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

Abstract

The invention discloses a signal transmission method and device, communication equipment and a readable storage medium, and belongs to the technical field of communication, and the signal transmission method comprises the steps that first equipment 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 of a first frequency on the second signal, and the second part is a signal obtained by performing frequency shift and filtering of a second frequency 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 of the second signal, and the first frequency and the second frequency are frequency pairs associated with the information bits to be transmitted and used for frequency shift. The first signal is a backscattering modulation signal of the second signal; and sending the first signal.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication, and particularly relates to a signal transmission method and device, a communication device and a readable storage medium. BACKGROUND

[0002] 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 related art proposes to apply CSS modulation to a backscatter communication system. 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 method 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 transmission coverage is a problem that needs to be solved at present. SUMMARY

[0003] 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 transmission coverage.

[0004] In a first aspect, a signal transmission method is provided, which is executed by a first device, and the method comprises:

[0005] 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;

[0006] The first device transmits the first signal.

[0007] In a second aspect, a signal transmission method is provided, which is executed by a second device, and the method comprises:

[0008] The second device receives the first signal sent by the first device; wherein the first signal is obtained by modulating 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 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.

[0009] The second device demodulates the first signal to obtain the information bits to be transmitted.

[0010] In a third aspect, a signal transmission apparatus is provided, applied to a first device, and including:

[0011] 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 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 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.

[0012] A sending module is configured to send the first signal.

[0013] In a fourth aspect, a signal transmission apparatus is provided, applied to a second device, and including:

[0014] A second receiving module is configured to receive a first signal sent by a first device; wherein the first signal is obtained by modulating 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 a 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 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.

[0015] demodulating the first signal to obtain the information bits to be transmitted.

[0016] 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.

[0017] In a sixth aspect, a communication device is provided, which comprises a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being 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.

[0018] In a seventh aspect, a communication device is provided, which comprises 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; 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 a first device; the processor is configured to demodulate the first signal to obtain 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 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 backscattering modulation signal of the second signal.

[0019] In an eighth aspect, a readable storage medium is provided, which stores programs or instructions, the programs or instructions being executed by a 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 ninth aspect, a wireless communication system is provided, which comprises a first device and a second device, the first device being configured to perform the steps of the method according to the first aspect, and the second device being configured to perform the steps of the method according to the second aspect.

[0021] In a tenth aspect, a chip is provided, which comprises a processor and a communication interface, the communication interface being coupled to the processor, the processor being configured to run programs 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.

[0022] In an eleventh aspect, a computer program / program product is provided, which is stored in a storage medium, and is executed by at least one processor to implement the steps of the method according to the first aspect, or to implement the steps of the method according to the second aspect.

[0023] By means of the scheme in the embodiments of the present application, the first signal obtained can satisfy the spread spectrum characteristic by performing frequency shift and filtering on the carrier signal in association with the frequency pair of the information bits to be transmitted, so that the transmission coverage of the first signal is improved, and the transmission coverage and transmission reliability are realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1A 、 Figure 1B 、 Figure 1C 、 Figure 1D and Figure 1E are schematic diagrams of the communication architecture based on backscattering in the embodiments of the present application;

[0025] Figure 2A is a schematic diagram of the frequency uplink mode of CSS modulation in the embodiments of the present application;

[0026] Figure 2B is a schematic diagram of the frequency downlink mode of CSS modulation in the embodiments of the present application;

[0027] Figure 2C is a schematic diagram of the CSS modulation mode in the specific embodiments of the present application;

[0028] Figure 3 is a flowchart of a signal transmission method provided by the embodiments of the present application;

[0029] Figure 4 is a flowchart of another signal transmission method provided by the embodiments of the present application;

[0030] Figure 5A 、 Figure 5B and Figure 5C are schematic diagrams of the related signals of the modulation scheme in the first embodiment of the present application;

[0031] Figure 6A 、 Figure 6B and Figure 6C are schematic diagrams of the related signals of the modulation scheme in the second embodiment of the present application;

[0032] Figure 7 is a schematic diagram of the demodulation scheme in the third embodiment of the present application;

[0033] Figure 8 is a structural schematic diagram of a signal transmission device provided by the embodiments of the present application;

[0034] Figure 9 is a structural schematic diagram of another signal transmission device provided by an embodiment of the present application;

[0035] Figure 10 is a structural schematic diagram of a communication device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0036] 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, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0037] 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 those illustrated or described herein, and the objects distinguished by "first", "second" are generally a category and do not limit 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 including 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.

[0038] The term "indication" in the present application can be a direct indication (or explicit indication) or an indirect indication (or implicit indication). Among them, the direct indication can be understood as that the sender explicitly informs the receiver of specific information, operations to be performed or requested results, 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 requested result according to the judgment result.

[0039] It is worth noting that the technology described in the embodiments of the present application is not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described technology can be used in the above-mentioned systems and radio technologies, as well as in other systems and radio technologies. The following description describes a New Radio (NR) system for example purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th Generation (6G) communication systems. th

[0040] In order to facilitate understanding of the embodiments of the present application, the following is first described.

[0041] Backscatter Communication (BSC) refers to a backscatter communication device using radio frequency signals in other devices or environments 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:

[0042] - Antenna unit: used for receiving radio frequency signals, control commands, and at the same time for sending modulated backscatter signals.

[0043] - 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.

[0044] ​- Microcontroller: including controlling baseband signal processing, energy storage or data scheduling state, switch switching, system synchronization, etc.

[0045] - Signal receiving module: for demodulating control commands or data, etc. sent by the reverse scattering communication receiving end or other network nodes.

[0046] - 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.

[0047] - Memory or sensing module: for storing device identification ID information, location information or sensing data, etc.

[0048] 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 sending power of the sending end.

[0049] Optionally, the basic constituent modules and main functions of the reverse scattering communication receiving end include:

[0050] - Antenna unit: for receiving modulated reverse scattering signals.

[0051] - Reverse scattering signal detection module: for detecting the reverse scattering signal sent by the reverse scattering communication sending end, including but not limited to ASK detection, PSK detection, FSK detection or QAM detection, etc.

[0052] - Demodulation and decoding module: demodulating and decoding the detected signal to recover the original information stream.

[0053] 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:

[0054]

[0055] Where Z0 is the antenna characteristic impedance; 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 properly controlling the reflection coefficient, the 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.

[0056] In an implementation, according to the tag capability and the source of the capability, the tag can be divided into:

[0057] - 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 the carrier generation capability, relies on RF as the radio frequency carrier for backscatter communication transmission, and has the lowest power consumption;

[0058] - 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 the carrier generation capability, relies on RF as the radio frequency carrier for backscatter communication transmission, and has the second lowest power consumption;

[0059] - Device C: The tag is an active tag with energy storage capacitor / battery, relies on non-RF signal for energy supply, has the carrier generation capability, and has the highest power consumption.

[0060] Optionally, the backscatter-based communication architecture can include at least the following modes:

[0061] (1) Topology structure Topology 1: as Figure 1AAs shown, the base station in Topology 1 is both the RF source or transmitting device and the receiving device, so Topology 1 is a Monostatic Backscatter Communication System (MBCS) architecture. A traditional RFID system is a typical MBCS, which contains an Ambient IoT Device (such as a Tag) and a Reader (such as a base station), and the Tag communicates directly with the Reader, which can have a Frequency Division Duplexing (FDD) function module. In Topology 1, the transmitting device of the control signaling and the receiving device of the backscatter signal are the same device, and the transmitting device of the RF carrier source can be the same device as the aforementioned device or an independent device.

[0062] (2) Topology 2: As shown in Figure 1B , in Topology 2, the Ambient IoT Device (such as a Tag) receives the control signaling and the carrier signal transmitted by the intermediate node, which can be indicated by the network device (such as a base station gNB) through the intermediate node, which can be a User Equipment (UE), a repeater, an IAB node, etc. The intermediate node can also forward the IoT data to the gNB as a relay.

[0063] (3) Topology 3: Topology 3 involves a Bi-Static Backscatter Communication System (BBCS), in which the RF source, the BSC transmitting device, and the BSC receiving device are separate; in Topology 3, the Ambient IoT Device (such as a Tag) transmits IoT data / uplink signaling to the base station and receives data / signaling transmitted by the auxiliary node, as shown in Figure 1C , or the Ambient IoT Device (such as a Tag) transmits IoT data / uplink signaling to the auxiliary node and receives data / signaling transmitted by the base station, as shown in Figure 1D ; the base station communicates with the auxiliary node through a Uu interface, and the auxiliary node can be a UE, a repeater, an IAB, etc.

