Signal transmission method and apparatus, and communication device and readable storage medium

Abstract

The present application belongs to the technical field of communications. Disclosed are a signal transmission method and apparatus, and a communication device and a readable storage medium. The signal transmission method in the embodiments of the present application comprises: a first device modulating an information bit to be transmitted, so as to obtain a first signal, wherein the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by performing frequency shifting of a first frequency and filtering on a second signal, the second part is a signal obtained by performing frequency shifting of a second frequency and filtering on the second signal, the frequency shift directions of the first part and the second part are opposite, the sum of the first frequency and the second frequency is equal to the bandwidth size of the second signal, the first frequency and the second frequency form a frequency pair associated with said information bit and used for frequency shifting, and the first signal is a backscatter modulation signal of the second signal; and sending the first signal.

Description

Signal transmission method and device, communication device, and readable storage medium

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410835760.8 filed on June 26, 2024 in China, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application belongs to the field of communication technology, and specifically relates to a signal transmission method and device, a communication device, and a readable storage medium. BACKGROUND

[0004] Chirp spread spectrum (CSS) modulation mainly uses a linear frequency modulation signal to carry information bits. Since CSS modulation has good transmission coverage and transmission reliability, the CSS modulation is applied to a backscatter communication system in the related art. The current backscatter modulation mainly realizes modulation by changing the amplitude, phase, and the like of a radio frequency carrier signal, that is, a CSS signal, and the receiving end realizes demodulation by extracting the amplitude, phase, and the like of the CSS signal. However, this backscatter modulation is essentially a superimposed communication, and does not utilize the spread spectrum characteristics of the CSS signal to realize backscatter modulation, thereby causing the receiving sensitivity performance to be generally poor and unable to realize transmission over a long distance. In this case, how to improve the transmission coverage is a problem that needs to be solved at present. SUMMARY

[0005] Embodiments of the present application provide a signal transmission method and device, a communication device, and a readable storage medium, which can solve the problem of how to improve the transmission coverage.

[0006] In a first aspect, a signal transmission method is provided, which is executed by a first device, and the method comprises:

[0007] The first device modulates information bits to be transmitted to obtain a first signal; wherein the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by performing frequency shift and filtering on a second signal at a first frequency, the second part is a signal obtained by performing frequency shift and filtering on 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 size of the second signal, the first frequency and the second frequency are a frequency pair for frequency shift associated with the information bits to be transmitted, and the first signal is a backscatter modulation signal of the second signal.

[0008] The first device transmits the first signal.

[0009] In a second aspect, a signal transmission method is provided, which is performed by a second device, and includes:

[0010] The second device receives a first signal sent by a first device, wherein the first signal is obtained by modulating information bits to be transmitted, and the first signal is obtained by adding a first part and a second part, the first part is obtained by frequency shifting and filtering a second signal at a first frequency, the second part is obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 size of the second signal, the first frequency and the second frequency are a frequency pair for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscatter modulation signal of the second signal.

[0011] The second device demodulates the first signal to obtain the information bits to be transmitted.

[0012] In a third aspect, a signal transmission apparatus is provided, which is applied to a first device and includes:

[0013] A modulation module is configured to modulate information bits to be transmitted to obtain a first signal, wherein the first signal is obtained by adding a first part and a second part, the first part is obtained by frequency shifting and filtering a second signal at a first frequency, the second part is obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 size of the second signal, the first frequency and the second frequency are a frequency pair for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscatter modulation signal of the second signal.

[0014] A sending module is configured to send the first signal.

[0015] In a fourth aspect, a signal transmission apparatus is provided, which is applied to a second device and includes:

[0016] The second receiving module is configured to receive a first signal sent by the first device, wherein the first signal is obtained by modulating information bits to be transmitted, and the first signal is obtained by adding a first part and a second part, the first part is obtained by frequency shifting and filtering the second signal at a first frequency, the second part is obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 size of the second signal, the first frequency and the second frequency are a frequency pair for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscatter modulated signal of the second signal.

[0017] The demodulating module is configured to demodulate the first signal to obtain the information bits to be transmitted.

[0018] In a fifth aspect, a signal transmission apparatus is provided, which is configured to perform the steps of the method according to the first aspect, or perform the steps of the method according to the second aspect.

[0019] In a sixth aspect, a communication device is provided, which includes a processor and a memory, the memory stores programs or instructions executable on the processor, and the programs or instructions are executed by the processor to implement the steps of the method according to the first aspect, or implement the steps of the method according to the second aspect.

[0020] In a seventh aspect, a communication device is provided, which includes a processor and a communication interface, when the communication device is a first device, the processor is configured to modulate information bits to be transmitted to obtain a first signal, and the communication interface is configured to send the first signal; or when the communication device is a second device, the communication interface is configured to receive a first signal sent by the first device, and the processor is configured to demodulate the first signal to obtain the information bits to be transmitted, wherein the first signal is obtained by adding a first part and a second part, the first part is obtained by frequency shifting and filtering a second signal at a first frequency, the second part is obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 size of the second signal, the first frequency and the second frequency are a frequency pair for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscatter modulated signal of the second signal.

[0021] In an eighth aspect, a readable storage medium is provided, and the readable storage medium stores a program or instructions, which, when executed by a processor, implement the steps of the method according to the first aspect or implement the steps of the method according to the second aspect.

[0022] In a ninth aspect, a wireless communication system is provided, and the wireless communication system includes a first device and a second device, the first device is configured to implement the steps of the method according to the first aspect, and the second device is configured to implement the steps of the method according to the second aspect.

[0023] In a tenth aspect, a chip is provided, and the chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is configured to run a program or instructions to implement the steps of the method according to the first aspect or implement the steps of the method according to the second aspect.

[0024] In an eleventh aspect, a computer program / program product is provided, and the computer program / program product is stored in a storage medium, and the computer program / program product is executed by at least one processor to implement the steps of the method according to the first aspect or implement the steps of the method according to the second aspect.

[0025] By means of the scheme in the embodiments of the present application, the first signal obtained by performing frequency shift and filtering on the carrier signal in association with the frequency pair of the information bits to be transmitted can satisfy the spread spectrum characteristic, so as to improve the transmission coverage of the first signal, and realize further transmission coverage and transmission reliability. BRIEF DESCRIPTION OF DRAWINGS

[0026] FIG. 1A, FIG. 1B, FIG. 1C, FIG. 1D and FIG. 1E are schematic diagrams of a communication architecture based on backscattering in embodiments of the present application;

[0027] FIG. 2A is a schematic diagram of a frequency uplink mode of CSS modulation in embodiments of the present application;

[0028] FIG. 2B is a schematic diagram of a frequency downlink mode of CSS modulation in embodiments of the present application;

[0029] FIG. 2C is a schematic diagram of a CSS modulation mode in specific embodiments of the present application;

[0030] FIG. 3 is a flowchart of a signal transmission method provided in embodiments of the present application;

[0031] FIG. 4 is a flowchart of another signal transmission method provided in embodiments of the present application;

[0032] FIG. 5A, FIG. 5B and FIG. 5C are schematic diagrams of related signals of a modulation scheme in Embodiment One of the present application;

[0033] FIG. 6A, FIG. 6B and FIG. 6C are diagrams of the correlation signals of the modulation scheme in Embodiment Two of the present application;

[0034] FIG. 7 is a diagram of the demodulation scheme in Embodiment Three of the present application;

[0035] FIG. 8 is a diagram of the structure of a signal transmission device according to an embodiment of the present application;

[0036] FIG. 9 is a diagram of the structure of another signal transmission device according to an embodiment of the present application;

[0037] FIG. 10 is a diagram of the structure of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0039] The terms "first", "second", and the like in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second" are usually a category, not limited to the number of objects, for example, the first object can be one or more. In addition, "or" in the present application means at least one of the connected objects. For example, the protection scope of "A or B" at least covers three schemes, namely, scheme one: including A and not including B; scheme two: including B and not including A; scheme three: including A and B. In addition, the terms "A and / or B", "at least one of A and B", "at least one of A or B" also at least cover the above three schemes respectively. The character " / " generally represents that the objects before and after are in an "or" relationship.

