each time unit in the first signal can be determined by the signal type and signal parameters of the first signal.

[0179] In one specific implementation, the first information includes: first instruction information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device;

[0180] The first indication information is used to indicate the signal type and signal parameters of the first signal.

[0181] The aforementioned third communication device can specifically be a BSC receiver in a BSC system.

[0182] In this embodiment of the application, a fourth communication device is used to configure or indicate the signal type and signal parameters of a specific first signal. Specifically, the fourth communication device can be any one of the first communication device, the second communication device, and the third communication device. That is, the configuration or indication of the signal type and signal parameters of the specific first signal can be achieved by any one of the radio frequency source, the BSC transmitter, and the BSC receiver in the BSC system. Alternatively, the fourth communication device can also be a third-party communication device, that is, the signal type and signal parameters of the first signal can be uniformly configured by setting up a separate fourth communication device.

[0183] In one specific implementation, when the first information includes: first indication information configured or indicated by a fourth communication device, and the fourth communication device is not the first communication device, before the first communication device determines the first signal based on the first information, the method further includes:

[0184] The first communication device receives the first information;

[0185] The first information is configured or indicated by the fourth communication device through at least one of the following: Radio Resource Control (RRC) signaling, Media Access Control Element (MAC CE), Downlink Control Information (DCI), Sidelink Control Information (SCI), and preamble sequence.

[0186] In the embodiments of this application, when the fourth communication device is not the same device as the first communication device (a third communication device or a third-party communication device), the first information is carried by at least one of RRC signaling, MAC CE, DCI, SCI and preamble sequence.

[0187] In one specific implementation, the method further includes:

[0188] When the first communication device and the third communication device are different devices, the first communication device sends a second instruction message to the second communication device and the third communication device;

[0189] When the first communication device and the third communication device are the same device, the first communication device sends a second instruction message to the second communication device;

[0190] The second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal.

[0191] The aforementioned second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in both amplitude and / or phase dimensions;

[0192] In this embodiment, the first communication device can indicate the signal type and signal parameters of the first signal to the second and third communication devices, and / or the signal modulation type and signal modulation parameters of the second signal. That is, the radio frequency source can indicate the signal type and signal parameters of the radio frequency signal to the BSC transmitter and the BSC receiver, or the modulation type and signal modulation parameters of the baseband signal used by the BSC transmitter to modulate the radio frequency signal can be directly indicated to the BSC transmitter and the BSC receiver.

[0193] Specifically, when the first communication device and the third communication device are different devices, it corresponds to a bistatic backscatter communication system. The first communication device sends second indication information to the second and third communication devices to indicate the signal type and signal parameters of the first signal, which corresponds to the signal type and signal parameters of the radio frequency signal sent by the radio frequency source to the BSC transmitter and the BSC receiver, and / or the modulation type and signal modulation parameters of the baseband signal.

[0194] When the first communication device and the third communication device are the same device, it corresponds to a monostatic backscatter communication system. The first communication device sends second indication information to the second communication device to indicate the signal type and signal parameters of the first signal, which corresponds to the signal type and signal parameters of the radio frequency signal sent by the radio frequency source to the BSC transmitter, and / or the modulation type and signal modulation parameters of the baseband signal.

[0195] In one specific implementation, the signal modulation type of the second signal includes any one of the following:

[0196] (1) First modulation type, the first modulation type is the modulation type of amplitude differential modulation of the first signal;

[0197] (2) Second modulation type, which is a modulation type that performs phase differential modulation on the first signal;

[0198] (3) The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0199] The signal modulation parameters of the second signal include one or more of the following:

[0200] (1) The length of one or more symbol periods of the second signal;

[0201] (2) The half-symbol period length of the second signal;

[0202] (3) The modulation order of the second signal, such as 2nd or 4th order.

[0203] By understanding the signal type and signal parameters of the second signal, it is possible to determine the baseband signal used by the second communication device when performing differential modulation of the amplitude and / or phase dimensions on the first signal. For example, it can be determined whether the modulation is specifically performed on the amplitude and / or phase dimensions, and the specific modulation order.

[0204] Table 1 provides a specific implementation example, in which an indicator bit is used to indicate the modulation scheme used by the second communication device:

[0205] Table 1

[0206] Indicator Bit Instruction information 00 Amplitude Differential Modulation 01 Phase differential modulation 10 Amplitude-phase differential modulation 11 reserve

[0207] In one specific implementation, the first communication device sends second indication information, including:

[0208] The first communication device transmits the second indication information via at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0209] The second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal.

[0210] See Figure 9 This application provides a backscatter communication method. The execution subject of the method is a second communication device. In some application scenarios, the second communication device can be a BSC transmitter in a BSC system, used to perform backscatter modulation on the radio frequency carrier signal provided to the radio frequency source, and send the modulated backscatter signal to the BSC receiver.

[0211] The method includes:

[0212] Step 901: The second communication device receives the first signal sent by the first communication device;

[0213] Step 902: The second communication device determines the second signal based on the second information;

[0214] Step 903: The second communication device modulates the first signal according to the second signal to generate the third signal;

[0215] Step 904: The second communication device sends a third signal to the third communication device;

[0216] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

[0217] In this embodiment, the first signal emitted by the first communication device includes a first portion occupying the length of a first time unit and a second portion occupying the length of a second time unit. The lengths of the first and second time units are the same, and the data in the first time unit is the same as the data in the second time unit, i.e., the first signal has a repetitive time-domain structure. Subsequently, the second communication device performs amplitude and / or phase differential modulation on the first signal based on the second signal to obtain a third signal. The third communication device then demodulates the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal. In this way, on the one hand, the repetitive time-domain structure of the first signal is used to eliminate link interference; on the other hand, amplitude and / or phase differential modulation is used to improve the modulation and demodulation performance of the signal, or to improve the bandwidth utilization of the system and increase the baseband signal rate. Link interference elimination and modulation signal demodulation are completed through amplitude and / or phase differential modulation.

[0218] For a detailed description of the first signal, please refer to the relevant description in the method of the first communication device, which will not be repeated here.

[0219] The BSC transmitter receives the radio frequency carrier signal transmitted by the radio frequency source, estimates the channel delay and delay spread from the radio frequency source to the BSC transmitter, and transmits the backscatter modulated signal after being modulated by the BSC baseband signal, starting from this delay.

[0220] In one specific implementation, the second communication device modulates the first signal according to the second signal, including:

[0221] (1) When the second communication device performs amplitude differential modulation on the first signal according to the second signal and the modulation order is second order, the second signal carries bit information through the amplitude difference value between the first half symbol period and the second half symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value; when the bit information is a second value, the amplitude value of the first half symbol period of the second signal is a second amplitude value, and the amplitude value of the second half symbol period of the second signal is a third amplitude value. The second amplitude value and the third amplitude value are different amplitude values.

[0222] This application embodiment corresponds to a modulation method using second-order differential amplitude modulation at the BSC transmitter; optionally, a first value of bit information can correspond to the case where bit information B = 0, and a second value of bit information can correspond to the case where bit information B = 1. Alternatively, a first value of bit information can correspond to the case where bit information B = 1, and a second value of bit information can correspond to the case where bit information B = 0.

[0223] (2) When the second communication device performs phase differential modulation on the first signal according to the second signal and the modulation order is second order, the second signal carries bit information through the phase difference value between the first half symbol period and the second half symbol period. When the bit information is a first value, the phase value of the second signal is a first phase value; when the bit information is a second value, the phase value of the first half symbol period of the second signal is a second phase value, and the amplitude value of the second half symbol period of the second signal is a third phase value. The second phase value and the third phase value are different phase values.

[0224] This application embodiment corresponds to a modulation method using second-order phase-amplitude modulation at the BSC transmitter; optionally, the first value of the bit information can correspond to the case where bit information B=0, and the second value of the bit information can correspond to the case where bit information B=1. Alternatively, the first value of the bit information can correspond to the case where bit information B=1, and the second value of the bit information can correspond to the case where bit information B=0.

[0225] (3) When the second communication device performs amplitude and phase differential modulation on the first signal according to the second signal, and the modulation order is second order, the second signal carries bit information through the amplitude and phase difference values ​​of the first half symbol period and the second half symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value, and the phase value of the second signal is a first phase value; when the bit information is a second value, the amplitude value of the first half symbol period of the second signal is a second amplitude value, the phase value of the first half symbol period of the second signal is a second phase value, the amplitude value of the second half symbol period of the second signal is a third amplitude value, and the phase value of the second half symbol period of the second signal is a third phase value. The second amplitude value and the third amplitude value are different amplitude values, and the second phase value and the third phase value are different phase values.

[0226] This application embodiment corresponds to a modulation method using second-order differential amplitude-phase modulation at the BSC transmitter; optionally, a first value of bit information can correspond to the case where bit information B = 0, and a second value of bit information can correspond to the case where bit information B = 1. Alternatively, a first value of bit information can correspond to the case where bit information B = 1, and a second value of bit information can correspond to the case where bit information B = 0.