[0064] (4) Topology 4: As shown in Figure 1E , in Topology 4, the UE communicates with the Tag as a Reader. This architecture also belongs to a monostatic backscatter communication architecture, with the difference being that the Reader is a UE rather than a base station.

[0065] Chirp modulation, or Chirp spread spectrum (CSS) modulation, mainly uses a linear frequency modulation signal to carry information bits. Specifically, the CSS modulation signal is divided into an up-chirp mode (as shown in Figure 2A ) and a down-chirp mode (as shown in Figure 2B ). When using the up-chirp modulation, the frequency of the CSS modulation signal increases over time; when using the down-chirp mode, the frequency of the CSS modulation signal decreases over time. But the frequency of the CSS modulation signal is always periodically changed between a low frequency f1 and a high frequency f2 along a certain rule, the sweep bandwidth is BW = f2-f1, the sweep time is T s , and the sweep slope is If the Chirp signal is expressed as a baseband signal, the up-chirp signal and the down-chirp signal can be represented as:

[0066]

[0067] The two chirp signals described above, whether in up-chirp mode or down-chirp mode, cannot directly transmit information bits. Therefore, CSS modulation actually achieves different information transmission by changing the initial frequency of the pilot. Since the initial frequency of the scan is changed, the linear frequency growth will exceed the specified scan termination frequency f2 or f1 during the entire signal scan period. At this time, the CSS modulation specifies that once the scan frequency exceeds the upper limit frequency f2 or the lower limit frequency f1 of the scan, the subsequent scan frequency is directly reduced by BW or the subsequent scan frequency is added by BW.

[0068] In combination with the parameters of CSS modulation, several important parameters are defined, such as the spreading factor (Spreading Factor, SF), the chip (chirp), and the symbol rate / chip rate, which are described as follows.

[0069] (1) Spreading factor SF:

[0070] The spreading factor represents the number of information bits contained in each symbol, that is, 1 symbol is spread to 2 SF chips for transmission, and different symbols are also mapped to different CSS modulation initial frequencies. Taking SF = 2 as an example, a symbol can contain at most 2 bits, and can represent 2 2 = 4 values, such as 0-3, and the number of chips is 4. Taking the up-chirp mode as an example, in a frequency rising period, the frequency range that can be changed can be divided into 2SF one chip.

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

[0072] The chirp rate is the transmission rate of each chip, which can be expressed as:

[0073] R c = BW

[0074] The transmission time of each chip is:

[0075]

[0076] Since each CSS symbol has 2 SF chips, the transmission time of the symbol is:

[0077]

[0078] Based on the above definition, the slope of the linearly increasing frequency in CSS modulation is:

[0079]

[0080] Referring to Figure 2C , four symbols of CSS modulation are given as an example with SF = 2. Among them, the starting frequency of symbol 1 is f1, and increases linearly to f2, representing the bit 00; the starting frequency of symbol 2 is , and first increases linearly to f2, and then increases linearly to with f1 as the starting frequency, representing the bit 01; the starting frequency of symbol 3 is , and first increases linearly to f2, and then increases linearly to with f1 as the starting frequency, representing the bit 10; the starting frequency of symbol 4 is , and first increases linearly to f2, and then increases linearly to with f1 as the starting frequency, representing the bit 11. Therefore, if the starting frequency of the corresponding symbol can be demodulated, and the mapping of the starting frequency and the symbol is performed, the input bit before CSS modulation can be obtained.

[0081] In the corresponding demodulation process, a reference Chirp signal opposite to the CSS modulation mode can be used for mixing, and the input bit is finally demodulated through fast Fourier transform (FFT) calculation. For example, if the up-chirp signal with linearly increasing frequency from f1 to f2 is used for CSS modulation, the down-chirp signal with linearly decreasing frequency from f2 to f1 is used for mixing at the receiving end.

[0082] Assuming CSS modulation uses up-chirp mode, its baseband signal can be expressed as:

[0083]

[0084] 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:

[0085]

[0086] The CSS modulated signal can be a cyclically shifted frequency of a reference up-chirp signal, expressed as:

[0087] s(t;f n )=c(t;f n )w(t;0,t n )+c(t;f n -BW)w(t;t n ,T)

[0088] in, The starting frequency of the CSS modulation symbol. w(t;t a ,t b ) is a rectangular window function, expressed as:

[0089]

[0090] Therefore, for a CSS modulation symbol carrying SF bits, it has 2 SF Optional starting frequency point.

[0091] 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:

[0092]

[0093] 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.

[0094] 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.

[0095] 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.

[0096] Please see Figure 3 , Figure 3 This is a flowchart illustrating a signal transmission method provided in an embodiment of this application. The method is executed by a first device, such as a backscattering device. Figure 3 As shown, the method includes the following steps:

[0097] Step 31: The first device modulates the information bits to be transmitted to obtain the first signal;

[0098] Step 32: The first device sends the first signal.

[0099] 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.

[0100] 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).

[0101] Optionally, the association between the information bits to be transmitted and the frequency pairs for frequency shift can be pre-configured by the network or protocol, or indicated by the indication information, and no limitation is made thereto.

[0102] Optionally, the scheme in the embodiments of the present application can be applied to different Ambient IoT topologies, such as the topologies shown in Figure 1B , Figure 1C , and the like.

[0103] By means of the scheme in the embodiments of the present application, the first signal obtained by frequency shift and filtering of the carrier signal in association with the information bits to be transmitted can still satisfy the linear spread spectrum characteristic of the CSS signal, thereby improving the transmission coverage of the first signal and realizing a longer transmission coverage and transmission reliability.

[0104] Optionally, the second signal can include at least one of the following:

[0105] a reference Chirp signal;

[0106] an unmodulated CSS signal;

[0107] a modulated CSS signal.

[0108] Thus, on the one hand, by taking the CSS signal or the Chirp signal as the carrier signal, the power consumption and implementation complexity of the backscattering device end can be reduced; on the other hand, by frequency shift and filtering of the CSS signal or the reference Chirp signal in association with the information bits to be transmitted, the generated signal can satisfy the linear spread spectrum characteristic of the CSS signal, thereby realizing a longer transmission coverage or transmission reliability by utilizing the spread spectrum transmission characteristic of the CSS signal.

[0109] Optionally, the filtering can be filtering with a center frequency f0 and a bandwidth interval of , where the f0 is the center frequency of the second signal, and the BW is the bandwidth of the second signal.

[0110] Optionally, the first signal can satisfy, but is not limited to, at least one of the following:

[0111] the bandwidth of the first signal is the same as that of the second signal;

[0112] the spreading factor of the first signal is the same as that of the second signal;

[0113] the symbol length of the first signal is the same as that of the second signal;

[0114] the slope of the linear frequency increase of the first signal is the same as that of the second signal.

[0115] In an alternative embodiment, the second signal can be a reference Chirp signal or an unmodulated CSS signal S1(t), and the relevant parameters of the second signal can include at least:

[0116] (I) a center frequency f0;

[0117] (II) a bandwidth BW;

[0118] (III) a spreading factor SF;

[0119] (IV) a single-symbol length

[0120] (IIV) a starting chirp frequency; wherein the starting chirp frequency of each symbol is fixed at

[0121] The unmodulated CSS signal S1(t) can be expressed in the following form:

[0122]

[0123] In another alternative embodiment, the second signal can be a modulated CSS signal S2(t), and the relevant parameters of the second signal can include at least:

[0124] (I) a center frequency f0;

[0125] (II) a bandwidth BW;

[0126] (III) a spreading factor SF;

[0127] (IV) a single-symbol length

[0128] (IIV) a starting chirp frequency of each symbol; wherein the starting chirp frequency of each symbol is related to the modulation information of the second signal, and is

[0129] The modulated CSS signal S2(t) can be expressed in the following form:

[0130]

[0131] In another alternative embodiment, the second signal can 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 can include at least:

[0132] (I) a center frequency f0;

[0133] (II) a bandwidth BW;

[0134] (III) Spreading factor SF;

[0135] (IV) Single symbol length

[0136] 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:

[0137] (a) Each symbol of the first signal carries log2 M information bits, and the symbol length is T. s ;

[0138] (b) The first signal is characterized by at least one of the following:

[0139] (I) The first signal C(t) is obtained by adding the first part C1(t) and the second part C2(t):

[0140] C(t) = C1(t) + C2(t)

[0141] (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 [missing information]. The signal generated after filtering:

[0142]

[0143] (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:

[0144]

[0145] As mentioned above: 1) This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. filtering; 2) m is the log2 M-bit information bit of the m-th input, m ∈ {1,..., M}; the mapping relationship between m and the log2 M-bit information bit can be pre-configured by the network or protocol, and the mapping mode 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 .

