Data sending and receiving method and device, storage medium, and electronic device

Abstract

Embodiments of the present application provide a data sending and receiving method and device, a storage medium and an electronic device, wherein the method comprises: determining Q pieces of data to be sent by a first device to a second device; performing a data flow mapping operation on the Q pieces of data to obtain a data vector; performing a precoding operation on the data vector by using a precoding matrix of the second device to obtain a first vector; performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal; and sending the target signal to the second device. Through the present application, the problems of limited data transmission rate, low spectrum efficiency and insufficient channel utilization in satellite communication in the related art are solved, and the effect of improving the utilization and transmission rate of the channel is achieved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the computer field, in particular, to a data sending and receiving method and device, a storage medium, and an electronic device. BACKGROUND

[0002] In a satellite communication system, in order to solve the technical problems of low bit error rate and low transmission efficiency in the satellite communication system, channel coding, interleaving, spread spectrum, forward error correction coding, space-time coding, space-time block coding, multiple-input multiple-output (MIMO), multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM), and the like are usually used to improve the performance and anti-interference ability of the satellite communication system.

[0003] However, the satellite communication system in the prior art cannot effectively use MIMO and space-time coding technology to increase system capacity and transmission reliability. On the other hand, the satellite communication system itself also faces the following challenges: due to the large-scale path loss caused by the satellite-ground link and the limitation of satellite energy and power consumption, the transmission power is insufficient, the landing power and signal-to-noise ratio are relatively insufficient, which becomes a restricting factor for the system peak rate and service reliability. In the satellite or beam overlapping coverage area, if the same frequency is used, it will cause serious co-frequency interference, and if the same frequency is not used, it will cause the frequency reuse ratio to decrease and the system capacity to decrease.

[0004] In view of the problems of limited data transmission rate, low spectrum efficiency, and insufficient channel utilization in satellite communication in the related art, an effective solution has not been proposed. SUMMARY

[0005] Embodiments of the present application provide a data sending and receiving method and device, a storage medium, and an electronic device to at least solve the problems of limited data transmission rate, low spectrum efficiency, and insufficient channel utilization in satellite communication in the related art.

[0006] According to an embodiment of the present application, a data sending method is provided, comprising: determining Q pieces of data to be sent by a first device to a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, and Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a data stream mapping operation on the Q pieces of data to obtain a data vector, wherein the data vector is used to represent a data stream set of the Q pieces of data; performing a precoding operation on the data vector by using a precoding matrix of the second device to obtain a first vector; performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal; and sending the target signal to the second device.

[0007] In one example embodiment, determining the Q paths of data to be transmitted by the first device to the second device comprises: obtaining original data to be transmitted to the second device; and splitting the original data into the Q paths of data in a case that a rank of a channel matrix of the satellite communication system is the Q.

[0008] In one example embodiment, performing a data stream mapping operation on the Q paths of data to obtain a data vector comprises: mapping the Q paths of data to Q transmit antennas respectively to obtain a plurality of mapped data streams, wherein the transmit antennas are used to represent signal transmission paths corresponding to antennas deployed in the first device; and converting the plurality of mapped data streams into a vector representation to obtain the data vector, wherein one element in the data vector represents data of one data stream.

[0009] In one example embodiment, obtaining coordinates of the first device and coordinates of the second device; calculating a distance between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating a path loss of a data signal transmitted between the first device and the second device according to a carrier frequency of the satellite communication system and the distance between the first device and the second device; and determining the precoding matrix using the path loss, wherein the precoding matrix is used to adjust signal transmission between the first device and the second device.

[0010] In one example embodiment, determining the precoding matrix using the path loss comprises: constructing a path loss matrix of the second device using the path loss; constructing a gain adjustment matrix of the first device using the path loss matrix in a case that the first device is determined to have a plurality of antenna ports, wherein the gain adjustment matrix is used to control intensity of signal transmission between the first device and the second device; performing normalization processing on the gain adjustment matrix to obtain a channel amplitude matrix; and determining the precoding matrix using the channel amplitude matrix.