[0040] The term "indication" in the present application can be a direct indication (or explicit indication) or an indirect indication (or implicit indication). The direct indication can be understood as that the sender explicitly informs the receiver of the specific information, the operation to be performed or the request result, etc. in the indication sent by the sender. The indirect indication can be understood as that the receiver determines the corresponding information according to the indication sent by the sender, or judges and determines the operation to be performed or the request result, etc. according to the judgment result.

[0041] It is worth noting that the techniques described in embodiments of the present application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, and can be applicable to other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" are often used interchangeably in embodiments of the present application, and the described techniques can be applicable to the above-mentioned systems and radio technologies, as well as other systems and radio technologies. The following description describes a New Radio (NR) system for the purpose of example, and NR terminology is used in most of the following description, but these techniques can also be applied to systems other than NR systems, such as 6th Generation (6G) communication systems. th

[0042] In order to facilitate understanding of embodiments of the present application, the following is first described.

[0043] Backscatter Communication (BSC) refers to a backscatter communication device using radio frequency signals in other devices or the environment for signal modulation to transmit its own information, which is a typical passive Internet of Things device. The basic composition modules and main functions of the backscatter communication sending end include:

[0044] - Antenna unit: used for receiving radio frequency signals, control commands, and at the same time for sending modulated backscatter signals.

[0045] - Energy harvesting module or power supply module: this module is used for radio frequency energy harvesting of the backscatter communication device, or other energy harvesting, including but not limited to solar energy, kinetic energy, mechanical energy, thermal energy, etc. In addition to including an energy harvesting module, a battery power supply module can also be included, 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.

[0046] ​- Microcontroller: including controlling baseband signal processing, energy storage or data scheduling state, switch switching, system synchronization, etc.

[0047] - Signal receiving module: for demodulating control commands or data, etc. sent by the reverse scattering communication receiving end or other network nodes.

[0048] - Encoding and modulation module: channel encoding and signal modulation under the control of the controller, and modulation is realized by selecting different load impedances under the control of the controller through the selection switch.

[0049] - Memory or sensing module: for storing identification ID information, location information or sensing data, etc. of the device.

[0050] In addition to the above typical constituent modules, the future reverse scattering communication sending end can also integrate tunnel diode amplifier module, low noise amplifier module, etc. to improve the receiving sensitivity and transmission power of the sending end.

[0051] Optionally, the basic constituent modules and main functions of the reverse scattering communication receiving end include:

[0052] - Antenna unit: for receiving modulated reverse scattering signals.

[0053] - Reverse scattering signal detection module: for detecting the reverse scattering signals sent by the reverse scattering communication sending end, including but not limited to ASK detection, PSK detection, FSK detection or QAM detection, etc.

[0054] - Demodulation and decoding module: demodulating and decoding the detected signals to recover the original information stream.

[0055] The reverse scattering communication device controls the reflection coefficient Γ of the modulation circuit by adjusting its internal impedance, thereby changing the amplitude, frequency, phase, etc. of the incident signal, realizing the modulation of the signal. The reflection coefficient Γ can be represented as:

[0056] Wherein, Z0 is the characteristic impedance of the antenna; Z1 is the load impedance; j represents a complex number, θ T represents the phase. Assuming that the incident signal is represented as S in (t), then the output signal is Therefore, by reasonably controlling the reflection coefficient, corresponding amplitude modulation, frequency modulation or phase modulation can be realized. Based on this, the backscatter communication device can be a tag in a traditional radio frequency identification (RFID), or a passive or semi-passive Internet of Things (IoT) device. Here, the backscatter communication device can be collectively referred to as a BSC device.

[0057] In an implementation, according to the tag capability and the source of the capability, the tag can be divided into:

[0058] - Device A: The tag is a passive tag without energy storage capacitor / battery, relies on radio frequency (RF) signal for energy supply, the received RF signal is the power signal of the rectifier, does not have carrier generation capability, relies on RF as a radio frequency carrier for backscatter communication transmission, and has the lowest power consumption;

[0059] - Device B: The tag is a semi-passive tag with energy storage capacitor / battery, relies on non-RF signal for energy supply, optionally has PA / LNA or other active devices, does not have carrier generation capability, relies on RF as a radio frequency carrier for backscatter communication transmission, and has the second lowest power consumption;

[0060] - Device C: The tag is an active tag with energy storage capacitor / battery, relies on non-RF signal for energy supply, has carrier generation capability, and has the highest power consumption.

[0061] Optionally, the backscatter-based communication architecture can include at least the following modes:

[0062] (1) 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. Traditional RFID systems are typical MBCS systems, which include ambient 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. In Topology 1, 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.

[0063] (2) Topology 2: As shown in Figure 1B, in Topology 2, the Ambient IoT Device (e.g., Tag) receives control signaling and carrier signals sent by intermediate nodes. The control signaling can be indicated by network devices (e.g., base station gNB) through intermediate nodes. The intermediate nodes can be User Equipment (UE), repeaters, IAB nodes, etc. The intermediate nodes can also act as relays to forward IoT data to the gNB.

[0064] (3) Topology 3: 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.

[0065] (4) 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.

[0066] Chirp modulation, also known as chirp spread spectrum (CSS) modulation, primarily uses a linear frequency modulated signal to carry information bits. Specifically, CSS modulation signals are divided into up-chirp mode (as shown in Figure 2A) and down-chirp mode (as shown in Figure 2B). When using 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. However, 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, with a sweep bandwidth of BW = f2 - f1 and a sweep time of T. s The sweep slope is If we represent the chirp signal using baseband signals, then the up-chirp signal and the down-chirp signal can be represented as follows:

[0067] Neither of the two chirp signals mentioned above, whether in up-chirp or down-chirp mode, can directly transmit information bits. Therefore, 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 signal scanning period will exceed the specified scanning termination frequency f2 or f1. Therefore, 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.

[0068] Based on the parameters used in CSS modulation, several important parameters are defined, such as the spreading factor (SF), chirp, and symbol rate / chip rate, as explained below.

[0069] (1) Spreading factor SF:

[0070] The spreading factor represents the number of information bits contained in each symbol, which is equivalent to spreading one symbol to 2^35. SF Transmission occurs on individual chips, and different symbols are mapped to different CSS modulation initial frequencies. For example, with SF=2, a symbol can contain a maximum of 2 bits and can represent 2^32 / ... 2 = 4 values, such as 0 to 3, and the number of chips is 4. Taking up-chirp mode as an example, within one frequency rise cycle, the variable frequency range can be divided into 2 SF Each code chip.

[0071] (2) Chirp rate, or symbol rate:

[0072] The chip rate, or transmission rate per chip, can be expressed as: R c =BW

[0073] The transmission time for each chip is:

[0074] Since each CSS symbol has 2 SF Therefore, the symbol transmission time is: (number of chips)

[0075] Based on the above definition, the slope of the linear frequency increase in CSS modulation is:

[0076] Referring to Figure 2C, the four symbols of CSS modulation are given as an example with SF=2. Symbol 1 starts at frequency f1 and increases linearly to f2, representing bit 00; symbol 2 starts at frequency... It first increases linearly to f2 with a frequency of f1, and then increases linearly to f2 again 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 again with a starting frequency of f1. The symbol represents bit 10; the starting frequency of symbol 4 is... It first increases linearly to f2 with a frequency of f1, and then increases linearly to f2 again with a starting frequency of f1. Characterized by bit 11. Therefore, if the start frequency of the corresponding symbol can be demodulated, and then mapped between the start frequency and the symbol, the input bits before CSS modulation can be obtained.

[0077] In the corresponding demodulation process, a reference chirp signal with the opposite modulation mode to the CSS modulation mode can be used for mixing, and the input bits can be finally demodulated by Fast Fourier Transform (FFT). For example, if the CSS modulation uses an up-chirp signal with a frequency that increases linearly from f1 to f2, the receiver uses a down-chirp signal with a frequency that decreases linearly from f2 to f1 for mixing.