[0146] (c) the first signal and the second signal are identical in the following parameters:

[0147] (I) bandwidth BW;

[0148] (II) spreading factor SF;

[0149] (III) frequency linear growth slope

[0150] (IV) symbol length

[0151] Optionally, the signal transmission method in the embodiments of the present application can further include:

[0152] The first device frequency shifts the first signal; for example, the first signal can be frequency shifted by f shift .

[0153] The above sending the first signal can include: the first device sending the frequency shifted first signal.

[0154] In this way, in the case that both the carrier signal and the backscatter modulated signal are CSS signals, by means of the frequency shifting operation, interference between the carrier signal and the backscatter modulated signal can be avoided.

[0155] In the embodiments of the present application, the first device can modulate the signal according to the configured or indicated information. The above modulating the information bit to be transmitted to obtain the first signal can include:

[0156] The first device modulates the information bit to be transmitted to obtain the first signal according to the obtained first information; the first information is information related to signal modulation, and the first information can include but is not limited to at least one of the following:

[0157] (a) the frequency value contained in the frequency pair for frequency shifting associated with the information bit to be transmitted; in this way, the frequency value contained in the frequency pair for frequency shifting associated with the information bit to be transmitted can be directly determined according to the information bit to be transmitted;

[0158] (b) the size of the physical resource block (PRB), resource block group (RBG) and / or bandwidth part (BWP) for frequency shift associated with the information bits to be transmitted; in this way, the frequency values contained in the frequency pair for frequency shift can be indirectly determined based on the size of the PRB\RGB\BWP configured or indicated;

[0159] (c) the modulation mode of the first signal, such as 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.;

[0160] (d) the modulation order of the first signal, such as the modulation order being M;

[0161] (e) the modulation rate or backscatter link frequency (BLF) of the first signal;

[0162] (f) the encoding mode of the first signal, such as but not limited to channel encoding mode, line encoding mode, etc.; the channel encoding mode is such as Reed-Solomon codes (RS codes), Polar codes, convolutional codes, repetition codes, etc.; the line encoding mode is such as FM0 encoding, Miller code, Manchester code, etc.; based on this encoding mode, the first device can generate a corresponding first signal;

[0163] (g) the coding rate of the first signal;

[0164] (h) the reflection coefficient or reflection signal amplification coefficient of the first signal;

[0165] (i) 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; wherein different first index information corresponds to different modulation and coding parameters, and each first index information can correspond to a set of modulation and coding parameters (as described in (a) to (h) above), and the corresponding relationship can be pre-configured by the network or protocol. With the first index information, the first device can obtain the associated modulation and coding parameters, thereby generating a corresponding backscatter modulation signal (i.e. the first signal).

[0166] In the embodiments of the present application, the first device can transmit the first signal according to the configured or indicated information. The above-mentioned transmitting the first signal can include:

[0167] The first device transmits the first signal according to obtained second information; the second information is information related to the transmission of the first signal, and the second information can include but is not limited to at least one of the following:

[0168] The transmission power of the first signal;

[0169] The preamble or synchronization sequence of the first signal;

[0170] The reference signal of the first signal, which can be used to estimate the channel or time-frequency information in the first signal;

[0171] The time domain resource information of the first signal, such as including the number of repeated transmissions of the signal, the signal period, the slot configuration information, the subframe information, etc.

[0172] The frequency domain resource information of the first signal, such as including the frequency, bandwidth, etc.

[0173] The spatial domain resource information of the first signal, such as including the antenna, code word, layer, antenna port, etc.

[0174] In the embodiments of the present application, the first device can be configured or indicated with related information for receiving a carrier signal. The above-mentioned signal transmission method can further include:

[0175] The first device receives the second signal according to obtained third information; the third information can include but is not limited to at least one of the following:

[0176] The frequency domain related parameter of the second signal;

[0177] The time domain related parameter of the second signal;

[0178] The signal waveform of the second signal;

[0179] The baseband signal parameter of the second signal;

[0180] The second index information associated with the signal parameter of the second signal, the second index information is used to indicate the signal parameter of the associated second signal; wherein 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 of the second signal, such as including the frequency domain related parameter, the time domain related parameter and / or the signal waveform, etc., and the relevant correspondence relationship can be pre-configured by the network or protocol. With the second index information, the first device can obtain the signal parameter of the associated second signal, so as to accurately receive the second signal.

[0181] It is pointed out that the second signal can be sent by the second device, i.e., at this time: the second device is both the receiving device receiving the first signal and the device providing the carrier signal for the first device; or the third device, which is the device providing the carrier signal; or the fourth device, which is the device different from the first device, the second device and the third device and having the network scheduling function, such as the gateway, the router, the access network device, the relay device, the IAB device, the Repeater device, the terminal device, the AP device, etc.

[0182] Optionally, the frequency domain related parameters of the second signal include but are not limited to at least one of the following:

[0183] (I) the center frequency point of the second signal;

[0184] (II) the bandwidth of the second signal;

[0185] (III) the scanning start frequency of the second signal;

[0186] (IV) the scanning cutoff frequency of the second signal;

[0187] (V) the scanning minimum frequency of the second signal;

[0188] (VI) the scanning maximum frequency of the second signal;

[0189] (VII) the slope of the scanning frequency of the second signal;

[0190] (VIII) the spreading factor of the second signal;

[0191] (IX) the chip rate of the second signal;

[0192] (X) the symbol rate or symbol period of the second signal;

[0193] (XI) the frequency sweeping mode of the second signal, such as the up-chirp mode or the down-chirp mode;

[0194] (XII) the frequency offset or frequency shift size of the second signal.

[0195] Optionally, the time domain related parameters of the second signal include but are not limited to at least one of the following:

[0196] (I) the time unit of the second signal, such as the RE, the slot, the subframe, etc.

[0197] (II) the signal period of the second signal;

[0198] (III) the signal length of the second signal;

[0199] (IV) the number of time-domain repetitions of the second signal;

[0200] (V) a synchronization signal or a synchronization sequence of the second signal.

[0201] Optionally, the signal waveform of the second signal can include, but is not limited to, at least one of the following:

[0202] a reference Chirp signal waveform;

[0203] a CSS modulated signal waveform.

[0204] In an optional embodiment, the second signal is a hybrid signal of a reference Chirp signal and a CSS modulated signal, such as a CSS modulated signal with a frame structure, and the signal of the frame structure at least includes a CSS modulated signal or a reference Chirp signal; the hybrid signal is, for example, a LoRa signal.

[0205] Optionally, the baseband signal parameters of the second signal can include at least one of the following:

[0206] (I) modulation parameters of the second signal, such as, but not limited to, a modulation mode, a modulation order, a modulation rate, etc.;

[0207] (II) encoding parameters of the second signal, such as, but not limited to, a channel encoding mode (such as: RS code, Polar code, convolutional code, repetition code, etc.), or a line encoding mode (such as: FM0 code, Miller code, Manchester code, etc.).

[0208] In the embodiments of the present application, the first device can obtain the first information in multiple ways. The signal transmission method can further include at least one of the following:

[0209] (a) the first device determines the first information, i.e., the first device itself has the ability to determine the configuration information;

[0210] (b) the first device receives the first information from the second device, and the second device is a receiving device of the first signal; that is, at this time: the second device is both a receiving device of the first signal and a device for configuring or indicating the first information; the second device can be an access network device such as a base station, a terminal device such as a UE, a relay device, a Repeater device, an IAB device, an AP device, etc.

[0211] (c) the first device receives the first information from a third device, the third device being a device providing the carrier signal; that is, at this time: the third device is both a device providing the carrier signal for the first device and a device configuring or indicating the first information; the third device can be an access network device such as a base station, a terminal device such as a UE, a relay device, a Repeater device, an IAB device, an AP device, a dedicated radio frequency source device, etc.

[0212] (d) the first device receives the first information from a fourth device, the fourth device being a device with network scheduling function; the fourth device is a device with network scheduling function different from the first device, the second device and the third device, such as a gateway, a router, an access network device, a relay device, an IAB device, a Repeater device, a terminal device, an AP device, etc.

[0213] It should be noted that in addition to the above-mentioned ways of determining or configuring / indicating the first information, the first information can also be configured / indicated by at least two of the first device to the fourth device.