[0011] In one example embodiment, determining the precoding matrix using the channel amplitude matrix comprises: constructing a phase adjustment matrix of the second device using the coordinates of the first device, the coordinates of the second device, and a number of antennas configured in the second device; constructing a channel matrix between the second device and the first device using the phase adjustment matrix, wherein the channel matrix includes amplitudes and phases of signals transmitted between the first device and the second device; and constructing the precoding matrix according to the channel matrix between the second device and the first device.

[0012] In an example embodiment, performing a precoding operation on a data vector by using a precoding matrix of the second device to obtain a first vector comprises: calculating a product between each element in the precoding matrix and each element in the data vector; and obtaining the first vector by using the product result.

[0013] In an example embodiment, performing a gain adjustment operation on the first vector according to antenna ports deployed in the second device to obtain a target signal comprises: adjusting a transmission power of the first vector according to a number of the antenna ports to obtain an adjusted vector; and converting the adjusted vector into a radio frequency signal to obtain the target signal.

[0014] According to another embodiment of the present application, a data receiving method is provided, comprising: receiving a target signal sent by a first device through antenna ports deployed in a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, the target signal is a signal determined based on Q pieces of data sent by the first device to the second device, the Q is a natural number less than or equal to a number of antennas deployed in the first device; performing a phase rotation operation on the target signal to obtain a third vector; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a data stream set of the Q pieces of data; and merging the data stream set of the Q pieces of data to obtain original data.

[0015] In an example embodiment, performing a phase rotation operation on the target signal to obtain a third vector comprises: obtaining coordinates of the first device and coordinates of the second device; calculating a relative position between the first device and the second device according to the coordinates of the first device and the coordinates of the second device.

[0016] calculating phase rotation adjustment values of a plurality of antenna ports deployed in the second device by using the relative position and the number of antennas deployed in the second device; constructing a phase rotation matrix based on the plurality of phase rotation adjustment values, wherein diagonal elements of the phase rotation matrix are phase rotation factors of the plurality of antenna ports; and performing the phase rotation operation on the target signal by using the phase rotation matrix to compensate for phase differences between the plurality of antenna ports to obtain the third vector.

[0017] In an example embodiment, the performing the demodulation operation and the decoding operation on the third vector to recover a data vector from the third vector comprises: performing the demodulation operation on the third vector to recover a demodulated data stream from the third vector; and performing the decoding operation on the demodulated data stream using a decoding matrix corresponding to a precoding matrix of the second device to obtain the data vector, wherein the precoding matrix is a matrix used by the first device when performing a precoding operation on the data vector.

[0018] In an example embodiment, the merging the set of data streams of the Q data to obtain original data comprises: serially mapping a plurality of parallel data streams in the set of data streams to convert the plurality of data streams in the set of data streams into a serial data stream; and merging the serial data stream to obtain the original data.

[0019] According to another embodiment of the present application, a data sending apparatus is provided, which comprises a first memory, a first processor, and a first computer program stored in the first memory and executable in the first processor, and when the first processor executes the first computer program, the following operations are implemented: determining Q data to be sent to a second device by a first device, wherein the first device and the second device are both devices deployed in a satellite communication system, and the Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a data stream mapping operation on the Q data to obtain a data vector, wherein the data vector is used to represent a set of data streams of the Q data; performing a precoding operation on the data vector using a precoding matrix of the second device to obtain a first vector; performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal; and sending the target signal to the second device.

[0020] According to another embodiment of the present application, a data receiving apparatus is provided, comprising a second memory, a second processor, and a second computer program stored in the second memory and executable on the second processor, wherein the second processor implements the following operations when executing the second computer program: receiving a target signal transmitted by a first device through an antenna port deployed in the second device, wherein the first device and the second device are both devices deployed in a satellite communication system, the target signal is a signal determined based on Q pieces of data transmitted by the first device to the second device, and the Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a phase rotation operation on the target signal to obtain a third vector; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a data stream set of the Q pieces of data; and merging the data stream set of the Q pieces of data to obtain original data.

