Signal synchronization method and communication device applied to ultra-wideband system

Abstract

The application is applied to a wireless personal local area network system based on an ultra wide band, comprises 802.15 series protocols, such as a 802.15. 4a protocol, a 802.15. 4z protocol or a 802.15. 4ab protocol and the like, and can also support a next generation Wi-Fi protocol of IEEE 802.11 ax, such as 802.11 be, Wi-Fi 7 or ultrahigh throughput, such as 802.11 b. The invention provides a signal synchronization method applied to an ultra-wideband system and a communication device. The method comprises: sending a narrowband signal, a PPDU of the narrowband signal comprising at least one pilot symbol, the pilot symbol and the PPDU being used by a receiving device to obtain time-frequency synchronization information of an ultra-wideband signal; and sending the ultra-wideband signal. By estimating the carrier frequency offset based on these inserted pilot symbols and the preamble in the PPDU, high-precision time-frequency synchronization of ultra-wideband signals between the transmitting device and the receiving device can be achieved.

Description

[0001] This application is a divisional application. The application number of the original application is 202210703945.4, and the original application date is June 21, 2022. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of ultra-wideband technology, and more specifically, to a signal synchronization method and a communication device applied to an ultra-wideband system. Background Art

[0003] Ultra wideband (UWB) technology is a wireless carrier communication technology that transmits data by sending and receiving extremely narrow pulses of nanoseconds or microseconds. UWB technology occupies a wide spectrum range and has a low radiation spectrum density, which makes it have the advantages of strong multipath resolution, low power consumption and strong confidentiality.

[0004] Since UWB technology uses extremely narrow pulses to achieve data transmission, it places high demands on the time-frequency synchronization between the transmitting device and the receiving device. Although the time-frequency synchronization of UWB signals can be assisted by providing initial time-frequency synchronization information through narrowband (NB) signals, the initial time-frequency synchronization information provided by existing NB signals has large errors, which will reduce the time-frequency synchronization accuracy of UWB signals. Summary of the invention

[0005] The present application provides a method and communication device for signal synchronization applied to an ultra-wideband system. By inserting at least one pilot symbol in the PPDU of the NB signal and estimating the carrier frequency offset based on the inserted pilot symbol and the original preamble code in the PPDU, this can support the estimation and compensation of the carrier frequency offset during the data reception process, and the estimation accuracy of the carrier frequency offset is higher, thereby realizing high-precision time-frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0006] In a first aspect, a method for synchronizing an ultra-wideband signal is provided, comprising: sending a narrowband signal, wherein a physical layer protocol data unit (PPDU) of the narrowband signal comprises at least one pilot symbol, wherein the at least one pilot symbol is used by a receiving device to obtain time-frequency synchronization information of the narrowband signal, and the at least one pilot symbol is a symbol agreed upon by a sending device and a receiving device; sending an ultra-wideband signal; wherein the time-frequency synchronization information of the narrowband signal is used by a receiving device to obtain time-frequency synchronization information of the ultra-wideband signal.

[0007] It should be understood that a narrowband signal can be understood as a signal with a bandwidth less than or equal to a first threshold, and an ultra-wideband signal can be understood as a signal with a bandwidth greater than or equal to a second threshold, where the second threshold is greater than the first threshold.

[0008] By inserting at least one pilot symbol in the PPDU of a narrowband signal and estimating the carrier frequency offset based on the inserted pilot symbol and the original preamble code in the PPDU, it is possible to support the estimation and compensation of the carrier frequency offset during the data reception process, and the estimation accuracy of the carrier frequency offset is higher, thereby achieving high-precision time-frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0009] In combination with the first aspect, in some implementations of the first aspect, a physical layer service data unit (PSDU) of a physical layer protocol data unit PPDU includes at least one pilot symbol.

[0010] Specifically, the number of bytes of the PDSU in the PPDU of the narrowband signal is variable. By embedding at least one pilot symbol for the receiving device to obtain the time and frequency synchronization information of the narrowband signal in the PSDU in the PPDU of the narrowband signal, the carrier frequency offset can be estimated and compensated during the data reception process without excessively changing the PPDU frame structure. The estimation accuracy of the carrier frequency offset is higher, thereby achieving high-precision time and frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0011] In combination with the first aspect, in some implementations of the first aspect, each pilot symbol includes M bits of 0, where M is an integer multiple of 4.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the narrowband signal and the ultra-wideband signal have a common local clock.

[0013] Specifically, the narrowband signal and the ultra-wideband signal have a common local clock, so that the receiving device can obtain the time and frequency synchronization information of the ultra-wideband signal based on the time and frequency synchronization information of the narrowband signal it receives, thereby achieving time and frequency synchronization of the receiving device and the sending device in the ultra-wideband signal.

[0014] In a second aspect, a method for synchronizing an ultra-wideband signal is provided, comprising: receiving a narrowband signal, wherein the physical layer protocol data unit of the narrowband signal comprises at least one pilot symbol, the pilot symbol is used by a receiving device to obtain time-frequency synchronization information of the narrowband signal, and the pilot symbol is a symbol agreed upon by a sending device and a receiving device; receiving an ultra-wideband signal; and obtaining time-frequency synchronization information of the ultra-wideband signal according to the time-frequency synchronization information of the narrowband signal.

[0015] In combination with the second aspect, in some implementations of the second aspect, a physical layer service data unit of a physical layer protocol data unit includes at least one pilot symbol.

[0016] In combination with the second aspect, in some implementations of the second aspect, each pilot symbol includes M bits of 0, where M is an integer multiple of 4.

