WO2026002141A1 - 信号传输方法、装置、通信设备及可读存储介质 - Google Patents

信号传输方法、装置、通信设备及可读存储介质

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Publication number
WO2026002141A1
WO2026002141A1 PCT/CN2025/103968 CN2025103968W WO2026002141A1 WO 2026002141 A1 WO2026002141 A1 WO 2026002141A1 CN 2025103968 W CN2025103968 W CN 2025103968W WO 2026002141 A1 WO2026002141 A1 WO 2026002141A1
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WIPO (PCT)
Prior art keywords
signal
frequency
css
information
symbols
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PCT/CN2025/103968
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English (en)
French (fr)
Inventor
黄伟
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Vivo Mobile Communication Co Ltd
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Vivo Mobile Communication Co Ltd
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Publication of WO2026002141A1 publication Critical patent/WO2026002141A1/zh
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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69—Spread spectrum techniques
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/22—Scatter propagation systems, e.g. ionospheric, tropospheric or meteor scatter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
    • H04L27/04—Modulator circuits; Transmitter circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/12—Modulator circuits; Transmitter circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits

Definitions

  • This application belongs to the field of communication technology, specifically relating to a signal transmission method, apparatus, communication equipment, and readable storage medium.
  • Chirp spread spectrum (CSS) modulation primarily uses linear frequency modulated (LFM) signals to carry information bits. Due to its excellent transmission coverage and reliability, CSS modulation has been proposed for application in backscatter communication systems.
  • a bistatic reader receives not only the backscattered CSS modulated signal from the backscattering device but also the CSS signal from the excitation source device.
  • the frequency of the useful backscattered CSS modulated signal received by the reader is almost identical to that of the CSS signal transmitted by the excitation source device, and the frequency of the CSS signal varies linearly, it is difficult for the reader to effectively eliminate CSS signal interference during demodulation, resulting in ineffective CSS signal interference removal.
  • This application provides a signal transmission method, apparatus, communication device, and readable storage medium, which can solve the problem of the inability to effectively eliminate CSS signal interference in related technologies.
  • a signal transmission method executed by a first device, the method comprising: the first device performing backscatter modulation based on information bits to be transmitted and a second signal to obtain a first signal; wherein the second signal is a carrier signal of the first signal; the first signal includes at least one first signal unit, each first signal unit including two chirped spread spectrum (CSS) symbols, the two CSS symbols having different average power or reflection coefficients, and the two CSS symbols having the same parameters other than average power and reflection coefficients, the information bits to be transmitted being modulated by the frequency of each CSS symbol in each first signal unit; and the first device transmitting the first signal.
  • the first device performing backscatter modulation based on information bits to be transmitted and a second signal to obtain a first signal
  • the second signal is a carrier signal of the first signal
  • the first signal includes at least one first signal unit, each first signal unit including two chirped spread spectrum (CSS) symbols, the two CSS symbols having different average power or reflection coefficients, and the two CSS symbols having the same parameters other than average power
  • a signal transmission method executed by a second device, the method comprising: the second device receiving a first signal transmitted by a first device; wherein the first signal is obtained by backscattering modulation based on information bits to be transmitted and a second signal, the second signal being a carrier signal of the first signal; the first signal comprising at least one first signal unit, each first signal unit comprising two CSS symbols, the two CSS symbols having different average power or reflection coefficients, and the two CSS symbols having the same parameters except for average power and reflection coefficients, the information bits to be transmitted being modulated by the frequency of each CSS symbol in each first signal unit; the second device performing a subtraction operation on the two CSS symbols in the first signal unit of the first signal to obtain a third signal; and the second device demodulating the third signal to obtain the information bits to be transmitted.
  • a signal transmission device applied to a first device, comprising: a modulation module for the first device to perform backscatter modulation based on information bits to be transmitted and a second signal to obtain a first signal; wherein the second signal is a carrier signal of the first signal; the first signal includes at least one first signal unit, each first signal unit including two CSS symbols, the average power or reflection coefficient of the two CSS symbols being different, and the other parameters of the two CSS symbols being the same except for the average power and reflection coefficient, the information bits to be transmitted being modulated by the frequency of each CSS symbol in each first signal unit; and a transmission module for transmitting the first signal.
  • a signal transmission device applied to a second device, comprising: a second receiving module for receiving a first signal transmitted by a first device; wherein the first signal is obtained by backscattering modulation based on information bits to be transmitted and a second signal, and the second signal is a carrier signal of the first signal; the first signal includes at least one first signal unit, each first signal unit including two CSS symbols, the average power or reflection coefficient of the two CSS symbols being different, and the other parameters of the two CSS symbols being the same except for the average power and reflection coefficient, and the information bits to be transmitted being modulated by the frequency of each CSS symbol in each first signal unit; a calculation module for performing a subtraction operation on the two CSS symbols in the first signal unit of the first signal to obtain a third signal; and a demodulation module for demodulating the third signal to obtain the information bits to be transmitted.
  • a signal transmission apparatus is provided, the apparatus being configured to perform the steps of the method described in the first aspect, or the steps of the method described in the second aspect.
  • a communication device 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 implementing the steps of the method as described in the second aspect.
  • a communication device including a processor and a communication interface.
  • the processor is configured to perform backscatter modulation based on information bits to be transmitted and a second signal to obtain a first signal
  • the communication interface is configured to transmit the first signal; or, when the communication device is a second device, the communication interface is configured to receive the first signal transmitted by the first device, wherein the first signal is obtained by backscatter modulation based on information bits to be transmitted and a second signal
  • the processor is configured to perform a subtraction operation on two CSS symbols in a first signal unit of the first signal to obtain a third signal, and demodulate the third signal to obtain the information bits to be transmitted;
  • the second signal is a carrier signal of the first signal
  • the first signal includes at least one first signal unit, each first signal unit includes two chirped spread spectrum CSS symbols, the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the two CSS symbols are the same except for the average power and reflection
  • a readable storage medium 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 implement the steps of the method described in the second aspect.
  • a ninth aspect provides a wireless communication system, comprising: a first device and a second device, wherein the first device is configured to perform the steps of the method as described in the first aspect, and the second device is configured to perform the steps of the method as described in the second aspect.
  • a chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.
  • a computer program/program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the method as described in the first aspect, or to implement the steps of the method as described in the second aspect.
  • the scheme in this application embodiment allows the first signal, i.e. the backscattered CSS signal, to have a repeating structure. That is, the information bits to be transmitted are modulated by the frequency of each CSS symbol in the first signal.
  • the CSS signal interference can be eliminated simply by subtraction, thereby effectively eliminating the CSS signal interference.
  • Figures 1A, 1B, 1C, 1D and 1E are schematic diagrams of a backscatter-based communication architecture in an embodiment of this application;
  • Figure 2A is a schematic diagram of the frequency uplink mode of CSS modulation in an embodiment of this application.
  • Figure 2B is a schematic diagram of the frequency downlink mode of CSS modulation in an embodiment of this application.
  • FIG. 2C is a schematic diagram of the CSS modulation method in a specific embodiment of this application.
  • FIG. 3 is a flowchart of a signal transmission method provided in an embodiment of this application.
  • FIG. 4 is a flowchart of another signal transmission method provided in an embodiment of this application.
  • FIGS. 5A and 5B are schematic diagrams of the centralized frame structure in Embodiment 1 of this application;
  • FIGS 6A and 6B are schematic diagrams of the distributed frame structure in Embodiment 1 of this application.
  • FIG. 7 is a schematic diagram of the LoRa frame structure in Embodiment 1 of this application.
  • FIGS 8A, 8B, and 8C are schematic diagrams of the modulation scheme-related signals in Embodiment 2 of this application;
  • FIGS 9A, 9B, and 9C are schematic diagrams of the modulation scheme-related signals in Embodiment 2 of this application;
  • Figure 10 is a schematic diagram of the demodulation scheme in Embodiment 3 of this application.
  • Figure 11 is a schematic diagram of a signal transmission device provided in an embodiment of this application.
  • Figure 12 is a schematic diagram of another signal transmission device provided in an embodiment of this application.
  • Figure 13 is a schematic diagram of the structure of a communication device provided in an embodiment of this application.
  • first and second 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, the first object can be one or more.
  • “or” in this application indicates at least one of the connected objects.
  • the scope of protection for "A or B” covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B.
  • the terms “A and/or B,” “at least one of A and B,” and “at least one of A or B” also cover at least the above three scenarios.
  • the character “/” generally indicates that the preceding and following objects are in an "or” relationship.
  • instruction in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction).
  • a direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent.
  • An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.
  • LTE Long Term Evolution
  • LTE-A Long Term Evolution-Advanced
  • CDMA Code Division Multiple Access
  • TDMA Time Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single-carrier Frequency-Division Multiple Access
  • NR New Radio
  • 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.
  • IoT passive Internet of Things
  • the basic components and main functions of a backscatter communication transmitter include:
  • Antenna unit Used to receive radio frequency signals and control commands, and also to transmit modulated backscattered signals.
  • Energy harvesting module or power supply module This module is used for radio frequency energy harvesting or other energy harvesting in the backscatter communication device, including but not limited to solar energy, kinetic energy, mechanical energy, and thermal energy. In addition to the energy harvesting module, it may also include a battery power supply module, in which case the backscatter communication device is a semi-passive device. The energy harvesting module or power supply module supplies power to all other modules in the device.
  • Microcontrollers include those for controlling baseband signal processing, energy storage or data scheduling, switching, and system synchronization.
  • Signal receiving module Used to demodulate control commands or data sent by the backscatter communication receiver or other network nodes.
  • Encoding and modulation module Under the control of the controller, it performs channel coding and signal modulation, and achieves modulation by selecting different load impedances through a selection switch under the control of the controller.
  • Memory or sensing module Used to store device identification ID information, location information, or sensing data, etc.
  • future backscatter communication transmitters can also integrate tunnel diode amplifier modules, low-noise amplifier modules, etc., to improve the receiver sensitivity and transmission power of the transmitter.
  • the basic components and main functions of the backscatter communication receiver include:
  • Antenna element Used to receive modulated backscattered signals.
  • Backscatter signal detection module used to detect the backscatter signal sent by the backscatter communication transmitter, including but not limited to ASK detection, PSK detection, FSK detection or QAM detection, etc.
  • Demodulation and decoding module Demodulates and decodes the detected signal to recover the original information stream.
  • Backscatter communication devices control the reflection coefficient ⁇ of the modulation circuit by adjusting its internal impedance, thereby changing the amplitude, frequency, and phase of the incident signal to achieve signal modulation.
  • the reflection coefficient ⁇ can be characterized as:
  • backscatter communication devices can be tags in traditional Radio Frequency Identification (RFID) systems, or passive or semi-passive Internet of Things (IoT) devices.
  • RFID Radio Frequency Identification
  • IoT Internet of Things
  • tags can be categorized as follows: Device A: Passive tags, without energy storage capacitors/batteries, powered by radio frequency (RF) signals. The received RF signal serves as the rectifier's power signal. They lack carrier generation capabilities and rely on RF as the radio frequency carrier for backscatter communication transmission, resulting in the lowest power consumption.
  • Device B Semi-passive tags, with energy storage capacitors/batteries, powered by non-RF signals. Optionally, they may have a PA/LNA or other active devices. They lack carrier generation capabilities and rely on RF as the radio frequency carrier for backscatter communication transmission, resulting in the next highest power consumption.
  • Device C Active tags, with energy storage capacitors/batteries, powered by non-RF signals, possessing carrier generation capabilities, resulting in the highest power consumption.
  • a backscatter-based communication architecture may include at least the following patterns:
  • Topology 1 As shown in Figure 1A, the base station in Topology 1 is both a radio frequency source/transmitter and a receiver. Therefore, Topology 1 is a Monostatic Backscatter Communication System (MBCS) architecture.
  • MBCS Monostatic Backscatter Communication System
  • Traditional RFID systems are typical MBCS systems, which include ambient-powered IoT devices (such as tags) and readers (such as base stations). The tags communicate directly with the readers, and the readers may have frequency division duplex (FDD) architecture modules.
  • FDD frequency division duplex
  • the device that transmits control signals and the device that receives backscattered signals are the same device, while the device that transmits the RF carrier source can be the same device as the aforementioned device or a separate device.
  • Topology 2 As shown in Figure 1B, in Topology 2, Ambient IoT Devices (e.g., Tags) receive control signaling and carrier signals sent by intermediate nodes.
  • the control signaling can be indicated by network devices (e.g., base stations gNBs) through intermediate nodes.
  • the intermediate nodes can be User Equipment (UE), repeaters, IAB nodes, etc.
  • Intermediate nodes can also act as relays to forward IoT data to gNBs.
  • UE User Equipment
  • Topology 3 involves a bistatic backscatter communication system (BBCS), in which the radio frequency source, BSC transmitting device and BSC receiving device are separate; in Topology 3, the Ambient IoT Device (e.g., Tag) sends IoT data/uplink signaling to the base station and receives data/signaling sent by the auxiliary node, as shown in Figure 1C; or, the Ambient IoT Device (e.g., Tag) sends IoT data/uplink signaling to the auxiliary node and receives data/signaling sent by the base station, as shown in Figure 1D; the base station and the auxiliary node communicate through the Uu interface, and the auxiliary node can be UE, repeater, IAB, etc.
  • BBCS bistatic backscatter communication system
  • Topology 4 As shown in Figure 1E, in Topology 4, the UE acts as the Reader to communicate with the Tag. This architecture also belongs to the monostatic backscatter communication architecture, the difference being that the Reader is the UE, not the base station.
  • Chirp modulation also known as chirp spread spectrum (CSS) modulation, primarily uses a linear frequency modulated signal to carry information bits.
  • CSS modulation signals are divided into up-chirp mode (as shown in Figure 2A) and down-chirp mode (as shown in Figure 2B).
  • up-chirp modulation the frequency of the CSS modulation signal increases with time; when using down-chirp mode, the frequency of the CSS modulation signal decreases with time.
  • the frequency of the CSS modulation signal always changes periodically between a low frequency f1 and a high frequency f2 according to a certain pattern.
  • the sweep time is T s
  • the sweep slope is...
  • CSS modulation actually achieves different information transmission by changing the initial frequency of the pilot. Because the initial scanning frequency is changed, the linear increase in frequency throughout the entire signal scanning period will exceed the specified scanning termination frequency f2 or f1 . In this case, CSS modulation stipulates that once the scanning frequency exceeds the upper limit frequency f2 or the lower limit frequency f1 , the subsequent scanning frequency is either subtracted from BW or added to BW.
  • the transmission time for each chip is:
  • Symbol 1 has a starting frequency of f1 , which increases linearly to f2 , representing bit 00; symbol 2 has a starting frequency of... It first increases linearly to f2 with a frequency of f1, and then increases linearly to f2 with a starting frequency of f1.
  • Representing bit 01; the starting frequency of symbol 3 is It first increases linearly to f2 with a frequency of f1, and then increases linearly to f2 with a starting frequency of f1.
  • the symbol represents bit 10; the starting frequency of symbol 4 is...
  • a reference chirp signal with the opposite modulation mode to the CSS modulation can be used for mixing, and the input bits are finally demodulated by Fast Fourier Transform (FFT).
  • FFT Fast Fourier Transform
  • f0 is the initial frequency
  • f0 is the initial frequency
  • w(t;t a ,t b ) is a rectangular window function, expressed as:
  • the receiver first performs mixing or dechirp processing on the reference down-chirp signal c * (t), such as using the following formula:
  • the receiver After obtaining s ′ (t; fn ) through mixing, the receiver performs FFT calculation and identifies the peak position of the frequency point in the frequency domain. And finally, the input bits are used for decision-making.
  • the solution in this application can be applied to LTE systems, 5G NR systems and NR evolution systems, such as 6G systems and 6G evolution systems, as well as IEEE 802.11 systems (such as WiFi systems), Bluetooth systems, LoRa systems, Zigbee systems, LP-WUS/WUR systems, backscatter communication systems, low-power IoT systems, Ambient IoT communication systems, etc.
  • 5G NR systems and NR evolution systems such as 6G systems and 6G evolution systems
  • IEEE 802.11 systems such as WiFi systems
  • Bluetooth systems such as Bluetooth systems
  • LoRa systems such as Zigbee systems
  • LP-WUS/WUR systems Low-power IoT systems
  • backscatter communication systems low-power IoT systems
  • Ambient IoT communication systems etc.
  • Figure 3 is a flowchart of a signal transmission method provided in an embodiment of this application.
  • the method is executed by a first device, such as a backscattering device.
  • the method includes the following steps:
  • Step 31 The first device performs backscatter modulation based on the information bits to be transmitted and the second signal to obtain the first signal;
  • Step 32 The first device sends the first signal.
  • the second signal is the carrier signal of the first signal
  • the first signal is the backscattered modulated signal of the second signal.
  • the first signal includes at least one first signal unit, and each first signal unit includes two CSS symbols, such as two adjacent CSS symbols; the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the two CSS symbols are the same except for the average power and reflection coefficient.
  • the information bits to be transmitted are modulated by the frequency of each CSS symbol in each first signal unit.
  • the other parameters include at least the following: frequency sweeping method; minimum frequency sweeping frequency; maximum frequency sweeping frequency; frequency sweeping start frequency; frequency sweeping stop frequency; center frequency; bandwidth; spreading factor; code rate; symbol rate; etc.
  • the waveform of the second signal can be set based on actual needs, as long as the second signal can be used to obtain the first signal with a repeating structure in the present application.
  • the solution in this application embodiment can be applied to different Ambient IoT topologies, such as the topologies shown in Figure 1B and Figure 1C.
  • the scheme in this application embodiment allows the first signal, i.e. the backscattered CSS signal, to have a repeating structure. That is, the information bits to be transmitted are modulated by the frequency of each CSS symbol in the first signal.
  • the CSS signal interference can be eliminated simply by subtraction, thereby effectively eliminating the CSS signal interference.
  • the second signal includes at least one second signal unit, each second signal unit including two CSS symbols or two reference Chirp symbols with the same parameters;
  • the first signal is obtained by adding a first part and a second part, the first part being a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part being a signal obtained by frequency shifting and filtering the second signal at a second frequency;
  • the frequency shift directions of the first part and the second part are opposite, and the sum of the first frequency and the second frequency is equal to the bandwidth of the CSS symbol (or signal) or reference Chirp symbol (or signal) in the second signal, the first frequency and the second frequency being a frequency pair for frequency shifting associated with the information bits to be transmitted.