[0078] Assuming CSS modulation uses up-chirp mode, its baseband signal can be expressed as:

[0079] Where f0 is the initial frequency. This represents the slope of the linear growth. For the reference up-chirp signal, For simplicity, the reference up-chirp signal can be denoted as:

[0080] The CSS modulated signal can be a frequency cyclically shifted reference up-chirp signal, expressed as: s(t; f n )=c(t;f n )w(t;0,t n )+c(t;f n -BW)w(t;t n ,T)

[0081] in, The starting frequency of the CSS modulation symbol. w(t;t a ,t b ) is a rectangular window function, expressed as:

[0082] Therefore, for a CSS modulation symbol carrying SF bits, it has 2 SF Optional starting frequency point.

[0083] In the receiving end, the receiving end uses the reference down-chirp signal c * (t) First, perform frequency mixing or chirp deprocessing, such as using the following formula:

[0084] In the mixing process, s′(t; f) is obtained. n After that, the receiving end 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.

[0085] Optionally, 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.

[0086] The signal transmission method, apparatus, communication device, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0087] Please refer to Figure 3, which 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. As shown in Figure 3, the method includes the following steps:

[0088] Step 31: The first device modulates the information bits to be transmitted to obtain the first signal;

[0089] Step 32: The first device sends the first signal.

[0090] In this embodiment, the first signal is obtained by adding a first part and a second part. The first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part is 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 second signal. The first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting. The first signal is a backscattered modulated signal of the second signal. The second signal is the carrier signal of the first signal.

[0091] The frequency shifts described above can be in opposite directions, one being a positive frequency shift and the other a negative frequency shift. For example, if the first frequency is f... 2m-1 The second frequency is f 2m Then the second signal can be subjected to f 2m-1 The frequency shift (i.e., the positive direction) and the -f operation on the second signal 2m The frequency shift (i.e., the negative direction); or, the second signal can be subjected to -f 2m-1 The frequency shift (i.e., the negative direction) and the f-shift of the second signal 2m The frequency shift (i.e., the positive direction).

[0092] Optionally, the association between the information bits to be transmitted and the frequency pairs used for frequency shifting can be pre-configured by the network or protocol, or indicated by indication information, without limitation.

[0093] Optionally, 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.

[0094] By employing the scheme in this application embodiment, and by frequency shifting and filtering the carrier signal in relation to the frequency pairs associated with the information bits to be transmitted, the obtained first signal can still satisfy the linear spread spectrum characteristics of the CSS signal, thereby improving the transmission coverage of the first signal and achieving longer transmission coverage and transmission reliability.

[0095] Optionally, the second signal may include at least one of the following:

[0096] Reference chirp signal;

[0097] Unmodulated CSS signal;

[0098] Modulated CSS signal.

[0099] Therefore, on the one hand, by using the CSS signal or chirp signal as the carrier signal, the power consumption and implementation complexity of the backscattering device can be reduced; on the other hand, by frequency shifting and filtering the frequency pair associated with the information bits to be transmitted on the CSS signal or reference chirp signal, the generated signal can satisfy the linear spread spectrum characteristics of the CSS signal, thereby utilizing the spread spectrum transmission characteristics of the CSS signal to achieve longer transmission coverage or transmission reliability.

[0100] Optionally, the filter can be a filter with a center frequency of f0 and a bandwidth of [missing information]. The filtering is performed where f0 is the center frequency of the second signal and BW is the bandwidth of the second signal.

[0101] Optionally, the first signal may satisfy, but is not limited to, at least one of the following:

[0102] The bandwidth of the first signal is the same as the bandwidth of the second signal;

[0103] The spreading factor of the first signal is the same as that of the second signal;

[0104] The symbol length of the first signal is the same as the symbol length of the second signal;

[0105] The slope of the linear frequency increase of the first signal is the same as the slope of the linear frequency increase of the second signal.

[0106] In one optional implementation, the second signal may be a reference chirp signal or an unmodulated CSS signal S1(t), and the relevant parameters of the second signal may include at least:

[0107] (I) Center frequency f0;

[0108] (II) Bandwidth BW;

[0109] (III) Spreading factor SF;

[0110] (IV) Single symbol length

[0111] (IIV) Starting sweep frequency; where the starting sweep frequency for each symbol is fixed, and is...

[0112] The unmodulated CSS signal S1(t) can be expressed in the following form:

[0113] In another alternative implementation, the second signal may be a modulated CSS signal S2(t), and the relevant parameters of the second signal may include at least:

[0114] (I) Center frequency f0;

[0115] (II) Bandwidth BW;

[0116] (III) Spreading factor SF;

[0117] (IV) Single symbol length

[0118] (IIV) The starting sweep frequency of each symbol; wherein, the starting sweep frequency of each symbol is related to the modulation information of the second signal, and is...

[0119] The modulated CSS signal S2(t) can be expressed in the following form:

[0120] In another alternative implementation, the second signal may be a hybrid signal of a reference chirp signal and a modulated CSS signal, such as a LoRa physical layer signal, and the relevant parameters of the second signal may include at least:

[0121] (I) Center frequency f0;

[0122] (II) Bandwidth BW;

[0123] (III) Spreading factor SF;

[0124] (IV) Single symbol length

[0125] In one optional embodiment, the first device (i.e., the backscattering device) can modulate the log2 M-bit information bits to be transmitted using a first signal, wherein the first signal is a second signal with a spreading factor of SF (1≤log2 M≤SF) after passing through frequency pairs (f... 2m-1 ,-f 2m The frequency shift of m∈{1,…,M} is added to the filtered signal to obtain the first signal, which may satisfy at least one of the following characteristics:

[0126] (a) Each symbol of the first signal carries log2 M information bits, and the symbol length is T. s ;

[0127] (b) The first signal is characterized by at least one of the following:

[0128] (I) The first signal C(t) is obtained by adding the first part C1(t) and the second part C2(t): C(t) = C1(t) + C2(t)

[0129] (II) The first part C1(t) is obtained by shifting the frequency of the second signal f 2m-1 (0≤f 2m-1 ≤BW,m∈{1,2, ... ,M}), and perform a test with a center frequency of f0 and a bandwidth of The signal generated after filtering:

[0130] (III) The second part C2(t) is obtained by frequency shifting the second signal by -f 2m (0≤f 2m ≤BW,m∈{1,2,...,M}), and perform a test with a center frequency of f0 and a bandwidth of [missing information]. The signal generated after filtering:

[0131] As mentioned above: 1) This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. 1) Filtering; 2) m is the log2 M-bit information bit of the m-th input in {1,…,M}; the mapping relationship between m and log2 M-bit information bits can be pre-configured by the network or protocol, and the mapping method can be one of Gray mapping, natural mapping, Contourwise-Gray mapping, etc.; 3) f 2m-1 +f 2m =BW, m∈{1,2,...,M}; and when k≠m, f 2m-1 ≠f 2k-1 f 2m ≠f 2k .

[0132] (c) The first signal and the second signal have the same parameters:

[0133] (I) Bandwidth (BW);

[0134] (II) Spreading factor SF;

[0135] (III) Slope of linear frequency growth

[0136] (IV) Symbol Length

[0137] Optionally, the signal transmission method in the embodiments of this application may further include:

[0138] The first device performs frequency shifting on the first signal; for example, it can perform f-shifting on the first signal. shift Frequency shifting.

[0139] The aforementioned transmission of the first signal may include: the first device transmitting the frequency-shifted first signal.

[0140] In this way, when both the carrier signal and the backscatter modulation signal are CSS signals, interference between the carrier signal and the backscatter modulation signal can be avoided by using frequency shifting.

[0141] In this embodiment, the first device can perform signal modulation based on configuration or indicated information. The modulation of the information bits to be transmitted to obtain the first signal may include:

[0142] The first device modulates the information bits to be transmitted based on the obtained first information to obtain a 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:

[0143] (a) The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; thus, the frequency values ​​contained in the associated frequency pair used for frequency shifting can be directly determined based on the information bits to be transmitted.

[0144] (b) The size of the Physical Resource Block (PRB), Resource Block Group (RBG), and / or Bandwidth Part (BWP) of the frequency pair used for frequency shifting associated with the information bits to be transmitted; thus, the frequency values ​​contained in the frequency pair used for frequency shifting can be indirectly determined based on the configured or indicated PRB\RGB\BWP sizes.