[0017] In combination with the second aspect, in certain implementations of the second aspect, the narrowband signal and the ultra-wideband signal have a common local clock.

[0018] According to a third aspect, a communication device is provided, comprising: a sending unit, configured to send a narrowband signal, wherein the physical layer protocol data unit of the narrowband signal comprises at least one pilot symbol, wherein the at least one pilot symbol is used by a receiving device to obtain time-frequency synchronization information of the narrowband signal, and the at least one pilot symbol is a symbol agreed upon by the communication device and the receiving device; the sending unit is also configured to send an ultra-wideband signal; wherein the time-frequency synchronization information of the narrowband signal is used by the receiving device to obtain the time-frequency synchronization information of the ultra-wideband signal.

[0019] In combination with the third aspect, in certain implementations of the third aspect, a physical layer service data unit of a physical layer protocol data unit includes at least one pilot symbol.

[0020] In combination with the third aspect, in certain implementations of the third aspect, the number of pilot symbols is associated with the number of bytes of the physical layer service data unit.

[0021] In combination with the third aspect, in certain implementations of the third aspect, each pilot symbol includes M bits of 0, where M is an integer multiple of 4.

[0022] In combination with the third aspect, in certain implementations of the third aspect, the narrowband signal and the ultra-wideband signal have a common local clock.

[0023] In a fourth aspect, a communication device is provided, comprising: a receiving unit, used to receive a narrowband signal, the physical layer protocol data unit of the narrowband signal comprising at least one pilot symbol, the pilot symbol being used by the communication device to obtain time and frequency synchronization information of the narrowband signal, the pilot symbol being a symbol agreed upon by the sending device and the communication device; the receiving unit, also used to receive an ultra-wideband signal; and a processing unit, used to obtain time and frequency synchronization information of the ultra-wideband signal based on the time and frequency synchronization information of the narrowband signal.

[0024] In combination with the fourth aspect, in certain implementations of the fourth aspect, a physical layer service data unit of a physical layer protocol data unit includes at least one pilot symbol.

[0025] In combination with the fourth aspect, in certain implementations of the fourth aspect, each pilot symbol includes M bits of 0, where M is an integer multiple of 4.

[0026] In combination with the fourth aspect, in certain implementations of the fourth aspect, the narrowband signal and the ultra-wideband signal have a common local clock.

[0027] In a fifth aspect, a communication device is provided, comprising a processor and a memory. Optionally, a transceiver may also be included. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, and control the transceiver to send and receive signals, so that the communication device executes the method in the first aspect, or any possible implementation of the first aspect.

[0028] In a sixth aspect, a communication device is provided, comprising a processor and a memory. Optionally, a transceiver may also be included. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, and control the transceiver to send and receive signals, so that the communication device executes the method in the second aspect, or any possible implementation of the second aspect.

[0029] In the seventh aspect, a communication device is provided, comprising a processor and a communication interface, wherein the communication interface is used to receive data and / or information and transmit the received data and / or information to the processor, and the processor processes the data and / or information, and the communication interface is also used to output the data and / or information processed by the processor, so that the method in the first aspect, or any possible implementation of the first aspect, is executed.

[0030] In an eighth aspect, a communication device is provided, comprising a processor and a communication interface, wherein the communication interface is used to receive (or input) data and / or information, and transmit the received data and / or information to the processor, and the processor processes the data and / or information, and the communication interface is also used to output the data and / or information processed by the processor, so that the method in the second aspect, or any possible implementation of the second aspect, is executed.

[0031] In a ninth aspect, a communication device is provided, comprising at least one processor, wherein the at least one processor is coupled to at least one memory, and the at least one processor is used to execute a computer program or instructions stored in the at least one memory so that the communication device performs a method as in the first aspect, or any possible implementation of the first aspect.

[0032] In a tenth aspect, a communication device is provided, comprising at least one processor, wherein the at least one processor is coupled to at least one memory, and the at least one processor is used to execute a computer program or instruction stored in the at least one memory so that the communication device performs a method as in the second aspect, or any possible implementation of the second aspect.

[0033] In an eleventh aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions. When the computer instructions are executed on a computer, the method in the first aspect, or any possible implementation of the first aspect, is executed.

[0034] In a twelfth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions. When the computer instructions are executed on a computer, the method in the second aspect, or any possible implementation of the second aspect, is executed.

[0035] In a thirteenth aspect, a computer program product is provided, the computer program product comprising a computer program code, and when the computer program code is run on a computer, the method in the first aspect, or any possible implementation of the first aspect, is executed.

[0036] In a fourteenth aspect, a computer program product is provided, the computer program product comprising a computer program code, and when the computer program code runs on a computer, the method in the second aspect, or any possible implementation of the second aspect, is executed.

[0037] In a fifteenth aspect, a wireless communication system is provided, comprising the communication device as described in the third aspect, and the communication device as described in the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a schematic diagram of the structure of PPDU 100 of a narrowband system.

[0039] Figure 2 It is an architecture diagram of a communication system 200 applicable to an embodiment of the present application.

[0040] Figure 3 It is an interactive flow chart of a method 300 for signal synchronization applied to an ultra-wideband system according to an embodiment of the present application.

[0041] Figure 4 It is a schematic diagram of the structure of the narrowband signal PPDU400 according to an embodiment of the present application.

[0042] Figure 5 It is a schematic diagram of simulation results of CFO based on PPDU400.

[0043] Figure 6 It is a schematic diagram of the internal structure of the sending device / receiving device.

[0044] Figure 7 It is a schematic block diagram of a communication device 700 according to an embodiment of the present application.