  • the frequency shift directions mentioned above can be reversed, with one being a positive frequency shift and the other a negative frequency shift.
  • the first frequency is f 2m-1 and the second frequency is f 2m
  • the second signal can be shifted by f 2m-1 (i.e., in the positive direction) and by -f 2m (i.e., in the negative direction); or, the second signal can be shifted by -f 2m-1 (i.e., in the negative direction) and by f 2m (i.e., in the positive direction).
  • the generated signal can satisfy the linear frequency modulation characteristics of the CSS signal, thereby utilizing the transmission characteristics of the CSS signal to achieve longer transmission coverage or transmission reliability.
  • the filter can be a filter with a center frequency of f0 and a bandwidth of [value missing].
  • the filtering is performed such that f0 is the center frequency of the CSS signal or the reference Chirp signal in the second signal, i.e., f0 is the center frequency of the second signal; and BW is the bandwidth of the CSS symbol or the reference Chirp symbol in the second signal, i.e., BW is the bandwidth of the second signal.
  • the second signal may satisfy at least one of the following:
  • the average power of the two CSS symbols in each second signal unit is the same, or the average power of the two reference Chirp symbols in each second signal unit is the same;
  • the time interval between two adjacent second signal units in the second signal is greater than or equal to 0.
  • the second signal S(t) is the radio frequency carrier signal of the first signal C(t), and at least satisfies the following characteristics:
  • a signal unit in S(t) includes two CSS symbols or reference Chirp symbols with the same parameters:
  • the length of a signal unit in S(t) is equal to 2T s time units; the time unit can be a unit specified by the protocol, such as a symbol, time slot, subframe, frame, etc., or a time unit such as a microsecond, millisecond, minute, etc.
  • the parameters of the CSS symbol S1 (t) may include at least the following:
  • (V) Average power of each symbol setting the same average power here can be used to ensure that the radio frequency interference is eliminated after subtracting the two consecutive CSS symbols in the first signal;
  • the first signal C(t) is a backscattered signal generated based on the second signal S(t), and at least satisfies the following characteristics:
  • a signal unit of the first signal C(t) includes two CSS symbols C1 ,n (t) with different average power or reflection coefficients, and the nth signal unit satisfies:
  • the characteristic of the CSS symbol C1,n ( tTs ) is that C1 ,n ( tTs ) is a signal delayed by Ts from C1 ,n (t), or C1 ,n ( tTs ) is a repetition of the signal C1 ,n (t) in the next symbol period Ts .
  • ⁇ 1 and ⁇ 2 are the reflection coefficients or average power of two CSS symbols in the signal unit, respectively; and ⁇ 1 ⁇ ⁇ 2 , to ensure that the third signal constructed later is valid;
  • One signal unit of the first signal can carry log 2 M (log 2 M ⁇ SF) information bits;
  • the first device can perform signal modulation based on configuration or indicated information.
  • the aforementioned backscatter modulation based on the information bits to be transmitted and the second signal to obtain the first signal may include:
  • the first device performs backscatter modulation on the information bits to be transmitted and the second signal based on the obtained first information to obtain the first signal;
  • the first information is information related to signal modulation, and the first information may include, but is not limited to, at least one of the following:
  • PRB physical resource block
  • RBG resource block group
  • BWP bandwidth part
  • the modulation method of the first signal such as including but not limited to FSK-CSS modulation, binary on/off keying (OOK) modulation, amplitude shift keying (ASK) modulation, phase shift keying (PSK) modulation, frequency shift keying (FSK) modulation, quadrature amplitude modulation (QAM), amplitude phase shift keying (APSK) modulation, etc.
  • the modulation order of the first signal for example, the modulation order is M;
  • the encoding method of the first signal such as including but not limited to channel coding method, line coding method, etc.;
  • the channel coding method is, for example, Reed-Solomon codes (RS codes), polar codes, convolutional codes, repetition codes, etc.;
  • the line coding method is, for example, biphase space code (FM0 code), Miller codes, Manchester codes, etc.; based on this encoding method, the first device can generate the corresponding first signal;
  • the reflection coefficient or amplification coefficient of the first signal such as the average power or reflection coefficient of the two CSS symbols in the first signal unit of the first signal;
  • First index information associated with the modulation and coding of the first signal wherein the first index information is used to indicate the associated modulation and coding parameters; wherein different first index information corresponds to different modulation and coding parameters, and each first index information may correspond to a set of modulation and coding parameters (as described in (a) to (h) above), and the relevant correspondence may be pre-configured by the network or protocol.
  • the first device can obtain the associated modulation and coding parameters, thereby generating the corresponding backscattered modulation signal (i.e., the first signal).
  • the first device may send a first signal based on configuration or indicated information. Sending the first signal may include:
  • the first device transmits a first signal based on the obtained second information.
  • the second information is information related to the transmission of the first signal, and may include, but is not limited to, at least one of the following: the transmission power of the first signal; the preamble or synchronization sequence of the first signal; a reference signal of the first signal, which can be used to estimate the channel or time-frequency information in the first signal; time-domain resource information of the first signal, such as the number of repetitions, signal period, time slot configuration information, subframe information, etc.; frequency-domain resource information of the first signal, such as frequency, bandwidth, etc.; and spatial-domain resource information of the first signal, such as antenna, codeword, layer, antenna port, etc.
  • relevant information for receiving carrier signals can be configured or indicated for the first device.
  • the signal transmission method described above may further include: the first device receiving a second signal based on obtained third information; the third information may include, but is not limited to, at least one of the following:
  • the baseband signal parameters of the second signal are the baseband signal parameters of the second signal.
  • the second index information is associated with the signal parameters of the second signal, and the second index information is used to indicate the associated carrier signal parameters; wherein, different second index information corresponds to different signal parameters of the second signal, and each second index information can correspond to a set of carrier signal parameters, such as frequency domain related parameters, time domain related parameters and/or signal waveforms, etc., and the related correspondence can be pre-configured by the network or protocol.
  • the first device can obtain the signal parameters of the associated second signal, thereby accurately receiving the second signal.
  • the second signal may be sent by a second device, that is, in this case: the second device is both the receiving device that receives the first signal and the device that provides the carrier signal to the first device; it may also be sent by a third device, which is the device that provides the carrier signal; or it may be sent by a fourth device, which is a device that is different from the first, second and third devices and has network scheduling functions, such as a gateway, router, access network device, relay device, IAB device, Repeater device, terminal device, AP device, etc.
  • network scheduling functions such as a gateway, router, access network device, relay device, IAB device, Repeater device, terminal device, AP device, etc.
  • the frequency domain related parameters of the second signal include, but are not limited to, at least one of the following: (I) the center frequency of the second signal; (II) the bandwidth of the second signal; (III) the scan start frequency of the second signal; (IV) the scan cutoff frequency of the second signal; (V) the scan minimum frequency of the second signal; (VI) the scan maximum frequency of the second signal; (VII) the slope of the scan frequency of the second signal; (VIII) the spreading factor of the second signal; (IX) the chip rate of the second signal; (X) the symbol rate or symbol period of the second signal; (XI) the frequency sweep mode of the second signal, such as up-chirp mode or down-chirp mode; and (XII) the frequency offset or shift magnitude of the second signal.
  • the time-domain related parameters of the second signal include, but are not limited to, at least one of the following: (I) the time unit of the second signal, such as RE, time slot, subframe, etc.; (II) the signal period of the second signal; (III) the signal length of the second signal; (IV) the time-domain repetition number of the second signal; (V) the synchronization signal or synchronization sequence of the second signal.
  • the signal waveform and frame structure of the second signal may include at least one of the following: 1) the second signal adopts a CSS signal waveform, and the number of CSS symbols or the number of second signal units included in the second signal; 2) the second signal adopts a reference chirp signal waveform, and the number of reference chirp symbols or the number of second signal units included in the second signal; 3) the second signal adopts a mixed waveform of CSS signal and reference chirp signal, and the ratio or number of CSS symbols and reference chirp symbols in the second signal.
  • the second signal is a hybrid signal of a reference chirp signal and a CSS modulation signal, such as a CSS modulation signal with a frame structure, wherein the frame structure signal includes at least a CSS modulation signal or a reference chirp signal;
  • the hybrid signal is, for example, a LoRa signal.
  • the baseband signal parameters of the second signal may include at least one of the following: (I) modulation parameters of the second signal, such as including but not limited to modulation method, modulation order, modulation rate, etc.; (II) coding parameters of the second signal, such as including but not limited to channel coding method (e.g., RS code, Polar code, convolutional code, repetition code, etc.) or line coding method (e.g., FM0 code, Miller code, Manchester code, etc.).
  • channel coding method e.g., RS code, Polar code, convolutional code, repetition code, etc.
  • line coding method e.g., FM0 code, Miller code, Manchester code, etc.
  • the first device can obtain the first information in multiple ways.
  • the signal transmission method may further include at least one of the following: (a) the first device determines the first information, i.e., the first device itself has the ability to determine configuration information; (b) the first device receives the first information from a second device, where the second device is a receiving device for the first signal; that is, at this time, the second device is both a receiving device for the first signal and a device for configuring or indicating the first information; the second device may be an access network device such as a base station, a terminal device such as a UE, a relay device, a repeater device, an IAB device, an AP device, etc.; (c) the first device receives the first information from a third device, where the third device is a device providing a carrier signal; that is, this...
  • the third device is both a device that provides carrier signals to the first device and a device that configures or indicates the first information;
  • the third device can be an access network device such as a base station, a terminal device such as a UE, a relay device, a repeater device, an IAB device, an AP device, a dedicated radio frequency source device, etc.;
  • the first device receives the first information from the fourth device, the fourth device being a device with network scheduling function; the fourth device is a device that is different from the first device, the second device and the third device and has network scheduling function, such as a gateway, a router, an access network device, a relay device, an IAB device, a repeater device, a terminal device, an AP device, etc.
  • the first information may also be configured/indicated by at least two of the first to fourth devices.
  • the first information when the first information is received by the first device, the first information can be configured or indicated through at least one of the following:
  • Radio Resource Control (RRC) signaling this method requires the first device to have the RRC protocol layer;
  • Non-Access Stratum (NAS) signaling this method requires the first device to have NSA protocol layer capabilities;
  • MAC CE Medium Access Control Element
  • DCI Downlink Control Information
  • SCI Sidelink Control Information
  • Layer 1 or physical layer signaling such as physical frame headers and preambles carrying control information, can be placed in the same physical frame as the effective data payload, or it can be placed in a separate physical frame.
  • Factory configuration information or default configuration information; for example, when the first device connects to the network for the first time or does not support RRC configuration information, the system configures the signal parameters related to the first signal.
  • the second and third information can adopt the same configuration/instruction method as the first information, and will not be repeated here to avoid repetition.
  • FIG 4 is a flowchart of a signal transmission method provided in an embodiment of this application.
  • the method is executed by a second device, such as an access network device like a base station, a terminal device like a UE, a relay device, a repeater device, an IAB device, an AP device, etc.
  • a second device such as an access network device like a base station, a terminal device like a UE, a relay device, a repeater device, an IAB device, an AP device, etc.
  • the method includes the following steps:
  • Step 41 The second device receives the first signal sent by the first device; the first signal is obtained by backscattering modulation based on the information bits to be transmitted and the second signal;
  • Step 42 The second device performs a subtraction operation on the two CSS symbols in the first signal unit of the first signal to obtain the third signal;
  • Step 43 The second device demodulates the third signal to obtain the information bits to be transmitted.
  • the second signal is the carrier signal of the first signal.
  • the first signal includes at least one first signal unit, and each first signal unit includes two CSS symbols, such as two adjacent CSS symbols; the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the two CSS symbols are the same except for the average power and reflection coefficient.
  • the information bits to be transmitted are modulated by the frequency of each CSS symbol in each first signal unit.
  • the other parameters include at least the following: frequency sweeping method; minimum frequency sweeping frequency; maximum frequency sweeping frequency; frequency sweeping start frequency; frequency sweeping stop frequency; center frequency; bandwidth; spreading factor; code rate; symbol rate; etc.
  • the waveform of the second signal can be set based on actual needs, as long as the second signal can be used to obtain the first signal with a repeating structure in the present application.
  • the second device can obtain the first signal on a specified time-frequency resource and perform necessary radio frequency, intermediate frequency, or baseband processing on the obtained first signal.
  • Each symbol of the third signal can be demodulated to extract the transmitted information bits.
  • the scheme in this application embodiment can make the first signal, i.e. the backscattered CSS signal, have a repeating structure, that is, the information bits to be transmitted are modulated by the frequency of each CSS symbol in the first signal.
  • the second device i.e. the receiving end
  • the CSS signal interference can be eliminated by simply using the subtraction operation, thereby effectively eliminating the CSS signal interference.
  • the second signal includes at least one second signal unit, each second signal unit including two CSS symbols or two reference Chirp symbols with the same parameters;
  • the first signal is obtained by adding a first part and a second part, the first part being a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part being a signal obtained by frequency shifting and filtering the second signal at a second frequency;
  • the frequency shift directions of the first part and the second part are opposite, and the sum of the first frequency and the second frequency is equal to the bandwidth of the CSS symbol (or signal) or reference Chirp symbol (or signal) in the second signal, the first frequency and the second frequency being a frequency pair for frequency shifting associated with the information bits to be transmitted.
  • the frequency shift directions mentioned above can be reversed, with one being a positive frequency shift and the other a negative frequency shift.
  • the first frequency is f 2m-1 and the second frequency is f 2m
  • the second signal can be shifted by f 2m-1 (i.e., in the positive direction) and by -f 2m (i.e., in the negative direction); or, the second signal can be shifted by -f 2m-1 (i.e., in the negative direction) and by f 2m (i.e., in the positive direction).
  • the generated signal can satisfy the linear spread spectrum characteristics of the CSS signal, thereby utilizing the transmission characteristics of the CSS signal to achieve longer transmission coverage or transmission reliability.
  • the third signal B(t) is a signal constructed based on the first signal obtained from the second device, and at least satisfies the following characteristics:
  • the time length of one CSS symbol of the third signal is T s time units; the time unit can be a unit specified by the protocol such as a symbol, time slot, subframe, frame, etc., or a time unit such as microsecond, millisecond, minute, etc.
  • the parameters of the symbols in the third signal may include the following:
  • the basic time unit interval between each signal unit in the third signal B(t) is T g /2 ⁇ 0.
  • the above demodulation of the third signal may include at least one of the following:
  • the second device uses the reference despreading signal to despread the third signal to obtain the fourth signal, and obtains the information bits to be transmitted based on the frequency points of the highest peak or the two highest peaks in the frequency domain of the fourth signal; for example, a threshold decision can be made based on the frequency points of the highest peak or the two highest peaks in the frequency domain of the fourth signal to obtain the information bits to be transmitted.
  • the second device uses the maximum likelihood detection algorithm to demodulate the third signal to obtain the information bits to be transmitted; for the specific demodulation process, please refer to the description in the following embodiment three.
  • the second device can perform demodulation based on configuration or indicated information.
  • the aforementioned demodulation of the third signal to obtain the information bits to be transmitted may include:
  • the second device demodulates the third signal based on the obtained fourth information to obtain the information bits to be transmitted;
  • the fourth information is information related to the demodulation parameters, and the fourth information may include, but is not limited to, at least one of the following:
  • the modulation method of the first signal such as including but not limited to FSK-CSS modulation, binary on/off keying (OOK) modulation, amplitude shift keying (ASK) modulation, phase shift keying (PSK) modulation, frequency shift keying (FSK) modulation, quadrature amplitude modulation (QAM), APSK modulation, CSS modulation, etc.;
  • the modulation order of the first signal for example, the modulation order is M;
  • the encoding method of the first signal for example, including but not limited to channel coding methods (e.g., RS code, Polar code, convolutional code, repetition code, etc.) or line coding methods (e.g., FMO code, Miller code, Manchester code, etc.);
  • channel coding methods e.g., RS code, Polar code, convolutional code, repetition code, etc.
  • line coding methods e.g., FMO code, Miller code, Manchester code, etc.
  • the way to construct the third signal is, for example, the previous CSS symbol minus the next CSS symbol, or the next CSS symbol minus the previous CSS symbol;
  • a third index information associated with the demodulation of the first signal the third index information being used to indicate the associated demodulation parameters; wherein, different third index information is associated with different demodulation parameters of the first signal, and each third index information may correspond to a set of demodulation parameters of the first signal, such as those described in a) to i) above; the relevant correspondence may be pre-configured by the network or protocol.
  • the signal parameters of the reference despread signal include at least one of the following: (I) the sweep mode of the reference despread signal; the sweep mode of the reference despread signal is the opposite of the sweep mode of the first signal; that is, if the first signal adopts an up-chirp sweep mode, the reference despread signal adopts a down-chirp sweep mode; if the first signal adopts a down-chirp sweep mode, the reference despread signal adopts an up-chirp sweep mode; (II) the lowest sweep frequency of the reference despread signal, which is the same as the lowest sweep frequency of the first signal; (III) the highest sweep frequency of the reference despread signal, which is the same as the highest sweep frequency of the first signal; (IV) the sweep start frequency of the reference despread signal, which is either the lowest sweep frequency or the highest sweep frequency; for example, if the reference despread signal is a down-chirp sweep mode, the corresponding sweep start frequency is the highest sweep frequency; or, if the reference despread signal is the
  • the corresponding frequency sweep start frequency is the lowest frequency sweep frequency
  • the frequency sweep cutoff frequency of the reference despread signal is either the lowest or the highest frequency sweep frequency; for example, if the reference despread signal is a down-chirp frequency sweep mode, the corresponding frequency sweep cutoff frequency is the lowest frequency sweep frequency; or, if the reference despread signal is an up-chirp frequency sweep mode, the corresponding frequency sweep cutoff frequency is the highest frequency sweep frequency;
  • IIIV the center frequency of the reference despread signal, the center frequency of the reference despread signal is the same as the first The center frequency of the signals is the same; (V) the bandwidth of the reference despread signal, which is the same as the bandwidth of the first signal; (VI) the spreading factor of the reference despread signal, which is the same as the spreading factor of the first signal; (VII) the code rate of the reference despread signal, which is the same as the code rate of the first signal; (VIII) the symbol rate of the reference despread signal
  • the second device can receive the first signal based on configured or indicated information.