[0214] Optionally, when the first information is received by the first device, the first information can be configured or indicated by at least one of the following:

[0215] Radio Resource Control (RRC) signaling; this requires the first device to have an RRC protocol layer;

[0216] Non-Access Stratum (NAS) signaling; this requires the first device to have an NSA protocol layer;

[0217] Medium Access Control Control Element (MAC CE); that is, the signal parameters of the first device are configured by MAC CE signaling, which is also applicable to the first device with weak capability that does not support RRC signaling or NAS signaling;

[0218] Downlink Control Information (DCI); this DCI is physical layer signaling, that is, the first information is dynamically indicated by physical layer signaling;

[0219] Sidelink Control Information (SCI); this SCI is physical layer signaling, that is, the first information is dynamically indicated by physical layer signaling;

[0220] Layer 1 or physical layer signaling, such as a physical frame header and preamble carrying control information, which can be placed in the same physical frame as the valid data payload, or which can be placed in a separate physical frame;

[0221] Factory configuration information or default configuration information; for example, when the first device accesses the network for the first time or does not support RRC configuration information, the system configures the signal parameters related to the first signal.

[0222] It should be noted that the second information and the third information can be configured / indicated in the same way as the first information, and details are not repeated here.

[0223] Please refer to Figure 4 , Figure 4 is a flowchart of a signal transmission method provided by an embodiment of the present application. The method is performed by a second device, such as an access network device, a terminal device, a relay device, a Repeater device, an IAB device, an AP device, etc. As shown in Figure 4 , the method includes the following steps:

[0224] Step 41: The second device receives a first signal sent by a first device; the first signal is obtained by modulating information bits to be transmitted;

[0225] Step 42: The second device demodulates the first signal to obtain the information bits to be transmitted.

[0226] In an embodiment of the present application, 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 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. The second signal is a carrier signal of the first signal. The above-mentioned opposite frequency shifting directions can be one positive direction frequency shift and the other negative direction frequency shift, for example: if the first frequency is f 2m-1 , and the second frequency is f 2m , then the second signal can be frequency shifted by f 2m-1 (i.e. positive direction), and the second signal can be frequency shifted by-f 2m (i.e. negative direction); or, the second signal can be frequency shifted by-f 2m-1 (i.e. negative direction), and the second signal can be frequency shifted by f 2m (i.e. positive direction).

[0227] Optionally, the association relationship between the information bits to be transmitted and the frequency pairs for frequency shift can be pre-configured by the network or protocol, and no limitation is made thereto.

[0228] By means of the scheme in the embodiments of the present application, the first signal obtained can satisfy the spread spectrum characteristic by means of frequency shift and filtering of the carrier signal in association with the information bits to be transmitted, so as to improve the transmission coverage of the first signal, and realize further transmission coverage and transmission reliability.

[0229] Optionally, the second signal can include at least one of the following:

[0230] a reference chirp signal;

[0231] an unmodulated CSS signal;

[0232] a modulated CSS signal.

[0233] Thus, on one hand, by taking the CSS signal or chirp signal as the carrier signal, the power consumption and implementation complexity of the backscattering device end can be reduced; on the other hand, by frequency shift and filtering of the CSS signal or chirp in association with the information bits to be transmitted, the generated signal can satisfy the linear spread spectrum characteristic of the CSS signal, so as to realize further transmission coverage or transmission reliability by means of the transmission characteristic of the CSS signal.

[0234] It is to be noted that the specific form of the second signal can be referred to the description in the above embodiments, and will not be described herein.

[0235] Optionally, the filtering can be filtering with a center frequency point f0 and a bandwidth interval of , wherein the f0 is the center frequency of the second signal, and the BW is the bandwidth of the second signal.

[0236] Optionally, the first signal can satisfy at least one of the following, but is not limited thereto:

[0237] the bandwidth of the first signal is the same as the bandwidth of the second signal;

[0238] the spreading factor of the first signal is the same as the spreading factor of the second signal;

[0239] the symbol length of the first signal is the same as the symbol length of the second signal;

[0240] 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.

[0241] Optionally, the second device can demodulate the first signal in the manner of demodulating the CSS signal. For example, the first signal is mixed or despread with a reference despread signal first, and then a fast Fourier transform (FFT) is performed on the mixed signal to identify the frequency peak position in the frequency domain and make a bit decision.

[0242] In the embodiments of the present application, the second device can demodulate according to the configured or indicated information. The above-mentioned demodulation of the first signal to obtain the information bits to be transmitted can include:

[0243] The second device demodulates the first signal according to the obtained fourth information to obtain the information bits to be transmitted; the fourth information is information related to the demodulation parameter, and the fourth information can include but is not limited to at least one of the following:

[0244] (a) a frequency value contained in a frequency pair associated with the information bits to be transmitted for frequency shift; in this way, the information bits to be transmitted can be demodulated based on the frequency value;

[0245] (b) the size of the PRB, RBG and / or BWP of the frequency pair associated with the information bits to be transmitted for frequency shift;

[0246] (c) the modulation mode of the first signal, such as 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.;

[0247] (d) the modulation order of the first signal, such as the modulation order M;

[0248] (e) the modulation rate of the first signal;

[0249] (f) the encoding mode of the first signal, such as but not limited to a channel encoding mode (such as RS code, Polar code, convolutional code, repetition code, etc.) or a line encoding mode (such as FM0 code, Miller code, Manchester code, etc.);

[0250] (g) the coding rate of the first signal;

[0251] (h) a signal parameter of a reference de-spreading signal corresponding to the first signal; wherein, when the sweep mode of the first signal is up-chirp mode, the reference de-spreading signal is conjugate to the first signal with the lowest frequency as the starting frequency of the sweep; or, when the sweep mode of the first signal is down-chirp mode, the reference de-spreading signal is conjugate to the first signal with the highest frequency as the starting frequency of the sweep; or, the reference de-spreading signal is conjugate to the first signal; based on the signal parameter, the first signal can be demodulated;

[0252] (i) third index information associated with the demodulation of the first signal, the third index information being used to indicate the associated demodulation parameter; wherein different third index information is associated with different demodulation parameters of the first signal, and each third index information can correspond to a set of demodulation parameters of the first signal, such as a) to h) described above; the corresponding relationship can be pre-configured by the network or protocol.

[0253] Optionally, the signal parameter of the reference de-spreading signal comprises at least one of the following:

[0254] (I) the sweep mode of the reference de-spreading signal; the sweep mode of the reference de-spreading signal is opposite to the sweep mode of the first signal; that is, if the first signal adopts up-chirp sweep mode, the reference de-spreading signal adopts down-chirp sweep mode; if the first signal adopts down-chirp sweep mode, the reference de-spreading signal adopts up-chirp sweep mode;

[0255] (II) the lowest sweep frequency of the reference de-spreading signal, which is the same as the lowest sweep frequency of the first signal;

[0256] (III) the highest sweep frequency of the reference de-spreading signal, which is the same as the highest sweep frequency of the first signal;

[0257] (IV) the starting frequency of the sweep of the reference de-spreading signal, which is the lowest sweep frequency or the highest sweep frequency; for example, if the reference de-spreading signal is down-chirp sweep mode, the corresponding starting frequency of the sweep is the highest sweep frequency; or, if the reference de-spreading signal is up-chirp sweep mode, the corresponding starting frequency of the sweep is the lowest sweep frequency;

[0258] (IIV) the sweep cutoff frequency of the reference de-spreading signal, which is the lowest sweep frequency or the highest sweep frequency; for example, if the reference de-spreading signal is down-chirp sweep mode, the corresponding sweep cutoff frequency is the lowest sweep frequency; or, if the reference de-spreading signal is up-chirp sweep mode, the corresponding sweep cutoff frequency is the highest sweep frequency;

[0259] (IIIV) a center frequency of the reference despreading signal, the center frequency of the reference despreading signal being the same as a center frequency of the first signal;

[0260] (V) a bandwidth of the reference despreading signal, the bandwidth of the reference despreading signal being the same as a bandwidth of the first signal;

[0261] (VI) a spreading factor of the reference despreading signal, the spreading factor of the reference despreading signal being the same as a spreading factor of the first signal;

[0262] (VII) a code rate of the reference despreading signal, the code rate of the reference despreading signal being the same as a code rate of the first signal;

[0263] (VIII) a symbol rate of the reference despreading signal, the symbol rate / symbol period of the reference despreading signal being the same as a symbol rate / symbol period of the first signal.

[0264] In the embodiments of the present application, the second device can receive the first signal according to the configured or indicated information. The above receiving the first signal sent by the first device can include:

[0265] The second device receives the first signal according to the obtained fifth information; the fifth information can include but is not limited to at least one of the following:

[0266] a preamble or a synchronization sequence of the first signal;

[0267] a reference signal of the first signal;

[0268] time domain resource information of the first signal, such as including a number of repeated transmissions of the signal, a signal period, time slot configuration information, subframe information, etc.;

[0269] frequency domain resource information of the first signal, such as including frequency, bandwidth, etc. information;

[0270] spatial domain resource information of the first signal, such as including antenna, codeword, layer, antenna port, etc. information.