[0227] (4) When the second communication device performs amplitude and phase differential modulation on the first signal based on the second signal, and the modulation order is fourth, the second signal carries bit information through the amplitude and phase difference values ​​of the first half symbol period and the second half symbol period. When the bit information is the first value, the amplitude value of the first half symbol period of the second signal is the first amplitude value, the phase value of the first half symbol period of the second signal is the first phase value, the amplitude value of the second half symbol period of the second signal is the second amplitude value, the phase value of the second half symbol period of the second signal is the second phase value, when the bit information is the second value, the amplitude value of the first half symbol period of the second signal is the third amplitude value, the phase value of the first half symbol period of the second signal is the third phase value, the amplitude value of the second half symbol period of the second signal is the fourth amplitude value, the phase value of the second half symbol period of the second signal is the fourth phase value, when the bit information is the third value, the amplitude value of the first half symbol period of the second signal is the fifth amplitude value, the first half symbol period of the second signal is the fifth amplitude value, the second half symbol period of the second signal is the fifth phase value, the first half symbol period of the second signal is the fifth phase value, the second ... The phase value of the period is the fifth phase value, the amplitude value of the second half of the symbol period of the second signal is the sixth amplitude value, the phase value of the second half of the symbol period of the second signal is the sixth phase value, when the bit information is the fourth value, the amplitude value of the first half of the symbol period of the second signal is the seventh amplitude value, the phase value of the first half of the symbol period of the second signal is the seventh phase value, the amplitude value of the second half of the symbol period of the second signal is the eighth amplitude value, the phase value of the second half of the symbol period of the second signal is the eighth phase value, the difference between the second amplitude value and the first amplitude value, the difference between the fourth amplitude value and the third amplitude value, the difference between the sixth amplitude value and the fifth amplitude value, and the difference between the eighth amplitude value and the seventh amplitude value are all different amplitude values, the difference between the second phase value and the first phase value, the difference between the fourth phase value and the third phase value, the difference between the sixth phase value and the fifth phase value, and the difference between the eighth phase value and the seventh phase value are all different phase values.

[0228] This application embodiment corresponds to a modulation method using 4th-order differential amplitude-phase modulation at the BSC transmitter; optionally, a first value of bit information can correspond to the case where bit information B = 00, a second value of bit information can correspond to the case where bit information B = 01, a third value of bit information can correspond to the case where bit information B = 11, and a fourth value of bit information can correspond to the case where bit information B = 10.

[0229] It should be noted that the bit information values ​​corresponding to the first, second, third, and fourth values ​​mentioned above are only examples. In reality, the first, second, third, and fourth values ​​can be any one of the bits 00, 01, 10, and 11, and they must be different from each other.

[0230] After determining the corresponding BSC baseband signal b(t) according to the modulation method, the BSC baseband signal b(t) is multiplied by the radio frequency carrier signal s(t) to obtain the backscattered signal d(t), and this signal is then transmitted.

[0231] d(t) = α·b(t)·h1s(t);

[0232] Where α is the backscattering factor or backscattering coefficient, and h1 is the channel coefficient from the radio frequency source to the backscattering transmitting device.

[0233] The above method enables the second communication device to perform differential modulation on the first signal in both amplitude and / or phase dimensions.

[0234] Furthermore, taking second-order modulation with first value of bit B=0 and second value of bit B=1 as examples; or fourth-order modulation with first value of bit B=00, second value of bit B=01, third value of bit B=11, and fourth value of bit B=10 as examples, the modulation method for differential amplitude-phase modulation is described as follows:

[0235] To represent a bit of information B by combining the magnitude and phase dimensions, we have:

[0236] (I) When the first signal is centrally distributed, the second signal b(t) is a signal of the first modulation type and a modulation order of 2, and satisfies the following property:

[0237] When B = 0, the second signal is:

[0238]

[0239] When B=1, the BSC baseband signal is:

[0240]

[0241] Where α, β, and γ represent the amplitudes of the BSC baseband signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the BSC baseband signal is T. b =2T s .

[0242] (II) When the first signal is distributed, the second signal b(t) is a signal of the second modulation type and a modulation order of 2, and satisfies the following property:

[0243] When B = 0, the second signal is:

[0244]

[0245] When B=1, the second signal is:

[0246]

[0247] Where α, β, and γ represent the amplitudes of the second signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the second signal is T. b =2T s +T a .

[0248] (3) Using amplitude and phase dimensions to represent different bit information respectively, we have:

[0249] (I) When the first signal is centrally distributed, the second signal b(t) is a signal of the third modulation type and a modulation order of 4, and satisfies the following property:

[0250] When B = 00, the second signal is:

[0251]

[0252] When B = 01, the second signal is:

[0253]

[0254] When B = 11, the second signal is:

[0255]

[0256] When B = 10, the second signal is:

[0257]

[0258] Among them, α1, α2, α3, α4, β, γ, κ, ξ represent the amplitude of the second signal, and (β-α1)≠(γ-α2)≠(κ-α3)≠(ξ-α4), θ 1, θ2, θ3, θ4, θ5, θ6, θ7, θ8 represent the phase of the signal, and (θ2-θ1)≠(θ4-θ3)≠(θ6-α5)≠(θ8-α7). The period of the second signal is T b =2T s .

[0259] (II) When the first signal is distributed, the second signal b(t) is a signal of the third modulation type and a modulation order of 4, and satisfies the following property:

[0260] When B = 00, the second signal is:

[0261]

[0262] When B = 01, the second signal is:

[0263]

[0264] When B = 11, the second signal is:

[0265]

[0266] When B = 10, the second signal is:

[0267]

[0268] Among them, α1, α2, α3, α4, β, γ, κ, ξ represent the amplitude of the second signal, and (β-α1)≠(γ-α2)≠(κ-α3)≠(ξ-α4), θ 1, θ2, θ3, θ4, θ5, θ6, θ7, θ8 represent the phase of the signal, and (θ2-θ1)≠(θ4-θ3)≠(θ6-θ5)≠(θ8-θ7). The period of the second signal is T b =2T s .

[0269] The second signal b(t) in each of the above modulation methods is described below with specific application examples:

[0270] (1) Second-order amplitude differential modulation;

[0271] Take M=1 and Q=0 as an example.

[0272] Modulation process:

[0273] The second signal b(t) is a signal of the first modulation type and a modulation order of 2, and satisfies the following property:

[0274] When B = 0, the second signal is:

[0275]

[0276] When B=1, the second signal is:

[0277]

[0278] Where α, β, and γ represent the amplitudes of the second signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the second signal is T. b =2T s Without loss of generality, we can take α = 1, β = 2, γ = 1, θ3 = 0, θ1 = 0, θ2 = 0, and its baseband signal can be expressed as:

[0279] When B = 0, the second signal is:

[0280] b[n]=e j0 n = 0, 1, ..., 2N-1;

[0281] When B=1, the second signal is:

[0282]

[0283] (2) Second-order phase differential modulation;

[0284] Take M=1 and Q=0 as an example.

[0285] Modulation process:

[0286] The second signal b(t) is a signal of the second modulation type and a modulation order of 2, and satisfies the following property:

[0287] When B = 0, the second signal is:

[0288]

[0289] When B=1, the second signal is:

[0290]

[0291] Where α, β, and γ represent the amplitudes of the second signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the second signal is T. b =2T s Without loss of generality, we can take α = β = γ = 1, θ3 = 0. Its baseband signal can be expressed as:

[0292] When B = 0, the second signal is:

[0293] b[n] = 0, n = 0, 1, ..., 2N-1;

[0294] When B=1, the second signal is:

[0295]

[0296] (3) Second-order amplitude-phase differential modulation;

[0297] Take M=1 and Q=0 as an example.

[0298] Modulation process:

[0299] The second signal b(t) is a signal of the third modulation type and a modulation order of 2, and satisfies the following property:

[0300] When B = 0, the second signal is:

[0301]

[0302] When B=1, the second signal is:

[0303]

[0304] Where α, β, and γ represent the amplitudes of the second signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the second signal is T. b =2T s Without loss of generality, we can take β = γ = 1 and α = 2. Its baseband signal can be expressed as:

[0305] When B = 0, the second signal is:

[0306] b[n]=e jπ / 2 n = 0, 1, ..., 2N-1;

[0307] When B=1, the second signal is:

[0308]

[0309] (4) Fourth-order amplitude-phase differential modulation;

[0310] Take M=1 and Q=0 as an example.

[0311] Modulation process:

[0312] The second signal b(t) is a third modulation type signal with a modulation order of 4, and satisfies the following properties:

[0313] When B = 00, the second signal is:

[0314]

[0315] When B = 01, the second signal is:

[0316]

[0317] When B = 11, the second signal is:

[0318]

[0319] When B = 10, the second signal is:

[0320]

[0321] Among them, α1, α2, α3, α4, β, γ, κ, ξ represent the amplitude of the second signal, and (β-α1)≠(γ-α2)≠(κ-α3)≠(ξ-α4), θ 1, θ2, θ3, θ4, θ5, θ6, θ7, θ8 represent the phase of the signal, and (θ2-θ1)≠(θ4-θ3)≠(θ6-θ5)≠(θ8-θ7). The period of the second signal is T b =2T s . Without loss of generality, take α1=α2=α3=α4=1, β=2, γ=3, κ=4, ξ=5,

[0322] In one specific implementation, the second information includes: second indication information indicated by the first communication device;

[0323] Alternatively, the second information may include: third instruction information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device;

[0324] The second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal; the third indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal.