  • Receiving the first signal sent by the first device can include: the second device receiving the first signal based on obtained fifth information; the fifth information may include, but is not limited to, at least one of the following: the preamble or synchronization sequence of the first signal; the reference signal of the first signal; the time-domain resource information of the first signal, such as the number of repetitions, signal period, time slot configuration information, subframe information, etc.; the frequency-domain resource information of the first signal, such as frequency, bandwidth, etc.; and the spatial-domain resource information of the first signal, such as antenna, codeword, layer, antenna port, etc.
  • the second device can be configured or instructed with relevant information for transmitting a carrier signal (i.e., the second signal).
  • the signal transmission method may further include: the second device transmitting the second signal based on obtained sixth information; the sixth information may include, but is not limited to, at least one of the following: frequency domain correlation parameters of the second signal; time domain correlation parameters of the second signal; signal waveform and frame structure of the second signal; baseband signal parameters of the second signal; and second index information associated with the signal parameters of the second signal, the second index information indicating the associated signal parameters of the second signal; wherein different second index information corresponds to different signal parameters of the second signal, and each second index information may correspond to a set of signal parameters of the second signal, such as including frequency domain correlation parameters, time domain correlation parameters, and/or signal waveforms, etc., and the corresponding relationship may be pre-configured by the network or protocol.
  • the first device can obtain the associated signal parameters of the second signal, thereby accurately transmitting the second signal.
  • the second device can obtain the fourth information in multiple ways.
  • the signal transmission method may further include at least one of the following: (a) the second device determines the fourth information, that is, the second device itself has the ability to determine configuration information; (b) the second device receives the fourth information from the first device; (c) the second device receives the fourth information from a third device, wherein the third device is a device that provides a carrier signal; that is, at this time: the third device is both a device that provides a carrier signal to the first device and a device that configures or indicates the fourth information; (d) the second device receives the first information from a fourth device, wherein the fourth device is a device with network scheduling function; the fourth device is a device different from the first device, the second device, and the third device.
  • fifth and sixth pieces of information can adopt the same configuration/indication method as the fourth piece of information, and will not be repeated here to avoid repetition.
  • the second signal is a periodic CSS signal or a reference chirp signal, where all symbol parameters of CSS symbols #n and #n+1 within the same symbol period k are identical. Specifically, the average power of CSS symbols #n and #n+1 is the same, and the time interval Tg between any signal unit k and signal unit k+1 is 0. Correspondingly, the time interval Tg between each signal unit k and signal unit k+1 in the first signal is 0, and the CSS symbol #n in each signal unit is the sum of the first and second parts of the signal generated after frequency shifting and filtering of the corresponding CSS symbol #n in the second signal (f 2m-1 , -f 2m ), m ⁇ 1,...,M ⁇ .
  • the average power or reflection coefficient ⁇ 1 of the CSS symbol #n in each signal unit is different from the average power or reflection coefficient ⁇ 2 of the CSS symbol #n+1, i.e., ⁇ 1 ⁇ ⁇ 2 .
  • the advantage of this design is that all the symbols of the second signal are used to modulate the information bits of the first device, thus resulting in a high modulation rate.
  • the second signal is a periodic CSS signal or a reference chirp signal, wherein all symbol parameters of CSS symbols #n and #n+1 within the same symbol period k are identical, specifically, the average power of CSS symbols #n and #n+1 is identical, and the time interval between two signal units k and signal unit k+1 may be Tg > 0.
  • Tg the time interval between any two signal units k and signal unit k+1 is Tg >0; or, (2) the time interval between some signal units k and signal unit k+1 is Tg > 0.
  • the time interval between two signal units k and signal unit k+1 in the first signal may be Tg > 0.
  • the CSS symbol #n in each signal unit is the sum of the first and second part signals generated by frequency shifting and filtering the corresponding CSS symbol #n in the second signal (f 2m-1 , -f 2m ), m ⁇ 1,...,M ⁇ .
  • the average power or reflection coefficient ⁇ 1 of the CSS symbol #n in each signal unit is different from the average power or reflection coefficient ⁇ 2 of the CSS symbol #n+1, i.e., ⁇ 1 ⁇ ⁇ 2 .
  • the advantage of this design is that the frame structure design of all second signals is flexible, and other data payloads in the frame structure can be used for other services.
  • this scheme only requires that the starting scan frequencies of the two CSS symbols in the same signal unit of the second signal be the same, but does not require that the starting scan frequencies of the CSS symbols in signal unit m and signal unit n (m ⁇ n) be the same. If the starting scan frequencies of the CSS symbols in signal unit k and signal unit k+1 are different, the second signal itself can also carry information bits or other services that the first device wants to send.
  • the LoRa frame structure is a typical example.
  • the starting sweep frequencies of the CSS symbols in signal unit m and signal unit n (m ⁇ n) are not necessarily the same, and the time interval between two signal units k and signal unit k+1 may be Tg > 0.
  • the LoRa frame structure includes four parts: preamble, header, payload, and cyclic redundancy check (CRC).
  • the preamble part does not require encoding and directly uses CSS modulation symbols, while subsequent data undergoes Hamming encoding to improve error correction capability.
  • the preamble can also contain three parts: variable preamble, sync word, and start frame delimiter (SFD).
  • the protocol specifies a variable preamble
  • the length of the variable preamble is fixed in a fixed scenario or over a period of time. Therefore, the length of the entire preamble is also fixed, making it very suitable as the second signal in this scheme.
  • the Payload, Header, and CRC portions are encoded and their starting scan frequencies are not fixed, from a simplicity perspective, these portions are generally not used as the second signal. These signals correspond to other data payload portions in this application, and their length can also vary.
  • the time interval between two signal units k and signal unit k+1 in this scheme may be Tg > 0, or more precisely, the time interval between some signal units k and signal unit k+1 is Tg > 0.
  • the Variable Preamble generally uses a reference up-chirp signal, and this part of the signal satisfies that the starting scan frequencies of the CSS symbols in signal unit m and signal unit n (m ⁇ n) are the same.
  • the Sync word and SFD use a reference down-chirp signal; therefore, the last signal unit of the variable preamble and the first signal unit of the sync word satisfy that the starting scan frequencies of the CSS symbols in signal unit m and signal unit n (m ⁇ n) are different.
  • Case 1 The second signal is the reference CSS signal or the Chirp signal.
  • the second signal used for the RF carrier is a reference chirp signal or a CSS signal S1 (t).
  • the second signal can satisfy the following characteristics:
  • the center frequency is f0 ;
  • the (IIIV) signal S1 (t) can be expressed as:
  • the frequencies of two adjacent CSS symbols in a signal unit of the second signal can be frequency shifted by f1 ( 0 ⁇ f1 ⁇ BW ) or f3 ( 0 ⁇ f3 ⁇ BW ) respectively, and the center frequency is f0 with a bandwidth range of [missing information].
  • the filtering process generates the first part of the first signal.
  • the frequencies of two adjacent CSS symbols in one signal unit of the second signal are shifted by -f2 ( 0 ⁇ f2 ⁇ BW ) or -f4 ( 0 ⁇ f4 ⁇ BW ) respectively, and a center frequency of f0 and a bandwidth range of [missing information].
  • the filtering process generates the second part of the first signal.
  • the first part and the second part of the first signal are added in the time domain, and different average power or reflection coefficients are assigned to two adjacent CSS symbols to generate the first signal.
  • This second embodiment uses...
  • the following example illustrates the signal modulation process of the transmitted bits when the second signal is a reference CSS signal or a Chirp signal.
  • Figures 8B and 8C show this process.
  • the second signal is a modulated CSS signal.
  • the starting scan frequency of the CSS signal representing bit "10" is f0
  • the starting scan frequencies of two adjacent CSS symbols (i.e., one signal unit) in the second signal must be the same. Therefore, the second signal shown in Figure 9A also transmits bits using two identical adjacent CSS symbols. At this time, the second signal satisfies the following characteristics:
  • the center frequency is f0 ;
  • the initial scan frequency of each symbol is related to the modulation information of the second signal, for n ⁇ 0,1,..., 2SF -1 ⁇ ;
  • the (IIIV) modulated CSS signal S2 (t) can be expressed as:
  • the frequencies of two adjacent CSS symbols (i.e., a signal unit) of the second signal can be frequency shifted by f1 ( 0 ⁇ f1 ⁇ BW ) or f3 ( 0 ⁇ f3 ⁇ BW ) respectively, and the center frequency is f0 with a bandwidth range of [missing information].
  • the filtering process generates the first part of the first signal.
  • the frequencies of two adjacent CSS symbols (i.e., one signal unit) of the second signal are frequency shifted by -f2 ( 0 ⁇ f2 ⁇ BW ) or -f4 ( 0 ⁇ f4 ⁇ BW ) respectively, and a center frequency of f0 and a bandwidth range of [missing information].
  • the filtering process generates the second part of the first signal.
  • the first part and the second part of the first signal are added in the time domain, and different average transmit power or reflection coefficients are assigned to two adjacent CSS symbols to generate the first signal.
  • This second embodiment uses... Let's take an example. As shown in Figure 9A, the second signal itself also modulates bit information.
  • the starting scan frequency of the second signal corresponding to the transmitted bit "0" is...
  • the second signal with an initial scanning frequency of f0 is shifted by -f4 , and the center frequency is f0 with a bandwidth range of...
  • the filtering process generates the second part of the first CSS symbol.
  • the second signal with an initial scanning frequency of f0 is shifted by -f4 , and the center frequency is f0 with a bandwidth range of...
  • the filtering process generates the second part of the second CSS symbol.
  • this third embodiment the corresponding demodulation process is given. Without loss of generality, this third embodiment only uses a centralized frame structure (Scheme 1 in this first embodiment) and a reference CSS symbol or Chirp signal as the second signal (Scheme 1 in this second embodiment) as an example for explanation. Similar demodulation schemes can be extended to demodulation in other schemes. The demodulation process is briefly described below:
  • the second device may first perform necessary time-frequency synchronization before starting to acquire the first signal
  • the second device performs radio frequency or intermediate frequency processing such as down-conversion and intermediate frequency filtering on the obtained first signal;
  • the second device performs baseband signal processing such as channel estimation, channel equalization, and channel decoding on the obtained first signal.
  • Each pair of CSS symbols in the obtained first signal is treated as a signal unit.
  • the average power or reflection coefficient (e.g., ⁇ 1 and ⁇ 2 ) of the preceding and following CSS symbols is determined based on indication or configuration information, or the second device itself determines the average power of the preceding and following CSS symbols.
  • B(t) can be expressed as: subtracting the previous CSS symbol from the next CSS symbol in each signal unit of the first signal.
  • B(t) can be expressed as: subtracting the next CSS symbol from the previous CSS symbol in each signal unit of the first signal.
  • the second device first uses the reference despread signal to despread the third signal, and then uses the FFT algorithm to find the frequency point of the highest peak in the frequency domain or the two highest peaks in the frequency domain, and makes a decision based on the preset threshold.
  • the second device through instruction or configuration information, first performs despreading processing on the obtained third signal using a reference despreading signal. Then, it uses FFT processing to find the frequency points of the highest peak or the two highest peaks in the frequency domain, and completes the demodulation of the information bits based on the decision thresholds corresponding to bits "0" and "1". Since the starting sweep frequencies of the third signal representing bits "0" and “1" are different, the transmitted bit can be determined as “0” or "1” based on the position of the first peak of the third signal and/or the difference between the second and first peaks. As shown in Figure 10, taking the parameters in this embodiment as an example, since the starting sweep frequency for transmitting bit "0" is... The starting scan frequency for transmitting bit "1" is Therefore, the receiving end can determine whether the transmitted bit is "0" or "1” by the frequency position of the highest peak of the FFT.
  • the demodulation rules are as follows:
  • This demodulation scheme is relatively simple to implement.
  • the second device uses the maximum likelihood detection algorithm for decision-making and demodulation.
  • the receiver can employ a maximum likelihood detection algorithm for demodulation. Specifically, the receiver first stores the third signal waveforms corresponding to different information bits. During demodulation, the third signal corresponding to different information bits is correlated with the obtained third signal, and the information bit with the largest correlation value is the corresponding demodulated information bit.
  • This demodulation scheme belongs to the optimal decision method in demodulation, therefore its BER or SER performance is better than that of hard decision methods.
  • the demodulation scheme corresponding to the modulation scheme in Embodiment 2 needs to consider the influence of the modulated information of the second signal itself. Since the second signal is a modulated CSS signal, when demodulating the information bits sent by the first device, it is necessary to first demodulate the information bits of the second signal itself sent by the second device, and remove the influence of the second signal on the first signal from the receiving end. Then, the original information bits are demodulated according to the modulation rules of the information bits.
  • One feasible scheme is that since the strength of the second signal received by the second device from the first device is greater than the strength of the first signal, the second device can first demodulate the information bits of the second signal.
  • the second device demodulates both the information bits of the first device and the information bits carried by the second signal simultaneously through a joint demodulation decision.
  • each CSS symbol of the first signal transmits only bit "0" or bit "1".
  • this scheme can also be extended to higher-order modulation, thereby further improving the modulation rate or spectral efficiency of the first signal transmitted by the first device.
  • the following description uses the second signal as a reference CSS signal or chirp signal as an example. The same scheme can be extended to the case where the second signal is a modulated CSS signal.
  • each pair of CSS symbols (i.e., one signal unit) can carry log 2 M bits.
  • the frequencies of adjacent pairs of CSS symbols in each signal unit of the second signal can be frequency-shifted by f 2m-1 (0 ⁇ f 2m-1 ⁇ BW, m ⁇ ⁇ 1, 2, ..., M ⁇ ) and a center frequency of f 0 with a bandwidth of [missing value].
  • the filtering process generates the first part of the first signal.
  • each adjacent two CSS symbols i.e., one signal unit
  • the frequency of each adjacent two CSS symbols (i.e., one signal unit) in each signal unit of the second signal is shifted by -f 2m (0 ⁇ f 2m ⁇ BW ,m ⁇ 1,2,...,M ⁇ ) and a center frequency of f0 with a bandwidth of [missing value].
  • the filtering process generates the second part of the first signal.
  • f 2m-1 + f 2m BW
  • f 2m ⁇ f 2n (n ⁇ m) the first and second parts of each CSS symbol of the first signal are added in the time domain, and different average power or reflection coefficients are assigned to adjacent CSS symbols to generate the first signal.
  • Table 1 provides a design example of (f 2m-1 , f 2m ).
  • the first device implements 8th-order modulation on the first signal, and each signal unit or every two CSS symbols can carry 3 bits.
  • the frequency shift of two adjacent CSS symbols (i.e., one signal unit) of the second signal can be f 2m-1 (0 ⁇ f 2m-1 ⁇ BW, m ⁇ 1,2, ... ,8 ⁇ ) and a center frequency of f0 with a bandwidth range of [missing information].
  • the filtering process generates the first part of the first signal.
  • the frequency of two adjacent CSS symbols (i.e., one signal unit) of the second signal is shifted by -f 2m (0 ⁇ f 2m ⁇ BW ,m ⁇ 1,2, ... ,8 ⁇ ) and a center frequency of f0 with a bandwidth of [missing value].
  • the filtering process generates the second part of the first signal.
  • f 2m-1 + f 2m BW, f 2m-1 ⁇ f 2n-1 (n ⁇ m), f 2m ⁇ f 2n (n ⁇ m).
  • the first and second parts of the first signal are added in the time domain, and different average powers or reflection coefficients are assigned to two adjacent CSS symbols to generate the first signal.
  • the specific modulation method in this fourth embodiment can be extended based on this first and second embodiment. Since the corresponding modulation methods are similar, they will not be described again here. Similarly, the corresponding demodulation process can also be extended based on the demodulation method described in this third embodiment for demodulation of higher-order modulation. The specific demodulation process will also not be described again.
  • the signal transmission method provided in this application can be executed by a signal transmission device.
  • This application uses an example of a signal transmission device executing the signal transmission method to illustrate the signal transmission device provided in this application.
  • the signal transmission device 110 includes: a modulation module 111, used by the first device to perform backscattering modulation based on the information bits to be transmitted and a second signal to obtain a first signal; wherein the second signal is the carrier signal of the first signal; the first signal includes at least one first signal unit, each first signal unit includes two CSS symbols, the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the two CSS symbols are the same except for the average power and reflection coefficient, and the information bits to be transmitted are modulated by the frequency of each CSS symbol in each first signal unit; and a transmission module 112, used to transmit the first signal.
  • a modulation module 111 used by the first device to perform backscattering modulation based on the information bits to be transmitted and a second signal to obtain a first signal
  • the second signal is the carrier signal of the first signal
  • the first signal includes at least one first signal unit, each first signal unit includes two CSS symbols, the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the
  • the second signal includes at least one second signal unit, each second signal unit including two CSS symbols or two reference chirp symbols with the same parameters;
  • the first signal is obtained by adding a first part and a second part, the first part being a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part being a signal obtained by frequency shifting and filtering the second signal at a second frequency;
  • the frequency shift directions of the first part and the second part are opposite, and the sum of the first frequency and the second frequency is equal to the bandwidth of the CSS symbols or reference chirp symbols in the second signal, the first frequency and the second frequency being a frequency pair for frequency shifting associated with the information bits to be transmitted.
  • the filtering is performed with a center frequency of f0 and a bandwidth of [value missing].
  • the filtering is performed where f0 is the center frequency of the CSS signal or the reference Chirp signal in the second signal, and BW is the bandwidth of the CSS symbol or the reference Chirp symbol in the second signal.
  • the second signal satisfies at least one of the following:
  • the average power of the two CSS symbols in each of the second signal units is the same, or the average power of the two reference Chirp symbols in each of the second signal units is the same;
  • the time interval between two adjacent second signal units in the second signal is greater than or equal to 0.
  • the modulation module 111 is specifically configured to: perform backscatter modulation on the information bit to be transmitted and the second signal according to the obtained first information to obtain the first signal; wherein, the first information includes at least one of the following: the frequency value contained in the frequency pair for frequency shifting associated with the information bit to be transmitted; the size of the physical resource block (PRB), resource block group (RBG), and/or bandwidth portion (BWP) of the frequency pair for frequency shifting associated with the information bit to be transmitted; the modulation scheme of the first signal; the modulation order of the first signal; the modulation rate or backscatter link frequency (BLF) of the first signal; the encoding scheme of the first signal; the coding rate of the first signal; the average power or reflection coefficient of the two CSS symbols in the first signal unit of the first signal; and first index information associated with the modulation coding of the first signal, wherein the first index information is used to indicate the associated modulation coding parameters.