[0045] Figure 8 It is a schematic structural diagram of a communication device 800 according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0047] The technical solution of the present application can be applied to wireless personal area network (WPAN). The standard currently adopted by WPAN is the Institute of Electrical and Electronics Engineers (IEEE) 802.15 series. WPAN can be used for communication between digital auxiliary devices within a small range, such as telephones, computers, and auxiliary devices. Technologies supporting wireless personal area networks include Bluetooth, ZigBee, ultra wideband (UWB), infrared data association (IrDA) connection technology, home radio frequency (HomeRF), etc. From the perspective of network composition, WPAN is located at the bottom layer of the entire network architecture and is used for wireless connection between devices within a small range, that is, point-to-point short-distance connection, which can be regarded as a short-distance wireless communication network. According to different application scenarios, WPAN is divided into high rate (HR)-WPAN and low rate (LR)-WPAN, among which HR-WPAN can be used to support various high-rate multimedia applications, including high-quality audio and video distribution, multi-megabyte music and image document transmission, etc. LR-WPAN can be used for general business in daily life.

[0048] In WPAN, devices can be divided into full-function devices (FFD) and reduced-function devices (RFD) according to their communication capabilities. FFDs can communicate with each other and with each other. RFDs cannot communicate directly with each other, but can only communicate with FFDs, or forward data outward through an FFD. The FFD associated with an RFD is called the coordinator of the RFD. RFD devices are mainly used for simple control applications, such as light switches, passive infrared sensors, etc. The amount of data transmitted is small, and the transmission and communication resources are not occupied much, so the cost of RFD is low. Among them, the coordinator can also be called a personal area network (PAN) coordinator or a central control node. The PAN coordinator is the main control node of the entire network, and there is generally only one PAN coordinator in each ad hoc network, which has member identity management, link information management, and packet forwarding functions.

[0049] Optionally, the device in the embodiment of the present application (eg, a sending device or a receiving device) may be a device supporting the 802.15 series, for example, a device supporting 802.15.4a and 802.15.4z, as well as multiple WPAN standards currently under discussion or subsequent versions.

[0050] Optionally, the present application can be applied to UWB-based wireless personal area network systems including 802.15 series protocols, such as 802.15.4a protocol, 802.15.4z protocol or 802.15.4ab protocol, etc. It can also support IEEE 802.11ax next generation Wi-Fi protocols, such as 802.11be, Wi-Fi7 or EHT, and 802.11b.

[0051] In the embodiments of the present application, the above-mentioned device may be a communication server, a router, a switch, a bridge, a computer or a mobile phone, a smart home device, a vehicle-mounted communication device, etc.

[0052] In an embodiment of the present application, the above-mentioned device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through a process, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer includes applications such as a browser, an address book, a word processing software, and an instant messaging software. In addition, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application, as long as it can communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application can be an FFD or an RFD, or a functional module in an FFD or RFD that can call a program and execute the program.

[0053] In addition, various aspects or features of the present application can be implemented as methods, devices, or articles of manufacture using standard programming and / or engineering techniques. The term "article of manufacture" as used in this application covers a computer program that can be accessed from any computer-readable device, carrier, or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memorts (EPROMs), cards, sticks, or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing, and / or carrying instructions and / or data.

[0054] The technical solution of the present application can also be applied to wireless local area network systems such as the Internet of Things (IoT) network or the vehicle to x (V2X). Of course, the embodiments of the present application can also be applied to other possible communication systems, such as long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) communication system, and future sixth generation (6G) communication system.

[0055] The above-mentioned communication system applicable to the present application is only an example for illustration, and the communication system applicable to the present application is not limited to this. A unified description is given here and no further elaboration is given below.

[0056] In WPAN, UWB technology uses nanosecond non-sinusoidal narrow pulses to transmit data, so it occupies a wide spectrum range. Due to its narrow pulses and extremely low radiation spectrum density, UWB technology has the advantages of strong multipath resolution, low power consumption, and strong confidentiality.

[0057] Currently, UWB technology has been written into the IEEE 802 series of wireless standards, and the WPAN standard IEEE 802.15.4a based on UWB technology and its evolutionary version IEEE 802.15.4z have been released. Currently, the formulation of the next generation WPAN standard 802.15.4ab for UWB technology has also been put on the agenda.

[0058] Since UWB technology transmits data by sending and receiving extremely narrow pulses with a duration of less than nanoseconds or microseconds, the synchronization of UWB signals between the sending device and the receiving device is crucial. The so-called synchronization of UWB signals between the sending device and the receiving device can be understood as follows: the physical layer protocol data unit (PPDU) of the sending device is sent in the form of a pulse signal, and the receiving device determines which pulse signal among the multiple received pulse signals is the PPDU it wants to receive; or, it can also be understood as: the receiving device compensates for the deviation between the carrier frequencies between the receiving device and the sending device.

[0059] Currently, the time and frequency synchronization of the UWB signal by the receiving device is mainly achieved by detecting the synchronization header (SHR) in the PPDU of the narrowband (NB) signal sent by the transmitting device to it. Specifically, the NB signal first sent by the transmitting device to the receiving device is used to provide initial time and frequency synchronization information for the UWB signal sent by the transmitting device to the receiving device. The receiving device can perform correlation detection on the SHR of the PPDU of the NB signal to determine the starting position of the PPDU of the UWB signal to be received and the carrier frequency deviation between the transmitting device and the receiving device, and perform carrier frequency offset compensation. The PPDU structure of the NB signal can be found in Figure 1 .