[0325] In this embodiment, the first communication device may indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal to the second communication device; alternatively, the fourth communication device may configure or indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal to the second communication device. That is, the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal, may be mutually indicated within the first, second, and third communication devices, or may be uniformly configured or indicated by a third-party communication device.

[0326] In one specific implementation, where the second information includes: second indication information indicated by the first communication device, or the second information includes: third indication information configured or indicated by the fourth communication device, and the fourth communication device is not the second communication device, the method further includes the following before the second communication device determines the second signal based on the second information:

[0327] The second communication device receives the second information;

[0328] The second information is indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0329] In one specific implementation, the method further includes:

[0330] The second communication device sends a fourth indication message to the third communication device via at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence;

[0331] The fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0332] In this embodiment, the second communication device indicates the signal modulation type and signal modulation parameters of the second signal to the third communication device, so that the BSC transmitter provides the signal modulation type and signal modulation parameters of the baseband signal it uses to the BSC receiver for demodulation.

[0333] In one specific implementation, the signal type of the first signal includes any one of the following:

[0334] (1) First signal type, the first signal of the first signal type includes a first part and a second part;

[0335] (2) Second signal type, the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of the third time unit;

[0336] When the signal type of the first signal is a first signal type, the signal parameters of the first signal include any one of the following:

[0337] (1) The length of the first time unit;

[0338] (2) The length of the second time unit;

[0339] (3) The sum of the lengths of the first time unit and the second time unit;

[0340] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0341] (1) The length of the first time unit and the length of the third time unit;

[0342] (2) The length of the second time unit and the length of the third time unit;

[0343] (3) The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0344] (4) The length of the first time unit, and the sum of the lengths of the second and third time units;

[0345] (5) The length of the second time unit, and the sum of the lengths of the first and third time units;

[0346] (6) The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0347] In one specific implementation, the signal modulation type of the second signal includes any one of the following:

[0348] (1) First modulation type, the first modulation type is the modulation type of amplitude differential modulation of the first signal;

[0349] (2) Second modulation type, which is a modulation type that performs phase differential modulation on the first signal;

[0350] (3) The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0351] The signal modulation parameters of the second signal include one or more of the following:

[0352] (1) The length of one or more symbol periods of the second signal;

[0353] (2) The half-symbol period length of the second signal;

[0354] (3) The modulation order of the second signal.

[0355] See Figure 10 This application provides a backscatter communication method, in which the execution subject is a third communication device. In some application scenarios, the third communication device may specifically be a BSC receiver in a BSC system, used to receive the modulation signal sent by the BSC transmitter and demodulate it.

[0356] The method includes:

[0357] Step 1001: The third communication device receives the third signal sent by the second communication device;

[0358] Step 1002: The third communication device determines the signal modulation type and signal modulation parameters of the second signal based on the third information;

[0359] Step 1003: The third communication device demodulates the bit information modulated by the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0360] The third signal is a backscattered signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0361] In this embodiment, the first signal emitted by the first communication device includes a first portion occupying the length of a first time unit and a second portion occupying the length of a second time unit. The lengths of the first and second time units are the same, and the data in the first and second time units are the same, meaning the first signal has a repetitive time-domain structure. Subsequently, the second communication device performs amplitude and / or phase differential modulation on the first signal based on the second signal to obtain a third signal. The third communication device then demodulates the bit information of the second signal from the third signal according to the signal modulation type and parameters of the second signal. Thus, on the one hand, the repetitive time-domain structure of the first signal is used to eliminate link interference; on the other hand, amplitude and / or phase differential modulation is used to improve the modulation and demodulation performance of the signal, or to improve the bandwidth utilization of the system and increase the baseband signal rate. Link interference elimination and modulation signal demodulation are achieved through amplitude and / or phase differential modulation.

[0362] In one specific implementation, the third information includes: second indication information indicated by the first communication device;

[0363] Alternatively, the third information may include: a fourth instruction information indicated by the second communication device;

[0364] Alternatively, the third information may include: the fifth instruction information configured or indicated by the fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device;

[0365] The second indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, the fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, and the fifth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0366] In one specific implementation, when the third information includes: second indication information indicated by the first communication device, or the third information includes: fourth indication information indicated by the second communication device, or the third information includes: fifth indication information configured or indicated by the fourth communication device, and the fourth communication device is not the third communication device, the method further includes:

[0367] The third communication device receives the third information;

[0368] The third information is configured or indicated through at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0369] In one specific implementation, the signal type of the first signal includes any one of the following:

[0370] (1) First signal type, the first signal of the first signal type includes a first part and a second part;

[0371] (2) Second signal type, the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of the third time unit;

[0372] When the signal type of the first signal is a first signal type, the signal parameters of the first signal include any one of the following:

[0373] (1) The length of the first time unit;

[0374] (2) The length of the second time unit;

[0375] (3) The sum of the lengths of the first time unit and the second time unit;

[0376] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0377] (1) The length of the first time unit and the length of the third time unit;

[0378] (2) The length of the second time unit and the length of the third time unit;

[0379] (3) The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0380] (4) The length of the first time unit, and the sum of the lengths of the second and third time units;

[0381] (5) The length of the second time unit, and the sum of the lengths of the first and third time units;

[0382] (6) The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0383] In one specific implementation, the signal modulation type of the second signal includes any one of the following:

[0384] (1) First modulation type, the first modulation type is the modulation type of amplitude differential modulation of the first signal;

[0385] (2) Second modulation type, which is a modulation type that performs phase differential modulation on the first signal;

[0386] (3) The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0387] The signal modulation parameters of the second signal include one or more of the following:

[0388] (1) The length of one or more symbol periods of the second signal;

[0389] (2) The half-symbol period length of the second signal;

[0390] (3) The modulation order of the second signal.

[0391] In one specific implementation, the third communication device demodulates the bit information modulated by the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal, including:

[0392] The third communication device subtracts the signal of the first half of a symbol period from the signal of the second half of a symbol period of the third signal to obtain a differential signal. In this way, by subtracting the signal of the first half of a symbol period from the signal of the second half of a symbol period, cross-link interference or direct link interference can be subtracted, thus eliminating link interference.

[0393] It should be noted that subtracting two signals can specifically involve subtracting the signal of the second half of the symbol period from the signal of the first half of the symbol period, or subtracting the signal of the first half of the symbol period from the signal of the second half of the symbol period. For convenience, the following description of specific embodiments will use the example of subtracting the signal of the second half of the symbol period from the signal of the first half of the symbol period.

[0394] The third communication device demodulates the bit information carried by the second signal based on the differential signal.

[0395] In one specific implementation, the third communication device demodulates the bit information of the second signal based on the differential signal, including:

[0396] The third communication device obtains the decision value of the differential signal through the decision function and the differential signal;

[0397] The third communication device demodulates the bit information carried by the second signal based on the decision threshold closest to the decision value. It should be noted that different decision thresholds can be set for different bit information. For example, for a 4th-order amplitude-phase differential modulation signal, the corresponding bit information could include 00, 01, 11, and 10, with optimal decision thresholds set for 00, 01, 11, and 10 respectively. Then, based on the decision threshold closest to the decision value of the differential signal, the bit information carried by the second signal is demodulated. For example, the decision threshold closest to the decision value of the differential signal is... Therefore, it can be determined that the bit information carried by the second signal demodulated from the differential signal is 00;

[0398] It is understood that the above is only an example, and in actual application scenarios, the correspondence between the decision threshold and the bit information can be flexibly adjusted according to the needs.

[0399] For example:

[0400] When the length of the repeating structure is N, the following differential signal is constructed to obtain:

[0401]

[0402] Where y0[n]=y b0 [n]+y d0 [n]+w0[n] represents the received signal of the BSC receiver, D is the minimum channel delay, and L is the maximum delay spread.

[0403]

[0404] v0[n] = w0[n] - w0[n+N];

[0405] The effective SNR of the backscattered signal is:

[0406]

[0407]

[0408]

[0409] The constructed statistical decision function is as follows:

[0410]

[0411] Based on the derivation, the optimal decision threshold performance is:

[0412]

[0413] in,

[0414]

[0415]

[0416]

[0417]

[0418]

[0419]

[0420] Γ(·) is the Gamma function.

[0421] It should be noted that the above examples are only for illustrating the method of constructing decision functions and decision thresholds to demodulate the carried bit information. In specific implementation scenarios, appropriate decision functions and decision thresholds can be selected according to requirements, and are not limited to the examples above.