  • PRB physical resource block
  • RBG resource block group
  • BWP bandwidth portion
  • the other parameters include at least the following: frequency sweeping method; minimum frequency sweeping frequency; maximum frequency sweeping frequency; frequency sweeping start frequency; frequency sweeping stop frequency; center frequency; bandwidth; spreading factor; code rate; symbol rate.
  • the transmitting module 112 is specifically configured to: transmit the first signal according to the obtained second information; wherein the second information includes at least one of the following: the transmission power of the first signal; the preamble or synchronization sequence of the first signal; the reference signal of the first signal; the time domain resource information of the first signal; the frequency domain resource information of the first signal; and the spatial domain resource information of the first signal.
  • the signal transmission device 110 further includes: a first receiving module, configured to receive the second signal according to the obtained third information; wherein the third information includes at least one of the following: frequency domain correlation parameters of the second signal; time domain correlation parameters of the second signal; signal waveform and frame structure of the second signal; baseband signal parameters of the second signal; and second index information associated with the signal parameters of the second signal, the second index information being used to indicate the associated carrier signal parameters.
  • a first receiving module configured to receive the second signal according to the obtained third information
  • the third information includes at least one of the following: frequency domain correlation parameters of the second signal; time domain correlation parameters of the second signal; signal waveform and frame structure of the second signal; baseband signal parameters of the second signal; and second index information associated with the signal parameters of the second signal, the second index information being used to indicate the associated carrier signal parameters.
  • the frequency domain correlation parameters of the second signal include at least one of the following: the center frequency of the second signal; the bandwidth of the second signal; the scan start frequency of the second signal; the scan cutoff frequency of the second signal; the minimum scan frequency of the second signal; the maximum scan frequency of the second signal; the slope of the scan frequency of the second signal; the spreading factor of the second signal; the chip rate of the second signal; the symbol rate or symbol period of the second signal; the frequency sweep mode of the second signal; and the frequency offset or frequency shift of the second signal.
  • the time-domain correlation parameters of the second signal include at least one of the following: the time unit of the second signal; the signal period of the second signal; the signal length of the second signal; the time-domain repetition number of the second signal; and the synchronization signal or synchronization sequence of the second signal.
  • the signal waveform and frame structure of the second signal include at least one of the following:
  • the second signal adopts a CSS signal waveform, and the number of CSS symbols or the number of second signal units included in the second signal;
  • the second signal adopts a reference Chirp signal waveform, and the number of reference Chirp symbols or the number of second signal units included in the second signal;
  • the second signal is a mixed waveform of the CSS signal and the reference Chirp signal, and the proportion or number of CSS symbols and reference Chirp symbols in the second signal.
  • the signal transmission device 110 provided in this application embodiment can implement the various processes implemented in the method embodiment shown in FIG3 and achieve the same technical effect. To avoid repetition, it will not be described again here.
  • FIG 12 is a schematic diagram of a signal transmission device provided in an embodiment of this application.
  • This device is applied to a second device, such as an access network device like a base station, a terminal device like a UE, a relay device, a repeater device, an IAB device, an AP device, etc.
  • a second device such as an access network device like a base station, a terminal device like a UE, a relay device, a repeater device, an IAB device, an AP device, etc.
  • the signal transmission device 120 includes: a second receiving module 121, used to receive a first signal sent by a first device; wherein, the first signal is obtained by backscattering modulation based on the information bits to be transmitted and a second signal, and the second signal is the carrier signal of the first signal; the first signal includes at least one first signal unit, each first signal unit includes two CSS symbols, the average power or reflection coefficient of the two CSS symbols is different, and the other parameters of the two CSS symbols are the same except for the average power and reflection coefficient, and the information bits to be transmitted are modulated by the frequency of each CSS symbol in each first signal unit; a calculation module 122, used to perform a subtraction operation on the two CSS symbols in the first signal unit of the first signal to obtain a third signal; and a demodulation module 123, used to demodulate the third signal to obtain the information bits to be transmitted.
  • a second receiving module 121 used to receive a first signal sent by a first device; wherein, the first signal is obtained by backscattering modulation
  • the second signal includes at least one second signal unit, each second signal unit including two CSS symbols or two Chirp symbols with the same parameters;
  • the first signal is obtained by adding a first part and a second part, the first part being a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part being a signal obtained by frequency shifting and filtering the second signal at a second frequency;
  • the frequency shift directions of the first part and the second part are opposite, and the sum of the first frequency and the second frequency is equal to the bandwidth of the CSS symbol or reference Chirp symbol in the second signal, the first frequency and the second frequency being a frequency pair for frequency shifting associated with the information bits to be transmitted.
  • the demodulation module 123 is specifically configured to perform at least one of the following:
  • the third signal is despread using a reference despread signal to obtain a fourth signal, and the information bits to be transmitted are obtained based on the frequency points of the highest frequency peak or the two highest frequency peaks in the fourth signal.
  • the third signal is demodulated using the maximum likelihood detection algorithm to obtain the information bits to be transmitted.
  • the demodulation module 123 is specifically configured to: demodulate the third signal according to the obtained fourth information to obtain the information bits to be transmitted; wherein the fourth information includes at least one of the following:
  • the modulation rate of the first signal is the modulation rate of the first signal
  • the signal parameters of the reference despread signal corresponding to the first signal wherein, when the frequency sweep mode of the first signal is up-chirp mode, the reference despread signal is conjugate with the CSS signal whose scan start frequency is the lowest frequency; or, when the frequency sweep mode of the first signal is down-chirp mode, the reference despread signal is conjugate with the CSS signal whose scan start frequency is the highest frequency; or, the reference despread signal is conjugate with the first signal;
  • a third index information associated with the demodulation of the first signal the third index information being used to indicate the associated demodulation parameters.
  • the signal parameters of the reference despread signal include at least one of the following: the frequency sweep mode of the reference despread signal; the lowest frequency sweep frequency of the reference despread signal; the highest frequency sweep frequency of the reference despread signal; the frequency sweep start frequency of the reference despread signal; the frequency sweep cutoff frequency of the reference despread signal; the center frequency of the reference despread signal; the bandwidth of the reference despread signal; the spreading factor of the reference despread signal; the code rate of the reference despread signal; and the symbol rate of the reference despread signal.
  • the second receiving module 121 is specifically configured to: receive the first signal according to the obtained fifth information; wherein the fifth information includes at least one of the following: the preamble or synchronization sequence of the first signal; the reference signal of the first signal; the time domain resource information of the first signal; the frequency domain resource information of the first signal; and the spatial domain resource information of the first signal.
  • the signal transmission device 120 provided in this application embodiment can implement the various processes implemented in the method embodiment shown in FIG3 and achieve the same technical effect. To avoid repetition, it will not be described again here.
  • this application embodiment also provides a communication device 130, including a processor 131 and a memory 132.
  • the memory 132 stores a program or instructions that can be executed on the processor 131.
  • the communication device 130 is a first device
  • the program or instructions are executed by the processor 131
  • the communication device 130 is a second device
  • the program or instructions are executed by the processor 131
  • they implement the various steps of the signal transmission method embodiment shown in Figure 4 above, and achieve the same technical effect. To avoid repetition, this will not be described again here.
  • This application also provides a readable storage medium storing a program or instructions.