[0060] Figure 1 1 is a schematic diagram of the structure of the PPDU 100 of the narrowband system. Figure 1 As shown, PPDU100 includes SHR, physical header (PHR) and physical layer (PHY) payload field. Among them, the PHY payload field can also be understood as a physical layer protocol service data unit (PSDU). In addition, SHR includes a preamble and a start-of-frame delimiter (SFD).

[0061] Specifically, the preamble is composed of 32 bits of 0, which is used for symbol and chip synchronization. SFD is fixed to 10100111, which is used to determine the end of the preamble and the beginning of the data frame. PHR is used to indicate the length of the PSDU, and its value can be 1-127, which is used to indicate that the number of bytes of the PSDU is 1-127.

[0062] Specifically, the NB signal used to assist the time-frequency synchronization of the UWB signal can be sent through the offset-quadrature phase shift keying (O-QPSK) modulation method. To enhance the robustness of the system, the 4-bit coded (or uncoded) bit information can be mapped to a spread spectrum code sequence of 8 or 32 bits in length before O-QPSK modulation, and the time-frequency synchronization information of the transmitted information bit can be determined by receiving the spread spectrum sequence. Exemplarily:

[0063] Data bit in PPDU → data symbol → chip → O-QPSK modulation → modulated data

[0064] Specifically, every four data bits in the PPDU 100 are mapped to a data symbol, and each data symbol is mapped to a spread spectrum code sequence including 32 chips. The mapping relationship between the data symbol and the spread spectrum code sequence is shown in Table 1.

[0065] Table 1

[0066] data symbol 32 chip values in the spreading code sequence 0 11011001110000110101001000101110 1 11101101100111000011010100100010 2 00101110110110011100001101010010 3 00100010111011011001110000110101 4 01010010001011101101100111000011 5 00110101001000101110110110011100 6 11000011010100100010111011011001 7 10011100001101010010001011101101 8 10001100100101100000011101111011 9 10111000110010010110000001110111 10 01111011100011001001011000000111 11 01110111101110001100100101100000 12 00000111011110111000110010010110 13 01100000011101111011100011001001 14 10010110000001110111101110001100 15 11001001011000000111011110111000

[0067] As mentioned above, the preamble in the PPDU100 of the NB signal is composed of 32 bits of 0, which can be mapped to 8 data symbols, specifically corresponding to the data symbol 0 in Table 1. In other words, the preamble in the PPDU100 can be mapped to 8 identical spreading code sequences corresponding to data symbol 0. In addition, the carrier frequency offset (CFO) performed by the receiving device based on the preamble in the PPDU100 of the NB signal of the transmitting device can be expressed as:

[0068]

[0069] Where Δf is used to represent CFO, and T represents the interval between two chips with the same value, where the two chips are located at the same position in the two spreading code sequences corresponding to the periodic data symbols. As can be seen from the previous text, the preamble can be mapped to 8 identical spreading code sequences. Therefore, the maximum value of T is T max =(32 / 2)*7*T c , the minimum value is T min =(32 / 2)*1*T c . T c Used to indicate the chip duration. In addition, the above "7" is used to indicate the number of spread spectrum code sequences between the first spread spectrum code sequence corresponding to data symbol 0 and the eighth spread spectrum code sequence. The above "1" is used to indicate the number of spread spectrum code sequences between the first spread spectrum code sequence corresponding to data symbol 0 and the second spread spectrum code sequence.

[0070] It can be seen from the above formula that the absolute value of the accuracy of the receiving device estimating Δf through the preamble code of the PPDU100 of the NB signal satisfies the following conditions:

[0071]

[0072] It can be understood that the NB signal and the UWB signal of the transmitting device or the receiving device have the same local clock. In other words, the NB signal and the UWB signal sent by the transmitting device or received by the receiving device have the same local clock, that is: for the transmitting device, the NB signal and the UWB signal sent by it have the same local clock; for the receiving device, the NB signal and the UWB signal received by it have the same local clock, but there is a frequency deviation between the transmitting device and the receiving device. For example, the frequency of the NB signal sent by the transmitting device is F1, and the frequency of the NB signal received by the receiving device is F2, |F2-F1|=Δf, the frequency of the UWB signal sent by the transmitting device is F3, and the frequency of the UWB signal received by the receiving device is F4, |F4-F3|=A*Δf, where A is a fixed parameter. Therefore, the receiving device can obtain the time-frequency synchronization information of the received UWB signal based on the time-frequency synchronization information of the NB signal received by the transmitting device.

[0073] From formula (2), it can be seen that the result obtained by the receiving device according to the preamble code in the PPDU100 of the NB signal of the sending device is affected by T max If T max If it is smaller, it will lead to a larger residual deviation, which will make the time and frequency synchronization of the UWB signal assisted by the NB signal inaccurate between the sending device and the receiving device.

[0074] In view of the above technical problems, the present application provides a method and a communication device for signal synchronization applied to an ultra-wideband system. By inserting at least one pilot symbol in the PPDU of the NB signal and estimating the carrier frequency offset based on the inserted pilot symbol and the original preamble code in the PPDU, it can support the estimation and compensation of the carrier frequency offset during the data reception process, and the CFO estimation accuracy is higher, thereby realizing high-precision time-frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0075] The following will describe the UWB signal synchronization method and its application scenarios according to the embodiments of the present application in conjunction with the accompanying drawings.