[0021] According to still another embodiment of the present application, a satellite communication system is further provided, comprising a transmitting device and a receiving device, wherein the transmitting device implements the steps of the method described in any one of the above embodiments, and the receiving device implements the steps of the method described in any one of the above embodiments.

[0022] According to still another embodiment of the present application, a computer program product is further provided, comprising a computer program, wherein the computer program implements the steps in any one of the above method embodiments when executed by a processor.

[0023] According to still another embodiment of the present application, a computer readable storage medium is further provided, wherein the computer readable storage medium stores a computer program, and the computer program is configured to execute the steps in any one of the above method embodiments when running.

[0024] According to still another embodiment of the present application, an electronic device is further provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to perform the steps in any one of the above method embodiments.

[0025] According to the application, the data stream mapping operation is performed on the Q data to be sent to the second device to obtain a data vector, the precoding matrix of the second device is used to perform the precoding operation on the data vector to obtain a first vector, the gain adjustment operation is performed on the first vector according to the antenna port deployed in the second device to obtain a target signal, and the target signal is sent to the second device. The spectrum can be more effectively utilized, the data stream on each subcarrier is independently modulated and transmitted through the precoding matrix, and even in the environment where the multipath propagation and channel interference are relatively serious, the high spectrum efficiency can be maintained. Moreover, through the dynamic adjustment of the precoding matrix, the transmission of the signal in the channel can be optimized, the interference between signals can be reduced, and the utilization rate of the channel can be improved. Therefore, the problems of the limited data transmission rate, the low spectrum efficiency and the insufficient channel utilization rate in the satellite communication in the related art can be solved, and the effect of improving the utilization rate and the transmission rate of the channel can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a hardware structure block diagram of a server device of a data sending method according to an embodiment of the application;

[0027] Figure 2 is a flow chart of a data sending method according to an embodiment of the application;

[0028] Figure 3 is a schematic diagram of an application scenario according to an embodiment of the application Figure 1 ;

[0029] Figure 4 is a schematic diagram of an application scenario according to an embodiment of the application Figure 2 ;

[0030] Figure 5 is a flow chart of a data receiving method according to an embodiment of the application;

[0031] Figure 6 is a structure block diagram of a satellite communication system according to an embodiment of the application;

[0032] Figure 7 is a schematic diagram of a system channel according to an embodiment of the application;

[0033] Figure 8 is a structure block diagram of a data sending device according to an embodiment of the application;

[0034] Figure 9 is a structure block diagram of a data receiving device according to an embodiment of the application. DETAILED DESCRIPTION

[0035] Hereinafter, the embodiments of the application will be described in detail with reference to the accompanying drawings and in combination with the embodiments.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and in the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence.

[0037] The method embodiments provided in the embodiments of the present application can be executed in a satellite server device in a satellite communication system or similar computing devices. Taking the case of running on a satellite server device, Figure 1 is a hardware structure block diagram of a satellite server device of a data sending method according to an embodiment of the present application. As shown in Figure 1 , the satellite server device, the server can be used as a ground station, receives data sent back by a satellite, and forwards the data to other ground stations or end users. It can include one or more (only one is shown in Figure 1 The processor 102 (the processor 102 can include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The processor is responsible for executing tasks related to communication, navigation, data processing, instruction analysis, system monitoring and fault recovery) and a memory 104 for storing data (in satellite communication, the memory is used to store communication protocols, user data, satellite state information, fault logs, and algorithms for data processing and forwarding) for storing data. The above satellite server device can also include a transmission device 106 for communication function (in a satellite, the transmission device is used to send and receive signals to realize wireless communication) and an input and output device 108 (in satellite communication, the input and output device can include an interface for communication with a ground station or other satellites, and an interface for communication with other systems on the satellite (such as power supply system, attitude control system). For example, the core network interface is used to establish a connection with other network components to realize the network transmission of data). Those skilled in the art can understand that Figure 1 The structure shown is only schematic, which does not limit the structure of the above satellite server device. For example, the satellite server device can also include more or less components than Figure 1 shown, or have a different configuration than Figure 1 shown.