[0422] Furthermore, the description of the bit information modulated by the second signal from the demodulated third signal is as follows:

[0423] The signals received from the BSC transmitting device and the signals received from the radio frequency source are represented as follows:

[0424] y(t)=αs(t-τ2)b(t)h1h2+h3s(t-τ3)+w(t);

[0425] In this context, the first term α·s(t-τ2)b(t)h1h2 is the useful backscattered signal transmitted from the BSC transmitting device, the second term h3s(t-τ3) is the direct link interference signal transmitted from the radio frequency source, w(t) is the Gaussian noise part, τ3 and τ2 are the multipath delays of the direct link and the backscattered cascaded link, respectively, and τ2>τ3, and τ=max{τ2,τ3} is defined.

[0426] (2) After synchronization, the receiving end determines the modulation and demodulation rules of the second signal based on the indication information (which may be from the radio frequency source, the transmitting end, or a third-party communication device), and then demodulates according to the following rules:

[0427] (a) If, according to the indication information, the radio frequency signal is a centralized signal format signal and the BSC modulation signal is a first modulation type signal with a modulation order of 2, then the BSC receiving device uses T... s A sampling rate of / MN samples the received signal 2MN times, resulting in a period of 2T. sThe signal (taking M=1 as an example, then it is a signal of length 2N)

[0428] (I) Based on the differential signal structure, the later T of the received signal s Periodic signal minus the previous T s The periodic signal is used to obtain the differential signal:

[0429] z(n)=y[n]-y[n+N],n=0,…,N-1;

[0430] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0431]

[0432] Where n = 0, ..., N-1. As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure of the BSC baseband signal, the direct link interference term is effectively eliminated. Furthermore, different results from the differential signal can represent two different bit information.

[0433] (II) Make the optimal decision based on the pre-obtained optimal decision threshold to complete the demodulation.

[0434]

[0435] in It is the calculated optimal decision threshold.

[0436] (b) If, according to the indication information, the radio frequency signal is a distributed signal format signal and the BSC modulation signal is a second modulation type signal with a modulation order of 2, then the BSC receiving device uses (2T) s +T a A sampling rate of M(2N+Q) is used to sample the received signal M times, resulting in a period of 2T. s +T a The signal (taking M=1 as an example, is a signal of length 2N+Q)

[0437] (I) Based on the differential signal structure, the received signal is then... Periodic signal minus the previous The periodic signal is used to obtain the differential signal:

[0438]

[0439] According to T b =2T sBased on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0440]

[0441] in As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure of the BSC baseband signal, the direct link interference term is effectively eliminated.

[0442] (II) Make the optimal decision based on the pre-obtained optimal decision threshold to complete the demodulation:

[0443]

[0444] in It is the calculated optimal decision threshold.

[0445] (c) If, according to the indication information, the radio frequency signal is a centralized signal format signal and the BSC modulation signal is a third modulation type signal with a modulation order of 2, then the BSC receiving device uses T... s A sampling rate of / MN samples the received signal 2MN times, resulting in a period of 2T. s The signal (taking M=1 as an example, then it is a signal of length 2N)

[0446] (I) Based on the differential signal structure, the later T of the received signal s Periodic signal minus the previous T s The periodic signal is used to obtain the differential signal:

[0447] z(n)=y[n]-y[n+N],n=0,…,N-1;

[0448] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0449] When B = 00

[0450]

[0451] Where n = 0, ..., N-1.

[0452] When B = 01

[0453]

[0454] Where n = 0, ..., N-1.

[0455] When B = 11

[0456]

[0457] Where n = 0, ..., N-1.

[0458] When B = 01

[0459]

[0460] Where n = 0, ..., N-1.

[0461] As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure of the BSC baseband signal, the direct link interference term is effectively eliminated.

[0462] (II) Based on the maximum likelihood detection principle, the bit information is obtained by demodulation.

[0463]

[0464] in These are the optimal decision thresholds when sending bits 00, 01, 11, and 10, respectively.

[0465] (d) If, according to the indication information, the radio frequency signal is a distributed signal format signal and the BSC modulation signal is a third modulation type signal with a modulation order of 4, then the BSC receiving device uses (2T) s +T a A sampling rate of M(2N+Q) is used to sample the received signal M times, resulting in a period of 2T. s +T a The signal (taking M=1 as an example, is a signal of length 2N+Q)

[0466] (I) Based on the differential signal structure, the received signal is then... Periodic signal minus the previous The periodic signal is used to obtain the differential signal:

[0467]

[0468] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0469] When B = 00

[0470]

[0471] in

[0472] When B = 01

[0473]

[0474] in

[0475] When B = 11

[0476]

[0477] in

[0478] When B = 01

[0479]

[0480] in

[0481] As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure of the BSC baseband signal, the direct link interference term is effectively eliminated.

[0482] (II) Based on the maximum likelihood detection principle, the bit information is obtained by demodulation.

[0483]

[0484] in These are the optimal decision thresholds when sending bits 00, 01, 11, and 10, respectively.

[0485] The following describes the demodulation process of the BSC receiver based on the modulation method used by the BSC transmitter, using a specific application example:

[0486] Example 1: Second-order phase differential modulation:

[0487] Taking M=1 and Q=0 as an example, explain its modulation and demodulation processes.

[0488] Modulation process:

[0489] The BSC modulated signal b(t) is a signal of the second modulation type and a modulation order of 2, and satisfies the following properties:

[0490] When B=0, the BSC baseband signal is:

[0491]

[0492] When B=1, the BSC baseband signal is:

[0493]

[0494] Where α, β, and γ represent the amplitudes of the second signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the BSC baseband signal is T. b =2T s Without loss of generality, we can take α = β = γ = 1, θ3 = 0. Its baseband signal can be expressed as:

[0495] When B=0, the BSC baseband signal is:

[0496] b[n] = 0, n = 0, 1, ..., 2N-1;

[0497] When B=1, the BSC baseband signal is:

[0498]

[0499] Demodulation process:

[0500] Based on the differential signal structure, the later T of the received signal s Periodic signal minus the previous T s The periodic signal is used to obtain the differential signal:

[0501] z(n)=y[n]-y[n+N],n=0,…,N-1;

[0502] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0503]

[0504] Where n = 0, ..., N-1. As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure adopted by the BSC baseband signal, the direct link interference term is effectively eliminated.

[0505] Demodulation is completed by making an optimal decision based on the pre-determined optimal decision threshold.

[0506]

[0507] in It is the calculated optimal decision threshold.

[0508] Compared to traditional schemes that modulate only in the amplitude dimension, Implementation 1 modulates and demodulates information only in the phase dimension. Due to the constant inclusion property of phase modulation, the decision threshold is less affected by the SNR, thus achieving better modulation and demodulation performance.

[0509] Example 2: Second-order amplitude-phase two-dimensional differential modulation

[0510] Taking M=1 and Q=0 as an example, explain its modulation and demodulation processes.

[0511] Modulation process:

[0512] The BSC modulated signal b(t) is a signal of the third modulation type and a modulation order of 2, and satisfies the following properties:

[0513] When B=0, the BSC baseband signal is:

[0514]

[0515] When B=1, the BSC baseband signal is:

[0516]

[0517] Where α, β, and γ represent the amplitudes of the BSC baseband signal, and α ≠ β; θ1, θ2, and θ3 represent the phases of the signal, and θ1 ≠ θ2. The period of the BSC baseband signal is T. b =2T s Without loss of generality, we can take β = γ = 1 and α = 2. Its baseband signal can be expressed as:

[0518] When B=0, the BSC baseband signal is:

[0519] b[n]=e jπ / 2 n = 0, 1, ..., 2N-1;

[0520] When B=1, the BSC baseband signal is:

[0521]

[0522] Demodulation process:

[0523] Based on the differential signal structure, the later T of the received signal s Periodic signal minus the previous T s The periodic signal is used to obtain the differential signal:

[0524] z(n)=y[n]-y[n+N],n=0,…,N-1;

[0525] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted, and the differential signal of the backscattered signal is obtained as follows:

[0526]

[0527] Where n = 0, ..., N-1. As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure adopted by the BSC baseband signal, the direct link interference term is effectively eliminated.

[0528] Demodulation is completed by making an optimal decision based on the pre-determined optimal decision threshold.

[0529]

[0530] in It is the calculated optimal decision threshold.

[0531] Compared to traditional schemes that only modulate in the amplitude dimension, Embodiment 2 modulates and demodulates information simultaneously in both amplitude and phase dimensions, thereby achieving a larger distance between constellation points in Euclidean space and improving modulation and demodulation performance. Compared to Embodiment 1, the added amplitude dimension increases the spacing between two constellation points, resulting in better performance.

[0532] Example 3: Higher-order amplitude-phase two-dimensional differential modulation

[0533] Taking M=1 and Q=0 as an example, explain its modulation and demodulation processes.