[0145] (c) 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.;

[0146] (d) The modulation order of the first signal, for example, the modulation order is M;

[0147] (e) The modulation rate or backscatter link frequency (BLF) of the first signal;

[0148] (f) 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;

[0149] (g) The coding rate of the first signal;

[0150] (h) The reflection coefficient or amplification coefficient of the first signal;

[0151] (i) 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. With the aid of the first index information, the first device can obtain the associated modulation and coding parameters, thereby generating the corresponding backscattered modulation signal (i.e., the first signal).

[0152] In this embodiment of the application, the first device may send a first signal based on configuration or indicated information. Sending the first signal may include:

[0153] The first device sends a first signal based on the obtained second information; the second information is information related to the transmission of the first signal, and the second information may include, but is not limited to, at least one of the following:

[0154] The transmission power of the first signal;

[0155] The preamble or synchronization sequence of the first signal;

[0156] The reference signal of the first signal can be used to estimate the channel or time-frequency information in the first signal;

[0157] The time-domain resource information of the first signal includes, for example, the number of times the signal is repeatedly transmitted, the signal period, the time slot configuration information, the subframe information, etc.

[0158] The frequency domain resource information of the first signal, such as frequency, bandwidth and other information;

[0159] The first signal's spatial resource information includes, for example, information such as antenna, codeword, layer, and antenna port.

[0160] In this embodiment, relevant information for receiving carrier signals can be configured or indicated for the first device. The signal transmission method described above may further include:

[0161] The first device receives the second signal based on the obtained third information; the third information may include, but is not limited to, at least one of the following:

[0162] Frequency domain correlation parameters of the second signal;

[0163] The time-domain correlation parameters of the second signal;

[0164] The signal waveform of the second signal;

[0165] The baseband signal parameters of the second signal;

[0166] The second index information is associated with the signal parameters of the second signal. This second index information indicates the signal parameters of the associated second signal. Different second index information corresponds to different signal parameters of the second signal. Each second index information can correspond to a set of signal parameters for the second signal, such as frequency-domain related parameters, time-domain related parameters, and / or signal waveforms. The corresponding relationships can be pre-configured by the network or protocol. Using the second index information, the first device can obtain the signal parameters of the associated second signal, thereby accurately receiving the second signal.

[0167] It should be noted that 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.

[0168] Optionally, the frequency domain correlation parameters of the second signal include, but are not limited to, at least one of the following:

[0169] (I) The center frequency of the second signal;

[0170] (II) The bandwidth of the second signal;

[0171] (III) The scanning start frequency of the second signal;

[0172] (IV) The scanning cutoff frequency of the second signal;

[0173] (V) The lowest scanning frequency of the second signal;

[0174] (VI) The highest scanning frequency of the second signal;

[0175] (VII) The slope of the scanning frequency of the second signal;

[0176] (VIII) The spreading factor of the second signal;

[0177] (IX) The chip rate of the second signal;

[0178] (X) The symbol rate or symbol period of the second signal;

[0179] (XI) The frequency sweeping method of the second signal, such as up-chirp mode or down-chirp mode;

[0180] (XII) The frequency offset or shift of the second signal.

[0181] Optionally, the time-domain correlation parameters of the second signal include, but are not limited to, at least one of the following:

[0182] (I) The time unit of the second signal, such as RE, time slot, subframe, etc.;

[0183] (II) The signal period of the second signal;

[0184] (III) The signal length of the second signal;

[0185] (IV) The number of time-domain repetitions of the second signal;

[0186] (V) The synchronization signal or synchronization sequence of the second signal.

[0187] Optionally, the signal waveform of the second signal may include, but is not limited to, at least one of the following:

[0188] Reference Chirp signal waveform;

[0189] CSS modulated signal waveform.

[0190] In one alternative embodiment, 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.

[0191] Optionally, the baseband signal parameters of the second signal may include at least one of the following:

[0192] (I) Modulation parameters of the second signal, such as including but not limited to modulation method, modulation order, modulation rate, etc.;

[0193] (II) The coding parameters of the second signal, such as 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., FM0 code, Miller code, Manchester code, etc.).

[0194] In this embodiment, the first device can obtain the first information in various ways. The signal transmission method may further include at least one of the following:

[0195] (a) The first device determines the first information, that is, the first device itself has the ability to determine the configuration information;

[0196] (b) The first device receives the first information from the second device, where the second device is the receiving device for the first signal; that is, at this time: the second device is both the receiving device for receiving the first signal and the 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.

[0197] (c) The first device receives the first information from the 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 first information; the third 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, a dedicated radio frequency source device, etc.

[0198] (d) The first device receives the first information from the fourth device, wherein the fourth device is a device with network scheduling function; the fourth device is different from the first device, the second device and the third device, and is a device with network scheduling function, such as a gateway, router, access network device, relay device, IAB device, Repeater device, terminal device, AP device, etc.

[0199] It should be noted that, in addition to the above-described methods of determining or configuring / indicating the first information, the first information may also be configured / indicated by at least two of the first to fourth devices.

[0200] Optionally, 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:

[0201] Radio Resource Control (RRC) signaling; this method requires the first device to have an RRC protocol layer;

[0202] Non-Access Stratum (NAS) signaling; this method requires the first device to have NSA protocol layer capabilities;

[0203] Medium Access Control Element (MAC CE); that is, using MAC CE signaling to configure the signal parameters of the first device. This is also applicable to first devices that do not support RRC signaling or have weak NAS signaling capabilities.

[0204] Downlink Control Information (DCI); This DCI is physical layer signaling, which dynamically indicates the first information through physical layer signaling;

[0205] Sidelink Control Information (SCI); This SCI is physical layer signaling, which dynamically indicates the first information through physical layer signaling;

[0206] 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.

[0207] 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.

[0208] It should be noted that 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.

[0209] Please refer to Figure 4, which is a flowchart of a signal transmission method provided in an embodiment of this application. This 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, or an AP device. As shown in Figure 4, the method includes the following steps:

[0210] Step 41: The second device receives the first signal sent by the first device; the first signal is obtained by modulating the information bits to be transmitted;

[0211] Step 42: The second device demodulates the first signal to obtain the information bits to be transmitted.

[0212] In this embodiment, the first signal is obtained by adding a first part and a second part. The first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, and the second part is 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 second signal. The first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting. The first signal is a backscattered modulated signal of the second signal. The second signal is the carrier signal of the first signal. The opposite frequency shift directions can be one positive and one negative, for example, if the first frequency is f... 2m-1 The second frequency is f 2m Then the second signal can be subjected to f 2m-1 The frequency shift (i.e., the positive direction) and the -f operation on the second signal 2m The frequency shift (i.e., the negative direction); or, the second signal can be subjected to -f 2m-1 The frequency shift (i.e., the negative direction) and the f-shift of the second signal 2m The frequency shift (i.e., the positive direction).

[0213] Optionally, the association between the information bits to be transmitted and the frequency pairs used for frequency shifting can be pre-configured by the network or protocol, and there are no limitations on this.

[0214] By using the scheme in the embodiments of this application, and by frequency shifting and filtering the carrier signal with frequency pairs associated with the information bits to be transmitted, the obtained first signal can satisfy the spread spectrum characteristics, thereby improving the transmission coverage of the first signal and achieving longer transmission coverage and transmission reliability.

[0215] Optionally, the second signal may include at least one of the following:

[0216] Reference chirp signal;

[0217] Unmodulated CSS signal;

[0218] Modulated CSS signal.

[0219] Therefore, on the one hand, by using the CSS signal or chirp signal as the carrier signal, the power consumption and implementation complexity of the backscattering device can be reduced; on the other hand, by frequency shifting and filtering the frequency pairs associated with the information bits to be transmitted in the CSS signal or chirp, 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.

[0220] It should be noted that the specific form of the second signal can be found in the above embodiments, and will not be repeated here.

[0221] Optionally, the filter can be a filter with a center frequency of f0 and a bandwidth of [missing information]. The filtering is performed where f0 is the center frequency of the second signal and BW is the bandwidth of the second signal.