[0076] Figure 2 2 is an architecture diagram of a communication system 200 applicable to an embodiment of the present application. Figure 2As shown, the communication system 200 includes at least one transmitting device 210 and one receiving device 220. The transmitting device 210 and the receiving device 220 can communicate with each other through UWB technology or NB technology. The transmitting device 210 and the receiving device 220 can include a UWB signal processing module and a NB signal processing module. For example, the transmitting device 210 includes a UWB signal transmitting module and a NB signal transmitting module. The receiving device 220 includes a UWB signal receiving module and a NB signal receiving module.

[0077] Understandably, Figure 2 The communication system 200 is described as including a transmitting device and a receiving device as an example, but the communication system 200 is not limited to including more other devices, for example, it can also include more receiving devices. In addition, in the embodiment of the present application, the transmitting device refers to a device that transmits UWB signals, and the receiving device refers to a device that receives UWB signals.

[0078] Optionally, the sending device and the receiving device may have multiple possible application scenarios. For example, in a star topology or a point-to-point topology, data communication between a central control node and one or more other devices in the star topology is also applicable to communication between different devices in the point-to-point topology.

[0079] In addition, the signal synchronization method for an ultra-wideband system provided in the present application is also applicable to any scenario where UWB signal synchronization may be required, and the embodiments of the present application are not limited thereto.

[0080] Figure 3 It is an interactive flow chart of a method 300 for signal synchronization applied to an ultra-wideband system according to an embodiment of the present application. Figure 3 The method flow in the method 300 may be executed by a sending device / receiving device, or by a module and / or device (e.g., a chip or an integrated circuit, etc.) with corresponding functions installed in the sending device / receiving device, without limitation. The following embodiments are described by taking a sending device / receiving device as an example. Method 300 includes:

[0081] S310: The sending device sends a NB signal. The PPDU of the NB signal includes at least one pilot symbol. The at least one pilot symbol is used by the receiving device to obtain time and frequency synchronization information of the NB signal.

[0082] It can be understood that a pilot symbol is a symbol agreed upon between a sending device and a receiving device.

[0083] Optionally, the pilot symbol may also be a symbol predefined by a protocol.

[0084] S320: The receiving device receives the NB signal.

[0085] Exemplarily, the sending device may be Figure 2 The sending device 210 shown in FIG. 1 and the receiving device 210 may be Figure 2 The receiving device 220 shown in .

[0086] It should be understood that a narrowband signal can be understood as a signal with a bandwidth less than or equal to a first threshold, and an ultra-wideband signal can be understood as a signal with a bandwidth greater than or equal to a second threshold, where the second threshold is greater than the first threshold.

[0087] Specifically, the transmitting device may transmit the NB signal through the Tx NB module, and correspondingly, the receiving device may receive the NB signal through the RxNB module.

[0088] The receiving device can obtain the time-frequency synchronization information of the NB signal by receiving and processing the NB signal. In other words, the receiving device can achieve time-frequency synchronization with the NB signal.

[0089] Exemplarily, the receiving device may process the NB signal through the NB signal processing module to obtain the time-frequency synchronization information of the NB signal. Further, the NB signal processing module of the receiving device provides the obtained time-frequency synchronization information of the NB signal to the UWB signal processing module of the receiving device.

[0090] In the technical solution of the present application, the receiving device receives and processes the NB signal from the transmitting device, and realizes the time-frequency synchronization with the transmitting device in the NB signal. It can be considered that the NB signal provides the receiving device with time-frequency synchronization information. Based on the time-frequency synchronization information, the receiving device estimates the time-frequency synchronization information of the UWB signal from the transmitting device.

[0091] S330: The sending device sends a UWB signal.

[0092] Exemplarily, the transmitting device may transmit a UWB signal via a Tx UWB module.

[0093] S340: The receiving device receives the UWB signal.

[0094] S350: The receiving device obtains the time-frequency synchronization information of the UWB signal according to the time-frequency synchronization information of the NB signal.

[0095] Specifically, the receiving device obtains the time-frequency synchronization information of the UWB signal based on the time-frequency synchronization information of the NB signal. That is, the receiving device can obtain more accurate time-frequency synchronization information of the UWB signal based on the time-frequency synchronization information provided by the NB signal.

[0096] As shown in S320, the NB signal processing module of the receiving device provides the obtained time-frequency synchronization information of the NB signal to the UWB signal processing module of the receiving device. On this basis, the UWB signal processing module of the receiving device obtains more accurate time-frequency synchronization information of the UWB signal based on the time-frequency synchronization information of the NB signal provided by the NB signal processing module.

[0097] It can be seen that this application proposes a "two-step UWB signal time-frequency synchronization" solution:

[0098] Step 1: The sending device sends the NB signal first, and the receiving device can obtain the initial time and frequency synchronization information;

[0099] Step 2: The sending device sends the UWB signal after the NB signal.

[0100] Optionally, the time-frequency synchronization information of the NB signal may include time synchronization information and frequency synchronization information.

[0101] Specifically, the PPDU of the NB signal received by the receiving device includes at least one pilot symbol, and the at least one pilot symbol is used by the receiving device to obtain more accurate time-frequency synchronization information of the NB signal. For example, by adding the pilot symbol, T in formula (2) max The value of is larger, so the accuracy of CFO estimation will be higher, and the time-frequency synchronization information of the UWB signal is obtained based on the time-frequency synchronization information of the NB signal. Among them, the structure of the PPDU including at least one pilot symbol can be referred to. Figure 4 .

[0102] Optionally, the present application does not impose any limitation on the specific form of the NB signal. For example, the frequency, bandwidth, frame format, and modulation mode of the NB signal are not limited. Exemplarily, the NB signal may be a zigbee / Bluetooth signal, a frequency in the 2.4 GHz industrial scientific medical (ISM) band, a bandwidth of 1 MHz or 2 MHz, or an O-QPSK modulation mode.