  • the program or instructions When the program or instructions are executed by a processor, they implement the various processes of the above-described signal transmission method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.
  • the processor mentioned above 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.
  • ROM computer read-only memory
  • RAM random access memory
  • magnetic disk magnetic disk
  • optical disk optical disk
  • the readable storage medium may be a non-transient readable storage medium.
  • This application 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 signal transmission method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.
  • 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.
  • 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 signal transmission method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.
  • This application also provides a communication system, including a first device and a second device, wherein the first device can be used to perform the steps of the signal transmission method as shown in FIG3 above, and the second device can be used to perform the steps of the signal transmission method as shown in FIG4 above.

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Abstract

本申请公开了一种信号传输方法、装置、通信设备及可读存储介质，属于通信技术领域，本申请实施例的信号传输方法包括：第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个啁啾扩频CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；发送所述第一信号。

Description

信号传输方法、装置、通信设备及可读存储介质
相关申请的交叉引用
本申请主张在2024年06月26日在中国提交的申请号为202410835677.0的中国专利的优先权，其全部内容通过引用包含于此。
技术领域
本申请属于通信技术领域，具体涉及一种信号传输方法、装置、通信设备及可读存储介质。
背景技术
啁啾扩频(Chirp spread spectrum，CSS)调制主要是利用线性调频信号来携带信息比特。由于CSS调制有很好的传输覆盖和传输可靠性，相关技术中提出了将CSS调制应用于反向散射通信系统。基于CSS信号的反向散射CSS调制系统中，双基地架构的读写器设备不仅接收到来自于反向散射设备发送的反向散射CSS调制信号，同时也接收到来自于激励源设备发送的CSS信号。而由于读写器设备接收到的有用反向散射CSS调制信号与激励源设备发送的CSS信号的频率几乎接近，并且CSS信号的频率是在线性变化的，因此读写器设备在解调制时对CSS信号干扰消除的难度较大，从而造成无法有效消除CSS信号干扰。
发明内容
本申请实施例提供一种信号传输方法、装置、通信设备及可读存储介质，能够解决相关技术中无法有效消除CSS信号干扰的问题。
第一方面，提供了一种信号传输方法，由第一设备执行，该方法包括：第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个啁啾扩频CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；所述第一设备发送所述第一信号。
第二方面，提供了一种信号传输方法，由第二设备执行，该方法包括：第二设备接收第一设备发送的第一信号；其中，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；所述第二设备对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；所述第二设备对所述第三信号进行解调制，得到所述待传输的信息比特。
第三方面，提供了一种信号传输装置，应用于第一设备，包括：调制模块，用于第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；发送模块，用于发送所述第一信号。
第四方面，提供了一种信号传输装置，应用于第二设备，包括：第二接收模块，用于接收第一设备发送的第一信号；其中，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；计算模块，用于对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；解调制模块，用于对所述第三信号进行解调制，得到所述待传输的信息比特。
第五方面，提供了一种信号传输装置，所述装置被配置为执行如第一方面所述的方法的步骤，或者执行如第二方面所述的方法的步骤。
第六方面，提供了一种通信设备，该通信设备包括处理器和存储器，所述存储器存储可在所述处理器上运行的程序或指令，所述程序或指令被所述处理器执行时实现如第一方面所述的方法的步骤，或者实现如第二方面所述的方法的步骤。
第七方面，提供了一种通信设备，包括处理器及通信接口，该通信设备为第一设备时，所述处理器用于根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号，所述通信接口用于发送所述第一信号；或者，该通信设备为第二设备时，所述通信接口用于接收第一设备发送的第一信号，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述处理器用于对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号，并对所述第三信号进行解调制，得到所述待传输的信息比特；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个啁啾扩频CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的。
第八方面，提供了一种可读存储介质，所述可读存储介质上存储程序或指令，所述程序或指令被处理器执行时实现如第一方面所述的方法的步骤，或者实现如第二方面所述的方法的步骤。
第九方面，提供了一种无线通信系统，包括：第一设备及第二设备，所述第一设备可用于执行如第一方面所述的方法的步骤，所述第二设备可用于执行如第二方面所述的方法的步骤。
第十方面，提供了一种芯片，所述芯片包括处理器和通信接口，所述通信接口和所述处理器耦合，所述处理器用于运行程序或指令，实现如第一方面所述的方法的步骤，或者实现如第二方面所述的方法的步骤。
第十一方面，提供了一种计算机程序/程序产品，所述计算机程序/程序产品被存储在存储介质中，所述计算机程序/程序产品被至少一个处理器执行以实现如第一方面所述的方法的步骤，或者实现如第二方面所述的方法的步骤。
通过本申请实施例中方案，可以使得第一信号即反向散射CSS信号具有重复结构，即待传输的信息比特是通过第一信号中每个CSS符号的频率进行调制的，从而在接收端进行信号解调制时，只需借助相减操作即可消除CSS信号干扰，从而有效消除CSS信号干扰。
附图说明
图1A、图1B、图1C、图1D和图1E是本申请实施例中的基于反向散射的通信架构示意图；
图2A是本申请实施例中CSS调制的频率上行模式的示意图；
图2B是本申请实施例中CSS调制的频率下行模式的示意图；
图2C是本申请具体实施例中CSS调制方式的示意图；
图3是本申请实施例提供的一种信号传输方法的流程图；
图4是本申请实施例提供的另一种信号传输方法的流程图；
图5A和图5B是本申请实施例一中集中式的帧结构示意图；
图6A和图6B是本申请实施例一中分布式的帧结构示意图；
图7是本申请实施例一中LoRa帧结构的示意图；
图8A、图8B和图8C是本申请实施例二中调制方案相关信号的示意图；
图9A、图9B和图9C是本申请实施例二中调制方案相关信号的示意图；
图10是本申请实施例三中解调制方案的示意图；
图11是本申请实施例提供的一种信号传输装置的结构示意图；
图12是本申请实施例提供的另一种信号传输装置的结构示意图；
图13是本申请实施例提供的一种通信设备的结构示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员所获得的所有其他实施例，都属于本申请保护的范围。
本申请的术语“第一”、“第二”等是用于区别类似的对象，而不用于描述特定的顺序或先后次序。应该理解这样使用的术语在适当情况下可以互换，以便本申请的实施例能够以除了在这里图示或描述的那些以外的顺序实施，且“第一”、“第二”所区别的对象通常为一类，并不限定对象的个数，例如第一对象可以是一个，也可以是多个。此外，本申请中的“或”表示所连接对象的至少其中之一。例如“A或B”的保护范围至少涵盖三种方案，即，方案一：包括A且不包括B；方案二：包括B且不包括A；方案三：既包括A又包括B。此外，术语“A和/或B”、“A和B中的至少一项”、“A或B中的至少一项”也分别至少涵盖上述三种方案。字符“/”一般表示前后关联对象是一种“或”的关系。
本申请的术语“指示”既可以是一个直接的指示(或者说显式的指示)，也可以是一个间接的指示(或者说隐含的指示)。其中，直接的指示可以理解为，发送方在发送的指示中明确告知了接收方具体的信息、需要执行的操作或请求结果等内容；间接的指示可以理解为，接收方根据发送方发送的指示确定对应的信息，或者进行判断并根据判断结果确定需要执行的操作或请求结果等。
值得指出的是，本申请实施例所描述的技术不限于长期演进型(Long Term Evolution，LTE)/LTE的演进(LTE-Advanced，LTE-A)系统，还可用于其他无线通信系统，诸如码分多址(Code Division Multiple Access，CDMA)、时分多址(Time Division Multiple Access，TDMA)、频分多址(Frequency Division Multiple Access，FDMA)、正交频分多址(Orthogonal Frequency Division Multiple Access，OFDMA)、单载波频分多址(Single-carrier Frequency-Division Multiple Access，SC-FDMA)或其他系统。本申请实施例中的术语“系统”和“网络”常被可互换地使用，所描述的技术既可用于以上提及的系统和无线电技术，也可用于其他系统和无线电技术。以下描述出于示例目的描述了新空口(New Radio，NR)系统，并且在以下大部分描述中使用NR术语，但是这些技术也可应用于NR系统以外的系统，如第6代(6th Generation，6G)通信系统。
为了便于理解本申请实施例，首先说明以下内容。
反向散射通信(Backscatter Communication，BSC)是指反向散射通信设备利用其它设备或者环境中的射频信号进行信号调制来传输自己信息，是一种比较典型的无源物联设备。反向散射通信发送端的基本构成模块及主要功能包括：
天线单元：用于接收射频信号、控制命令，同时用于发送调制的反向散射信号。
能量采集模块或供能模块：该模块用于反向散射通信设备进行射频能量采集，或者其它能量采集，包括但不限于太阳能、动能、机械能、热能等。另外除了包括能量采集模块，也可能包括电池供能模块，此时反向散射通信设备为半无源设备。能量采集模块或供能模块给设备中的其它所有模块进行供电。
微控制器：包括控制基带信号处理、储能或数据调度状态、开关切换、系统同步等。
信号接收模块：用于解调反向散射通信接收端或是其它网络节点发送的控制命令或数据等。
编码和调制模块：在控制器的控制下进行信道编码和信号调制，并通过选择开关在控制器的控制下通过选择不同的负载阻抗来实现调制。
存储器或传感模块：用于存储设备的标识ID信息、位置信息或是传感数据等。
除了上述典型的构成模块之外，未来的反向散射通信发送端还可以集成隧道二极管放大器模块、低噪声放大器模块等，用于提升发送端的接收灵敏度和发送功率。
可选地，反向散射通信接收端的基本构成模块及主要功能包括：
天线单元：用于接收调制的反向散射信号。
反向散射信号检波模块：用于对反向散射通信发送端发送的反向散射信号进行检波，包括但不限于ASK检波、PSK检波、FSK检波或QAM检波等。
解调和解码模块：对检波出的信号进行解调制和解码，以恢复出原始信息流。
反向散射通信设备通过调节其内部阻抗来控制调制电路的反射系数Γ，从而改变入射信号的幅度、频率、相位等，实现信号的调制。反射系数Γ可以表征为：
其中，Z0为天线特性阻抗；Z1是负载阻抗；j表示复数，θT表示相位。假设入射信号表示为Sin(t)，则输出信号为因此，通过合理的控制反射系数可实现对应的幅度调制、频率调制或相位调制。基于此，反向散射通信设备，可以是传统射频识别标识(Radio Frequency Identification，RFID)中的标签Tag，也可以是无源或半无源物联网(Passive/Semi-passive Internet of Things，IoT)设备。这里，反向散射通信设备可统称为BSC设备。
一种实现方式中，按照标签能力与能力来源，标签可以分为：Device A：标签是无源tag，无储能电容/电池，依靠射频(Radio Frequency，RF)信号进行供能，接收的RF信号即为整流器的电源信号，不具有载波生成能力，依靠RF作为射频载波进行反向散射通信传输，功耗最低；Device B：标签是半无源tag，具有储能电容/电池，依靠非RF信号进行供能，可选地，具有PA/LNA或其它有源器件，不具有载波生成能力，依靠RF作为射频载波进行反向散射通信传输，功耗次之；Device C：标签是有源tag，具有储能电容/电池，依靠非RF信号进行供能，具有载波生成能力，功耗最大。
可选地，基于反向散射的通信架构至少可以包括以下几种模式：
(1)拓扑结构Topology 1：如图1A所示，Topology 1中的基站既是射频源或者发送设备也是接收设备，因此Topology1是单基地反向散射通信系统(Monostatic Backscatter Communication System，MBCS)架构。传统的RFID系统就是典型的MBCS，其中包含环境供能的物联网设备Ambient IoT Device(比如Tag)和读写器Reader(比如基站)，且Tag与Reader直接通信，Reader可能具有频分双工(Frequency Division Duplexing，FDD)架构的功能模块。在Topology 1中，控制信令的发送设备和反向散射信号的接收设备是同一个设备，而RF载波源的发送设备可以与前述设备是同一设备，也可以是独立的设备。
(2)拓扑结构Topology 2：如图1B所示，在Topology 2中，Ambient IoT Device(比如Tag)接收中间节点发送的控制信令和载波信号，所述控制信令可以是网络设备(比如基站gNB)通过中间节点进行指示的，所述中间节点可以为用户设备(User Equipment，UE)、中继器(repeater)、IAB节点等。中间节点还可以作为中继将IoT数据转发给gNB。
(3)拓扑结构Topology 3：Topology 3涉及双基地反向散射通信系统(BBCS)，其中的射频源、BSC发送设备和BSC接收设备是分开的；在Topology 3中，Ambient IoT Device(比如Tag)向基站发送IoT数据/上行信令，并接收辅助节点发送的数据/信令，如图1C所示；或者，Ambient IoT Device(比如Tag)向辅助节点发送IoT数据/上行信令，并接收基站发送的数据/信令，如图1D所示；基站与辅助节点通过Uu口通信，辅助节点可以为UE、repeater、IAB等。
(4)拓扑结构Topology 4：如图1E所示，在Topology 4中，UE作为Reader与Tag进行通信。此架构也属于单基地反向散射通信架构，区别在于Reader是UE，而非基站。
Chirp调制，或称为啁啾扩频(Chirp spread spectrum，CSS)调制，主要是利用线性调频信号来携带信息比特。具体来说，CSS调制信号分为频率上行(up-chirp)模式(如图2A所示)和频率下行(down-chirp)模式(如图2B所示)。当使用频率上行调制时，CSS调制信号的频率会随时间的增加而升高；当使用频率下行模式时，CSS调制信号的频率会随时间的增加而降低。但CSS调制信号的频率总是在低频f1和高频f2之间沿着某种规律周期性变化，扫频带宽为BW＝f2-f1，扫频时间为Ts，扫频斜率为如果将Chirp信号用基带信号表述，则up-chirp信号和down-chirp信号可分别表示为：
上述的两种chirp信号，不管是up-chirp模式还是down-chirp模式，都是无法直接传递信息比特的。因此CSS调制实际上是通过改变导频的初始频率，来实现不同的信息传递。由于改变了扫描的初始频率，因此在整个信号扫描周期内，频率线性增长会超过规定的扫描终止频率f2或f1，则此时CSS调制规定，一旦扫描频率超过扫描频率上限频率f2或扫描下限频率f1，那么直接将后续的扫描频率减去BW或将后续的扫描频率加上BW。
结合CSS调制时的参数，定义几个重要的参数，如扩频因子(Spreading Factor，SF)、码片(chirp)、符号率/码片率，说明如下。
(1)扩频因子SF：
扩频因子表示每个符号包含的信息比特数，也就是将1个符号扩频到2SF个码片上进行传输，同时也将不同的符号映射到不同的CSS调制初始频率上。以SF＝2为例，则一个符号最多可以包含2个比特，并且能表示22＝4个值，比如0～3，而且码片的数量为4。以频率上行(up-chirp)模式为例，在一个频率上升的周期内，可变化的频率范围可以分为2SF个码片。
(2)码片率(chirp rate)、或称为符号率(symbol rate)：
码片率即为每个码片的传输速率，可表示为：
Rc＝BW
每个码片的传输时间为：
由于每个CSS符号有2SF个码片，因此符号的传输时间为：
基于上述定义，CSS调制中频率线性增长的斜率为：
参见图2C所示，以SF＝2为例给出CSS调制的4个符号。其中，符号1的起始频率为f1，并以频率线性增长到f2，表征比特00；符号2的起始频率为并以频率先线性增长到f2，之后又以f1为起始频率线性增长到表征比特01；符号3的起始频率为并以频率先线性增长到f2，之后又以f1为起始频率线性增长到表征比特10；符号4的起始频率为并以频率先线性增长到f2，之后又以f1为起始频率线性增长到表征比特11。因此，如果能够解调出相应符号的起始频率，再经过起始频率与符号的映射，就可以获得进行CSS调制前的输入比特。
对应的解调制过程中，可以用与CSS调制模式相反的基准Chirp信号进行混频，并通过快速傅里叶变换FFT计算来最终解调输入比特。比如，如果CSS调制用的是频率为f1到f2线性循环增长的up-chirp信号，则接收端用频率为f2到f1线性循环减少的down-chirp信号进行混频。
假设CSS调制采用up-chirp模式进行调制，其基带信号可表示为：
其中，f0是初始频率，表示线性增长的斜率。对于基准up-chirp信号而言，为了简便，可以将基准up-chirp信号记为：
CSS调制信号可以是基准up-chirp信号的频率循环移位，表述为：
s(t；fn)＝c(t；fn)w(t；0,tn)+c(t；fn-BW)w(t；tn,T)
其中，为CSS调制符号的起始频率，w(t；ta,tb)为矩形窗函数，表示为：
因此，对一个携带SF个比特的CSS调制符号，其有2SF可选的起始频率点。
接收端中，接收端通过利用基准down-chirp信号c*(t)先进行混频或解chirp处理，如采用如下公式进行处理：
在混频得到s′(t；fn)后，接收端再进行FFT计算，并且在频域识别频点峰值位置并且最终进行输入比特判决。
可选地，本申请中方案可应用于LTE系统、5G NR系统以及NR演进系统，比如6G系统和6G演进系统，以及IEEE 802.11系统(如WiFi系统)、蓝牙系统、LoRa系统、Zigbee系统、LP-WUS/WUR系统、反向散射通信系统、低功耗物联网系统、Ambient IoT通信系统等。
下面结合附图，通过一些实施例及其应用场景对本申请实施例提供的信号传输方法、装置、通信设备及可读存储介质进行详细地说明。
请参见图3，图3是本申请实施例提供的一种信号传输方法的流程图，该方法由第一设备执行，所述第一设备比如为反向散射设备等；如图3所示，该方法包括如下步骤：
步骤31：第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；
步骤32：第一设备发送第一信号。
本申请实施例中，所述第二信号是所述第一信号的载波信号，所述第一信号是所述第二信号的反向散射调制信号。所述第一信号包括至少一个第一信号单元，每个第一信号单元包括两个CSS符号，比如包括相邻的两个CSS符号；所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个第一信号单元中的每个CSS符号的频率进行调制的。
可选地，所述其他参数至少包括以下内容：扫频方式；最低扫频频率；最高扫频频率；扫频起始频率；扫频截止频率；中心频点；带宽；扩频因子；码率；符号率；等等。
可选地，所述第二信号的波形形式可以基于实际需求设置，只需基于第二信号能够得到本申请方案中具有重复结构的第一信号即可。
可选地，本申请实施例中方案可以适用于不同Ambient IoT拓扑结构，比如图1B、图1C等所示的拓扑结构。
通过本申请实施例中方案，可以使得第一信号即反向散射CSS信号具有重复结构，即待传输的信息比特是通过第一信号中每个CSS符号的频率进行调制的，从而在接收端进行信号解调制时，只需借助相减操作即可消除CSS信号干扰，从而有效消除CSS信号干扰。
可选地，所述第二信号包括至少一个第二信号单元，每个第二信号单元包括参数相同的两个CSS符号或两个基准Chirp符号；所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号(或信号)或基准Chirp符号(或信号)的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。上述频移方向相反可以是一个正方向频移，另一个负方向频移，比如：若第一频率为f2m-1，第二频率为f2m，则可以对第二信号进行f2m-1的频移(即正方向)，和对第二信号进行-f2m的频移(即负方向)；或者，可以对第二信号进行-f2m-1的频移(即负方向)，和对第二信号进行f2m的频移(即正方向)。