[0222] Optionally, the first signal may satisfy, but is not limited to, at least one of the following:

[0223] The bandwidth of the first signal is the same as the bandwidth of the second signal;

[0224] The spreading factor of the first signal is the same as that of the second signal;

[0225] The symbol length of the first signal is the same as the symbol length of the second signal;

[0226] The slope of the linear frequency increase of the first signal is the same as the slope of the linear frequency increase of the second signal.

[0227] Optionally, when the second device demodulates the first signal, it can use a CSS signal demodulation method. For example, the first signal can be first mixed or despread using a reference despread signal, and then a Fast Fourier Transform (FFT) can be performed on the mixed signal to identify the peak position of the frequency point in the frequency domain and make input bit decisions.

[0228] In this embodiment, the second device can perform demodulation based on configuration or indicated information. The aforementioned demodulation of the first signal to obtain the information bits to be transmitted may include:

[0229] The second device demodulates the first 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:

[0230] (a) The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; thus, the information bits to be transmitted can be obtained by demodulation based on these frequency values;

[0231] (b) The size of the PRB, RBG and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted;

[0232] (c) 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.;

[0233] (d) The modulation order of the first signal, for example, the modulation order is M;

[0234] (e) The modulation rate of the first signal;

[0235] (f) 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.);

[0236] (g) The coding rate of the first signal;

[0237] (h) 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 to the first signal with the lowest sweep start frequency; or, when the frequency sweep mode of the first signal is down-chirp mode, the reference despread signal is conjugate to the first signal with the highest sweep start frequency; or, the reference despread signal is conjugate to the first signal; based on these signal parameters, the first signal can be demodulated;

[0238] (i) 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 h) above; the relevant correspondence may be pre-configured by the network or protocol.

[0239] Optionally, the signal parameters of the reference despread signal include at least one of the following:

[0240] (I) The frequency sweeping mode of the reference despreading signal; the frequency sweeping mode of the reference despreading signal is the opposite of the frequency sweeping mode of the first signal; that is, if the first signal adopts the up-chirp frequency sweeping mode, the reference despreading signal adopts the down-chirp scanning mode; if the first signal adopts the down-chirp frequency sweeping mode, the reference despreading signal adopts the up-chirp scanning mode.

[0241] (II) The lowest sweep frequency of the reference despread signal, which is the same as the lowest sweep frequency of the first signal;

[0242] (III) The highest sweep frequency of the reference despread signal, which is the same as the highest sweep frequency of the first signal;

[0243] (IV) The sweep start frequency of the reference despread signal is either the lowest or the highest sweep frequency; for example, if the reference despread signal is a down-chirp sweep, the corresponding sweep start frequency is the highest sweep frequency; or, if the reference despread signal is an up-chirp sweep, the corresponding sweep start frequency is the lowest sweep frequency.

[0244] (IIV) The sweep cutoff frequency of the reference despreading signal is either the lowest sweep frequency or the highest sweep frequency; for example, if the reference despreading signal is a down-chirp sweep, the corresponding sweep cutoff frequency is the lowest sweep frequency; or, if the reference despreading signal is an up-chirp sweep, the corresponding sweep cutoff frequency is the highest sweep frequency.

[0245] (IIIV) The center frequency of the reference despread signal, which is the same as the center frequency of the first signal;

[0246] (V) The bandwidth of the reference despread signal, which is the same as the bandwidth of the first signal;

[0247] (VI) The spreading factor of the reference despread signal, which is the same as the spreading factor of the first signal;

[0248] (VII) The code rate of the reference despread signal, which is the same as the code rate of the first signal;

[0249] (VIII) The symbol rate of the reference despread signal, wherein the symbol rate / symbol period of the reference despread signal is the same as the symbol rate / symbol period of the first signal.

[0250] In this embodiment of the application, the second device can receive the first signal based on configuration or indicated information. Receiving the first signal sent by the first device may include:

[0251] The second device receives the first signal based on the obtained fifth information; the fifth information may include, but is not limited to, at least one of the following:

[0252] The preamble or synchronization sequence of the first signal;

[0253] The reference signal of the first signal;

[0254] The time-domain resource information of the first signal includes, for example, the number of times the signal is repeatedly transmitted, the signal period, the time slot configuration information, the subframe information, etc.

[0255] The frequency domain resource information of the first signal, such as frequency, bandwidth and other information;

[0256] The first signal's spatial resource information includes, for example, information such as antenna, codeword, layer, and antenna port.

[0257] In this embodiment of the application, relevant information for transmitting a carrier signal (i.e., a second signal) can be configured or indicated for the second device. The above signal transmission method may further include:

[0258] The second device sends a second signal based on the obtained sixth information; the sixth information may include, but is not limited to, at least one of the following:

[0259] Frequency domain correlation parameters of the second signal;

[0260] The time-domain correlation parameters of the second signal;

[0261] The signal waveform of the second signal;

[0262] The baseband signal parameters of the second signal;

[0263] The second index information is associated with the signal parameters of the second signal. This second index information indicates the signal parameters of the associated second signal. Different second index information corresponds to different signal parameters of the second signal. Each second index information can correspond to a set of signal parameters for the second signal, such as frequency domain related parameters, time domain related parameters, and / or signal waveforms. The corresponding relationships can be pre-configured by the network or protocol. Using the second index information, the first device can obtain the signal parameters of the associated second signal, thereby accurately transmitting the second signal.

[0264] It should be noted that the specific content of the sixth information can be found in the description of the third information in the above embodiments, and will not be repeated here.

[0265] In this embodiment, the second device can obtain the fourth information in various ways. The signal transmission method may further include at least one of the following:

[0266] (a) The second device determines the fourth information, that is, the second device itself has the ability to determine the configuration information;

[0267] (b) The second device receives the fourth information from the first device;

[0268] (c) The second device receives the fourth information from the third device, which 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;

[0269] (d) The second device receives the first information from the 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.

[0270] It should be noted that the 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.

[0271] The application will be described below with reference to specific embodiments.

[0272] Example 1

[0273] In this first embodiment, as shown in Figure 5A, the second signal used for the radio frequency carrier is either a reference chirp signal or an unmodulated CSS signal S1(t). The second signal then satisfies the following characteristics:

[0274] (I) The center frequency is f0;

[0275] (II) Bandwidth is BW;

[0276] (III) The spreading factor is SF;

[0277] (IV) The length of a single symbol is

[0278] (IIV) The initial sweep frequency for each symbol is fixed, which is...

[0279] The (IIIV) signal S1(t) can be expressed as:

[0280] According to the method described in this application, in this first embodiment, second-order modulation (M=2) is considered, that is, the bit to be transmitted is "0" or "1". The frequency 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 C1(t) of the first signal; simultaneously, the frequency of the second signal is shifted by -f2 (0≤f2≤BW) or -f4 (0≤f4≤BW) and a frequency distribution with a center frequency of f0 and a bandwidth of [missing information]. The filtering process generates the second part C2(t) of the first signal, where f1+f2=BW, f3+f4=BW, f1≠f3, and f2≠f4. Finally, the first and second parts are added in the time domain to generate the first signal. Optionally, the first signal can be frequency-shifted by f... shift (f shift ≥0), thus avoiding self-interference or cross-link interference with the second signal in the second device (receiving end). In this embodiment, f is used as...shift =0, Let's take an example to illustrate.

[0281] The following diagrams, 5B and 5C, illustrate the signal modulation process of the transmitted bits when the second signal is the reference chirp signal or the unmodulated CSS signal.

[0282] (1) The transmitted bit is "0":

[0283] (a) For the initial scan frequency of The second signal is frequency shifted by f1 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the first part C1(t) of the first signal:

[0284] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 5B. The red dotted line represents the second signal before frequency shift, and the solid green line represents the first part of the first signal. The solid green line represents the portion of the signal within the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0285] (b) For the initial scan frequency of The second signal is frequency shifted by -f2 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the second part C2(t) of the first signal:

[0286] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 5B. The red dotted line represents the second signal before frequency shift, and the solid blue line represents the second part of the first signal. The solid blue line represents the portion of the signal within the bandwidth... The useful signal within, while the blue dashed line represents the bandwidth. External filtering signals.