[0271] In the embodiments of the present application, the second device can be configured or indicated with related information for transmitting a carrier signal (i.e. a second signal). The above signal transmission method can further include:

[0272] The second device transmits the second signal according to the obtained sixth information; the sixth information can include but is not limited to at least one of the following:

[0273] frequency domain related parameters of the second signal;

[0274] time domain related parameters of the second signal;

[0275] a signal waveform of the second signal;

[0276] a baseband signal parameter of the second signal;

[0277] second index information associated with the signal parameter of the second signal, the second index information being used to indicate the associated signal parameter of the second signal; wherein different second index information corresponds to different signal parameter of the second signal, and each second index information can correspond to a set of signal parameter of the second signal, such as including frequency domain related parameters, time domain related parameters and / or signal waveform, etc., and the related correspondence can be pre-configured by network or protocol. With the second index information, the first device can obtain the signal parameter of the associated second signal, so as to accurately send the second signal.

[0278] It is pointed out that the specific content included in the sixth information can refer to the description of the third information in the above embodiments, which will not be repeated here.

[0279] In the embodiments of the present application, the second device can obtain the fourth information in multiple ways. The signal transmission method can further include at least one of the following:

[0280] (a) The second device determines the fourth information, i.e., the second device itself has the ability to determine the configuration information;

[0281] (b) The second device receives the fourth information from the first device;

[0282] (c) The second device receives the fourth information from the third device, and the third device is a device providing a carrier signal; that is, at this time: the third device is a device providing a carrier signal for the first device, and also a device configuring or indicating the fourth information;

[0283] (d) The second device receives the first information from the fourth device, and the fourth device is a device with network scheduling function; and the fourth device is a device different from the first device, the second device and the third device.

[0284] It is pointed out that the fifth information and the sixth information can be configured / indicated in the same way as the fourth information, and details will not be repeated here to avoid repetition.

[0285] The application will be described in detail below with reference to specific embodiments.

[0286] Embodiment one

[0287] In this embodiment one, as shown in FIG. 1, the second signal for the radio frequency carrier is a reference Chirp signal or an unmodulated CSS signal S1(t), at this time the second signal satisfies the following characteristics: Figure 5A

[0288] ​(I) the center frequency is f0;

[0289] (II) the bandwidth is BW;

[0290] (III) the spreading factor is SF;

[0291] (IV) the single-symbol length is

[0292] (IIV) the starting sweeping frequency of each symbol is fixed, being

[0293] (IIIV) the signal S1(t) can be expressed as:

[0294]

[0295] According to the method of the scheme of the present application, in the first embodiment, the second order modulation (M=2) is considered, i.e. the bit to be transmitted is "0" or "1", the frequency of the second signal is shifted by f1 (0≤f1≤BW) or f3 (0≤f3≤BW) respectively and filtered with the center frequency f0 and the bandwidth interval , thereby generating the first part C1(t) of the first signal; meanwhile, the frequency of the second signal is shifted by -f2 (0≤f2≤BW) or -f4 (0≤f4≤BW) respectively and filtered with the center frequency f0 and the bandwidth interval , thereby generating the second part C2(t) of the first signal, wherein f1+f2=BW, f3+f4=BW, f1≠f3, f2≠f4. Finally, the first part and the second part are added in the time domain, thereby generating the first signal. Optionally, the first signal can be shifted by f shift (f shift ≥0), thereby avoiding self-interference or cross-link interference with the second signal at the second device (the receiving end). In the first embodiment, f shift =0, is taken as an example for illustration.

[0296] The signal modulation process of the transmission bit when the second signal is the reference Chirp signal or the unmodulated CSS signal is illustrated below. Figure 5B Figure 5C The signal modulation process of the transmission bit when the second signal is the reference Chirp signal or the unmodulated CSS signal is illustrated below.

[0297] (1) the transmission bit is "0":

[0298] (a) the second signal with the starting sweeping frequency is shifted by f1 and filtered with the center frequency f0 and the bandwidth interval , thereby generating the first part C1(t) of the first signal: ​

[0299]

[0300] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval As shown in Figure 5B , the red dotted line is the second signal before frequency shift, and the solid green part represents the first part of the first signal, wherein: the solid green part represents the useful signal within the bandwidth , and the dotted green part represents the filtered signal outside the bandwidth

[0301] (b) frequency shift the second signal with a starting scanning frequency by -f2and filter it with a center frequency f0and a bandwidth interval , thereby generating the second part C2(t) of the first signal:

[0302]

[0303] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval As shown in Figure 5B , the red dotted line is the second signal before frequency shift, and the solid blue part represents the second part of the first signal, wherein: the solid blue part represents the useful signal within the bandwidth , and the dotted blue part represents the filtered signal outside the bandwidth

[0304] (c) add the first part of the first signal and the second part of the first signal, thereby obtaining the first signal:

[0305]

[0306] (2) the transmission bit is "1":

[0307] (a) frequency shift the second signal with a starting scanning frequency by f3and filter it with a center frequency f0and a bandwidth interval , thereby generating the first part C1(t) of the first signal:

[0308]

[0309] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval As shown in Figure 5C , the red dotted line is the second signal before frequency shift, and the solid green part represents the first part of the first signal, wherein: the solid green part represents the useful signal within the bandwidth​​ useful signal within the bandwidth rejection signal outside the bandwidth

[0310] (b) frequency shift the second signal by -f4and filter with a center frequency f0and a bandwidth interval , thereby generating a second portion C2(t) of the first signal:

[0311]

[0312] wherein represents filtering the signal with a center frequency f0and a bandwidth interval . As shown in Figure 5C , the red dotted line is the second signal before frequency shift, and the solid blue portion represents the second portion of the first signal, wherein: the blue solid portion represents the useful signal within the bandwidth , and the blue dotted portion represents the rejection signal outside the bandwidth

[0313] (c) add the first portion of the first signal and the second portion of the first signal, thereby obtaining the first signal:

[0314]

[0315] Example Two

[0316] In this Example Two, as shown in Figure 6A , the second signal for the radio frequency carrier is a modulated CSS signal S2(t), which is also illustrated by taking M=2 as an example. At this time, the second signal satisfies the following characteristics:

[0317] (I) the center frequency is f0;

[0318] (II) the bandwidth is BW;

[0319] (III) the spreading factor is SF;

[0320] (IV) the single symbol length is

[0321] (IIV) the starting scanning frequency of each symbol is related to the modulation information of the second signal, which is

[0322] (IIIV) the signal S2(t) can be represented as:

[0323]

[0324] Figure 6A ​​The modulated CSS signal 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.

[0325] 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.

[0326] The following is based on Figure 6B and Figure 6C The diagram illustrates the signal modulation process of the transmitted bits when the second signal is a modulated CSS signal.

[0327] (1) The transmitted bit is "0":

[0328] (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:

[0329]

[0330] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering. For example... Figure 6BAs shown, the red dotted dashed line represents the modulated second signal (carrying bits "01") before frequency shift, and the solid green part represents the first part of the first signal. The solid green part represents the portion within the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0331] (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:

[0332]

[0333] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering. For example... Figure 6B As shown, the red dotted dashed 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.

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

[0335]

[0336] (2) The transmitted bit is "1":

[0337] (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:

[0338]

[0339] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering. For example... Figure 6C As shown, the red dotted dashed 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 portion of the signal within the bandwidth... The useful signal within, while the green dashed line represents the bandwidth. External filtering signals.

[0340] (b) frequency shifting the second signal by -f4 and filtering with a center frequency f0 and a bandwidth interval of to generate a second portion C2(t) of the first signal:

[0341]

[0342] wherein, represents filtering with a center frequency f0 and a bandwidth interval of As shown in Figure 6C , the red dotted line is the second signal before frequency shifting, and the blue solid line represents the second portion of the first signal, wherein: the blue solid line represents the useful signal within the bandwidth , and the blue dotted line represents the filtered signal outside the bandwidth .

[0343] (c) adding the first portion of the first signal and the second portion of the first signal to obtain the first signal:

[0344]

[0345] Embodiment Three

[0346] In this embodiment three, a corresponding demodulation process is given.