[0038] The memory 104 can be used to store computer programs, such as software programs of application software and modules, such as a computer program corresponding to the data sending method in the embodiments of the present application. The processor 102 can execute various functional applications and data processing, i.e., implement the above method, by running the computer programs stored in the memory 104. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include memories remotely arranged with respect to the processor 102, which can be connected to a satellite server device through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0039] The transmission device 106 is used to receive or send data via a network. Specific examples of the above network can include a wireless network provided by a communication provider of the satellite server device. In one example, the transmission device 106 includes a network adapter (NIC) which can be connected to other network devices through a base station so as to be able to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module which is used to communicate with the Internet in a wireless manner.

[0040] In the embodiments, a data sending method is provided, Figure 2 which is a flowchart of the data sending method according to the embodiments of the present application, as shown in Figure 2 which includes the following steps:

[0041] In step S202, Q pieces of data to be sent by a first device to a second device are determined, wherein the first device and the second device are both devices deployed in a satellite communication system, and Q is a natural number less than or equal to the number of antennas deployed in the first device.

[0042] Optionally, the embodiments include but are not limited to being applied to a scenario in which a plurality of transmitting antennas and receiving antennas are used at a transmitting end and a receiving end in a satellite communication system, respectively, so that signals are transmitted and received through the plurality of antennas of the transmitting end and the receiving end. Spatial resources can be fully utilized, multiple transmission and multiple reception can be realized through the plurality of antennas, and the system channel capacity can be doubled without increasing the frequency spectrum resources and the antenna transmitting power. For example, as shown in Figure 3 the embodiments are applicable to a scenario in which a satellite has two or more independent antenna ports and a terminal has two or more independent antenna ports in a low-orbit single-satellite beam coverage range, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing. For another example, as shown in Figure 4As shown, the embodiment is applicable to the scenario of constructing a MIMO communication system for spatial diversity and spatial multiplexing in the low-orbit single-satellite or adjacent-satellite multi-beam overlapping coverage range, where the satellite has one or more independent antenna ports, and the terminal has two or more independent antenna ports.

[0043] Optionally, the satellite communication system in the embodiment refers to data transmission using an artificial satellite, and is applied to civil and commercial communication fields, for example, a MIMO-based communication system.

[0044] Optionally, the first device in the embodiment refers to a device for transmitting data, which can be a communication payload on a satellite or other transmitting terminal. The second device refers to a device for receiving data, which can be a ground station, other satellite or mobile terminal (for example, user equipment).

[0045] Optionally, the Q-path data in the embodiment represents the number of data streams to be transmitted, and the value of Q is a natural number and is less than or equal to the number of antennas configured by the first device (transmitting end). The number of data streams corresponds to the number of data streams in the MIMO technology. The Q-path data transmitted by the first device to the second device includes the following aspects: the data to be transmitted by one first device to one second device is Q-path data, and the Q-path data is generated by one first device; the data to be transmitted by one first device to multiple second devices is Q-path data, and the Q-path data is generated by one first device; the data to be transmitted by multiple first devices to one second device is Q-path data, and the Q-path data is generated by multiple first devices; and the data to be transmitted by multiple first devices to multiple second devices is Q-path data, and the Q-path data is generated by multiple first devices and is transmitted to the multiple second devices. For example, in a MIMO (Multiple Input Multiple Output) system, the value of Q is usually related to the antenna configuration and channel conditions in the system, and it represents the number of independent data streams that can be transmitted simultaneously by the transmitting end. The value of Q depends on several key factors: the number of transmitting end antennas, the number of receiving end antennas, channel conditions, precoding and signal processing, system design and resource allocation. Therefore, the value of Q is a dynamically adjusted parameter, which is jointly affected by the hardware configuration of the transmitting end and the receiving end, the channel state, the signal processing strategy and the system resource allocation strategy. In the optimal case, Q can be equal to the number of transmitting end antennas N_t, but in actual application, Q is usually less than N_t, depending on the comprehensive influence of the above factors.