[0287] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0288] (2) The transmitted bit is "1":

[0289] (a) For the initial scan frequency of The second signal is frequency shifted by f3 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the first part C1(t) of the first signal:

[0290] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 5C. The red dashed line represents the second signal before frequency shift, and the solid green part represents the first part of the first signal. The solid green part represents the signal within the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0291] (b) For the initial scan frequency of The second signal is frequency shifted by -f4 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the second part C2(t) of the first signal:

[0292] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 5C. The red dashed line represents the second signal before frequency shift, and the solid blue line represents the second part of the first signal. The solid blue line represents the portion of the signal within the bandwidth... The useful signal within, while the blue dashed line represents the bandwidth. External filtering signals.

[0293] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0294] Example 2

[0295] In this second embodiment, as shown in Figure 6A, the second signal used for the radio frequency carrier is the modulated CSS signal S2(t), which will also be explained using M=2 as an example. The second signal then satisfies the following characteristics:

[0296] (I) The center frequency is f0;

[0297] (II) Bandwidth is BW;

[0298] (III) The spreading factor is SF;

[0299] (IV) The length of a single symbol is

[0300] (IIV) The initial scan frequency of each symbol is related to the modulation information of the second signal, for

[0301] The (IIIV) signal S2(t) can be expressed as:

[0302] The modulated CSS signal shown in Figure 6A has SF=2, where the starting sweep frequency of the CSS signal representing bits "01" is... The starting scan frequency of the CSS signal, which represents bit "10", is f0.

[0303] According to the method described in this application, depending on whether the bit to be transmitted is "0" or "1", the frequency of the second signal can be frequency shifted by f1 (0≤f1≤BW) or f3 (0≤f3≤BW) respectively, and a center frequency of f0 and a bandwidth range of [missing information]. The filtering process generates the first part C1(t) of the first signal; simultaneously, the frequency of the second signal is shifted by -f2 (0≤f2≤BW) or -f4 (0≤f4≤BW) and a frequency distribution with a center frequency of f0 and a bandwidth of [missing information]. The filtering process generates the second part C2(t) of the first signal, where f1+f2=BW, f3+f4=BW, f1≠f3, and f2≠f4. Finally, the first and second parts of the first signal are added in the time domain to generate the first signal. Optionally, the first signal can be frequency-shifted by f... shift (f shift ≥0), thus avoiding self-interference or cross-link interference with the second signal in the second device (receiving end). In this second embodiment, f is used. shift =0, Let's take an example. Without loss of generality, the starting scan frequency of the second signal corresponding to the transmitted bit "0" is... The starting scan frequency f of the second signal corresponding to the transmitted bit "1" start =f0.

[0304] The following explanation, using Figures 6B and 6C, illustrates the signal modulation process of the transmitted bits when the second signal is a modulated CSS signal.

[0305] (1) The transmitted bit is "0":

[0306] (a) For the initial scan frequency of The second signal is frequency shifted by f1 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the first part C1(t) of the first signal:

[0307] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 6B. The red dotted line represents the modulated second signal (carrying bits "01") before frequency shift, and the solid green line represents the first part of the first signal. The solid green line represents the portion within the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0308] (b) For the initial scan frequency of The second signal is frequency shifted by -f2 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the second part C2(t) of the first signal:

[0309] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 6B. The red dotted line represents the second signal before frequency shift (carrying bit "10"), and the solid blue line represents the second part of the first signal. The solid blue line represents the portion of the signal within the bandwidth... The useful signal within, while the blue dashed line represents the bandwidth. External filtering signals.

[0310] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0311] (2) The transmitted bit is "1":

[0312] (a) Shift the frequency of the second signal, which has an initial scanning frequency of f0, by f3 and perform a frequency shift with a center frequency of f0 and a bandwidth range of f3. The filtering process generates the first part C1(t) of the first signal:

[0313] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 6C. The red dotted line represents the second signal before frequency shift, and the solid green line represents the first part of the first signal. The solid green line portion represents the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0314] (b) Shift the frequency of the second signal, which starts at scan frequency f0, by -f4 and perform a frequency shift with center frequency f0 and bandwidth range of f4. The filtering process generates the second part C2(t) of the first signal:

[0315] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. The filtering is shown in Figure 6C. The red dashed line represents the second signal before frequency shift, and the solid blue line represents the second part of the first signal. The solid blue line represents the portion of the signal within the bandwidth... The useful signal within, while the blue dashed line represents the bandwidth. External filtering signals.

[0316] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0317] Example 3

[0318] In this third embodiment, the corresponding demodulation process is given.

[0319] In one possible demodulation scheme, the second device, through configuration or instruction information, first performs despreading processing on the received first signal using the same 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 demodulation of the information bits based on the decision thresholds corresponding to bits "0" and "1". Since the starting scan frequencies of the first signal corresponding to bits "0" and "1" are different, the position of the first peak of the first signal and / or the difference between the second peak and the first peak can be used to determine whether the transmitted bit is "0" or "1". As shown in Figure 7, taking the parameters in this embodiment as an example, since the starting scan frequency for transmitting bit "0" is... The starting scan frequency of 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:

[0320] In another possible demodulation scheme, since CSS symbols with the same SF value but different starting scan frequencies, and CSS symbols with different SF values, exhibit quasi-orthogonality, the receiver can also use the maximum likelihood detection algorithm for demodulation. Specifically, the receiver first stores the first signal waveforms corresponding to different information bits. During demodulation, the first signals corresponding to different information bits are correlated with the received first signal, and the information bit with the largest correlation value is the corresponding demodulated information bit. This demodulation scheme is considered the optimal decision method in demodulation, with good BER or SER performance.

[0321] It is worth noting that the demodulation scheme corresponding to the modulation scheme in Embodiment 2 needs to consider the influence of the modulated signal of the second signal itself. Since the second signal is a modulated CSS signal, when demodulating the original information bits, it is necessary to first demodulate the information bits of the second signal itself and remove the influence of the second signal on the first signal from the receiving end, and then demodulate the original information bits 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. Then, when demodulating the first signal, the influence of the modulated information bits of the second signal is removed, and demodulation is performed using the same scheme as described above. In another feasible scheme, the second device can simultaneously demodulate the information bits of the first device and the information bits carried by the second signal through a joint demodulation decision.

[0322] Example 4

[0323] In the above embodiments one, two, and three, second-order modulation is used as an example, that is, each symbol of the first signal transmits only bit "0" or bit "1". However, 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. Without loss of generality, the following explanation 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.

[0324] When M(0≤M≤2) is realized in the first signal SF ()-order modulation, where each CSS symbol can carry log2 M bits. Based on the log2 M bits to be transmitted, the frequency of the second signal is shifted by f. 2m-1 (0≤f 2m-1 ≤BW,m∈{1,2,...,M}) and perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal; simultaneously, the frequency of the second signal is shifted by -f. 2m (0≤f2m ≤BW,m∈{1,2,...,M}) and perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal, where f 2m-1 +f 2m =BW,f 2m-1 ≠f 2n-1 (n≠m),f 2m ≠f 2n (n≠m). Finally, the first part of the first signal and the second part of the first signal are added together in the time domain to generate the first signal.

[0325] When M = 8, (f 2m-1 ,f 2m The possible values ​​for ) can be found in Table 1 below:

[0326] Table 1

[0327] Taking M=8 as an example, and using Gray mapping for bit-symbols, Table 1 gives one (f 2m-1 ,f 2m ),m∈{1,2, … Design example of ,M}. In this case, the first device implements 8th-order modulation in the first signal, where each CSS symbol can carry 3 bits. Based on the 3 bits to be transmitted, the frequency of the second signal is shifted by f. 2m-1 (0≤f 2m-1 ≤BW,m∈{1,2,...,8}) and perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal; simultaneously, the frequency of the second signal is shifted by -f. 2m (0≤f 2m ≤BW,m∈{1,2,…,8}) and perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal, where f 2m-1 +f 2m =BW,f 2m-1 ≠f 2n-1 (n≠m),f 2m ≠f 2n (n≠m). Finally, the first part of the first signal and the second part of the first signal are added together in the time domain to generate the first signal.