[0347] In a possible demodulation scheme, the second device first performs despreading processing on the received first signal by using the same reference despread signal through configuration or indication information, and then finds the frequency point of the highest peak or the highest two peaks in the frequency domain through FFT processing, and completes demodulation of the information bits according to the decision threshold corresponding to the bit "0" and the bit "1". Since the starting scanning frequency of the first signal corresponding to the bit "0" and the bit "1" is different, the position of the first peak and / or the difference between the second peak and the first peak of the first signal can be used to determine whether the transmitted bit is "0" or "1". As shown in Figure 7 , taking the parameters in the embodiment one as an example, since the starting scanning frequency of the transmitted bit "0" is and the starting scanning frequency of the bit "1" is Therefore, the receiving end can determine whether the transmitted bit is "0" or "1" through the position of the highest peak of the FFT, and the demodulation rule is as follows:

[0348]

[0349] In another possible demodulation scheme, the received signal can also be demodulated by using the maximum likelihood detection algorithm, because the CSS symbols with the same SF value but different initial scanning frequencies and the CSS symbols with different SF values have quasi-orthogonal characteristics. Specifically, the receiver first stores the first signal waveforms corresponding to different information bits, and then performs correlation calculation on the first signal corresponding to different information bits and the received first signal in the demodulation process, where the information bit with the maximum correlation value is the information bit corresponding to the demodulated information bit. This demodulation scheme belongs to the optimal decision method in demodulation, and has better BER or SER performance.

[0350] It is worth noting that the demodulation scheme corresponding to the modulation scheme of the second embodiment needs to consider the influence of the second signal itself. Because the second signal is a modulated CSS signal, when demodulating the original information bit, the information bit of the second signal itself needs to be demodulated first, and the influence of the second signal on the first signal needs to be removed from the receiver, and then the original information bit is demodulated according to the modulation rule of the information bit. A feasible scheme is that because the second signal received by the second device from the first device has a strength greater than that of the first signal, the second device can first demodulate the information bit of the second signal. Then, when demodulating the first signal, the influence of the modulated information bit of the second signal is removed, and the demodulation is performed by using the same scheme as described above. In another feasible scheme, the second device can simultaneously demodulate the information bit of the first device and the information bit carried by the second signal by using the joint demodulation decision method.

[0351] Embodiment four

[0352] In the above-mentioned embodiments one, two and three, the second-order modulation is taken as an example, that is, each symbol of the first signal only transmits bit “0” or bit “1”. However, the present scheme can also be extended to high-order modulation, so as to further improve the modulation rate or spectral efficiency of the first signal transmitted by the first device. Without loss of generality, the second signal is taken as a benchmark CSS signal or Chirp signal as an example for description, and the same scheme can be extended to the case where the second signal is a modulated CSS signal.

[0353] When M (0≤M≤2 SF order modulation is implemented in the first signal, each CSS symbol can carry log2 M bits. According to the log2 M bits to be transmitted, the frequency shift f 2m-1 (0≤f 2m-1 ≤BW, m∈{1, 2,..., M}) of the second signal is adjusted, and filtering is performed on the second signal with the center frequency f0 and the bandwidth interval , so as to generate the first part C1(t) of the first signal; at the same time, the frequency shift-f 2m (0≤f2m ≤ BW, m e {1, 2,..., M} and filtered with a filter whose center frequency is f0and bandwidth interval is 2m-1 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 in the time domain, thereby generating the first signal.

[0354] When M = 8, the value of (f 2m-1 , f 2m ) can be seen from the following table 1:

[0355] Table 1

[0356]

[0357] Taking M = 8 as an example, and when the bit-symbol adopts Gray mapping, table 1 gives a design example of (f 2m-1 , f 2m ), m e {1, 2,..., M}. At this time, the first device realizes 8-order modulation in the first signal, and at this time each CSS symbol can carry 3 bits. According to the 3 bits to be transmitted, the frequency shift f 2m-1 (0 ≤ f 2m-1 ≤ BW, m e {1, 2,..., 8}) of the second signal is performed and filtered with a filter whose center frequency is f0and bandwidth interval is , thereby generating the first part C1(t) of the first signal; at the same time, the frequency shift -f 2m (0 ≤ f 2m ≤ BW, m e {1, 2,..., 8}) of the second signal is performed and filtered with a filter whose center frequency is f0and bandwidth interval is , thereby generating the second part C2(t) of the first signal, wherein 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 in the time domain, thereby generating the first signal.

[0358] The modulation process in this embodiment is described below in combination with table 1.

[0359] (1) m = 1, the transmission bit is "000":

[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]

[0362] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0363] (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:

[0364]

[0365] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0366] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0367]

[0368] (2) m = 2, the transmitted bits are "001":

[0369] (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:

[0370]

[0371] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0372] (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:

[0373]

[0374] wherein, represents filtering of the signal with a center frequency f0and a bandwidth interval .

[0375] (c) adding the first portion of the first signal and the second portion of the first signal, thereby obtaining the first signal:

[0376]

[0377] (3) m = 3, the transmitted bits are "011":

[0378] (a) frequency shifting a second signal with a starting scan frequency by and filtering the signal with a center frequency f0and a bandwidth interval , thereby generating a first portion C1(t) of the first signal:

[0379]

[0380] wherein, represents filtering of the signal with a center frequency f0and a bandwidth interval .

[0381] (b) frequency shifting a second signal with a starting scan frequency by and filtering the signal with a center frequency f0and a bandwidth interval , thereby generating a second portion C2(t) of the first signal:

[0382]

[0383] wherein, represents filtering of the signal with a center frequency f0and a bandwidth interval .

[0384] (c) adding the first portion of the first signal and the second portion of the first signal, thereby obtaining the first signal:

[0385]

[0386] (4) m = 4, the transmitted bits are "010":

[0387] (a) frequency shifting a second signal with a starting scan frequency by and filtering the signal with a center frequency f0and a bandwidth interval , thereby generating a first portion C1(t) of the first signal:

[0388]

[0389] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval .

[0390] (b) frequency shifting a second signal with a starting scan frequency and filtering with a center frequency f0and a bandwidth interval , thereby generating a second portion C2(t) of the first signal:

[0391]

[0392] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval .

[0393] (c) adding the first portion of the first signal and the second portion of the first signal, thereby obtaining the first signal:

[0394]

[0395] (5) m = 5, the transmitted bits are "110":

[0396] (a) frequency shifting a second signal with a starting scan frequency and filtering with a center frequency f0and a bandwidth interval , thereby generating a first portion C1(t) of the first signal:

[0397]

[0398] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval .

[0399] (b) frequency shifting a second signal with a starting scan frequency and filtering with a center frequency f0and a bandwidth interval , thereby generating a second portion C2(t) of the first signal:

[0400]

[0401] wherein, represents filtering of a signal with a center frequency f0and a bandwidth interval .

[0402] ​​​(c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0403]

[0404] (6) m = 6, the transmitted bits are "111":

[0405] (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:

[0406]

[0407] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0408] (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:

[0409]

[0410] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0411] (c) Add the first part of the first signal and the second part of the first signal to obtain the first signal:

[0412]

[0413] (7) m = 7, the transmitted bits are "101":

[0414] (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:

[0415]

[0416] in, This indicates that the signal has a center frequency of f0 and a bandwidth of [value missing]. Filtering.

[0417] (b) shifting the second signal by -BW from the starting scan frequency of and filtering with a center frequency of f0 and a bandwidth interval of to generate a second portion C2(t) of the first signal:

[0418]

[0419] wherein represents filtering a signal with a center frequency of f0 and a bandwidth interval of

[0420] (c) adding the first portion of the first signal and the second portion of the first signal to obtain the first signal:

[0421]

[0422] (8) m = 8, the transmitted bits are "100":

[0423] (a) shifting the second signal by -BW from the starting scan frequency of and filtering with a center frequency of f0 and a bandwidth interval of to generate a first portion C1(t) of the first signal:

[0424]

[0425] wherein represents filtering a signal with a center frequency of f0 and a bandwidth interval of

[0426] (b) shifting the second signal by -BW from the starting scan frequency of and filtering with a center frequency of f0 and a bandwidth interval of to generate a second portion C2(t) of the first signal:

[0427]

[0428] wherein represents filtering a signal with a center frequency of f0 and a bandwidth interval of

[0429] (c) adding the first portion of the first signal and the second portion of the first signal to obtain the first signal:

[0430]

[0431] ​​​​Correspondingly, when the second signal is a modulated CSS signal, the extension can be based on the content when the second signal is a reference CSS signal. Since the corresponding modulation mode is similar, it will not be described again. And the corresponding demodulation process can also be extended based on the demodulation method in Embodiment Three to demodulate high-order modulation. The specific demodulation process will not be described again.

[0432] The signal transmission method provided in the embodiments of the present application can be executed by a signal transmission device. In the embodiments of the present application, the signal transmission method is executed by a signal transmission device as an example to illustrate the signal transmission device provided in the embodiments of the present application.

[0433] Please refer to Figure 8 , Figure 8 is a structural schematic diagram of a signal transmission device provided in the embodiments of the present application. The device is applied to a first device, such as a backscattering device and the like. As shown in Figure 8 , the signal transmission device 80 comprises:

[0434] a modulation module 81, 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 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 backscattering modulation signal of the second signal;

[0435] a sending module 82, configured to send the first signal.