[0534] Modulation process:

[0535] The BSC modulated signal b(t) is a signal of the third modulation type and a modulation order of 4, and satisfies the following properties:

[0536] When B=00, the BSC baseband signal is:

[0537]

[0538] When B=01, the BSC baseband signal is:

[0539]

[0540] When B=11, the BSC baseband signal is:

[0541]

[0542] When B=10, the BSC baseband signal is:

[0543]

[0544] Where α1, α2, α3, α4, β, γ, κ, ξ represent the amplitude of the BSC baseband signal, and (α1-β)≠(α2-γ)≠(α3-κ)≠(α4-ξ); θ1, θ2, θ3, θ4, θ5, θ6, θ7, θ7 represent the phase of the signal, and (θ1-θ2)≠(θ3-θ4)≠(θ5-θ6)≠(θ7-θ8). The period of the BSC baseband signal is T. b =2T s . Without loss of generality, take α1=α2=α3=α4=1, β=2, γ=3, κ=4, ξ=5,

[0545] Demodulation process:

[0546] Based on the differential signal structure, the later T of the received signal s Periodic signal minus the previous T s The periodic signal is used to obtain the differential signal:

[0547] z(n)=y[n]-y[n+N],n=0,…,N-1;

[0548] According to T b =2T s Based on the relationship and differential properties, it can be seen that cross-link interference or direct link interference is subtracted.

[0549] When B = 00

[0550]

[0551] Where n = 0, ..., N-1.

[0552] When B = 01,

[0553]

[0554] Where n = 0, ..., N-1.

[0555] When B = 11,

[0556]

[0557] Where n = 0, ..., N-1.

[0558] When B = 01,

[0559]

[0560] Where n = 0, ..., N-1.

[0561] As can be seen from the above equation, due to the repetitive time-domain structure of the source signal and the differential structure of the BSC baseband signal, the direct link interference term is effectively eliminated.

[0562] The bit information is obtained by demodulation based on the maximum likelihood detection principle.

[0563]

[0564] in These are the optimal decision thresholds when sending bits 00, 01, 11, and 10, respectively.

[0565] Compared to the traditional scheme and Embodiment 1, which only performs single-bit modulation, Embodiment 3 simultaneously performs high-order information modulation and demodulation in both amplitude and phase dimensions, effectively improving the system's bandwidth efficiency and increasing the baseband signal modulation rate.

[0566] See Figure 11 This application provides a backscatter communication method, in which the execution subject is a fourth communication device. In some application scenarios, the fourth communication device is used to uniformly configure the radio frequency source, BSC transmitter and BSC receiver in the BSC system.

[0567] The method includes:

[0568] Step 1101: Includes one or more of the following:

[0569] The fourth communication device configures or instructs the first communication device with the first information;

[0570] The fourth communication device configures or instructs the second communication device to provide second information;

[0571] The fourth communication device configures or instructs the third communication device to provide third information;

[0572] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0573] In one specific implementation,

[0574] The first information includes: first indication information configured or indicated by the fourth communication device, wherein the first indication information is used to indicate the signal type and signal parameters of the first signal;

[0575] The second information includes: third indication information configured or indicated by the fourth communication device, the third indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal;

[0576] The third information includes: fifth indication information configured or indicated by the fourth communication device, the fifth indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0577] The above method enables the fourth communication device to uniformly configure the BSC communication of the first, second, and third communication devices. For example, it configures the signal type and signal parameters of the first signal sent by the first communication device, configures the signal modulation type and signal modulation parameters of the second signal used for signal modulation by the second communication device, and configures the signal modulation type and signal modulation parameters of the second signal by the third communication device, so that the third communication device can know the signal modulation method used by the second communication device. In this way, the third communication device can use the corresponding demodulation method to demodulate the signal.

[0578] In one specific implementation, the signal type of the first signal includes any one of the following:

[0579] (1) First signal type, the first signal of the first signal type includes a first part and a second part;

[0580] (2) Second signal type, the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of the third time unit;

[0581] When the signal type of the first signal is a first signal type, the signal parameters of the first signal include any one of the following:

[0582] (1) The length of the first time unit;

[0583] (2) The length of the second time unit;

[0584] (3) The sum of the lengths of the first time unit and the second time unit;

[0585] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0586] (1) The length of the first time unit and the length of the third time unit;

[0587] (2) The length of the second time unit and the length of the third time unit;

[0588] (3) The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0589] (4) The length of the first time unit, and the sum of the lengths of the second and third time units;

[0590] (5) The length of the second time unit, and the sum of the lengths of the first and third time units;

[0591] (6) The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0592] In one specific implementation, the signal modulation type of the second signal includes any one of the following:

[0593] (1) First modulation type, the first modulation type is the modulation type of amplitude differential modulation of the first signal;

[0594] (2) Second modulation type, which is a modulation type that performs phase differential modulation on the first signal;

[0595] (3) The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0596] The signal modulation parameters of the second signal include one or more of the following:

[0597] (1) The length of one or more symbol periods of the second signal;

[0598] (2) The half-symbol period length of the second signal;

[0599] (3) The modulation order of the second signal.

[0600] In one specific implementation,

[0601] The first, second, and / or third information is configured or indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0602] The backscatter communication method provided in this application can be executed by a backscatter communication device. This application uses a backscatter communication device executing the backscatter communication method as an example to illustrate the backscatter communication device provided in this application.

[0603] See Figure 12aThis application provides a backscatter communication device 1210, which can be applied to the aforementioned first communication device to execute the method of the aforementioned first communication device. The backscatter communication device includes:

[0604] The first determining module 1211 is used to determine the first signal based on the first information;

[0605] The first transmitting module 1212 is used to transmit a first signal to the second communication device;

[0606] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0607] In a specific implementation, the first information is used to indicate the signal type and signal parameters of the first signal;

[0608] The signal type of the first signal includes any one of the following:

[0609] A first signal type, wherein the first signal of the first signal type includes the first part and the second part;

[0610] The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit;

[0611] When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following:

[0612] The length of the first time unit;

[0613] The length of the second time unit;

[0614] The sum of the lengths of the first time unit and the second time unit;

[0615] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0616] The length of the first time unit and the length of the third time unit;

[0617] The length of the second time unit and the length of the third time unit;

[0618] The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0619] The length of the first time unit, and the sum of the lengths of the second and third time units;

[0620] The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit;

[0621] The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0622] In a specific implementation, the first information includes: first indication information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the backscatter communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device;

[0623] The first indication information is used to indicate the signal type and signal parameters of the first signal.

[0624] In a specific implementation, where the first information includes: first indication information configured or indicated by the fourth communication device, and the fourth communication device is not the backscatter communication device, before the backscatter communication device determines the first signal based on the first information, the device further includes:

[0625] The third receiving module is used for the first communication device to receive the first information;

[0626] The first information is configured or indicated by the fourth communication device through at least one of the following: Radio Resource Control (RRC) signaling, Media Access Control Unit (MAC CE), Downlink Control Information (DCI), Sidelink Control Information (SCI), and preamble sequence.

[0627] In a specific implementation, the device further includes:

[0628] The third sending module is used for:

[0629] In the case that the backscatter communication device and the third communication device are different devices, a second indication message is sent to both the second communication device and the third communication device;

[0630] If the backscatter communication device and the third communication device are the same device, the second indication information is sent to the second communication device;

[0631] Wherein, the second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal, wherein the second signal is the baseband signal used by the second communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

[0632] In specific implementation, the signal type of the first signal includes any one of the following:

[0633] A first signal type, wherein the first signal of the first signal type includes the first part and the second part;

[0634] The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit;

[0635] When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following:

[0636] The length of the first time unit;

[0637] The length of the second time unit;

[0638] The sum of the lengths of the first time unit and the second time unit;

[0639] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0640] The length of the first time unit and the length of the third time unit;

[0641] The length of the second time unit and the length of the third time unit;

[0642] The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0643] The length of the first time unit, and the sum of the lengths of the second and third time units;

[0644] The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit;

[0645] The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0646] In specific implementation, the signal modulation type of the second signal includes any one of the following:

[0647] The first modulation type is a modulation type that performs amplitude differential modulation on the first signal;

[0648] The second modulation type is a modulation type that performs phase differential modulation on the first signal;

[0649] The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0650] The signal modulation parameters of the second signal include one or more of the following:

[0651] The length of one or more symbol periods of the second signal;

[0652] The half-symbol period length of the second signal;

[0653] The modulation order of the second signal.

[0654] In practical implementation, a third sending module is implemented for:

[0655] The second indication information is transmitted via at least one of RRC signaling, MAC CE, DCI, SCI, and a preamble sequence.

[0656] See Figure 12b This application provides a backscatter communication device 1220, which can be applied to the aforementioned second communication device to execute the method of the aforementioned second communication device. The backscatter communication device includes:

[0657] The first receiving module 1221 is used to receive a first signal sent by the first communication device;

[0658] The second determining module 1222 is used to determine the second signal based on the second information;

[0659] Modulation module 1223 is used to backscatter modulate the first signal according to the second signal to generate a third signal;

[0660] The second transmitting module 1224 is used to transmit the third signal to the third communication device;

[0661] The first signal comprises a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the backscatter communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

[0662] In a specific implementation, the modulation module is used for:

[0663] When the first signal is subjected to amplitude differential modulation based on the second signal, and the modulation order is second order, the second signal carries bit information through the amplitude difference between the first half of the symbol period and the second half of the symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value; when the bit information is a second value, the amplitude value of the first half of the symbol period of the second signal is a second amplitude value, and the amplitude value of the second half of the symbol period of the second signal is a third amplitude value. The second amplitude value and the third amplitude value are different amplitude values.