[0328] The modulation process in this embodiment will be described below with reference to Table 1.

[0329] (1) m = 1, the transmitted bits are “000”:

[0330] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0331] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0332] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0333] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0334] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0335] (2) m = 2, the transmitted bits are "001":

[0336] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0337] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0338] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0339] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0340] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0341] (3) m = 3, the transmitted bits are "011":

[0342] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0343] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0344] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0345] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0346] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0347] (4) m = 4, the transmitted bits are "010":

[0348] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0349] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0350] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0351] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0352] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0353] (5) m = 5, the transmitted bits are "110":

[0354] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0355] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0356] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0357] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0358] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0359] (6) m = 6, the transmitted bits are "111":

[0360] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0361] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0362] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0363] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0364] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0365] (7) m = 7, the transmitted bits are "101":

[0366] (a) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the first part C1(t) of the first signal:

[0367] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0368] (b) For the initial scan frequency of Second signal frequency shift And perform a test with a center frequency of f0 and a bandwidth of The filtering process generates the second part C2(t) of the first signal:

[0369] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0370] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0371] (8) m = 8, the transmitted bits are "100":

[0372] (a) For the initial scan frequency of The second signal is frequency-shifted by 0 and the center frequency is f0 with a bandwidth of [missing information]. The filtering process generates the first part C1(t) of the first signal:

[0373] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0374] (b) For the initial scan frequency of The second signal is frequency shifted by -BW and the center frequency is f0 with a bandwidth range of The filtering process generates the second part C2(t) of the first signal:

[0375] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0376] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0377] Correspondingly, when the second signal is a modulated CSS signal, the content can be expanded based on the content when the second signal is the reference CSS signal. Since the corresponding modulation methods are similar, they will not be described again here. The corresponding demodulation process can also be extended from the demodulation method in Embodiment 3 to demodulate higher-order modulations. The specific demodulation process will also not be described again.

[0378] 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.

[0379] Please refer to Figure 8, which is a schematic diagram of a signal transmission device provided in an embodiment of this application. This device is applied to a first device, such as a backscattering device. As shown in Figure 8, the signal transmission device 80 includes:

[0380] Modulation module 81 is used to modulate the information bits to be transmitted to obtain a first signal; wherein, the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulation signal of the second signal;

[0381] The transmitting module 82 is used to transmit the first signal.

[0382] Optionally, the second signal includes at least one of the following:

[0383] Reference chirp signal;

[0384] Unmodulated chirped spread spectrum (CSS) signal;

[0385] Modulated CSS signal.

[0386] Optionally, the filtering is performed with a center frequency of f0 and a bandwidth of [missing information]. The filtering is performed where f0 is the center frequency of the second signal and BW is the bandwidth of the second signal.

[0387] Optionally, the first signal satisfies at least one of the following:

[0388] The bandwidth of the first signal is the same as the bandwidth of the second signal;

[0389] The spreading factor of the first signal is the same as that of the second signal;

[0390] The symbol length of the first signal is the same as the symbol length of the second signal;

[0391] The slope of the linear frequency increase of the first signal is the same as the slope of the linear frequency increase of the second signal.

[0392] Optionally, the signal transmission device 80 further includes:

[0393] The processing module is used to frequency shift the first signal;

[0394] The transmitting module 82 is specifically used to transmit the frequency-shifted first signal.

[0395] Optionally, the modulation module 81 is specifically used to: modulate the information bits to be transmitted according to the obtained first information to obtain the first signal;

[0396] The first information includes at least one of the following:

[0397] The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted;

[0398] The size of the physical resource block (PRB), resource block group (RBG), and / or bandwidth portion (BWP) of the frequency pair associated with the information bits to be transmitted for frequency shifting.

[0399] The modulation method of the first signal;

[0400] The modulation order of the first signal;

[0401] The modulation rate or backscatter link frequency (BLF) of the first signal;

[0402] The encoding method of the first signal;

[0403] The coding rate of the first signal;

[0404] The reflection coefficient or amplification coefficient of the first signal;

[0405] A first index information associated with the modulation and coding of the first signal, the first index information being used to indicate the associated modulation and coding parameters.

[0406] Optionally, the sending module 82 is specifically used to: send the first signal according to the obtained second information;

[0407] The second information includes at least one of the following:

[0408] The transmission power of the first signal;

[0409] The preamble or synchronization sequence of the first signal;

[0410] The reference signal of the first signal;

[0411] The time-domain resource information of the first signal;

[0412] Frequency domain resource information of the first signal;

[0413] The spatial resource information of the first signal.

[0414] Optionally, the signal transmission device 80 further includes:

[0415] The first receiving module is used to receive the second signal based on the obtained third information;

[0416] The third information includes at least one of the following:

[0417] Frequency domain correlation parameters of the second signal;

[0418] The time-domain correlation parameters of the second signal;

[0419] The signal waveform of the second signal;

[0420] The baseband signal parameters of the second signal;

[0421] Second index information associated with the signal parameters of the second signal, the second index information being used to indicate the signal parameters of the associated second signal.

[0422] Optionally, the frequency domain correlation parameters of the second signal include at least one of the following:

[0423] The center frequency of the second signal;

[0424] The bandwidth of the second signal;

[0425] The scan start frequency of the second signal;

[0426] The scanning cutoff frequency of the second signal;

[0427] The lowest scanning frequency of the second signal;

[0428] The highest scanning frequency of the second signal;

[0429] The slope of the scanning frequency of the second signal;

[0430] The spreading factor of the second signal;

[0431] The chip rate of the second signal;

[0432] The symbol rate or symbol period of the second signal;

[0433] The frequency sweep method of the second signal;

[0434] The frequency offset or shift magnitude of the second signal.

[0435] Optionally, the time-domain correlation parameters of the second signal include at least one of the following:

[0436] The time unit of the second signal;

[0437] The signal period of the second signal;

[0438] The signal length of the second signal;

[0439] The number of time-domain repetitions of the second signal;

[0440] The second signal is a synchronization signal or synchronization sequence.

[0441] The signal transmission device 80 provided in this application embodiment can implement the various processes implemented in the method embodiment of FIG3 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0442] Please refer to Figure 9, which 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. As shown in Figure 9, the signal transmission device 90 includes:

[0443] The second receiving module 91 is used to receive a first signal sent by the first device; wherein the first signal is obtained by modulating the information bits to be transmitted; the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulated signal of the second signal;

[0444] The demodulation module 92 is used to demodulate the first signal to obtain the information bits to be transmitted.

[0445] Optionally, the demodulation module 92 is specifically used to: demodulate the first signal according to the obtained fourth information to obtain the information bits to be transmitted;

[0446] The fourth piece of information includes at least one of the following:

[0447] The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted;

[0448] The size of the PRB, RBG, and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted;

[0449] The modulation method of the first signal;

[0450] The modulation order of the first signal;

[0451] The modulation rate of the first signal;

[0452] The encoding method of the first signal;

[0453] The coding rate of the first signal;

[0454] 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 to the first signal with the lowest scan start frequency; or, when the frequency sweep mode of the first signal is down-chirp mode, the reference despread signal is conjugate to the first signal with the highest scan start frequency; or, the reference despread signal is conjugate to the first signal.

[0455] A third index information associated with the demodulation of the first signal, the third index information being used to indicate the associated demodulation parameters.

[0456] Optionally, the signal parameters of the reference despread signal include at least one of the following:

[0457] The frequency sweep method of the reference despread signal;

[0458] The lowest sweep frequency of the reference despread signal;

[0459] The highest sweep frequency of the reference despread signal;

[0460] The sweep start frequency of the reference despread signal;

[0461] The sweep cutoff frequency of the reference despread signal;

[0462] The center frequency point of the reference despread signal;

[0463] The bandwidth of the reference despread signal;

[0464] The spreading factor of the reference despread signal;

[0465] The code rate of the reference despread signal;

[0466] The symbol rate of the reference despread signal.