[0103] By inserting at least one pilot symbol in the PPDU of the NB signal and estimating the CFO based on the inserted pilot symbol and the original preamble code in the PPDU, it supports the estimation and compensation of CFO during the data reception process, and the estimation accuracy of CFO is higher, thereby achieving high-precision time and frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0104] The structure of a PPDU including at least one pilot symbol and related simulation result schematic diagrams will be described below in conjunction with the accompanying drawings.

[0105] Figure 4 4 is a schematic diagram of the structure of the PPDU400 of the embodiment of the present application. Figure 4 As shown, the PSDU of the PPDU 400 includes at least one pilot symbol. Exemplarily, the at least one pilot symbol may be distributed between the PSDUs periodically or aperiodically.

[0106] In a possible implementation, the number of pilot symbols is associated with the number of bytes of the PSDU. For details, see Table 2.

[0107] Table 2

[0108] the number of pilot symbols the number of bytes of the PSDU 4 ≥95 3 [62，95) 2 [31，62) 1 <31

[0109] In Table 2, when the number of bytes of the PSDU is ≥ 95, the number of pilot symbols may be 4. When the number of bytes of the PSDU is between 62 and 95, the number of pilot symbols may be 3. When the number of bytes of the PSDU is between 31 and 62, the number of pilot symbols may be 2. When the number of bytes of the PSDU is less than 31, the number of pilot symbols may be 1. It should be understood that the contents shown in Table 2 are only for exemplary understanding.

[0110] In one possible implementation, the pilot symbols are periodically distributed within the PSDU, wherein the position of the pilot symbols is determined by an initial offset and an interval period. The initial offset refers to the number of symbols between the first pilot symbol and the start position of the PSDU.

[0111] Optionally, the interval period of the pilot symbols is fixed, that is, the pilot symbols are periodically inserted into the PSDU.

[0112] Specifically, the number of bytes of the PDSU in the PPDU of the narrowband signal is variable. By embedding at least one pilot symbol for the receiving device to obtain the time and frequency synchronization information of the narrowband signal in the PSDU in the PPDU of the narrowband signal, it is possible to estimate and compensate for the carrier frequency offset during the data reception process without excessively changing the structure of the PPDU, and the estimation accuracy of the carrier frequency offset is higher, thereby achieving high-precision time and frequency synchronization of the UWB signal between the transmitting device and the receiving device.

[0113] In a possible implementation, each pilot symbol includes M bits, where M is an integer multiple of 4, for example, M=4, 8, 12, . . . .

[0114] In a possible implementation, each pilot symbol includes M bits, wherein the M bits may be all bits 0, all bits 1, or include both bits 0 and bits 1, which is not limited in the embodiment of the present application.

[0115] Optionally, the bits constituting the pilot symbols may remain unchanged within a data packet of a PPDU.

[0116] Figure 5 This is a schematic diagram of the simulation results of CFO based on PPDU400. Figure 5 As shown, under an additive white gaussian noise (AWGN) channel, the number of bytes of the PSDU including the pilot symbol in the PPDU 400 is 127, and each pilot symbol consists of 4 bits of 0. Figure 5 The horizontal axis represents the power ratio of each code chip to the background noise (in decibels (dB)), and the vertical axis represents the bit error rate at the receiving end. Figure 5 The simulation results of CFO estimation based on preamble and CFO estimation based on preamble and different numbers of inserted pilot symbols are shown. Figure 5 .

[0117] Specifically, Figure 5 The different curves in the figure show the decoding results based on different CFO estimation methods. Figure 5 The "*" solid line curve in the figure represents the decoding result of the CFO estimation method based on the preamble code; the "+" solid line curve represents the decoding result of the CFO estimation method based on the preamble code and 4 pilot symbols (each pilot symbol consists of 4 all-0 bits); the "+" dotted line curve represents the decoding result of the CFO estimation method based on the preamble code and 4 pilot symbols (each pilot symbol consists of 8 all-0 bits); the "Δ" solid line curve represents the decoding result of the CFO estimation method based on the preamble code and 6 pilot symbols (each pilot symbol consists of 4 all-0 bits); the "Δ" dotted line curve represents the decoding result of the CFO estimation method based on the preamble code and 6 pilot symbols (each pilot symbol consists of 4 all-0 bits). The solid line curve "□" represents the decoding result of the CFO estimation method based on the preamble code and 4 pilot symbols (each pilot symbol consists of 4 all-0 bits); the dotted line curve "□" represents the decoding result of the CFO estimation method based on the preamble code and 6 pilot symbols (each pilot symbol consists of 8 all-0 bits); the solid line curve "☆" represents the decoding result of the CFO estimation method based on the preamble code and 8 pilot symbols; the dotted line curve "☆" represents the decoding result of the CFO estimation method based on the preamble code and 10 pilot symbols (each pilot symbol consists of 4 all-0 bits).

[0118] From the comparison between different curves, it can be seen that the decoding results of the CFO estimation method based on the preamble are different from those of the CFO estimation method based on the preamble and 4 pilot symbols, the CFO estimation method based on the preamble and 4 pilot symbols, and the CFO estimation method based on the preamble and 6 pilot symbols. Under the same bit error rate, for example, 10 -3 When the simulation result of CFO estimation based on multiple inserted pilot symbols and preamble codes corresponds to a lower chip-to-background noise power ratio, it can be explained that the performance of CFO estimation based on multiple inserted pilot symbols and preamble codes is better and more accurate, thereby verifying that by inserting at least one pilot symbol in the PPDU of the NB signal and estimating CFO based on the inserted pilot symbol and the original preamble code in the PPDU, it can support CFO estimation and compensation during data reception, which can improve the estimation accuracy of CFO, and further realize high-precision time-frequency synchronization of UWB signals between the transmitting device and the receiving device.