[0436] Optionally, the second signal comprises at least one of the following:

[0437] a reference Chirp signal;

[0438] an unmodulated Chirp spread spectrum (CSS) signal;

[0439] a modulated CSS signal.

[0440] Optionally, the filtering is filtering with a center frequency point f0 and a bandwidth interval of , the f0 is a center frequency of the second signal, and the BW is a bandwidth of the second signal.

[0441] Optionally, the first signal satisfies at least one of the following:

[0442] The bandwidth of the first signal is the same as the bandwidth of the second signal.

[0443] The spreading factor of the first signal is the same as the spreading factor of the second signal.

[0444] The symbol length of the first signal is the same as the symbol length of the second signal.

[0445] The slope of the frequency linear growth of the first signal is the same as the slope of the frequency linear growth of the second signal.

[0446] Optionally, the signal transmission apparatus 80 further comprises:

[0447] a processing module, configured to perform frequency shift on the first signal.

[0448] The sending module 82 is specifically configured to send the first signal after frequency shift.

[0449] Optionally, the modulation module 81 is specifically configured to modulate the information bits to be transmitted according to the obtained first information, to obtain the first signal.

[0450] The first information comprises at least one of the following:

[0451] a frequency value contained in a frequency pair for frequency shift associated with the information bits to be transmitted;

[0452] a size of a physical resource block (PRB), a resource block group (RBG) and / or a bandwidth part (BWP) of the frequency pair for frequency shift associated with the information bits to be transmitted;

[0453] a modulation mode of the first signal;

[0454] a modulation order of the first signal;

[0455] a modulation rate or a backscatter link frequency (BLF) of the first signal;

[0456] an encoding mode of the first signal;

[0457] an encoding code rate of the first signal;

[0458] a reflection coefficient or a reflection signal amplification coefficient of the first signal;

[0459] first index information associated with modulation and encoding of the first signal, the first index information being used to indicate associated modulation and encoding parameters.

[0460] Optionally, the sending module 82 is specifically configured to send the first signal according to the obtained second information.

[0461] The second information includes at least one of the following:

[0462] The sending power of the first signal;

[0463] The preamble or synchronization sequence of the first signal;

[0464] The reference signal of the first signal;

[0465] The time domain resource information of the first signal;

[0466] The frequency domain resource information of the first signal;

[0467] The spatial domain resource information of the first signal.

[0468] Optionally, the signal transmission device 80 further includes:

[0469] The first receiving module is configured to receive the second signal according to the obtained third information;

[0470] The third information includes at least one of the following:

[0471] The frequency domain related parameter of the second signal;

[0472] The time domain related parameter of the second signal;

[0473] The signal waveform of the second signal;

[0474] The baseband signal parameter of the second signal;

[0475] The second index information associated with the signal parameter of the second signal, the second index information being used to indicate the associated signal parameter of the second signal.

[0476] Optionally, the frequency domain related parameter of the second signal includes at least one of the following:

[0477] The center frequency point of the second signal;

[0478] The bandwidth of the second signal;

[0479] The scanning start frequency of the second signal;

[0480] The scanning cutoff frequency of the second signal;

[0481] The scanning minimum frequency of the second signal;

[0482] The scanning maximum frequency of the second signal;

[0483] The slope of the scanning frequency of the second signal;

[0484] The spreading factor of the second signal;

[0485] a chip rate of the second signal;

[0486] a symbol rate or a symbol period of the second signal;

[0487] a sweep mode of the second signal;

[0488] a frequency offset or a frequency shift size of the second signal.

[0489] Optionally, the time domain related parameters of the second signal comprise at least one of:

[0490] a time unit of the second signal;

[0491] a signal period of the second signal;

[0492] a signal length of the second signal;

[0493] a time domain repetition number of the second signal;

[0494] a synchronization signal or a synchronization sequence of the second signal.

[0495] The signal transmission apparatus 80 provided by the embodiment of the present application can implement each process of the method embodiment and achieve the same technical effects. To avoid repetition, details are not described herein. Figure 3

[0496] Please refer to Figure 9 , Figure 9 is a structural schematic diagram of a signal transmission apparatus provided by the embodiment of the present application. The apparatus 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 apparatus 90 comprises:

[0497] a second receiving module 91, configured to receive a first signal sent by a first device; wherein the first signal is obtained by modulating 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 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 used for frequency shift associated with the information bits to be transmitted, and the first signal is a backscatter modulated signal of the second signal;

[0498] ​The demodulation module 92 is configured to demodulate the first signal to obtain the information bits to be transmitted.

[0499] Optionally, the demodulation module 92 is specifically configured to demodulate the first signal according to the obtained fourth information to obtain the information bits to be transmitted.

[0500] The fourth information includes at least one of the following:

[0501] A frequency value contained in a frequency pair for frequency shift associated with the information bits to be transmitted;

[0502] A size of a PRB, RBG and / or BWP of the frequency pair for frequency shift associated with the information bits to be transmitted;

[0503] A modulation mode of the first signal;

[0504] A modulation order of the first signal;

[0505] A modulation rate of the first signal;

[0506] An encoding mode of the first signal;

[0507] An encoding code rate of the first signal;

[0508] A signal parameter of a reference despreading signal corresponding to the first signal; when a sweep frequency mode of the first signal is an up-chirp mode, the reference despreading signal is conjugate to the first signal with a lowest frequency as a sweep start frequency; or when the sweep frequency mode of the first signal is a down-chirp mode, the reference despreading signal is conjugate to the first signal with a highest frequency as the sweep start frequency; or the reference despreading signal is conjugate to the first signal;

[0509] Third index information associated with the demodulation of the first signal, the third index information being used to indicate an associated demodulation parameter.

[0510] Optionally, the signal parameter of the reference despreading signal includes at least one of the following:

[0511] A sweep frequency mode of the reference despreading signal;

[0512] A lowest sweep frequency of the reference despreading signal;

[0513] A highest sweep frequency of the reference despreading signal;

[0514] A sweep start frequency of the reference despreading signal;

[0515] A sweep cutoff frequency of the reference despreading signal;

[0516] a center frequency of the reference despreading signal;

[0517] a bandwidth of the reference despreading signal;

[0518] a spreading factor of the reference despreading signal;

[0519] a code rate of the reference despreading signal;

[0520] a symbol rate of the reference despreading signal.

[0521] Optionally, the second receiving module 91 is specifically configured to receive the first signal according to the obtained fifth information.

[0522] The fifth information includes at least one of the following:

[0523] a preamble or a synchronization sequence of the first signal;

[0524] a reference signal of the first signal;

[0525] time domain resource information of the first signal;

[0526] frequency domain resource information of the first signal;

[0527] spatial domain resource information of the first signal.

[0528] The signal transmission apparatus 90 provided by the embodiments of the present application can implement each process of the method embodiments and achieve the same technical effects, and thus, details are not repeated here. Figure 4 The embodiments of the present application further provide a communication device 100, as shown in the accompanying drawings, which comprises a processor 101 and a memory 102, and the memory 102 stores programs or instructions which can be run on the processor 101. For example, when the communication device 100 is a first device, the programs or instructions are executed by the processor 101 to implement each step of the signal transmission method embodiments shown in the accompanying drawings, and achieve the same technical effects. When the communication device 100 is a second device, the programs or instructions are executed by the processor 101 to implement each step of the signal transmission method embodiments shown in the accompanying drawings, and achieve the same technical effects. For the sake of brevity, details are not repeated here. The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here.

[0529] The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here. Figure 10 The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here. Figure 3 The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here. Figure 4 The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here. The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here.

[0530] The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here. The embodiments of the present application further provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to implement each process of the signal transmission method embodiments and achieve the same technical effects, and thus, details are not repeated here.

[0531] The processor is the processor in the terminal described in the above embodiments. The readable storage medium includes a computer readable storage medium, such as a computer readable only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc. In some examples, the readable storage medium can be a non-transitory readable storage medium.

[0532] The embodiment of the present application further provides a chip, which comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running programs or instructions to realize the processes of the above signal transmission method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0533] It should be understood that the chip mentioned in the embodiment of the present application can also be referred to as a system chip, a system chip, a chip system or a system on chip, etc.

[0534] The embodiment of the present application further provides a computer program / program product stored in a storage medium, which is executed by at least one processor to realize the processes of the above signal transmission method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0535] The embodiment of the present application further provides a communication system, which comprises a first device and a second device, the first device can be used to execute the steps of the above signal transmission method, and the second device can be used to execute the steps of the above signal transmission method. Figure 3 The embodiment of the present application further provides a communication system, which comprises a first device and a second device, the first device can be used to execute the steps of the above signal transmission method, and the second device can be used to execute the steps of the above signal transmission method. Figure 4 The embodiment of the present application further provides a communication system, which comprises a first device and a second device, the first device can be used to execute the steps of the above signal transmission method, and the second device can be used to execute the steps of the above signal transmission method.