由此，一方面利用反向散射CSS信号(即第一信号)的重复结构，可以消除CSS载波信号的干扰；另一方面通过对每个CSS符号进行与待传输的信息比特关联的频率对的频移和滤波，可以使得生成的信号满足CSS信号线性调频特性，从而利用CSS信号的传输特性实现更远的传输覆盖或传输可靠性。
可选地，所述滤波可以为中心频点为f0且带宽区间为的滤波，所述f0为所述第二信号中的CSS信号或基准Chirp信号的中心频率，即所述f0为所述第二信号的中心频率；所述BW为所述第二信号中的CSS符号或基准Chirp符号的带宽，即所述BW为所述第二信号的带宽。
可选地，所述第二信号可以满足以下至少一项：
每个第二信号单元中的两个CSS符号的平均功率相同，或者，每个第二信号单元中的两个基准Chirp符号的平均功率相同；
所述第二信号中的相邻两个第二信号单元之间的时间间隔大于或等于0。
一种可选实施方式中，所述第二信号S(t)是第一信号C(t)的射频载波信号，至少可满足如下特性：
(a)S(t)中的一个信号单元包括参数相同的两个CSS符号或者基准Chirp符号：
(b)S(t)中的一个信号单元的长度等于2Ts个时间单元；该时间单元可以是符号、时隙、子帧、帧等协议规定的单位，也可以是微妙、毫秒、分钟等时间单位；
(c)CSS符号S1(t)的参数至少可包括以下内容：
(I)中心频率f0；
(II)带宽BW；
(III)扩频因子SF；
(IV)符号长度
(IIV)频率线性增长斜率或
(IIIV)每个符号的起始扫频频率fstart；
(V)每个符号的平均功率；此处设置相同的平均功率，可以用来保证第一信号中前后两个CSS符号相减之后，射频干扰会被消除；
(d)CSS符号S1(t)可以表示为：
(e)第二信号S(t)中各个信号单元之间的基本时间单元间隔为Tg≥0。
另一种可选实施方式中，所述第一信号C(t)是基于第二信号S(t)生成的反向散射信号，至少可满足如下特性：
(a)所述第一信号C(t)的一个信号单元中包括平均功率或者反射系数不同的两个CSS符号C1,n(t)，第n个信号单元满足：
(b)CSS符号C1,n(t)至少可满足如下特征：
(I)由第一部分和第二部分的和组成：
(II)所述第一部分是通过对第二信号中的S1(t)频移f2m-1(0≤f2m-1≤BW,m∈{1,2,…,M})并进行中心频点为f0且带宽区间为的滤波后生成的信号：
(III)所述第二部分是通过对第二信号中的S1(t)频移-f2m(0≤f2m≤BW,m∈{1,2,…,M})并进行中心频点为f0且带宽区间为的滤波后生成的信号：
如上所述：1)表示对信号进行中心频点为f0且带宽区间为的滤波；2)m是第m∈{1,…,M}个输入的log2 M位信息比特；m与log2 M位信息比特的映射关系可以是网络或协议预先配置的，映射方式可以是Gray映射、自然映射、Contourwise-Gray映射等方式之一；3)f2m-1+f2m＝BW,m∈{1,2…,M}；且在k≠m时，f2m-1≠f2k-1，f2m≠f2k。
(c)CSS符号C1,n(t-Ts)的特性在于：C1,n(t-Ts)为C1,n(t)的延迟Ts后的信号，或者C1,n(t-Ts)为信号C1,n(t)在下一个符号周期Ts的重复；
(d)β1和β2分别为信号单元中两个CSS符号的反射系数或者平均功率；并且β1≠β2，以保证后续构建出的第三信号是有效的；
(e)第一信号的一个信号单元传输可以携带log2 M(log2 M≤SF)个信息比特；
(f)一个信号单元的长度为2Ts个时间单元；
(g)所述第一信号与第二信号的下列参数相同：
(I)带宽BW；
(II)扩频因子SF；
(III)频率线性增长斜率
(IV)符号周期
本申请实施例中，第一设备可以根据配置或指示的信息进行信号调制。上述根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号可以包括：
第一设备根据获得的第一信息，对所述待传输的信息比特和第二信号进行反向散射调制，得到所述第一信号；所述第一信息是与信号调制相关的信息，所述第一信息可以包括但不限于以下至少一项：
(a)与待传输的信息比特关联的用于频移的频率对包含的频率值；这样根据待传输的信息比特，可直接确定出所关联的用于频移的频率对包含的频率值；
(b)与待传输的信息比特关联的用于频移的频率对的物理资源块(Physical Resource Block，PRB)、资源块组(Resource block group，RBG)和/或带宽部分(Bandwidth Part，BWP)的大小；这样可以基于配置或指示的PRB\RGB\BWP的大小，间接确定出用于频移的频率对包含的频率值；
(c)所述第一信号的调制方式，比如包括但不限于FSK-CSS调制、二进制启闭键控(OOK)调制、幅移键控(ASK)调制、相移键控(PSK)调制、频移键控(FSK)调制、正交幅度调制(Quadrature Amplitude Modulation，QAM)、幅度相移键控(Amplitude Phase Shift Keying，APSK)调制等；
(d)所述第一信号的调制阶数，比如该调制阶数为M；
(e)所述第一信号的调制速率或者反向散射链路频率(Backscatter Link Frequency，BLF)；
(f)所述第一信号的编码方式，比如包括但不限于信道编码方式、线编码方式等；该信道编码方式比如为里德-所罗门码(Reed-Solomon codes，RS码)、极化码(Polar码)、卷积码、重复码等；该线编码方式比如为双相间空号编码(FM0编码)、密勒码(Miller码)、曼彻斯特码(Manchester码)等；基于此编码方式，可使得第一设备生成相应的第一信号；
(g)所述第一信号的编码码率；
(h)所述第一信号的反射系数或反射信号放大系数，比如所述第一信号的第一信号单元中的两个CSS符号的平均功率或者反射系数；
(i)与所述第一信号的调制编码关联的第一索引信息，所述第一索引信息用于指示关联的调制编码参数；其中，不同的第一索引信息对应不同的调制编码参数，每个第一索引信息可对应一套调制编码参数(如上述(a)至(h)所述)，相关对应关系可以是网络或协议预配置的。借助所述第一索引信息，可使得第一设备获得关联的调制编码参数，从而生成相应的反向散射调制信号(即第一信号)。
本申请实施例中，第一设备可以根据配置或指示的信息来发送第一信号。上述发送第一信号可以包括：
第一设备根据获得的第二信息，发送第一信号；所述第二信息是与第一信号的传输相关的信息，所述第二信息可以包括但不限于以下至少一项：所述第一信号的发送功率；所述第一信号的前导码或者同步序列；所述第一信号的参考信号，此参考信号可用于估计第一信号中的信道或者时频信息；所述第一信号的时域资源信息，比如包括信号的重复传输次数、信号周期、时隙配置信息、子帧信息等；所述第一信号的频域资源信息，比如包括频率、带宽等信息；所述第一信号的空域资源信息，比如包括天线、码字、层、天线端口等信息。
本申请实施例中，可以为第一设备配置或指示用于接收载波信号的相关信息。上述信号传输方法还可以包括：第一设备根据获得的第三信息，接收第二信号；所述第三信息可以包括但不限于以下至少一项：
所述第二信号的频域相关参数；
所述第二信号的时域相关参数；
所述第二信号的信号波形及帧结构；
所述第二信号的基带信号参数；
与所述第二信号的信号参数关联的第二索引信息，所述第二索引信息用于指示关联的载波信号参数；其中，不同的第二索引信息对应不同的第二信号的信号参数，每个第二索引信息可对应一套载波信号参数，比如包括频域相关参数、时域相关参数和/或信号波形等，相关对应关系可以是网络或协议预配置的。借助所述第二索引信息，可使得第一设备获得关联的第二信号的信号参数，从而准确接收第二信号。
需指出的，所述第二信号可以是第二设备发送的，即此时：第二设备既是接收第一信号的接收设备，也是为第一设备提供载波信号的设备；也可以是第三设备发送的，该第三设备为提供载波信号的设备；也可以是第四设备发送的，该第四设备为不同于第一设备、第二设备和第三设备且具备网络调度功能的设备，比如为网关、路由器、接入网设备、中继设备、IAB设备、Repeater设备、终端设备、AP设备等。
可选地，所述第二信号的频域相关参数包括但不限于以下至少一项：(I)所述第二信号的中心频点；(Ⅱ)所述第二信号的带宽；(Ⅲ)所述第二信号的扫描起始频率；(Ⅳ)所述第二信号的扫描截止频率；(Ⅴ)所述第二信号的扫描最低频率；(Ⅵ)所述第二信号的扫描最高频率；(Ⅶ)所述第二信号的扫描频率的斜率；(Ⅷ)所述第二信号的扩频因子；(Ⅸ)所述第二信号的码片率；(Ⅹ)所述第二信号的符号率或符号周期；(Ⅺ)所述第二信号的扫频方式，比如为up-chirp模式或down-chirp模式；(Ⅻ)所述第二信号的频率偏移或搬频大小。
可选地，所述第二信号的时域相关参数包括但不限于以下至少一项：(I)所述第二信号的时间单元，比如为RE、时隙、子帧等；(Ⅱ)所述第二信号的信号周期；(Ⅲ)所述第二信号的信号长度；(Ⅳ)所述第二信号的时域重复次数；(Ⅴ)所述第二信号的同步信号或同步序列。
可选地，所述第二信号的信号波形及帧结构可包括以下至少一项：1)所述第二信号采用CSS信号波形，以及所述第二信号中包括的CSS符号的个数或者第二信号单元的个数；2)所述第二信号采用基准Chirp信号波形，以及所述第二信号中包括的基准Chirp符号的个数或第二信号单元的个数；3)所述第二信号采用CSS信号和基准Chirp信号的混合波形，以及所述第二信号中的CSS符号和基准Chirp符号的占比或者个数。
一种可选实施方式中，所述第二信号为基准Chirp信号和CSS调制信号的混合信号，比如为具有帧结构的CSS调制信号，且该帧结构的信号中至少包括CSS调制信号或者基准chirp信号；该混合信号比如为LoRa信号。
可选地，所述第二信号的基带信号参数可以包括以下至少一项：(I)第二信号的调制参数，比如包括但不限于调制方式、调制阶数、调制速率等；(II)第二信号的编码参数，比如包括但不限于信道编码方式(比如：RS码、Polar码、卷积码、重复码等)，或者线编码方式(比如：FM0码、Miller码、Manchester码等)。
本申请实施例中，第一设备可以采用多种方式来获得第一信息。所述信号传输方法还可以包括以下至少一项：(a)第一设备确定所述第一信息，即第一设备自身具有确定配置信息的能力；(b)第一设备从第二设备接收所述第一信息，所述第二设备为所述第一信号的接收设备；即此时：第二设备既为接收第一信号的接收设备，也为配置或指示第一信息的设备；所述第二设备可以为基站等接入网设备、UE等终端设备、中继设备、Repeater设备、IAB设备、AP设备等；(c)第一设备从第三设备接收所述第一信息，所述第三设备为提供载波信号的设备；即此时：第三设备既为第一设备提供载波信号的设备，也为配置或指示第一信息的设备；所述第三设备可以为基站等接入网设备、UE等终端设备、中继设备、Repeater设备、IAB设备、AP设备、专用射频源设备等；(d)第一设备从第四设备接收所述第一信息，所述第四设备为具备网络调度功能的设备；所述第四设备为不同于第一设备、第二设备和第三设备，且具备网络调度功能的设备，比如为网关、路由器、接入网设备、中继设备、IAB设备、Repeater设备、终端设备、AP设备等。
需指出的，除了上述确定或配置/指示第一信息的方式之外，所述第一信息也可以由第一设备至第四设备中的至少两者来配置/指示。
可选地，当所述第一信息是由所述第一设备接收时，所述第一信息可以通过以下至少一项配置或指示：
无线资源控制(Radio Resource Control，RRC)信令；这种方式需要第一设备具备RRC协议层；
非接入层(Non-Access Stratum，NAS)信令；这种方式需要第一设备具备NSA协议层；
媒体接入控制控制单元(Medium Access Control Control Element，MAC CE)；即利用MAC CE信令来配置第一设备的信号参数，这种情况也适用于不支持RRC信令或者NAS信令的能力较弱的第一设备；
下行控制信息(Downlink Control Information，DCI)；此DCI为物理层信令，即通过物理层信令动态指示第一信息；
副链路控制信息(Sidelink Control Information，SCI)；此SCI为物理层信令，即通过物理层信令动态指示第一信息；
层1或物理层信令，比如携带控制信息的物理帧头和前导码，此层1或物理层信令可以与有效数据载荷统一放在相同物理帧中，层1或物理层信令也可以单独放在物理帧中；
出厂配置信息或默认配置信息；比如，第一设备第一次接入网络或者不支持RRC配置信息等时，系统配置与第一信号相关的信号参数。
需指出的，所述第二信息和所述第三信息可以采用与第一信息相同的配置/指示方式，为避免重复，在此不再赘述。
请参见图4，图4是本申请实施例提供的一种信号传输方法的流程图，该方法由第二设备执行，所述第二设备比如为基站等接入网设备、UE等终端设备、中继设备、Repeater设备、IAB设备、AP设备等。
如图4所示，该方法包括如下步骤：
步骤41：第二设备接收第一设备发送的第一信号；所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到；
步骤42：第二设备对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；
步骤43：第二设备对第三信号进行解调制，得到所述待传输的信息比特。
本申请实施例中，所述第二信号是所述第一信号的载波信号。所述第一信号包括至少一个第一信号单元，每个第一信号单元包括两个CSS符号，比如包括相邻的两个CSS符号；所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的。
可选地，所述其他参数至少包括以下内容：扫频方式；最低扫频频率；最高扫频频率；扫频起始频率；扫频截止频率；中心频点；带宽；扩频因子；码率；符号率；等等。
可选地，所述第二信号的波形形式可以基于实际需求设置，只需基于第二信号能够得到本申请方案中具有重复结构的第一信号即可。
可选地，第二设备可以在指定的时频资源上获得第一信号，并对获得的第一信号进行必要的射频、中频或者基带处理等。第三信号的每个符号都可解调制出传输的信息比特。
通过本申请实施例中方案，可以使得第一信号即反向散射CSS信号具有重复结构，即待传输的信息比特是通过第一信号中每个CSS符号的频率进行调制的，从而在第二设备(即接收端)进行信号解调制时，只需借助相减操作即可消除CSS信号干扰，从而有效消除CSS信号干扰。
可选地，所述第二信号包括至少一个第二信号单元，每个第二信号单元包括参数相同的两个CSS符号或两个基准Chirp符号；所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号(或信号)或基准Chirp符号(或信号)的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。上述频移方向相反可以是一个正方向频移，另一个负方向频移，比如：若第一频率为f2m-1，第二频率为f2m，则可以对第二信号进行f2m-1的频移(即正方向)，和对第二信号进行-f2m的频移(即负方向)；或者，可以对第二信号进行-f2m-1的频移(即负方向)，和对第二信号进行f2m的频移(即正方向)。
由此，一方面利用反向散射CSS信号(即第一信号)的重复结构，可以消除CSS载波信号的干扰；另一方面通过对每个CSS符号进行与待传输的信息比特关联的频率对的频移和滤波，可以使得生成的信号满足CSS信号线性扩频特性，从而利用CSS信号的传输特性实现更远的传输覆盖或传输可靠性。
一种可选实施方式中，所述第三信号B(t)是基于第二设备获得的第一信号构建出的信号，至少可满足如下特性：
(a)B(t)为第一信号的每个信号单元中的前后两个CSS符号的差：
(I)当β2>β1时，B(t)满足：
B(nTs+t)＝C(2nTs+t+Ts)-C(2nTs+t)＝β2C1,n(t)-β1C1,n(t),nTs≤t≤(n+1)Ts-1
(II)当β1>β2时，B(t)满足：
B(nTs+t)＝C(2nTs+t)-C(2nTs+t-Ts)＝β1C1,n(t)-β2C1,n(t),nTs≤t≤(n+1)Ts-1
(b)所述第三信号的一个CSS符号的时间长度为Ts个时间单元；该时间单元可以是符号、时隙、子帧、帧等协议规定的单位，也可以是微妙、毫秒、分钟等时间单位；
(c)所述第三信号中符号的参数可包括以下内容：
(II)带宽BW；
(III)扩频因子SF；
(IIV)频率线性增长斜率或
(IIIV)每个符号的起始扫频频率fstart。
(e)所述第三信号B(t)中各个信号单元之间的基本时间单元间隔为Tg/2≥0。
可选地，上述对第三信号进行解调制可以包括以下至少一项：
(1)第二设备利用基准解扩频信号对所述第三信号进行解扩频处理，得到第四信号，并根据所述第四信号中的频域最高峰或者频域最高的两个峰的频点，获得待传输的信息比特；比如，可以根据所述第四信号中的频域最高峰或者频域最高的两个峰的频点，进行阈值判决，从而得到待传输的信息比特；
(2)第二设备利用最大似然检测算法对第三信号进行解调制，得到待传输的信息比特；具体解调制过程，可以参见下述实施例三中的说明。
本申请实施例中，第二设备可以根据配置或指示的信息进行解调制。上述对第三信号进行解调制，得到所述待传输的信息比特可以包括：
第二设备根据获得的第四信息，对第三信号进行解调制，得到所述待传输的信息比特；所述第四信息是与解调制参数相关的信息，所述第四信息可以包括但不限于以下至少一项：
(a)与待传输的信息比特关联的用于频移的频率对包含的频率值；这样可基于此频率值解调制得到待传输的信息比特；
(b)与待传输的信息比特关联的用于频移的频率对的PRB、RBG和/或BWP的大小；
(c)所述第一信号的调制方式，比如包括但不限于FSK-CSS调制、二进制启闭键控(OOK)调制、幅移键控(ASK)调制、相移键控(PSK)调制、频移键控(FSK)调制、正交幅度调制QAM、APSK调制、CSS调制等；
(d)所述第一信号的调制阶数，比如该调制阶数为M；
(e)所述第一信号的调制速率；
(f)所述第一信号的编码方式，比如，包括但不限于信道编码方式(比如：RS码、Polar码、卷积码、重复码等)或者线编码方式(比如：FM0码、Miller码、Manchester码等)；
(g)所述第一信号的编码码率；
(h)构建第三信号的方式，比如可以是前一个CSS符号减去后一个CSS符号，也可以是后一个CSS符号减去前一个CSS符号；
(i)所述第一信号对应的基准解扩信号的信号参数；其中，当所述第一信号的扫频方式为up-chirp模式时，所述基准解扩信号是与扫描起始频率为最低频率的CSS信号共轭的；或者，当所述第一信号的扫频方式为down-chirp模式时，所述基准解扩信号是与扫描起始频率为最高频率的CSS信号共轭的；或者，所述基准解扩信号是与所述第一信号共轭的；
(j)与所述第一信号的解调制关联的第三索引信息，所述第三索引信息用于指示关联的解调制参数；其中，不同的第三索引信息关联不同的第一信号的解调制参数，每个第三索引信息可对应一组第一信号的解调制参数，比如上述a)至i)中所述；相关对应关系可以是网络或协议预配置的。
可选地，所述基准解扩信号的信号参数包括以下至少一项：(I)所述基准解扩信号的扫频方式；该基准解扩信号的扫频方式与第一信号的扫频方式相反；即，如果第一信号采用up-chirp扫频模式，则基准解扩信号采用down-chirp扫描模式；如果第一信号采用down-chirp扫频方式，则基准解扩信号采用up-chirp扫描方式；(II)所述基准解扩信号的最低扫频频率，该基准解扩信号的最低扫频频率与第一信号的最低扫频频率相同；(III)所述基准解扩信号的最高扫频频率，该基准解扩信号的最高扫频频率与第一信号的最高扫频频率相同；(IV)所述基准解扩信号的扫频起始频率，即为最低扫频频率或最高扫频频率；比如，若基准解扩信号为down-chirp扫频方式，则相应扫频起始频率为最高扫频频率；或者，若基准解扩信号为up-chirp扫频方式，则相应扫频起始频率为最低扫频频率；(IIV)所述基准解扩信号的扫频截止频率，即为最低扫频频率或最高扫频频率；比如，若基准解扩信号为down-chirp扫频方式，则相应扫频截止频率为最低扫频频率；或者，若基准解扩信号为up-chirp扫频方式，则相应扫频截止频率为最高扫频频率；(IIIV)所述基准解扩信号的中心频点，该基准解扩信号的中心频点与第一信号的中心频点相同；(V)所述基准解扩信号的带宽，该基准解扩信号的带宽与第一信号的带宽相同；(VI)所述基准解扩信号的扩频因子，该基准解扩信号的扩频因子与第一信号的扩频因子相同；(VII)所述基准解扩信号的码率，该基准解扩信号的码率与第一信号的码率相同；(VIII)所述基准解扩信号的符号率，该基准解扩信号的符号率/符号周期与第一信号的符号率/符号周期相同。
本申请实施例中，第二设备可以根据配置或指示的信息来接收第一信号。上述接收第一设备发送的第一信号可以包括：第二设备根据获得的第五信息，接收第一信号；所述第五信息可以包括但不限于以下至少一项：所述第一信号的前导码或者同步序列；所述第一信号的参考信号；所述第一信号的时域资源信息，比如包括信号的重复传输次数、信号周期、时隙配置信息、子帧信息等；所述第一信号的频域资源信息，比如包括频率、带宽等信息；所述第一信号的空域资源信息，比如包括天线、码字、层、天线端口等信息。
本申请实施例中，可以为第二设备配置或指示用于发送载波信号(即第二信号)的相关信息。上述信号传输方法还可以包括：第二设备根据获得的第六信息，发送第二信号；所述第六信息可以包括但不限于以下至少一项：所述第二信号的频域相关参数；所述第二信号的时域相关参数；所述第二信号的信号波形及帧结构；所述第二信号的基带信号参数；与所述第二信号的信号参数关联的第二索引信息，所述第二索引信息用于指示关联的第二信号的信号参数；其中，不同的第二索引信息对应不同的第二信号的信号参数，每个第二索引信息可对应一套第二信号的信号参数，比如包括频域相关参数、时域相关参数和/或信号波形等，相关对应关系可以是网络或协议预配置的。借助所述第二索引信息，可使得第一设备获得关联的第二信号的信号参数，从而准确发送第二信号。
需指出的，所述第六信息包括的具体内容可以参见上述实施例中对第三信息的说明，在此不再赘述。
本申请实施例中，第二设备可以采用多种方式来获得第四信息。所述信号传输方法还可以包括以下至少一项：(a)第二设备确定所述第四信息，即第二设备自身具有确定配置信息的能力；(b)第二设备从第一设备接收所述第四信息；(c)第二设备从第三设备接收所述第四信息，所述第三设备为提供载波信号的设备；即此时：第三设备既为第一设备提供载波信号的设备，也为配置或指示第四信息的设备；(d)第二设备从第四设备接收所述第一信息，所述第四设备为具备网络调度功能的设备；所述第四设备为不同于第一设备、第二设备和第三设备的设备。
需指出的，所述第五信息和所述第六信息可以采用与第四信息相同的配置/指示方式，为避免重复，在此不再赘述。
下面结合具体实施例对本申请进行说明。
实施例一
在本实施例一中，给出了第二信号与第一信号的帧结构设计实例。
一种可能的实例中，如图5A和图5B所示，第二信号是周期性的CSS信号或者基准Chirp信号，其中同一个符号周期k中的CSS符号#n和CSS符号#n+1的所有符号参数相同，特别的CSS符号#n和CSS符号#n+1的平均功率相同，并且任意信号单元k与信号单元k+1之间的时间间隔Tg＝0。与之对应的，第一信号中的每个信号单元k与信号单元k+1之间的时间间隔Tg＝0，并且每个信号单元中的CSS符号#n为对应的第二信号中的CSS符号#n分别经过频率(f2m-1,-f2m),m∈{1,...,M}频移与滤波后生成的第一部分信号和第二部分信号的相加。特别的，每个信号单元中的CSS符号#n的平均功率或者反射系数β1和CSS符号#n+1的平均功率或者反射系数β2不同，即β1≠β2。这种设计的好处在于所有的第二信号的符号都用于调制第一设备的信息比特，因此调制速率高。