[0119] In a possible implementation, the number of pilot symbols is 4 or 6. Each pilot symbol includes 4 all-0 bits. In this way, a balance between time-frequency synchronization performance and resource overhead can be achieved.

[0120] The communication device according to the embodiment of the present application will be described below in conjunction with the accompanying drawings.

[0121] Figure 6 It is a schematic diagram of the internal structure of the sending device / receiving device. Figure 6 As shown, taking the receiving device as an example, the receiving device may include a NB signal processing module and a UWB signal processing module, wherein the NB signal processing module may process the NB signal received from the transmitting device through the RF module; the UWB signal processing module may process the UWB signal received from the transmitting device through the RF module. In addition, the NB signal processing module and the UWB signal processing module may exchange data and / or information. For example, the NB signal processing module sends the rough time-frequency synchronization information obtained by processing the received NB signal from the transmitting device to the UWB signal processing module. The transmitting device is similar and will not be described in detail.

[0122] Figure 7 is a schematic block diagram of a communication device 700 according to an embodiment of the present application. Figure 7 As shown, the communication device 700 includes a processing unit 710 and a receiving unit 720 .

[0123] Optionally, the communication device 700 may correspond to the receiving device in the embodiment of the present application.

[0124] At this time, each unit of the communication device 700 is used to implement the following functions:

[0125] The processing unit 710 is configured to:

[0126] The narrowband signal is processed to obtain the time-frequency synchronization information of the UWB signal according to the time-frequency synchronization information of the NB signal; the receiving unit 720 is used to receive the NB signal and the UWB signal.

[0127] Optionally, in one embodiment, the receiving unit 720 is configured to receive a UWB signal according to the time-frequency synchronization information of the NB signal;

[0128] And, the processing unit 710 is used to detect the UWB signal and obtain the time-frequency synchronization information of the UWB signal.

[0129] In the above implementations, the receiving unit 720 and the sending unit 730 may also be integrated into a transceiver unit, which has both receiving and sending functions, which is not limited here.

[0130] In various embodiments of the communication device 700 corresponding to a receiving device, the processing unit 710 is used to perform processing and / or operations implemented by the receiving device in addition to the sending and receiving actions. The receiving unit 720 is used to perform the receiving action of the receiving device, and the sending unit 730 is used to perform the sending action of the receiving device.

[0131] Optionally, the communication device 700 may correspond to the sending device in the embodiment of the present application. Optionally, the communication device 700 further includes a sending unit 730.

[0132] At this time, each unit of the communication device 700 is used to implement the following functions:

[0133] A processing unit 710, configured to generate a NB signal and a UWB signal;

[0134] The sending unit 730 is configured to:

[0135] Send NB signal;

[0136] Send UWB signal.

[0137] In the above implementations, the receiving unit 720 and the sending unit 730 may also be integrated into a transceiver unit, which has both receiving and sending functions, which is not limited here.

[0138] In each embodiment of the communication device 700 corresponding to a sending device, the processing unit 710 is used to perform processing and / or operations implemented by the sending device in addition to the sending and receiving actions. The receiving unit 720 is used to perform the receiving action of the sending device, and the sending unit 730 is used to perform the sending action of the sending device.

[0139] Figure 88 is a schematic structural diagram of a communication device 800 according to an embodiment of the present application. Figure 8 As shown, the communication device 800 includes: one or more processors 810, one or more memories 820, and one or more communication interfaces 830. The processor 810 is used to control the communication interface 830 to send and receive signals, the memory 820 is used to store a computer program, and the processor 810 is used to call and run the computer program from the storage 820, so that the communication device 800 performs the processing performed by the receiving device or the sending device in each method embodiment of the present application.

[0140] For example, processor 810 may have Figure 7 The functions of the processing unit 710 shown in FIG. 8 , the communication interface 830 may have Figure 7 Specifically, the processor 810 may be used to execute the processing or operation executed by the communication device, and the communication interface 830 may be used to execute the sending and / or receiving operation of the communication device.

[0141] Optionally, in one implementation, the communication device 800 may be a receiving device in the method embodiment. In this implementation, the communication interface 830 may be a transceiver of the receiving device. The transceiver may include a receiver and / or a transmitter. Optionally, the processor 810 may be a baseband device of the receiving device, and the communication interface 830 may be a radio frequency device.

[0142] In another implementation, the communication device 800 may be a chip (or chip system) installed in a receiving device. In this implementation, the communication interface 830 may be an interface circuit or an input / output interface.

[0143] Optionally, in one implementation, the communication device 800 may be a sending device in the method embodiment. In this implementation, the communication interface 830 may be a transceiver of the sending device. The transceiver may include a receiver and / or a transmitter. Optionally, the processor 810 may be a baseband device of the sending device, and the communication interface 830 may be a radio frequency device.

[0144] In another implementation, the communication device 800 may be a chip (or chip system) installed in a transmitting device. In this implementation, the communication interface 830 may be an interface circuit or an input / output interface.

[0145] in, Figure 8 A dashed box behind a component (eg, a processor, a memory, or a communication interface) indicates that there may be more than one of the component.

[0146] In addition, the present application also provides a computer-readable storage medium, in which computer instructions are stored. When the computer instructions are run on a computer, the operations and / or processing performed by the receiving device in each method embodiment of the present application are executed.