[0664] When the first signal is subjected to phase differential modulation based on the second signal, and the modulation order is second order, the second signal carries bit information through the phase difference between the first half of the symbol period and the second half of the symbol period. When the bit information is a first value, the phase value of the second signal is a first phase value; when the bit information is a second value, the phase value of the first half of the symbol period of the second signal is a second phase value, and the amplitude value of the second half of the symbol period of the second signal is a third phase value. The second phase value and the third phase value are different phase values.

[0665] When the first signal is subjected to amplitude and phase differential modulation according to the second signal, and the modulation order is second order, the second signal carries bit information through the amplitude and phase difference values ​​of the first half symbol period and the second half symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value, and the phase value of the second signal is a first phase value. When the bit information is a second value, the amplitude value of the first half symbol period of the second signal is a second amplitude value, the phase value of the first half symbol period of the second signal is a second phase value, the amplitude value of the second half symbol period of the second signal is a third amplitude value, and the phase value of the second half symbol period of the second signal is a third phase value. The second amplitude value and the third amplitude value are different amplitude values, and the second phase value and the third phase value are different phase values.

[0666] When the first signal is subjected to amplitude and phase differential modulation based on the second signal, and the modulation order is fourth, the second signal carries bit information through the amplitude and phase difference values ​​of the first half-symbol period and the second half-symbol period. When the bit information is a first value, the amplitude value of the first half-symbol period of the second signal is a first amplitude value, the phase value of the first half-symbol period of the second signal is a first phase value, the amplitude value of the second half-symbol period of the second signal is a second amplitude value, the phase value of the second half-symbol period of the second signal is a second phase value, and when the bit information is a second value, the amplitude value of the first half-symbol period of the second signal is a third amplitude value, the phase value of the first half-symbol period of the second signal is a third phase value, the amplitude value of the second half-symbol period of the second signal is a fourth amplitude value, and when the bit information is a third value, the amplitude value of the first half-symbol period of the second signal is a fifth amplitude value. The phase value of one symbol period is the fifth phase value, the amplitude value of the second half symbol period is the sixth amplitude value, the phase value of the second half symbol period is the sixth phase value, when the bit information is the fourth value, the amplitude value of the first half symbol period of the second signal is the seventh amplitude value, the phase value of the first half symbol period of the second signal is the seventh phase value, the amplitude value of the second half symbol period of the second signal is the eighth amplitude value, the phase value of the second half symbol period of the second signal is the eighth phase value, the difference between the second amplitude value and the first amplitude value, the difference between the fourth amplitude value and the third amplitude value, the difference between the sixth amplitude value and the fifth amplitude value, and the difference between the eighth amplitude value and the seventh amplitude value are all different amplitude values, the difference between the second phase value and the first phase value, the difference between the fourth phase value and the third phase value, the difference between the sixth phase value and the fifth phase value, and the difference between the eighth phase value and the seventh phase value are all different phase values.

[0667] In a specific implementation, the second information includes: second indication information indicated by the first communication device;

[0668] or,

[0669] The second information includes: third indication information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the backscatter communication device, and the third communication device, or the fourth communication device is a third-party communication device;

[0670] Wherein, the second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal, and the third indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal.

[0671] In a specific implementation, where the second information includes: second indication information indicated by the first communication device, or the second information includes: third indication information configured or indicated by the fourth communication device, and the fourth communication device is not the backscatter communication device, the device further includes:

[0672] The fourth receiving module is used to receive the second information;

[0673] The second information is indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0674] In a specific implementation, the device further includes:

[0675] The fourth transmitting module is used to transmit a fourth indication message to the third communication device via at least one of RRC signaling, MAC CE, DCI, SCI and preamble sequence;

[0676] The fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0677] In specific implementation, the signal type of the first signal includes any one of the following:

[0678] A first signal type, wherein the first signal of the first signal type includes the first part and the second part;

[0679] The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit;

[0680] When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following:

[0681] The length of the first time unit;

[0682] The length of the second time unit;

[0683] The sum of the lengths of the first time unit and the second time unit;

[0684] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0685] The length of the first time unit and the length of the third time unit;

[0686] The length of the second time unit and the length of the third time unit;

[0687] The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0688] The length of the first time unit, and the sum of the lengths of the second and third time units;

[0689] The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit;

[0690] The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0691] In specific implementation, the signal modulation type of the second signal includes any one of the following:

[0692] The first modulation type is a modulation type that performs amplitude differential modulation on the first signal;

[0693] The second modulation type is a modulation type that performs phase differential modulation on the first signal;

[0694] The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0695] The signal modulation parameters of the second signal include one or more of the following:

[0696] The length of one or more symbol periods of the second signal;

[0697] The half-symbol period length of the second signal;

[0698] The modulation order of the second signal.

[0699] See Figure 12c This application provides a backscatter communication device 1230, which can be applied to the aforementioned third communication device to execute the method of the aforementioned third communication device. The backscatter communication device includes:

[0700] The second receiving module 1231 is used to receive the third signal sent by the second communication device;

[0701] The third determining module 1232 is used to determine the signal modulation type and signal modulation parameters of the second signal based on the third information;

[0702] The demodulation module 1233 is used to demodulate the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0703] The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0704] In a specific implementation, the third information includes: second indication information indicated by the first communication device;

[0705] or,

[0706] The third information includes: fourth indication information indicated by the second communication device;

[0707] or,

[0708] The third information includes: fifth indication information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the backscatter communication device, or the fourth communication device is a third-party communication device;

[0709] Wherein, the second indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, the fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, and the fifth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0710] In a specific implementation, if the third information includes: second indication information indicated by the first communication device, or the third information includes: fourth indication information indicated by the second communication device, or the third information includes: fifth indication information configured or indicated by the fourth communication device, and the fourth communication device is not the backscatter communication device, the device further includes:

[0711] The fifth receiving module is used to receive the third information;

[0712] The third information is configured or indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

[0713] In specific implementation, the signal type of the first signal includes any one of the following:

[0714] A first signal type, wherein the first signal of the first signal type includes the first part and the second part;

[0715] The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit;

[0716] When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following:

[0717] The length of the first time unit;

[0718] The length of the second time unit;

[0719] The sum of the lengths of the first time unit and the second time unit;

[0720] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0721] The length of the first time unit and the length of the third time unit;

[0722] The length of the second time unit and the length of the third time unit;

[0723] The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0724] The length of the first time unit, and the sum of the lengths of the second and third time units;

[0725] The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit;

[0726] The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0727] In specific implementation, the signal modulation type of the second signal includes any one of the following:

[0728] The first modulation type is a modulation type that performs amplitude differential modulation on the first signal;

[0729] The second modulation type is a modulation type that performs phase differential modulation on the first signal;

[0730] The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0731] The signal modulation parameters of the second signal include one or more of the following:

[0732] The length of one or more symbol periods of the second signal;

[0733] The half-symbol period length of the second signal;

[0734] The modulation order of the second signal.

[0735] In specific implementation, the demodulation module is used for:

[0736] The differential signal is obtained by subtracting the signal of the first half of the symbol period from the signal of the second half of the symbol period in one symbol period of the third signal.

[0737] Based on the differential signal, the bit information carried by the second signal is demodulated.

[0738] In specific implementation, the demodulation module is used for:

[0739] The decision value of the differential signal is obtained through the decision function and the differential signal;

[0740] The bit information carried by the second signal is demodulated based on the decision threshold closest to the decision value.

[0741] See Figure 12d This application provides a backscatter communication device 1240, which can be applied to the aforementioned fourth communication device to execute the method of the aforementioned fourth communication device. The backscatter communication device includes:

[0742] Configuration module 1241 is used for one or more of the following:

[0743] Configure or instruct the first communication device to provide first information;

[0744] Configure or instruct a second communication device to provide second information;

[0745] Configure or instruct third information to a third communication device;

[0746] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0747] In practice,

[0748] The first information includes: first indication information configured or indicated by the fourth communication device, wherein the first indication information is used to indicate the signal type and signal parameters of the first signal;

[0749] The second information includes: third indication information configured or indicated by the fourth communication device, the third indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal;

[0750] The third information includes: fifth indication information configured or indicated by the fourth communication device, the fifth indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal.

[0751] In specific implementation, the signal type of the first signal includes any one of the following:

[0752] A first signal type, wherein the first signal of the first signal type includes the first part and the second part;

[0753] The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit;

[0754] When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following:

[0755] The length of the first time unit;

[0756] The length of the second time unit;

[0757] The sum of the lengths of the first time unit and the second time unit;

[0758] When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following:

[0759] The length of the first time unit and the length of the third time unit;

[0760] The length of the second time unit and the length of the third time unit;

[0761] The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit;

[0762] The length of the first time unit, and the sum of the lengths of the second and third time units;

[0763] The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit;

[0764] The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

[0765] In specific implementation, the signal modulation type of the second signal includes any one of the following:

[0766] The first modulation type is a modulation type that performs amplitude differential modulation on the first signal;

[0767] The second modulation type is a modulation type that performs phase differential modulation on the first signal;

[0768] The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal;

[0769] The signal parameters of the second signal include one or more of the following:

[0770] The length of one or more repetition periods of the second signal;

[0771] The half-repetition period length of the second signal;

[0772] The modulation order of the second signal.