[0046] For example, in the scenario of the MIMO system described above, if the transmitting end (the first device, such as a satellite) has 4 antenna ports, theoretically Q can take the value of 4. However, if the receiving end (the second device, such as a ground station) has only 2 antenna ports, and the channel condition (such as the LOS channel) limits the rank of the channel, Q can only take the value of 2 or less, even if the transmitting end has additional antenna ports available. In this case, the transmitting end can only use part of the antenna ports for spatial multiplexing, and the remaining antenna ports can be used to provide additional spatial diversity or for other purposes, or the remaining antenna ports are used to send data to other receiving ends.

[0047] In step S204, a data stream mapping operation is performed on the Q-path data to obtain a data vector, wherein the data vector is used to represent a set of data streams of the Q-path data.

[0048] Optionally, the data stream mapping operation in the present embodiment is a process of mapping the original data stream to multiple antennas of the transmitting end, so as to use MIMO for spatial multiplexing or diversity. For example, in a MIMO system, multiple antennas can be used for transmission and reception at the same time, which provides the possibility for parallel data transmission, thereby significantly improving the capacity and data transmission rate of the system. Data stream mapping is an important link to achieve this goal, which converts the original data stream into a format suitable for MIMO transmission. Factors considered in the data stream mapping operation include but are not limited to: channel state information, antenna configuration, data stream allocation strategy, precoding matrix, resource efficiency.

[0049] Optionally, the data vector in the present embodiment represents a set of Q-path data, which is usually a column vector, wherein each element corresponds to a data stream.

[0050] In step S206, a precoding operation is performed on the data vector using a precoding matrix of the second device to obtain a first vector.

[0051] Optionally, in a MIMO system, the precoding matrix is a matrix used to encode the data vector, which optimizes the transmission of data in space, improves the channel utilization rate and the reliability of data transmission.

[0052] In step S208, a gain adjustment operation is performed on the first vector according to the antenna ports deployed in the second device to obtain a target signal.

[0053] Optionally, the first vector and the target signal respectively represent the data vector after the precoding operation and the gain adjustment operation.

[0054] Optionally, the gain adjustment operation needs to adjust the amplitude of the transmitting signal according to the antenna configuration of the second device (the receiving end), to ensure that the signal can be correctly decoded at the receiving end.

[0055] Step S210, sending the target signal to the second device.

[0056] For example, in one specific embodiment, assuming that the first device (satellite) is configured with 4 antenna ports, and the second device (ground terminal) is configured with 2 antenna ports, including the following steps:

[0057] Step S302, determining Q pieces of data to be sent by the satellite to the ground terminal. For example, Q=2, i.e., the satellite is ready to send 2 pieces of data stream.

[0058] Step S304, performing data stream mapping operation on the 2 pieces of data stream to obtain a data vector.

[0059] Step S306, performing precoding operation on the data vector by using the precoding matrix to obtain a first vector.

[0060] Step S308, performing gain adjustment operation on the first vector according to the 2 antenna ports of the ground terminal.

[0061] Step S310, the satellite sends the target signal to the ground terminal. The ground terminal receives and processes the signal, and restores the original 2 pieces of data stream through deprecoding and demodulation.

[0062] The execution subject of the above steps in the embodiment can be a terminal, a server, a specific processor arranged in the terminal or the server, or a processor or processing device arranged independently of the terminal or the server, but is not limited thereto. For example, the satellite to be sent data in the MIMO system.

[0063] Through the above steps, since the data stream mapping operation is performed on the Q pieces of data to be sent to the second device to obtain a data vector, the precoding operation is performed on the data vector by using the precoding matrix of the second device to obtain a first vector; the gain adjustment operation is performed on the first vector according to the antenna port deployed in the second device to obtain a target signal; and the target signal is sent to the second device. The spectrum can be more effectively utilized, and the data stream on each subcarrier is independently modulated and transmitted through the precoding matrix. Moreover, through the dynamic adjustment of the precoding matrix, the transmission of the signal in the channel can be optimized, the interference between signals can be reduced, and the utilization rate of the channel can be improved. Therefore, the problems of limited data transmission rate, low spectrum efficiency and insufficient channel utilization rate in satellite communication in the related art can be solved, and the effect of improving the utilization rate and transmission rate of the channel is achieved.