另外一种可能的实例中，如图6A和图6B所示，第二信号是周期性的CSS信号或者基准Chirp信号，其中同一个符号周期k中的CSS符号#n和CSS符号#n+1的所有符号参数相同，特别的CSS符号#n和CSS符号#n+1的平均功率相同，并且两个信号单元k与信号单元k+1之间的时间间隔可能为Tg>0。此包括：(1)任意两个信号单元k与信号单元k+1之间的时间间隔都为Tg>0；或者，(2)部分信号单元k与信号单元k+1之间的时间间隔都为Tg>0。与之对应的，第一信号中两个信号单元k与信号单元k+1之间的时间间隔可能为Tg>0。此包括：(1)任意两个信号单元k与信号单元k+1之间的时间间隔都为Tg>0；或者，(2)部分信号单元k与信号单元k+1之间的时间间隔都为Tg>0。并且每个信号单元中的CSS符号#n为对应的第二信号中的CSS符号#n分别经过频率(f2m-1,-f2m),m∈{1,…,M}频移与滤波后生成的第一部分信号和第二部分信号的相加。特别的，每个信号单元中的CSS符号#n的平均功率或者反射系数β1和CSS符号#n+1的平均功率或者反射系数β2不同，即β1≠β2。这种设计的好处在于所有的第二信号的的帧结构设计灵活，帧结构中的其它数据载荷可用于其它业务。
值得说明的是，本方案中只要求第二信号的同一个信号单元中的两个CSS符号的起始扫描频率相同，但不要求信号单元m与信号单元n(m≠n)中的CSS符号的起始扫频频率相同。如果信号单元k与信号单元k+1中的CSS符号的起始扫频频率不同，则第二信号本身也可以携带第一设备想要发送的信息比特或者其他业务。
比如，LoRa帧结构就是一种典型的信号单元m与信号单元n(m≠n)中的CSS符号的起始扫频频率不一定相同，并且两个信号单元k与信号单元k+1之间的时间间隔可能为Tg>0。如图7所示，LoRa帧结构中包含前导码(Preamble)、数据包头(Header)、有效载荷(Payload)和循环冗余校验(CRC)四部分。其中，Preamble部分不需要编码而直接采用CSS调制符号，而往后的数据都经过Hamming编码以提高纠错能力。更进一步，前导码中也可包含三部分：可变前导(variable preamble)、帧同步字(Sync word)和帧起始分隔符(Start Frame Delimiter，SFD)。从一次传输来看，虽然协议规定了variable preamble，但在固定场景下或者一段时间内的variable preamble的长度是固定的，因此从这点来说，整个Preamble的长度也是固定的，因此非常适用于作为本方案中的第二信号。另外，由于Payload、Header和CRC部分采用了编码并且起始扫描频率是不固定的，从方案简单的角度来说，这部分一般不用于作为第二信号，并且这部分信号也就对应本申请方案中的其它数据载荷部分，并且长度也是可以变。这即满足本方案中的两个信号单元k与信号单元k+1之间的时间间隔可能为Tg>0，或者准确来说，是部分信号单元k与信号单元k+1之间的时间间隔都为Tg>0。而从Preamble来看，Variable preamble一般采用基准up-chirp信号，这部分的信号满足信号单元m与信号单元n(m≠n)中的CSS符号的起始扫频频率相同；而Sync word和SFD采用基准down-chirp信号，因此variable preamble最后一个信号单元与sync word的第一个信号单元就满足信号单元m与信号单元n(m≠n)中的CSS符号的起始扫频频率不相同。
实施例二
在本实施例二中，给出了具体的调制过程示例。不失一般性的，以实施例一中的第一信号和第二信号采用集中式设计为例，相同的方案也可以很容易扩展到其它类型的帧结构，这里不再赘述。
情况一：第二信号为基准CSS信号或Chirp信号。
如图8A所示，用于射频载波的第二信号为基准Chirp信号或者CSS信号S1(t)，此时第二信号可满足如下特性：
(I)中心频率为f0；
(II)带宽为BW；
(III)扩频因子为SF；
(IV)单符号长度为
(IIV)每个符号的起始扫频频率是固定的，为
(IIIV)信号S1(t)可以表示为：
根据本申请方案所述的方法，本实施例二中考虑二阶调制(M＝2)，即待传输的比特为“0”或者“1”，可以对第二信号的一个信号单元中的相邻两个CSS符号的频率分别频移f1(0≤f1≤BW)或f3(0≤f3≤BW)并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第一部分和同时对第二信号的一个信号单元中的相邻两个CSS符号的频率分别频移-f2(0≤f2≤BW)或-f4(0≤f4≤BW)并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第二部分和其中f1+f2＝BW,f3+f4＝BW,f1≠f3,f2≠f4。最后将第一信号的第一部分和第一信号的第二部分在时域相加，并给相邻的两个CSS符号分配不同的平均功率或者反射系数，从而生成第一信号。
本实施例二以为例进行说明。以图8B和图8C所示，说明第二信号为基准CSS信号或者Chirp信号时的传输比特的信号调制过程。
(1)传输比特“0”：
(a)生成一个信号单元中的第1个CSS符号：
(I)对起始扫描频率为的第二信号频移f1并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8B所示，红色点虚线为频移前的第二信号，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽外的滤除信号。
(II)对起始扫描频率为第二信号频移-f2并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8B所示，红色点虚线为频移前的第二信号，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽外的滤除信号。
(III)将第1个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第1个CSS符号：
(b)生成一个信号单元中的第2个CSS符号：
(I)对起始扫描频率为的第二信号频移f1并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8B所示，红色点虚线为频移前的第二信号，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽外的滤除信号。
(II)对起始扫描频率为第二信号频移-f2并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8B所示，红色点虚线为频移前的第二信号，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽外的滤除信号。
(III)将第2个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第2个CSS符号：
(c)分别给这两个CSS符号设置不同的平均功率或者反射系数，并组成表征比特“0”的信号单元，如图8B所示：
(2)传输比特“1”：
(a)生成一个信号单元中的第1个CSS符号：
(I)对起始扫描频率为的第二信号频移f3并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8C所示，红色点虚线为频移前的第二信号，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽外的滤除信号。
(II)对起始扫描频率为第二信号频移-f4并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8C所示，红色点虚线为频移前的第二信号，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽外的滤除信号。
(III)将第1个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第1个CSS符号：
(b)生成一个信号单元中的第2个CSS符号：
(I)对起始扫描频率为的第二信号频移f3并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8C所示，红色点虚线为频移前的第二信号，实线绿色部分表示第一信号的第一部分，其中绿色信号的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽外的滤除信号。
(II)对起始扫描频率为第二信号频移-f4并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图8C所示，红色点虚线为频移前的第二信号，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽外的滤除信号。
(III)将第2个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第2个CSS符号：
(c)分别给这两个CSS符号设置不同的平均功率或者反射系数，并组成表征比特“1”的信号单元，如图8C所示：
情况二：第二信号为已调制CSS信号。
按照相同的方式，也可以扩展到第二信号为非基准CSS信号或者已调制CSS信号。图9A所示的已调制CSS信号的SF＝2，其中表征比特“01”的CSS信号的起始扫频频率为而表征比特“10”的CSS信号的起始扫描频率为f0，并且第二信号相邻的两个CSS符号(即一个信号单元)中的扫描起始频率必须相同，因此图9A所示的第二信号也是用完全相同的两个相邻CSS符号传输比特。此时第二信号可满足如下特性：
(I)中心频率为f0；
(II)带宽为BW；
(III)扩频因子为SF；
(IV)单符号长度为
(IIV)每个符号的起始扫瞄频率与第二信号的调制信息是相关的，为n∈{0,1,…,2SF-1}；
(IIIV)已调制CSS信号S2(t)可以表示为：
根据本申请方案所述的方法，根据待传输的比特为“0”或者“1”，可以对第二信号的相邻两个CSS符号(即一个信号单元)的频率分别频移f1(0≤f1≤BW)或f3(0≤f3≤BW)并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第一部分和同时对第二信号的相邻两个CSS符号(即一个信号单元)的频率分别频移-f2(0≤f2≤BW)或-f4(0≤f4≤BW)并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第二部分和其中f1+f2＝BW,f3+f4＝BW,f1≠f3,f2≠f4。最后将第一信号的第一部分和第一信号的第二部分在时域相加，并给相邻的两个CSS符号分配不同的平均发送功率或者反射系数，从而生成第一信号。
本实施例二以为例进行说明。以图9A所示为例，第二信号自身也调制比特信息，传输比特“0”对应的第二信号的起始扫描频率为传输比特“1”对应的第二信号的起始扫描频率fstart＝f0，说明第二信号为已调制CSS信号时的传输比特的调制过程。
下面以图9B和图9C所示，说明第二信号为已调制CSS信号时的传输比特的信号调制过程。
(1)传输比特“0”：
(a)生成一个信号单元中的第1个CSS符号：
(I)对起始扫描频率为的第二信号频移f1并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9B所示，红色点虚线为频移前的已调制第二信号(携带比特“01”)，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽 外的滤除信号。
(II)对起始扫描频率为第二信号频移-f2并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9B所示，红色点虚线为频移前的已调制第二信号(携带比特“01”)，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽 外的滤除信号。
(III)将第1个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第1个CSS符号：
(b)生成一个信号单元中的第2个CSS符号：
(I)对起始扫描频率为的第二信号频移f1并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9B所示，红色点虚线为频移前的已调制第二信号(携带比特“01”)，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽 外的滤除信号。
(II)对起始扫描频率为第二信号频移-f2并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9B所示，红色点虚线为频移前的已调制第二信号(携带比特“01”)，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽 外的滤除信号。
(III)将第2个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第2个CSS符号：
(c)分别给这两个CSS符号设置不同的平均功率或者反射系数，并组成表征比特“0”的信号单元，如图9B所示：
(2)传输比特“1”：
(a)生成一个信号单元中的第1个CSS符号：
(I)对起始扫描频率为f0的第二信号频移f3并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9C所示，红色点虚线为频移前的已调制第二信号(携带比特“10”)，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽 外的滤除信号。
(II)对起始扫描频率为f0第二信号频移-f4并进行中心频点为f0且带宽区间为的滤波，从而生成第1个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9C所示，红色点虚线为频移前的已调制第二信号(携带比特“10”)，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽 外的滤除信号。
(III)将第1个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第1个CSS符号：
(b)生成一个信号单元中的第2个CSS符号：
(I)对起始扫描频率为f0的第二信号频移f3并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第一部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9C所示，红色点虚线为频移前的已调制第二信号(携带比特“10”)，实线绿色部分表示第一信号的第一部分，其中绿色的实线部分表示在带宽内的有用信号，而绿色的虚线部分表示在带宽 外的滤除信号。
(II)对起始扫描频率为f0第二信号频移-f4并进行中心频点为f0且带宽区间为的滤波，从而生成第2个CSS符号的第二部分
其中，表示对信号进行中心频点为f0且带宽区间为的滤波。如图9C所示，红色点虚线为频移前的已调制第二信号(携带比特“10”)，实线蓝色部分表示第一信号的第二部分，其中蓝色的实线部分表示在带宽内的有用信号，而蓝色的虚线部分表示在带宽 外的滤除信号。
(III)将第2个CSS符号的第一部分和第二部分相加，生成一个信号单元中的第2个CSS符号：
(c)分别给这两个CSS符号设置不同的平均功率或者反射系数，并组成表征比特“1”的信号单元，如图9C所示：
实施例三
在本实施例三中，给出了对应的解调制过程。不失一般性的，本实施例三只以帧结构为集中式(本实施例一中的方案1)并且采用基准CSS符号或Chirp信号作为第二信号(本实施例二中的方案1)为例进行说明。类似的解调制方案可以扩展到其它方案中的解调。下面简述解调制过程：
(1)获得第一信号；
(a)可选地，第二设备先进行必要的时频同步之后，开始获取第一信号；
(b)可选地，第二设备对获得的第一信号进行下变频、中频滤波等射频或中频处理；
(c)可选地，第二设备对获得的第一信号进行信道估计、信道均衡、信道译码等基带信号处理。
(2)获得第三信号并且删除第二信号的干扰：将获得的第一信号中的每两个CSS符号作为一个信号单元，并根据指示或配置信息确定前后两个CSS符号的平均功率或者反射系数大小(如β1和β2)，或者第二设备自己确定前后两个CSS符号的平均功率，从而确定第三信号B(t)是信号单元中的前一个CSS符号减去后一个CSS符号，或者是后一个CSS符号减去前一个CSS符号。即，B(t)中的一个符号为第一信号的每个信号单元中的前后两个CSS符号的差：
(a)当β2>β1时，B(t)可以通过第一信号的每个信号单元中的后一个CSS符号减去前一个CSS符号，表示为：
B(nTs+t)＝C(2nTs+t+Ts)-C(2nTs+t)＝β2C1,n(t)-β1C1,n(t),nTs≤t≤(n+1)Ts-1
(b)当β1>β2时，B(t)可以通过第一信号的每个信号单元中的前一个CSS符号减去后一个CSS符号，表示为：
B(nTs+t)＝C(2nTs+t)-C(2nTs+t-Ts)＝β1C1,n(t)-β2C1,n(t),nTs≤t≤(n+1)Ts-1
(c)更进一步的，由于第二设备接收到的第二信号(载波信号)也按照(a)或(b)的步骤进行了相减处理，并且由于第二信号中同一个信号单元中的前后两个CSS符号的平均功率或者反射系数相同，因此第二信号的每个信号单元中前后两个CSS符号相减为0，从而可以有效的删除/消除第二信号对解调制第三信号的影响。
(3)根据获得的第三信号，通过以下至少一种方式进行解调制：
(a)第二设备先利用基准解扩频信号对第三信号进行解扩频处理，之后采用FFT算法寻找频域最高峰或者频域最高的两个峰的频点，并根据预设的阈值进行判决。
一种可能的解调制方案中，第二设备通过指示或配置信息，先利用基准解扩频信号对获得的第三信号进行解扩频处理，之后通过FFT处理寻找频域最高峰或者频域最高的两个峰的频点，并根据比特“0”和比特“1”对应的判决阈值完成对信息比特的解调制。由于表征比特“0”和比特“1”对应的第三信号的起始扫频频率不同，可以根据第三信号的第一个峰的位置，和/或第二个峰与第一个峰的差值来判决传输的比特为“0”或者“1”。如图10所示，以本实施例一中的参数为例，由于传输比特“0”的起始扫描频率为传输比特“1”的起始扫描频率为因此接收端可以通过FFT最高峰的频点位置来判决传输的比特是“0”还是“1”，解调规则如下：
这种解调制方案的实现比较简单。
(b)第二设备利用最大似然检测算法进行判决与解调制。
一种可能的解调制方案中，由于相同SF值但不同起始扫描频率的CSS符号，以及不同SF值的CSS符号之间具有准正交特性，因此接收端可以采用最大似然检测算法来进行解调制。具体的，接收端先保存不同信息比特对应的第三信号波形，解调制时用不同信息比特对应的第三信号与获得的第三信号进行相关计算，其中相关值最大的信息比特即为对应解调制的信息比特。这种解调制方案属于解调制中的最优判决方法，因此BER或者SER性能比硬判决的BER或者SER性能要好。
(4)按照(1)-(3)所述的解调制方法，逐次对第三信号的所有符号进行解调制，并获得第一设备的传输比特。
注意，上述解调制方案只是给出两种可能的解调制方法，但不限于此，不再赘述。
值得注意的，与本实施例二中调制方案对应的解调制方案需要考虑第二信号本身已调制信息的影响。由于第二信号为已调制的CSS信号，因此在解调第一设备发送的信息比特时，需要先解调出第二设备发送的第二信号本身的信息比特，并将第二信号对第一信号的影响从接收端中删除，之后再按照信息比特的调制规则来解调出原始信息比特。一种可行的方案是，由于第二设备接收到的来自于第一设备发送的第二信号强度大于第一信号强度，因此第二设备可以先解调出第二信号的信息比特。之后，在解调制第一信号时，删除第二信号的已调制信息比特的影响，并通过与上述相同的方案进行解调制。另一种可行的方案中，第二设备的通过联合解调判决的方式，同时解调值第一设备的信息比特以及第二信号承载的信息比特。
实施例四
在上述实施例一、实施例二和实施例三中，都是以二阶调制为例，即第一信号的每个CSS符号只传输比特“0”或者比特“1”。但本方案也可以扩展到高阶调制，从而进一步提高第一设备发送的第一信号的调制速率或者频谱效率。不失一般性，下面以第二信号为基准CSS信号或Chirp信号为例进行说明，相同的方案可以扩展到第二信号为已调制CSS信号的情况。
当在第一信号中实现M(0≤M≤2SF)阶调制，此时每两个CSS符号(即一个信号单元)可以携带log2 M个比特。根据待传输的log2 M个比特，可以对第二信号的每个信号单元中的相邻两个CSS符号的频率都频移f2m-1(0≤f2m-1≤BW,m∈{1,2,…,M})并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第一部分和同时对第二信号的每个信号单元中的相邻两个CSS符号(即一个信号单元)频移-f2m(0≤f2m≤BW,m∈{1,2,…,M})并进行中心频点为f0且带宽区间为 的滤波，从而生成第一信号的第二部分和其中f2m-1+f2m＝BW,f2m-1≠f2n-1(n≠m),f2m≠f2n(n≠m)。最后将第一信号的每个CSS符号中的第一部分和第二部分在时域相加，并给相邻的两个CSS符号分配不同的平均功率或者反射系数，从而生成第一信号。
例如，当M＝8时，(f2m-1,f2m)的取值可以如下表1所示：
表1
以M＝8为例，且比特-符号采用Gray映射，表1给出了一种(f2m-1,f2m)的设计实例。此时，第一设备在第一信号实现8阶调制，每个信号单元或者每两个CSS符号可以携带3个比特。根据待传输的3个比特，可以对第二信号的相邻两个CSS符号(即一个信号单元)的频移f2m-1(0≤f2m-1≤BW,m∈{1,2,…,8})并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第一部分和同时对第二信号的相邻两个CSS符号(即一个信号单元)频移-f2m(0≤f2m≤BW,m∈{1,2,…,8})并进行中心频点为f0且带宽区间为的滤波，从而生成第一信号的第二部分和其中f2m-1+f2m＝BW,f2m-1≠f2n-1(n≠m),f2m≠f2n(n≠m)。最后将第一信号的第一部分和第二部分在时域相加，并给相邻的两个CSS符号分配不同的平均功率或者反射系数，从而生成第一信号。
本实施例四中具体的调制方式可以基于本实施例一和二进行扩展。由于相应的调制方式类似，在此不再赘述。而相应的解调制过程，也可基于本实施例三中所述的解调制方法对高阶调制的解调制进行扩展。具体解调制过程也不再赘述。
本申请实施例提供的信号传输方法，执行主体可以为信号传输装置。本申请实施例中以信号传输装置执行信号传输方法为例，说明本申请实施例提供的信号传输装置。
请参见图11，图11是本申请实施例提供的一种信号传输装置的结构示意图，该装置应用于第一设备，所述第一设备比如为反向散射设备等等。如图11所示，信号传输装置110包括：调制模块111，用于第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；发送模块112，用于发送所述第一信号。
可选地，所述第二信号包括至少一个第二信号单元，每个所述第二信号单元包括参数相同的两个CSS符号或两个基准啁啾Chirp符号；所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对所述第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对所述第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号或基准Chirp符号的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。
可选地，所述滤波为中心频点为f0且带宽区间为的滤波，所述f0为所述第二信号中的CSS信号或基准Chirp信号的中心频率，所述BW为所述第二信号中的CSS符号或基准Chirp符号的带宽。