[0773] In specific implementation, the first information, the second information, and / or the third information are configured or indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequences.

[0774] The backscatter communication device in this application embodiment can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or other devices besides a terminal. For example, the terminal can include, but is not limited to, the type of terminal 11 listed above; other devices can be servers, network attached storage (NAS), etc., and this application embodiment does not specifically limit the type.

[0775] The backscatter communication device provided in this application embodiment can achieve... Figures 7 to 11 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0776] Optionally, as shown in FIG12, this application embodiment also provides a communication device 1200, including a processor 1201 and a memory 1202. The memory 1202 stores a program or instructions that can run on the processor 1201. For example, when the communication device 1200 is a terminal, the program or instructions executed by the processor 1201 implement the various steps of the above-described method embodiment and achieve the same technical effect. When the communication device 1200 is a network-side device, the program or instructions executed by the processor 1201 implement the various steps of the above-described backscatter communication method embodiment and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0777] This application also provides a communication device, including a processor and a communication interface;

[0778] When this communication device is used as the first communication device mentioned above:

[0779] The processor is used by the first communication device to determine the first signal based on the first information;

[0780] The communication interface is used for the first communication device to send a first signal to the second device;

[0781] The first signal comprises a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first and second time units are the same, and the data in the first and second time units are the same.

[0782] When this communication device is used as the second communication device mentioned above:

[0783] The communication interface is used for the second communication device to receive the first signal sent by the first communication device;

[0784] The processor is used by the second communication device to determine the second signal based on the second information;

[0785] The processor is used by the second communication device to modulate the first signal according to the second signal to generate a third signal;

[0786] The communication interface is used for the second communication device to send the third signal to the third communication device;

[0787] The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing amplitude and / or phase dimension differential modulation on the first signal.

[0788] When this communication device is used as the aforementioned third communication device:

[0789] The communication interface is used for the third communication device to receive a third signal sent by the second communication device;

[0790] The processor is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal based on the third information.

[0791] The processor is used by the third communication device to demodulate the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal;

[0792] The third signal is a signal generated by the second communication device through backscatter modulation of the first signal sent by the first communication device based on the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude and / or phase dimensions. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

[0793] When this communication device is used as the fourth communication device mentioned above:

[0794] The communication interface is used for:

[0795] The fourth communication device configures or instructs the first communication device with first information;

[0796] The fourth communication device configures or instructs the second communication device with second information;

[0797] The fourth communication device configures or instructs the third communication device with third information;

[0798] Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

[0799] 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 backscatter communication method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0800] 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.

[0801] 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 backscatter communication method embodiments and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0802] 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.

[0803] 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 backscatter communication method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0804] This application also provides a backscatter communication system, including: a first communication device, a second communication device, a third communication device, and a fourth communication device. The first communication device can be used to perform the steps of the backscatter communication method as described in the first aspect, the second communication device can be used to perform the steps of the backscatter communication method as described in the second aspect, the third communication device can be used to perform the steps of the backscatter communication method as described in the third aspect, and the fourth communication device can be used to perform the steps of the backscatter communication method as described in the fourth aspect.

[0805] In this application embodiment, the fourth communication device can be any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device can be a third-party communication device; optionally, the first communication device and the third communication device can also be combined into the same hardware device in actual application scenarios.

[0806] 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.

[0807] 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.

[0808] 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 backscatter communication method, characterized in that, include: The first communication device determines the first signal based on the first information; The first communication device sends the first signal to the second communication device; The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

2. The method according to claim 1, characterized in that, The first information is used to indicate the signal type and signal parameters of the first signal; The signal type of the first signal includes any one of the following: A first signal type, wherein the first signal of the first signal type includes the first part and the second part; The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit; When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit; The length of the second time unit; The sum of the lengths of the first time unit and the second time unit; When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit and the length of the third time unit; The length of the second time unit and the length of the third time unit; The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the first time unit, and the sum of the lengths of the second and third time units; The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

3. The method according to claim 1, characterized in that, The first information includes: first indication information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device; The first indication information is used to indicate the signal type and signal parameters of the first signal.

4. The method according to claim 3, characterized in that, If the first information includes first indication information configured or indicated by the fourth communication device, and the fourth communication device is not the first communication device, the method further includes the following steps before the first communication device determines the first signal based on the first information: The first communication device receives the first information; The first information is configured or indicated by the fourth communication device through at least one of the following: Radio Resource Control (RRC) signaling, Media Access Control Unit (MAC CE), Downlink Control Information (DCI), Sidelink Control Information (SCI), and preamble sequence.

5. The method according to claim 3, characterized in that, The method further includes: When the first communication device and the third communication device are different devices, the first communication device sends a second instruction message to the second communication device and the third communication device; When the first communication device and the third communication device are the same device, the first communication device sends the second indication information to the second communication device; Wherein, the second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal, wherein the second signal is the baseband signal used by the second communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

6. The method according to claim 5, characterized in that, The signal modulation type of the second signal includes any one of the following: The first modulation type is a modulation type that performs amplitude differential modulation on the first signal; The second modulation type is a modulation type that performs phase differential modulation on the first signal; The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal; The signal modulation parameters of the second signal include one or more of the following: The length of one or more symbol periods of the second signal; The half-symbol period length of the second signal; The modulation order of the second signal.

7. The method according to claim 5, characterized in that, The first communication device sends the second indication information, including: The first communication device transmits the second indication information via at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

8. A backscatter communication method, characterized in that, include: The second communication device receives the first signal sent by the first communication device; The second communication device determines the second signal based on the second information; The second communication device modulates the first signal according to the second signal to generate a third signal; The second communication device sends the third signal to the third communication device; The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing amplitude and / or phase dimension differential modulation on the first signal.

9. The method according to claim 8, characterized in that, The second communication device modulates the first signal according to the second signal, including: When the second communication device performs amplitude differential modulation on the first signal based on the second signal, and the modulation order is second order, the second signal carries bit information through the amplitude difference value between the first half symbol period and the second half symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value; when the bit information is a second value, the amplitude value of the first half symbol period of the second signal is a second amplitude value, and the amplitude value of the second half symbol period of the second signal is a third amplitude value. The second amplitude value and the third amplitude value are different amplitude values. When the second communication device performs phase differential modulation on the first signal based on the second signal, and the modulation order is second order, the second signal carries bit information through the phase difference between the first half of the symbol period and the second half of the symbol period. When the bit information is a first value, the phase value of the second signal is a first phase value; when the bit information is a second value, the phase value of the first half of the symbol period of the second signal is a second phase value, and the amplitude value of the second half of the symbol period of the second signal is a third phase value. The second phase value and the third phase value are different phase values. When the second communication device performs amplitude and phase differential modulation on the first signal based on the second signal, and the modulation order is second order, the second signal carries bit information through the amplitude and phase difference values ​​of the first half symbol period and the second half symbol period. When the bit information is a first value, the amplitude value of the second signal is a first amplitude value, and the phase value of the second signal is a first phase value. When the bit information is a second value, the amplitude value of the first half symbol period of the second signal is a second amplitude value, the phase value of the first half symbol period of the second signal is a second phase value, the amplitude value of the second half symbol period of the second signal is a third amplitude value, and the phase value of the second half symbol period of the second signal is a third phase value. The second amplitude value and the third amplitude value are different amplitude values, and the second phase value and the third phase value are different phase values. When the second communication device performs amplitude and phase differential modulation on the first signal based on the second signal, and the modulation order is fourth, the second signal carries bit information through the amplitude and phase difference values ​​of the first half-symbol period and the second half-symbol period. When the bit information is a first value, the amplitude value of the first half-symbol period of the second signal is a first amplitude value, the phase value of the first half-symbol period of the second signal is a first phase value, the amplitude value of the second half-symbol period of the second signal is a second amplitude value, the phase value of the second half-symbol period of the second signal is a second phase value, and when the bit information is a second value, the amplitude value of the first half-symbol period of the second signal is a third amplitude value, the phase value of the first half-symbol period of the second signal is a third phase value, the amplitude value of the second half-symbol period of the second signal is a fourth amplitude value, and when the bit information is a third value, the amplitude value of the first half-symbol period of the second signal is a fifth amplitude value. The phase value of the first half of the symbol period of the second signal is the fifth phase value, the amplitude value of the second half of the symbol period of the second signal is the sixth amplitude value, the phase value of the second half of the symbol period of the second signal is the sixth phase value, when the bit information is the fourth value, the amplitude value of the first half of the symbol period of the second signal is the seventh amplitude value, the phase value of the first half of the symbol period of the second signal is the seventh phase value, the amplitude value of the second half of the symbol period of the second signal is the eighth amplitude value, the difference between the second amplitude value and the first amplitude value, the difference between the fourth amplitude value and the third amplitude value, the difference between the sixth amplitude value and the fifth amplitude value, and the difference between the eighth amplitude value and the seventh amplitude value are all different amplitude values, the difference between the second phase value and the first phase value, the difference between the fourth phase value and the third phase value, the difference between the sixth phase value and the fifth phase value, and the difference between the eighth phase value and the seventh phase value are all different phase values.