[0064] In one example embodiment, determining Q pieces of data to be sent by the first device to the second device includes: obtaining original data to be sent to the second device; and in the case that the rank of the channel matrix of the satellite communication system is Q, the original data is divided into Q pieces of data.

[0065] Optionally, in a satellite communication system, the raw data can be signals from different data sources, such as sensor data, user uploaded files, real-time video streams, voice call data, etc. These data can be subjected to some basic encoding processes, such as error control coding (e.g. forward error correction code), before transmission to increase their robustness during transmission, but they have not yet been mapped to data streams for specific antennas in a MIMO system, nor have they undergone MIMO-specific processing steps such as precoding or modulation. For example, in a low-orbit satellite communication system, a satellite (first device) can receive high-definition video streams transmitted from a ground control center, which need to be transmitted in real time to multiple ground receiving stations (second devices). Before the satellite prepares to transmit these video streams to the receiving stations, these video streams are the raw data to be transmitted to the second devices. For another example, when a user uses a satellite phone service, the user's voice data is collected and encoded by a mobile phone (first device) into digital signals. These digital signals, i.e. the user's voice data, are the raw data to be transmitted to the satellite (second device) to implement remote communication.

[0066] Optionally, in a satellite communication system, when the rank of the system channel matrix is determined to be Q, the raw data is divided into Q data streams. This process allows the system to take advantage of the spatial multiplexing capability of the multiple-input multiple-output (MIMO) technology to transmit multiple independent data streams simultaneously through different antenna ports, thereby significantly improving the system capacity and data transmission rate.

[0067] where the rank of the channel matrix reflects the number of independent transmission paths in the channel. This means that if the rank of the channel matrix is Q, theoretically Q independent data streams can be transmitted simultaneously, each of which can be independently encoded, modulated and precoded to fully utilize the spatial resources.

[0068] The specific division steps include:

[0069] S1, the satellite or its ground control station collects or generates raw data, which can be text, images, audio, video or any other type of information.

[0070] S2, the satellite calculates the system channel matrix according to the current channel state information (CSI), including path loss, atmospheric attenuation, multipath effect, etc., and determines its rank to be Q. This step requires the use of the location information of the satellite and the receiving terminal, the known gain adjustment and phase adjustment parameters, and the knowledge of the precoding matrix.

[0071] S3, the raw data is divided into Q independent data streams. This division can be done by dividing the data streams in time, frequency or code division multiplexing, or using a special data division algorithm that takes into account the characteristics of the data and the characteristics of the channel matrix.

[0072] The embodiment can significantly increase the amount of data transmitted at a time by splitting the original data into Q parallel transmissions, thereby improving the transmission rate. It can also improve the reliability and flexibility of transmission, reduce the delay, and provide users with higher quality, more efficient and more reliable communication services.

[0073] In one example embodiment, the data stream mapping operation is performed on the Q data to obtain a data vector, including: mapping the Q data to Q transmit antennas respectively to obtain a plurality of mapped data streams, wherein the transmit antennas are used to represent the signal transmission paths corresponding to the antennas deployed in the first device; and converting the plurality of mapped data streams into a vector representation to obtain the data vector, wherein one element in the data vector represents the data of one data stream.

[0074] Optionally, mapping the Q data to the Q transmit antennas respectively specifically includes the following steps:

[0075] S1, data stream generation: the satellite communication system first generates Q independent data streams, each of which can carry different information or data packets.

[0076] S2, transmit antenna definition: each transmit antenna corresponds to a signal path from the satellite to the ground station. Even if only a small number of physical antennas are configured on the satellite, through channel modeling and precoding technology, a transmission path can be defined for each data stream, thereby simulating the effect of multi-antenna transmission.