[0536] It should be noted that in this paper, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to the order of performing the functions as shown or discussed, but can also include performing the functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method can be performed in an order different from the described order, and various steps can also be added, omitted or combined. In addition, the features described with reference to some examples can be combined in other examples.

[0537] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned example methods can be realized by means of a computer software product and a general hardware platform as necessary, and of course can also be realized by hardware. The computer software product is stored in a storage medium (such as a ROM, a RAM, a magnetic disc, an optical disc, etc.), and includes a plurality of instructions for enabling a terminal or a network side device to execute the method described in each embodiment of the present application.

[0538] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative rather than limiting. Those skilled in the art can make many forms of embodiments under the inspiration of the present application without departing from the scope of the present application and the scope protected by the claims, and these embodiments all belong to the protection of the present application.

Claims

1. A signal transmission method, characterized by, The method comprises: A 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 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 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; The first device transmits the first signal.

2. The method of claim 1, wherein, The second signal comprises at least one of: A reference Chirp signal; An unmodulated Chirp spread spectrum (CSS) signal; A modulated CSS signal.

3. The method according to claim 1 or 2, characterized in that, 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, characterized in that, The first signal satisfies at least one of: 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 the spreading factor 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, characterized in that, The method further comprises: The first device frequency shifts the first signal; Wherein, the first device transmitting the first signal comprises: The first device transmits the frequency-shifted first signal.

6. The method according to any one of claims 1 to 5, characterized in that, The first device modulates information bits to be transmitted to obtain a first signal, comprising: The first device modulates the information bits to be transmitted according to the obtained first information to obtain the first signal; Wherein, the first information comprises at least one of: The frequency values contained in the frequency pair 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 part (BWP) of the frequency pair for frequency shifting associated with the information bits to be transmitted; The modulation mode 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 mode of the first signal; The coding rate of the first signal; The reflection coefficient or reflection signal amplification coefficient of the first signal; The first index information associated with the modulation and coding of the first signal, which is used to indicate the associated modulation and coding parameters.

7. The method according to any one of claims 1 to 6, characterized in that, The first device transmits the first signal, comprising: The first device transmits the first signal according to the obtained second information; Wherein, the second information comprises at least one of: The transmission power of the first signal; The preamble or synchronization sequence of the first signal; The reference signal of the first signal; The time domain resource information of the first signal; The frequency domain resource information of the first signal; The spatial domain resource information of the first signal.

8. The method according to any one of claims 1 to 7, characterized in that, The method further comprises: The first device receives the second signal according to the obtained third information; Wherein, the third information comprises at least one of: The frequency domain related parameters of the second signal; a time domain related parameter of the second signal; a signal waveform of the second signal; a baseband signal parameter of the second signal; second index information associated with a signal parameter of the second signal, the second index information being used to indicate the associated signal parameter of the second signal.

9. The method of claim 8, wherein, a frequency domain related parameter of the second signal includes at least one of: a center frequency point of the second signal; a bandwidth of the second signal; a scanning start frequency of the second signal; a scanning cut-off frequency of the second signal; a scanning minimum frequency of the second signal; a scanning maximum frequency of the second signal; a slope of a scanning frequency of the second signal; a spreading factor of the second signal; a chip rate of the second signal; a symbol rate or symbol period of the second signal; a scanning mode of the second signal; a frequency offset or frequency shift size of the second signal.

10. The method of claim 8, wherein, a time domain related parameter of the second signal includes at least one of: a time unit of the second signal; a signal period of the second signal; a signal length of the second signal; a time domain repetition number of the second signal; a synchronization signal or synchronization sequence of the second signal.

11. A signal transmission method, characterized by, comprises: The second device receives the 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 obtained by frequency shifting and filtering the second signal at a first frequency, and 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 used for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscattering modulation signal of the second signal; The second device demodulates the first signal to obtain the information bits to be transmitted.

12. The method of claim 11, wherein, The second device demodulates the first signal to obtain the information bits to be transmitted, comprising: The second device demodulates the first signal to obtain the information bits to be transmitted according to the obtained fourth information; Wherein, the fourth information includes at least one of: The frequency value contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; The size of PRB, RBG and / or BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted; The modulation mode of the first signal; The modulation order of the first signal; The modulation rate of the first signal; The encoding mode of the first signal; The coding rate of the first signal; a signal parameter of a reference despreading signal corresponding to the first signal; wherein, when a sweep frequency mode of the first signal is an up-chirp mode, the reference despreading signal is conjugate to the first signal with a lowest frequency as a sweep start frequency; or, when the sweep frequency mode of the first signal is a down-chirp mode, the reference despreading signal is conjugate to the first signal with a highest frequency as the sweep start frequency; or, the reference despreading signal is conjugate to the first signal; third index information associated with demodulation of the first signal, the third index information being used to indicate an associated demodulation parameter.

13. The method of claim 12, wherein, The signal parameter of the reference despreading signal includes at least one of the following: a sweep frequency mode of the reference despreading signal; a lowest sweep frequency of the reference despreading signal; a highest sweep frequency of the reference despreading signal; a sweep start frequency of the reference despreading signal; a sweep stop frequency of the reference despreading signal; a center frequency point of the reference despreading signal; a bandwidth of the reference despreading signal; a spreading factor of the reference despreading signal; a code rate of the reference despreading signal. The second device receives the first signal sent by the first device, including:

14. The method according to any one of claims 11 to 13, characterized in that, The second device receives the first signal according to the obtained fifth information; The fifth information includes at least one of the following: a preamble or a synchronization sequence of the first signal; a reference signal of the first signal; time domain resource information of the first signal; frequency domain resource information of the first signal; space domain resource information of the first signal. including:

15. A signal transmission device, characterized by comprising: a modulation module, 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 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 used for frequency shift associated with the information bits to be transmitted, and the first signal is a backscatter modulation signal of the second signal; a sending module, configured to send the first signal. The second signal includes at least one of the following:

16. The apparatus of claim 15, wherein, a reference Chirp signal; an unmodulated Chirp Spread Spectrum (CSS) signal; a modulated CSS signal.

17. The apparatus of claim 15 or 16, characterized in that: the modulation module is specifically configured to modulate the information bits to be transmitted according to obtained first information to obtain the first signal; The first information includes at least one of the following: a frequency value contained in a frequency pair used for frequency shift associated with the information bits to be transmitted; a size of PRB, RBG and / or BWP of the frequency pair used for frequency shift associated with the information bits to be transmitted; a modulation mode of the first signal; a modulation order of the first signal; ​ a modulation rate or a backscatter link frequency BLF of the first signal; a modulation mode of the first signal; a modulation order of the first signal; a modulation rate of the first signal; 18. A signal transmission device, characterized by comprising: 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. comprising: a second receiving module, configured to receive a first signal sent by a first device; wherein the first signal is obtained by modulating information bits to be transmitted; 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 used for frequency shifting associated with the information bits to be transmitted, and the first signal is a backscatter modulation signal of the second signal; a demodulation module, configured to demodulate the first signal to obtain the information bits to be transmitted.

19. The apparatus of claim 18, wherein the demodulation module is specifically configured to demodulate the first signal according to obtained fourth information to obtain the information bits to be transmitted; wherein the fourth information comprises at least one of the following: a frequency value contained in the frequency pair used for frequency shifting associated with the information bits to be transmitted; a size of a PRB, a RBG and / or a BWP of the frequency pair used for frequency shifting associated with the information bits to be transmitted; a modulation mode of the first signal; a modulation order of the first signal; a modulation rate of the first signal; a modulation mode of the first signal; a modulation code rate of the first signal; a signal parameter of a reference despreading signal corresponding to the first signal; wherein when a sweep frequency mode of the first signal is an up-chirp mode, the reference despreading signal is conjugate to the first signal with a lowest frequency as a sweep starting frequency; or when the sweep frequency mode of the first signal is a down-chirp mode, the reference despreading signal is conjugate to the first signal with a highest frequency as a sweep starting frequency; or the reference despreading signal is conjugate to the first signal; 20. A communications device, characterized by a third index information associated with the demodulation of the first signal, the third index information being used to indicate the associated demodulation parameters. comprising a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions being executed by the processor to implement the steps of the signal transmission method according to any one of claims 1 to 10, or the steps of the signal transmission method according to any one of claims 11 to 14.

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