[0147] The present application also provides a computer-readable storage medium, in which computer instructions are stored. When the computer instructions are executed on a computer, the operations and / or processing performed by the sending device in each method embodiment of the present application are executed.

[0148] The present application also provides a computer program product, which includes computer program code or instructions. When the computer program code or instructions are run on a computer, the operations and / or processing performed by a receiving device in each method embodiment of the present application are executed.

[0149] The present application also provides a computer program product, which includes computer program code or instructions. When the computer program code or instructions are run on a computer, the operations and / or processing performed by the sending device in the various method embodiments of the present application are executed.

[0150] The present application also provides a chip, which includes a processor, a memory for storing computer programs which is set independently of the chip, and the processor is used to execute the computer program stored in the memory, so that a communication device equipped with the chip performs the operations and / or processing performed by a receiving device in any method embodiment.

[0151] The present application also provides a chip, which includes a processor, a memory for storing computer programs which is set independently of the chip, and the processor is used to execute the computer program stored in the memory, so that a communication device equipped with the chip performs the operations and / or processing performed by the sending device in any method embodiment.

[0152] Furthermore, the chip may further include a communication interface. The communication interface may be an input / output interface, or an interface circuit, etc. Furthermore, the chip may further include the memory.

[0153] Optionally, the processor may be one or more, the memory may be one or more, and the memory may be one or more.

[0154] The present application also provides a communication device (for example, a chip or a chip system), including a processor and a communication interface, wherein the communication interface is used to receive (or is called input) data and / or information, and transmit the received data and / or information to the processor, and the processor processes the data and / or information, and the communication interface is also used to output (or is called output) the data and / or information processed by the processor, so that the operations and / or processing performed by the receiving device in any method embodiment are executed.

[0155] The present application also provides a communication device (for example, a chip or a chip system), including a processor and a communication interface, wherein the communication interface is used to receive (or is called input) data and / or information, and transmit the received data and / or information to the processor, and the processor processes the data and / or information, and the communication interface is also used to output (or is called output) the data and / or information processed by the processor, so that the operations and / or processing performed by the sending device in any method embodiment are executed.

[0156] The present application also provides a communication device, comprising at least one processor, wherein the at least one processor is coupled to at least one memory, and the at least one processor is used to execute a computer program or instruction stored in the at least one memory, so that the communication device performs the operations and / or processing performed by a receiving device in any one of the method embodiments.

[0157] The present application also provides a communication device, comprising at least one processor, wherein the at least one processor is coupled to at least one memory, and the at least one processor is used to execute a computer program or instruction stored in the at least one memory, so that the communication device performs the operations and / or processing performed by the sending device in any one of the method embodiments.

[0158] The present application also provides a wireless communication system, including the receiving device in the method embodiment of the present application. Optionally, it may also include the sending device in the method embodiment.

[0159] The processor in the embodiment of the present application can be an integrated circuit chip with the ability to process signals. In the implementation process, each step of the above method embodiment can be completed by the hardware integrated logic circuit or software instructions in the processor. The processor can be a general-purpose processor, a digital signal processor (digital signal processor, DSP), an application-specific integrated circuit (application-specific integrated circuit, ASIC), a field programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware coding processor to perform, or the hardware and software modules in the coding processor are combined and performed. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, and other mature storage media in the art. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0160] The memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DRRAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0161] The method provided in the above embodiment can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product may include one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated.

[0162] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0163] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0164] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0165] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0166] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0167] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks or optical disks.

[0168] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for signal synchronization applied to an ultra-wideband system, It is characterized in that include: Sending a narrowband signal, wherein a physical layer protocol data unit PPDU of the narrowband signal includes at least one pilot symbol, wherein the at least one pilot symbol is used by a receiving device to obtain time and frequency synchronization information of the narrowband signal, and the at least one pilot symbol is a symbol agreed upon by the sending device and the receiving device; each of the pilot symbols includes M bits of 0, where M is an integer multiple of 4; Sending ultra-wideband signals.

2. The method according to claim 1, Features A physical layer service data unit PSDU of the PPDU includes the at least one pilot symbol.

3. The method according to claim 1 or 2, It is characterized in that The time-frequency synchronization information of the narrowband signal is used by the receiving device to acquire the time-frequency synchronization information of the ultra-wideband signal.

4. The method according to any one of claims 1 to 3, It is characterized in that The narrowband signal and the ultra-wideband signal have a common local clock.

5. A communication device, It is characterized in that include: A sending unit, configured to send a narrowband signal, wherein a physical layer protocol data unit PPDU of the narrowband signal includes at least one pilot symbol, wherein the at least one pilot symbol is used by a receiving device to obtain time-frequency synchronization information of the narrowband signal, and the at least one pilot symbol is a symbol agreed upon by the communication device and the receiving device; each of the pilot symbols includes M bits of 0, where M is an integer multiple of 4; The sending unit is also used to send ultra-wideband signals.

6. The device according to claim 5, Features A physical layer service data unit PSDU of the PPDU includes the at least one pilot symbol.

7. The device according to claim 5 or 6, It is characterized in that The time-frequency synchronization information of the narrowband signal is used by the receiving device to acquire the time-frequency synchronization information of the ultra-wideband signal.

8. The device according to any one of claims 5 to 7, It is characterized in that The narrowband signal and the ultra-wideband signal have a common local clock.

9. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the method according to any one of claims 1 to 4 is executed.

10. A computer program product, It is characterized in that The computer program product comprises a computer program code, and when the computer program code is run on a computer, the method according to any one of claims 1 to 4 is executed.

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