[0077] S3, layer mapping: mapping the Q data streams to the Q transmit antennas respectively. This step can be regarded as matching the data stream with a specific signal transmission path, and each data stream is transmitted through a different transmit antenna path to achieve spatial multiplexing.

[0078] For example, consider a low-orbit satellite communication system in which the satellite is configured with 2 physical antennas, but through channel characteristic analysis, the system can support the transmission of 4 independent data streams. In this case, 4 transmit antennas can be defined, each corresponding to a signal path adjusted through precoding technology. The satellite splits the original data into 4 streams, each data stream is mapped to a transmit antenna, and then processed using a precoding matrix so that the data streams can be transmitted independently in space. By mapping the data stream to the case where the number of physical antennas is limited, the satellite communication system can also achieve spatial multiplexing, improve spectral efficiency, and increase data transmission rate.

[0079] The embodiment can achieve more efficient data transmission, improve spectral efficiency and data transmission rate, reduce signal interference, and enhance the reliability and throughput of communication by representing the data stream as a vector.

[0080] In one example embodiment, before performing the precoding operation on the data vector using the precoding matrix of the second device to obtain the first vector, the method further comprises: obtaining the coordinates of the first device and the coordinates of the second device; calculating the distance between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating the path loss of the data signal transmitted between the first device and the second device according to the carrier frequency of the satellite communication system and the distance between the first device and the second device; and determining the precoding matrix using the path loss, wherein the precoding matrix is used to represent the adjustment of the signal transmission between the first device and the second device.

[0081] Optionally, the first device in the embodiment includes but is not limited to a satellite device, and can be multiple or one. The second device includes but is not limited to a user device, and can be multiple or one. For example, in the case that the first device includes L satellite devices and the second device includes K user devices, the coordinates of the L satellite devices and the K user devices are obtained from a global navigation satellite system or ephemeris data, which can provide the accurate positions of the satellites, including longitude, latitude and altitude. The position information of the user devices can also be obtained in a similar way, or determined by the position information reported by the user devices to the satellites.

[0082] Optionally, the distance between each satellite device and each user device can be calculated using the formula for the distance between two points in a three-dimensional space according to the coordinates of the L satellite devices and the K user devices. For example, according to the known coordinates of the L satellites P sat,l (l=1,2...L) and the coordinates of the K terminals P ue,k (k=1,2...K), the distances d l,k (l=1,2...L k=1,2...K) between the L satellites and the K terminals can be calculated.

[0083] Optionally, the path loss loss l,k between the L satellite devices and the K user devices can be calculated using the free space path loss formula according to the carrier frequency f c of the satellite communication system and the calculated satellite-terrestrial distance d l,k : wherein 32.45 is the path loss of the reference point (at 1 MHz and 1 km), log{} represents the logarithm with {} as the base, f c is the carrier frequency in MHz, and d l,k is the distance in km.

[0084] Optionally, the precoding matrix is determined using the path loss, including: constructing a path loss matrix of the second device using the path loss; constructing a gain adjustment matrix of the first device using the path loss matrix, in a case that the first device has multiple antenna ports, wherein the gain adjustment matrix is used to control the strength of signal transmission between the first device and the second device; performing normalization processing on the gain adjustment matrix to obtain a channel amplitude matrix; and determining the precoding matrix using the channel amplitude matrix.

[0085] In the embodiment, the path loss matrix reflects the attenuation of signal transmission between the satellite device and the user device. Given L satellite devices and K user devices, a path loss matrix can be constructed, where each element represents the path loss from the lth satellite device to the kth user device. For example, when the second device is user k, the path loss matrix of user k is established as: .

[0086] Optionally, if the first device (i.e., the satellite device) has multiple antenna ports, a gain adjustment matrix can be constructed using the path loss matrix to control the strength of signal transmission. The construction goal of the gain adjustment matrix is usually to optimize the signal quality in the satellite-ground link, considering the path loss between all satellite devices and user devices. In a simple scenario, the construction of the gain adjustment matrix can be based on the criteria of minimizing the total path loss of all user devices or maximizing the channel capacity. For example, the gain adjustment matrix of the first device is constructed using the path loss matrix as: , where g M is used to represent the gain of the 1st to Mth antenna.