[0467] Optionally, the second receiving module 91 is specifically used to: receive the first signal according to the obtained fifth information;

[0468] The fifth piece of information includes at least one of the following:

[0469] The preamble or synchronization sequence of the first signal;

[0470] The reference signal of the first signal;

[0471] The time-domain resource information of the first signal;

[0472] Frequency domain resource information of the first signal;

[0473] The spatial resource information of the first signal.

[0474] The signal transmission device 90 provided in this application embodiment can implement the various processes implemented in the method embodiment of FIG4 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0475] As shown in Figure 10, this application embodiment also provides a communication device 100, including a processor 101 and a memory 102. The memory 102 stores a program or instructions that can run on the processor 101. For example, when the communication device 100 is a first device, when the program or instructions are executed by the processor 101, they implement the various steps of the signal transmission method embodiment shown in Figure 3 above, and achieve the same technical effect. When the communication device 100 is a second device, when the program or instructions are executed by the processor 101, 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 repeated here.

[0476] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described signal transmission method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0477] 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. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0478] 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.

[0479] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0480] 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.

[0481] 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.

[0482] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0483] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0484] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A signal transmission method, comprising: The first device modulates the information bits to be transmitted to obtain a first signal; wherein the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulated signal of the second signal; The first device sends the first signal.

2. The method according to claim 1, wherein, The second signal includes at least one of the following: Reference chirp signal; Unmodulated chirped spread spectrum (CSS) signal; Modulated CSS signal.

3. The method according to claim 1 or 2, wherein, The filtering is performed with a center frequency of f0 and a bandwidth range of... The filtering is performed where f0 is the center frequency of the second signal and BW is the bandwidth of the second signal.

4. The method according to any one of claims 1 to 3, wherein, The first signal satisfies at least one of the following: The bandwidth of the first signal is the same as the bandwidth of the second signal; The spreading factor of the first signal is the same as that of the second signal; The symbol length of the first signal is the same as the symbol length of the second signal; The slope of the linear frequency increase of the first signal is the same as the slope of the linear frequency increase of the second signal.

5. The method according to any one of claims 1 to 4, wherein, The method further includes: The first device performs frequency shifting on the first signal; Wherein, the first device sends the first signal, including: The first device transmits the frequency-shifted first signal.

6. The method according to any one of claims 1 to 5, wherein, The first device modulates the information bits to be transmitted to obtain a first signal, including: The first device modulates the information bits to be transmitted based on the first information obtained to obtain the first signal; The first information includes at least one of the following: The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; The size of the physical resource block (PRB), resource block group (RBG), and / or bandwidth portion (BWP) of the frequency pair associated with the information bits to be transmitted for frequency shifting. The modulation method 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 method of the first signal; The coding rate of the first signal; The reflection coefficient or amplification coefficient of the first signal; A first index information associated with the modulation and coding of the first signal, the first index information being used to indicate the associated modulation and coding parameters.

7. The method according to any one of claims 1 to 6, wherein, The first device sends the first signal, including: The first device sends the first signal based on the obtained second information; 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; Frequency domain resource information of the first signal; The spatial resource information of the first signal.

8. The method according to any one of claims 1 to 7, wherein, The method further includes: The first device receives the second signal based on the obtained third information; The third information includes at least one of the following: Frequency domain correlation parameters of the second signal; The time-domain correlation parameters of the second signal; The signal waveform of the second signal; The baseband signal parameters of the second signal; Second index information associated with the signal parameters of the second signal, the second index information being used to indicate the signal parameters of the associated second signal.

9. The method according to claim 8, wherein, 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 scanning cutoff frequency of the second signal; The lowest scanning frequency of the second signal; The highest scanning frequency of the second signal; The slope of the scanning 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 method of the second signal; The frequency offset or shift magnitude of the second signal.

10. The method according to claim 8, wherein, 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 number of time-domain repetitions of the second signal; The second signal is a synchronization signal or synchronization sequence.

11. A signal transmission method, comprising: The second device receives a first signal sent by the first device; wherein the first signal is obtained by modulating the information bits to be transmitted; the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulated signal of the second signal; The second device demodulates the first signal to obtain the information bits to be transmitted.

12. The method according to claim 11, wherein, The second device demodulates the first signal to obtain the information bits to be transmitted, including: The second device demodulates the first signal based on the obtained fourth information to obtain the information bits to be transmitted; The fourth piece of information includes at least one of the following: The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; The size of the PRB, RBG, and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted; The modulation method of the first signal; The modulation order of the first signal; The modulation rate of the first signal; The encoding method of the first signal; The coding 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 to the first signal with the lowest scan start frequency; or, when the frequency sweep mode of the first signal is down-chirp mode, the reference despread signal is conjugate to the first signal with the highest scan start frequency; or, the reference despread signal is conjugate to 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.

13. The method according to claim 12, wherein, The signal parameters of the reference despread signal include at least one of the following: The frequency sweep method of the reference despread signal; The lowest sweep frequency of the reference despread signal; The highest sweep frequency of the reference despread signal; The sweep start frequency of the reference despread signal; The sweep cutoff frequency of the reference despread signal; The center frequency point 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; The symbol rate of the reference despread signal.

14. The method according to any one of claims 11 to 13, wherein, The second device receives a first signal sent by the first device, including: The second device receives the first signal based on the obtained fifth information; The fifth piece of 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; Frequency domain resource information of the first signal; The spatial resource information of the first signal.

15. A signal transmission device, comprising: A modulation module is used to modulate the information bits to be transmitted to obtain a first signal; wherein the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering a second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering a second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulation signal of the second signal; A transmitting module is used to transmit the first signal.

16. The apparatus according to claim 15, wherein, The second signal includes at least one of the following: Reference chirp signal; Unmodulated chirped spread spectrum (CSS) signal; Modulated CSS signal.

17. The apparatus according to claim 15 or 16, wherein, The modulation module is specifically used to: modulate the information bits to be transmitted according to the obtained first information to obtain the first signal; The first information includes at least one of the following: The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; The size of the PRB, RBG, and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted; The modulation method 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 method of the first signal; The coding rate of the first signal; A first index information associated with the modulation and coding of the first signal, the first index information being used to indicate the associated modulation and coding parameters.

18. A signal transmission device, comprising: The second receiving module is used to receive a first signal sent by the first device; wherein the first signal is obtained by modulating the information bits to be transmitted; the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by frequency shifting and filtering the second signal at a first frequency, the second part is a signal obtained by frequency shifting and filtering the second signal at a second frequency, the frequency shifting 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 second signal, the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted for frequency shifting, and the first signal is a backscattered modulated signal of the second signal; The demodulation module is used to demodulate the first signal to obtain the information bits to be transmitted.

19. The apparatus according to claim 18, wherein, The demodulation module is specifically used to: demodulate the first signal according to the obtained fourth information to obtain the information bits to be transmitted; The fourth piece of information includes at least one of the following: The frequency values ​​contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; The size of the PRB, RBG, and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted; The modulation method of the first signal; The modulation order of the first signal; The modulation rate of the first signal; The encoding method of the first signal; The coding 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 to the first signal with the lowest scan start frequency; or, when the frequency sweep mode of the first signal is down-chirp mode, the reference despread signal is conjugate to the first signal with the highest scan start frequency; or, the reference despread signal is conjugate to 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.

20. A communication device comprising 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 signal transmission method as claimed in any one of claims 1 to 10, or the steps of the signal transmission method as claimed in any one of claims 11 to 14.

21. A readable storage medium storing a computer program that, when executed by a processor, implements the steps of the signal transmission method as claimed in any one of claims 1 to 10, or the steps of the signal transmission method as claimed in any one of claims 11 to 14.

22. A computer program product, said computer program product being executed by at least one processor to implement the steps of the signal transmission method as claimed in any one of claims 1 to 10, or the steps of the signal transmission method as claimed in any one of claims 11 to 14.

23. An electronic device comprising a device configured to perform the steps of the signal transmission method as claimed in any one of claims 1 to 10, or the steps of the signal transmission method as claimed in any one of claims 11 to 14.

24. A chip comprising 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 signal transmission method as claimed in any one of claims 1 to 10, or the steps of the signal transmission method as claimed in any one of claims 11 to 14.

Images