10. The method according to claim 8, characterized in that, The second information includes: second indication information indicated by the first communication device; or, The second information includes: third indication information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device; Wherein, the second indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal, and the third indication information is used to indicate the signal type and signal parameters of the first signal, and / or the signal modulation type and signal modulation parameters of the second signal.

11. The method according to claim 10, characterized in that, If the second information includes: second indication information indicated by the first communication device, or if the second information includes: third indication information configured or indicated by the fourth communication device, and the fourth communication device is not the second communication device, the method further includes, before the second communication device determines the second signal based on the second information: The second communication device receives the second information; The second information is indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

12. The method according to claim 8, characterized in that, The method further includes: The second communication device sends a fourth indication message to the third communication device via at least one of RRC signaling, MAC CE, DCI, SCI, and a preamble sequence; The fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

13. The method according to claim 10, characterized in that, The signal type of the first signal includes any one of the following: A first signal type, wherein the first signal of the first signal type includes the first part and the second part; The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit; When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit; The length of the second time unit; The sum of the lengths of the first time unit and the second time unit; When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit and the length of the third time unit; The length of the second time unit and the length of the third time unit; The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the first time unit, and the sum of the lengths of the second and third time units; The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

14. The method according to claim 10 or 12, characterized in that, The signal modulation type of the second signal includes any one of the following: The first modulation type is a modulation type that performs amplitude differential modulation on the first signal; The second modulation type is a modulation type that performs phase differential modulation on the first signal; The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal; The signal modulation parameters of the second signal include one or more of the following: The length of one or more symbol periods of the second signal; The half-symbol period length of the second signal; The modulation order of the second signal.

15. A backscatter communication method, characterized in that, include: The third communication device receives the third signal sent by the second communication device; The third communication device determines the signal modulation type and signal modulation parameters of the second signal based on the third information; The third communication device demodulates the bit information of the second signal modulation from the third signal according to the signal modulation type and signal modulation parameters of the second signal; The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

16. The method according to claim 15, characterized in that, The third information includes: second indication information indicated by the first communication device; or, The third information includes: fourth indication information indicated by the second communication device; or, The third information includes: fifth instruction information configured or indicated by a fourth communication device, wherein the fourth communication device is any one of the first communication device, the second communication device, and the third communication device, or the fourth communication device is a third-party communication device; Wherein, the second indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, the fourth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal, and the fifth indication information is used to indicate the signal modulation type and signal modulation parameters of the second signal.

17. The method according to claim 16, characterized in that, If the third information includes: second indication information indicated by the first communication device, or the third information includes: fourth indication information indicated by the second communication device, or the third information includes: fifth indication information configured or indicated by the fourth communication device, and the fourth communication device is not the third communication device, the method further includes: The third communication device receives the third information; The third information is configured or indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequence.

18. The method according to claim 15, characterized in that, The signal type of the first signal includes any one of the following: A first signal type, wherein the first signal of the first signal type includes the first part and the second part; The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit; When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit; The length of the second time unit; The sum of the lengths of the first time unit and the second time unit; When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit and the length of the third time unit; The length of the second time unit and the length of the third time unit; The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the first time unit, and the sum of the lengths of the second and third time units; The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

19. The method according to claim 15 or 16, characterized in that, The signal modulation type of the second signal includes any one of the following: The first modulation type is a modulation type that performs amplitude differential modulation on the first signal; The second modulation type is a modulation type that performs phase differential modulation on the first signal; The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal; The signal modulation parameters of the second signal include one or more of the following: The length of one or more symbol periods of the second signal; The half-symbol period length of the second signal; The modulation order of the second signal.

20. The method according to claim 15, characterized in that, The third communication device demodulates the second signal modulation bit information from the third signal according to the signal modulation type and signal modulation parameters of the second signal, including: The third communication device subtracts the signal of the first half of a symbol period from the signal of the second half of a symbol period of the third signal to obtain a differential signal. The third communication device demodulates the bit information carried by the second signal based on the differential signal.

21. The method according to claim 20, characterized in that, The third communication device demodulates the bit information of the second signal based on the differential signal, including: The third communication device obtains the decision value of the differential signal through the decision function and the differential signal; The third communication device demodulates the bit information carried by the second signal based on the decision threshold closest to the decision value.

22. A backscatter communication method, characterized in that, Includes one or more of the following: The fourth communication device configures or instructs the first communication device with the first information; The fourth communication device configures or instructs the second communication device with second information; The fourth communication device configures or instructs the third communication device with third information; Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

23. The method according to claim 22, characterized in that, The first information includes: first indication information configured or indicated by the fourth communication device, wherein the first indication information is used to indicate the signal type and signal parameters of the first signal; The second information includes: third indication information configured or indicated by the fourth communication device, the third indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal; The third information includes: fifth indication information configured or indicated by the fourth communication device, the fifth indication information being used to indicate the signal modulation type and signal modulation parameters of the second signal.

24. The method according to claim 23, characterized in that, The signal type of the first signal includes any one of the following: A first signal type, wherein the first signal of the first signal type includes the first part and the second part; The second signal type, wherein the first signal of the second signal type includes a first part, a second part and a third part, the third part is located between the first part and the second part, and the third part occupies the length of a third time unit; When the signal type of the first signal is the first signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit; The length of the second time unit; The sum of the lengths of the first time unit and the second time unit; When the signal type of the first signal is the second signal type, the signal parameters of the first signal include any one of the following: The length of the first time unit and the length of the third time unit; The length of the second time unit and the length of the third time unit; The length of the first time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the first time unit, and the sum of the lengths of the second and third time units; The length of the second time unit, and the sum of the lengths of the first time unit and the third time unit; The length of the second time unit, and the sum of the lengths of the second time unit and the third time unit.

25. The method according to claim 23, characterized in that, The signal modulation type of the second signal includes any one of the following: The first modulation type is a modulation type that performs amplitude differential modulation on the first signal; The second modulation type is a modulation type that performs phase differential modulation on the first signal; The third modulation type is a modulation type that performs amplitude and phase differential modulation on the first signal; The signal parameters of the second signal include one or more of the following: The length of one or more repetition periods of the second signal; The half-repetition period length of the second signal; The modulation order of the second signal.

26. The method according to claim 22, characterized in that... in, The first information, the second information, and / or the third information are configured or indicated by at least one of RRC signaling, MAC CE, DCI, SCI, and preamble sequences.

27. A backscatter communication device, characterized in that, include: The first determining module is used to determine the first signal based on the first information; The first transmitting module is used to transmit the first signal to the second communication device; The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

28. A backscatter communication device, characterized in that, include: The first receiving module is used to receive the first signal sent by the first communication device; The second determining module is used to determine the second signal based on the second information; A modulation module is used to perform backscatter modulation on the first signal based on the second signal to generate a third signal; The second transmitting module is used to transmit the third signal to the third communication device; The first signal comprises a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The lengths of the first time unit and the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the backscatter communication device to perform differential modulation of the first signal in amplitude dimension and / or phase dimension.

29. A backscatter communication device, characterized in that, include: The second receiving module is used to receive the third signal sent by the second communication device; The third determining module is used to determine the signal modulation type and signal modulation parameters of the second signal based on the third information. The demodulation module is used to demodulate the bit information of the second signal from the third signal according to the signal modulation type and signal modulation parameters of the second signal; The third signal is a signal generated by the second communication device modulating the first signal sent by the first communication device according to the second signal. The second signal is a baseband signal used by the second communication device when performing differential modulation of the first signal in amplitude dimension and / or phase dimension. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same, and the data in the first time unit is the same as the data in the second time unit.

30. A backscatter communication device, characterized in that, include: Configuration module, used for one or more of the following: Configure or instruct the first communication device to provide first information; Configure or instruct a second communication device to provide second information; Configure or instruct third information to a third communication device; Wherein, the first information is used by the first communication device to determine the first signal, the second information is used by the second communication device to determine the second signal, and the third information is used by the third communication device to determine the signal modulation type and signal modulation parameters of the second signal. The first signal includes a first part and a second part. The first part occupies the length of a first time unit, and the second part occupies the length of a second time unit. The length of the first time unit and the length of the second time unit are the same. The data in the first time unit is the same as the data in the second time unit. The second signal is the baseband signal used by the second communication device when performing differential modulation of the first signal in the amplitude dimension and / or phase dimension.

31. A communication device, characterized in that, The method includes a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions being executed by the processor to implement the steps of the backscatter communication method as described in any one of claims 1 to 7, or the steps of the backscatter communication method as described in any one of claims 8 to 14, or the steps of the backscatter communication method as described in any one of claims 15 to 21, or the steps of the backscatter communication method as described in any one of claims 22 to 26.

32. 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 backscatter communication method as described in any one of claims 1 to 7, or the steps of the backscatter communication method as described in any one of claims 8 to 14, or the steps of the backscatter communication method as described in any one of claims 15 to 21, or the steps of the backscatter communication method as described in any one of claims 22 to 26.

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