可选地，所述第二信号满足以下至少一项：
每个所述第二信号单元中的两个CSS符号的平均功率相同，或者，每个所述第二信号单元中的两个基准Chirp符号的平均功率相同；
所述第二信号中的相邻两个第二信号单元之间的时间间隔大于或等于0。
可选地，所述调制模块111具体用于：根据获得的第一信息，对所述待传输的信息比特和第二信号进行反向散射调制，得到所述第一信号；其中，所述第一信息包括以下至少一项：与待传输的信息比特关联的用于频移的频率对包含的频率值；与待传输的信息比特关联的用于频移的频率对的物理资源块PRB、资源块组RBG和/或带宽部分BWP的大小；所述第一信号的调制方式；所述第一信号的调制阶数；所述第一信号的调制速率或者反向散射链路频率BLF；所述第一信号的编码方式；所述第一信号的编码码率；所述第一信号的第一信号单元中的两个CSS符号的平均功率或者反射系数；与所述第一信号的调制编码关联的第一索引信息，所述第一索引信息用于指示关联的调制编码参数。
可选地，所述其他参数至少包括以下内容：扫频方式；最低扫频频率；最高扫频频率；扫频起始频率；扫频截止频率；中心频点；带宽；扩频因子；码率；符号率。
可选地，所述发送模块112具体用于：根据获得的第二信息，发送所述第一信号；其中，所述第二信息包括以下至少一项：所述第一信号的发送功率；所述第一信号的前导码或者同步序列；所述第一信号的参考信号；所述第一信号的时域资源信息；所述第一信号的频域资源信息；所述第一信号的空域资源信息。
可选地，信号传输装置110还包括：第一接收模块，用于根据获得的第三信息，接收所述第二信号；其中，所述第三信息包括以下至少一项：所述第二信号的频域相关参数；所述第二信号的时域相关参数；所述第二信号的信号波形及帧结构；所述第二信号的基带信号参数；与所述第二信号的信号参数关联的第二索引信息，所述第二索引信息用于指示关联的载波信号参数。
可选地，所述第二信号的频域相关参数包括以下至少一项：所述第二信号的中心频点；所述第二信号的带宽；所述第二信号的扫描起始频率；所述第二信号的扫描截止频率；所述第二信号的扫描最低频率；所述第二信号的扫描最高频率；所述第二信号的扫描频率的斜率；所述第二信号的扩频因子；所述第二信号的码片率；所述第二信号的符号率或符号周期；所述第二信号的扫频方式；所述第二信号的频率偏移或搬频大小。
可选地，所述第二信号的时域相关参数包括以下至少一项：所述第二信号的时间单元；所述第二信号的信号周期；所述第二信号的信号长度；所述第二信号的时域重复次数；所述第二信号的同步信号或同步序列。
可选地，所述第二信号的信号波形及帧结构，包括以下至少一项：
所述第二信号采用CSS信号波形，以及所述第二信号中包括的CSS符号的个数或者第二信号单元的个数；
所述第二信号采用基准Chirp信号波形，以及所述第二信号中包括的基准Chirp符号的个数或第二信号单元的个数；
所述第二信号采用CSS信号和基准Chirp信号的混合波形，以及所述第二信号中的CSS符号和基准Chirp符号的占比或者个数。
本申请实施例提供的信号传输装置110能够实现图3中所示的方法实施例实现的各个过程，并达到相同的技术效果，为避免重复，这里不再赘述。
请参见图12，图12是本申请实施例提供的一种信号传输装置的结构示意图，该装置应用于第二设备，所述第二设备比如为基站等接入网设备、UE等终端设备、中继设备、Repeater设备、IAB设备、AP设备等。如图12所示，信号传输装置120包括：第二接收模块121，用于接收第一设备发送的第一信号；其中，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；计算模块122，用于对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；解调制模块123，用于对所述第三信号进行解调制，得到所述待传输的信息比特。
可选地，所述第二信号包括至少一个第二信号单元，每个所述第二信号单元包括参数相同的两个CSS符号或两个Chirp符号；所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对所述第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对所述第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号或基准Chirp符号的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。
可选地，所述解调制模块123具体用于执行以下至少一项：
利用基准解扩频信号对所述第三信号进行解扩频处理，得到第四信号，并根据所述第四信号中的频域最高峰或者频域最高的两个峰的频点，获得所述待传输的信息比特；
利用最大似然检测算法对所述第三信号进行解调制，得到所述待传输的信息比特。
可选地，所述解调制模块123具体用于：根据获得的第四信息，对所述第三信号进行解调制，得到所述待传输的信息比特；其中，所述第四信息包括以下至少一项：
与待传输的信息比特关联的用于频移的频率对包含的频率值；
与待传输的信息比特关联的用于频移的频率对的PRB、RBG和/或BWP的大小；
所述第一信号的调制方式；
所述第一信号的调制阶数；
所述第一信号的调制速率；
所述第一信号的编码方式；
所述第一信号的编码码率；
构建所述第三信号的方式；
所述第一信号对应的基准解扩信号的信号参数；其中，当所述第一信号的扫频方式为up-chirp模式时，所述基准解扩信号是与扫描起始频率为最低频率的CSS信号共轭的；或者，当所述第一信号的扫频方式为down-chirp模式时，所述基准解扩信号是与扫描起始频率为最高频率的CSS信号共轭的；或者，所述基准解扩信号是与所述第一信号共轭的；
与所述第一信号的解调制关联的第三索引信息，所述第三索引信息用于指示关联的解调制参数。
可选地，所述基准解扩信号的信号参数包括以下至少一项：所述基准解扩信号的扫频方式；所述基准解扩信号的最低扫频频率；所述基准解扩信号的最高扫频频率；所述基准解扩信号的扫频起始频率；所述基准解扩信号的扫频截止频率；所述基准解扩信号的中心频点；所述基准解扩信号的带宽；所述基准解扩信号的扩频因子；所述基准解扩信号的码率；所述基准解扩信号的符号率。
可选地，所述第二接收模块121具体用于：根据获得的第五信息，接收所述第一信号；其中，所述第五信息包括以下至少一项：所述第一信号的前导码或者同步序列；所述第一信号的参考信号；所述第一信号的时域资源信息；所述第一信号的频域资源信息；所述第一信号的空域资源信息。
本申请实施例提供的信号传输装置120能够实现图3中所示的方法实施例实现的各个过程，并达到相同的技术效果，为避免重复，这里不再赘述。
如图13所示，本申请实施例还提供一种通信设备130，包括处理器131和存储器132，存储器132上存储有可在所述处理器131上运行的程序或指令，例如，该通信设备130为第一设备时，该程序或指令被处理器131执行时实现上述图3所示的信号传输方法实施例的各个步骤，且能达到相同的技术效果。该通信设备130为第二设备时，该程序或指令被处理器131执行时实现上述图4所示的信号传输方法实施例的各个步骤，且能达到相同的技术效果，为避免重复，这里不再赘述。
本申请实施例还提供一种可读存储介质，所述可读存储介质上存储有程序或指令，该程序或指令被处理器执行时实现上述信号传输方法实施例的各个过程，且能达到相同的技术效果，为避免重复，这里不再赘述。
其中，所述处理器为上述实施例中所述的终端中的处理器。所述可读存储介质，包括计算机可读存储介质，如计算机只读存储器ROM、随机存取存储器RAM、磁碟或者光盘等。在一些示例中，可读存储介质可以是非瞬态的可读存储介质。
本申请实施例另提供了一种芯片，所述芯片包括处理器和通信接口，所述通信接口和所述处理器耦合，所述处理器用于运行程序或指令，实现上述信号传输方法实施例的各个过程，且能达到相同的技术效果，为避免重复，这里不再赘述。
应理解，本申请实施例提到的芯片还可以称为系统级芯片，系统芯片，芯片系统或片上系统芯片等。
本申请实施例另提供了一种计算机程序/程序产品，所述计算机程序/程序产品被存储在存储介质中，所述计算机程序/程序产品被至少一个处理器执行以实现上述信号传输方法实施例的各个过程，且能达到相同的技术效果，为避免重复，这里不再赘述。
本申请实施例还提供了一种通信系统，包括：第一设备及第二设备，所述第一设备可用于执行如上图3所述的信号传输方法的步骤，所述第二设备可用于执行如上图4所述的信号传输方法的步骤。
需要说明的是，在本文中，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者装置不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者装置所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括该要素的过程、方法、物品或者装置中还存在另外的相同要素。此外，需要指出的是，本申请实施方式中的方法和装置的范围不限于按照示出或讨论的顺序来执行功能，还可包括根据所涉及的功能按基本同时的方式或按相反的顺序来执行功能，例如，可以按不同于所描述的次序来执行所描述的方法，并且还可以添加、省去或组合各种步骤。另外，参照某些示例所描述的特征可在其他示例中被组合。
通过以上的实施方式的描述，本领域的技术人员可以清楚地了解到上述实施例方法可借助计算机软件产品加必需的通用硬件平台的方式来实现，当然也可以通过硬件。该计算机软件产品存储在存储介质(如ROM、RAM、磁碟、光盘等)中，包括若干指令，用以使得终端或者网络侧设备执行本申请各个实施例所述的方法。
上面结合附图对本申请的实施例进行了描述，但是本申请并不局限于上述的具体实施方式，上述的具体实施方式仅仅是示意性的，而不是限制性的，本领域的普通技术人员在本申请的启示下，在不脱离本申请宗旨和权利要求所保护的范围情况下，还可做出很多形式的实施方式，这些实施方式均属于本申请的保护之内。

Claims (24)

  1. 一种信号传输方法，包括：
    第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个啁啾扩频CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；
    所述第一设备发送所述第一信号。
  2. 根据权利要求1所述的方法，其中，所述第二信号包括至少一个第二信号单元，每个所述第二信号单元包括参数相同的两个CSS符号或两个基准啁啾Chirp符号；
    所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对所述第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对所述第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号或基准Chirp符号的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。
  3. 根据权利要求2所述的方法，其中，所述滤波为中心频点为f0且带宽区间为的滤波，所述f0为所述第二信号中的CSS信号或基准Chirp信号的中心频率，所述BW为所述第二信号中的CSS符号或基准Chirp符号的带宽。
  4. 根据权利要求2或3所述的方法，其中，所述第二信号满足以下至少一项：
    每个所述第二信号单元中的两个CSS符号的平均功率相同，或者，每个所述第二信号单元中的两个基准Chirp符号的平均功率相同；
    所述第二信号中的相邻两个第二信号单元之间的时间间隔大于或等于0。
  5. 根据权利要求2至4任一项所述的方法，其中，所述第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号，包括：
    所述第一设备根据获得的第一信息，对所述待传输的信息比特和第二信号进行反向散射调制，得到所述第一信号；
    其中，所述第一信息包括以下至少一项：
    与待传输的信息比特关联的用于频移的频率对包含的频率值；
    与待传输的信息比特关联的用于频移的频率对的物理资源块PRB、资源块组RBG和/或带宽部分BWP的大小；
    所述第一信号的调制方式；
    所述第一信号的调制阶数；
    所述第一信号的调制速率或者反向散射链路频率BLF；
    所述第一信号的编码方式；
    所述第一信号的编码码率；
    所述第一信号的第一信号单元中的两个CSS符号的平均功率或者反射系数；
    与所述第一信号的调制编码关联的第一索引信息，所述第一索引信息用于指示关联的调制编码参数。
  6. 根据权利要求1至5任一项所述的方法，其中，所述其他参数至少包括以下内容：
    扫频方式；最低扫频频率；最高扫频频率；扫频起始频率；扫频截止频率；中心频点；带宽；扩频因子；码率；符号率。
  7. 根据权利要求1至6任一项所述的方法，其中，所述第一设备发送所述第一信号，包括：
    所述第一设备根据获得的第二信息，发送所述第一信号；
    其中，所述第二信息包括以下至少一项：
    所述第一信号的发送功率；
    所述第一信号的前导码或者同步序列；
    所述第一信号的参考信号；
    所述第一信号的时域资源信息；
    所述第一信号的频域资源信息；
    所述第一信号的空域资源信息。
  8. 根据权利要求1至7任一项所述的方法，其中，所述方法还包括：
    所述第一设备根据获得的第三信息，接收所述第二信号；
    其中，所述第三信息包括以下至少一项：
    所述第二信号的频域相关参数；
    所述第二信号的时域相关参数；
    所述第二信号的信号波形及帧结构；
    所述第二信号的基带信号参数；
    与所述第二信号的信号参数关联的第二索引信息，所述第二索引信息用于指示关联的载波信号参数。
  9. 根据权利要求8所述的方法，其中，所述第二信号的频域相关参数包括以下至少一项：
    所述第二信号的中心频点；
    所述第二信号的带宽；
    所述第二信号的扫描起始频率；
    所述第二信号的扫描截止频率；
    所述第二信号的扫描最低频率；
    所述第二信号的扫描最高频率；
    所述第二信号的扫描频率的斜率；
    所述第二信号的扩频因子；
    所述第二信号的码片率；
    所述第二信号的符号率或符号周期；
    所述第二信号的扫频方式；
    所述第二信号的频率偏移或搬频大小。
  10. 根据权利要求8所述的方法，其中，所述第二信号的时域相关参数包括以下至少一项：
    所述第二信号的时间单元；
    所述第二信号的信号周期；
    所述第二信号的信号长度；
    所述第二信号的时域重复次数；
    所述第二信号的同步信号或同步序列。
  11. 根据权利要求8所述的方法，其中，所述第二信号的信号波形及帧结构，包括以下至少一项：
    所述第二信号采用CSS信号波形，以及所述第二信号中包括的CSS符号的个数或者第二信号单元的个数；
    所述第二信号采用基准Chirp信号波形，以及所述第二信号中包括的基准Chirp符号的个数或第二信号单元的个数；
    所述第二信号采用CSS信号和基准Chirp信号的混合波形，以及所述第二信号中的CSS符号和基准Chirp符号的占比或者个数。
  12. 一种信号传输方法，包括：
    第二设备接收第一设备发送的第一信号；其中，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；
    所述第二设备对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；
    所述第二设备对所述第三信号进行解调制，得到所述待传输的信息比特。
  13. 根据权利要求12所述的方法，其中，所述第二信号包括至少一个第二信号单元，每个所述第二信号单元包括参数相同的两个CSS符号或两个Chirp符号；
    所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对所述第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对所述第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号或基准Chirp符号的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。
  14. 根据权利要求12或13所述的方法，其中，所述第二设备对所述第三信号进行解调制，得到所述待传输的信息比特，包括以下至少一项：
    所述第二设备利用基准解扩频信号对所述第三信号进行解扩频处理，得到第四信号，并根据所述第四信号中的频域最高峰或者频域最高的两个峰的频点，获得所述待传输的信息比特；
    所述第二设备利用最大似然检测算法对所述第三信号进行解调制，得到所述待传输的信息比特。
  15. 根据权利要求12至14任一项所述的方法，其中，所述第二设备对所述第三信号进行解调制，得到所述待传输的信息比特，包括：
    所述第二设备根据获得的第四信息，对所述第三信号进行解调制，得到所述待传输的信息比特；
    其中，所述第四信息包括以下至少一项：
    与待传输的信息比特关联的用于频移的频率对包含的频率值；
    与待传输的信息比特关联的用于频移的频率对的PRB、RBG和/或BWP的大小；
    所述第一信号的调制方式；
    所述第一信号的调制阶数；
    所述第一信号的调制速率；
    所述第一信号的编码方式；
    所述第一信号的编码码率；
    构建所述第三信号的方式；
    所述第一信号对应的基准解扩信号的信号参数；其中，当所述第一信号的扫频方式为up-chirp模式时，所述基准解扩信号是与扫描起始频率为最低频率的CSS信号共轭的；或者，当所述第一信号的扫频方式为down-chirp模式时，所述基准解扩信号是与扫描起始频率为最高频率的CSS信号共轭的；或者，所述基准解扩信号是与所述第一信号共轭的；
    与所述第一信号的解调制关联的第三索引信息，所述第三索引信息用于指示关联的解调制参数。
  16. 根据权利要求15所述的方法，其中，所述基准解扩信号的信号参数包括以下至少一项：
    所述基准解扩信号的扫频方式；
    所述基准解扩信号的最低扫频频率；
    所述基准解扩信号的最高扫频频率；
    所述基准解扩信号的扫频起始频率；
    所述基准解扩信号的扫频截止频率；
    所述基准解扩信号的中心频点；
    所述基准解扩信号的带宽；
    所述基准解扩信号的扩频因子；
    所述基准解扩信号的码率；
    所述基准解扩信号的符号率。
  17. 根据权利要求12至16任一项所述的方法，其中，所述第二设备接收第一设备发送的第一信号，包括：
    所述第二设备根据获得的第五信息，接收所述第一信号；
    其中，所述第五信息包括以下至少一项：
    所述第一信号的前导码或者同步序列；
    所述第一信号的参考信号；
    所述第一信号的时域资源信息；
    所述第一信号的频域资源信息；
    所述第一信号的空域资源信息。
  18. 一种信号传输装置，包括：
    调制模块，用于第一设备根据待传输的信息比特和第二信号进行反向散射调制，得到第一信号；其中，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；
    发送模块，用于发送所述第一信号。
  19. 根据权利要求18所述的装置，其中，所述第二信号包括至少一个第二信号单元，每个所述第二信号单元包括参数相同的两个CSS符号或两个Chirp符号；
    所述第一信号是根据第一部分和第二部分的相加得到，所述第一部分是对所述第二信号进行第一频率的频移和滤波后得到的信号，所述第二部分是对所述第二信号进行第二频率的频移和滤波后得到的信号；所述第一部分和所述第二部分的频移方向相反，且所述第一频率和所述第二频率之和等于所述第二信号中的CSS符号或基准Chirp符号的带宽大小，所述第一频率和所述第二频率是与所述待传输的信息比特关联的用于频移的频率对。
  20. 根据权利要求18或19所述的装置，其中，
    所述调制模块具体用于：根据获得的第一信息，对所述待传输的信息比特和第二信号进行反向散射调制，得到所述第一信号；
    其中，所述第一信息包括以下至少一项：
    与待传输的信息比特关联的用于频移的频率对包含的频率值；
    与待传输的信息比特关联的用于频移的频率对的PRB、RBG和/或BWP的大小；
    所述第一信号的调制方式；
    所述第一信号的调制阶数；
    所述第一信号的调制速率或者反向散射链路频率BLF；
    所述第一信号的编码方式；
    所述第一信号的编码码率；
    所述第一信号的第一信号单元中的两个CSS符号的平均功率或者反射系数；
    与所述第一信号的调制编码关联的第一索引信息，所述第一索引信息用于指示关联的调制编码参数。
  21. 一种信号传输装置，包括：
    第二接收模块，用于接收第一设备发送的第一信号；其中，所述第一信号是根据待传输的信息比特和第二信号进行反向散射调制得到，所述第二信号是所述第一信号的载波信号；所述第一信号包括至少一个第一信号单元，每个所述第一信号单元包括两个CSS符号，所述两个CSS符号的平均功率或者反射系数不同，所述两个CSS符号的除平均功率和反射系数外的其他参数相同，所述待传输的信息比特是通过每个所述第一信号单元中的每个CSS符号的频率进行调制的；
    计算模块，用于对所述第一信号的第一信号单元中的两个CSS符号进行相减操作，得到第三信号；
    解调制模块，用于对所述第三信号进行解调制，得到所述待传输的信息比特。
  22. 根据权利要求21所述的装置，其中，所述解调制模块具体用于执行以下至少一项：
    利用基准解扩频信号对所述第三信号进行解扩频处理，得到第四信号，并根据所述第四信号中的频域最高峰或者频域最高的两个峰的频点，获得所述待传输的信息比特；
    利用最大似然检测算法对所述第三信号进行解调制，得到所述待传输的信息比特。
  23. 根据权利要求21或22所述的装置，其中，
    所述解调制模块具体用于：根据获得的第四信息，对所述第三信号进行解调制，得到所述待传输的信息比特；
    其中，所述第四信息包括以下至少一项：
    与待传输的信息比特关联的用于频移的频率对包含的频率值；
    与待传输的信息比特关联的用于频移的频率对的PRB、RBG和/或BWP的大小；
    所述第一信号的调制方式；
    所述第一信号的调制阶数；
    所述第一信号的调制速率；
    所述第一信号的编码方式；
    所述第一信号的编码码率；
    构建所述第三信号的方式；
    所述第一信号对应的基准解扩信号的信号参数；其中，当所述第一信号的扫频方式为up-chirp模式时，所述基准解扩信号是与扫描起始频率为最低频率的CSS信号共轭的；或者，当所述第一信号的扫频方式为down-chirp模式时，所述基准解扩信号是与扫描起始频率为最高频率的CSS信号共轭的；或者，所述基准解扩信号是与所述第一信号共轭的；
    与所述第一信号的解调制关联的第三索引信息，所述第三索引信息用于指示关联的解调制参数。
  24. 一种通信设备，包括处理器和存储器，所述存储器存储可在所述处理器上运行的程序或指令，所述程序或指令被所述处理器执行时实现如权利要求1至11任一项所述的信号传输方法的步骤，或者实现如权利要求12至17任一项所述的信号传输方法的步骤。
PCT/CN2025/103968 2024-06-26 2025-06-26 信号传输方法、装置、通信设备及可读存储介质 Pending WO2026002141A1 (zh)

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