[0087] Optionally, normalization processing is performed on the gain adjustment matrix to obtain a channel amplitude matrix. Normalization processing is usually to ensure fair power allocation on all signal transmission paths and avoid communication problems caused by excessive or insufficient signal strength. The specific normalization method can be to divide each row or column in the gain adjustment matrix by the norm (or sum) of its row or column to ensure that the transmission power of each antenna port remains constant or meets a certain power allocation strategy. For example, after the gain adjustment matrix is normalized, the channel amplitude matrix formed is: .

[0088] Optionally, the precoding matrix is determined using the channel amplitude matrix, including: constructing a phase adjustment matrix of the second device using the coordinates of the first device, the coordinates of the second device, and the number of antennas configured in the second device; constructing a channel matrix between the second device and the first device using the phase adjustment matrix, wherein the channel matrix includes the amplitude and phase of the signal transmission between the first device and the second device; and constructing the precoding matrix according to the channel matrix between the second device and the first device.

[0089] In this embodiment, the calculation of the precoding matrix generally relies on the channel state information of the system, but in this scenario, due to the characteristics of the satellite-to-ground LOS channel, the CSI may not be completely obtained using traditional channel estimation methods. Therefore, the calculation of the precoding matrix can be based on the channel matrix and other prior information about the satellite-to-ground LOS channel, such as Doppler shift, phase rotation, etc.

[0090] The design goal of the precoding matrix is to optimize the spatial multiplexing capability of the MIMO system, reduce the interference between signals, and improve the channel capacity. This may involve the use of linear precoding methods such as minimum mean square error (MMSE), zero forcing (ZF), etc., or more complex precoding techniques such as machine learning-based methods to further improve communication performance.

[0091] For example, for user k (the second device), the phase adjustment matrix is established as: wherein, The channel matrix between the first device and the second device containing the amplitude and phase for user k can be obtained as: ;

[0092] For K M*N K MIMO systems, the channel matrix is: wherein, M is the total number of antennas configured by the satellite, N K is the number of antennas configured for the Kth user. The corresponding space-time precoding matrix can be obtained using methods such as ZF, MMSE, etc. Here, taking MMSE as an example, the space-time precoding matrix is: wherein, W k represents the precoding matrix of the Kth user.

[0093] Through the above steps, the satellite communication system can construct a series of matrices (path loss matrix, gain adjustment matrix, channel amplitude matrix, and precoding matrix) based on the characteristics of the satellite-to-ground distance and the LOS channel to reduce the interference of signals and thereby improve the communication performance and capacity of the system.

[0094] In one exemplary embodiment, a precoding operation is performed on a data vector using the precoding matrix of the second device to obtain a first vector, including: calculating the product between each element in the precoding matrix and each element in the data vector; and calculating the first vector using the product results.

[0095] Optionally, performing a precoding operation on a data vector using the precoding matrix of the second device (usually referring to the receiving end, but in the context of satellite communication, it may refer to a ground terminal or another satellite) is an important part of signal processing in MIMO systems, and the purpose is to more effectively decode and separate the respective data streams at the receiving end.

[0096] Optionally, the precoding operation is essentially a matrix multiplication of the data vector with the precoding matrix. This means that for each element in the data vector, the corresponding element in the precoding matrix is multiplied, and then the results are added to generate the first vector.

[0097] The purpose of the precoding operation in this embodiment is to optimize the transmission of signals in the MIMO system, ensuring that the data stream can be transmitted with less interference and greater channel capacity under the complex satellite communication star-ground LOS channel conditions. At the receiving end, by using the same precoding matrix or its inverse matrix, different data streams can be effectively decoded and separated, thereby realizing the communication gain of spatial diversity and spatial multiplexing.

[0098] In an exemplary embodiment, the gain adjustment operation is performed on the first vector according to the antenna ports deployed in the second device to obtain a target signal, including: adjusting the transmission power of the first vector according to the number of antenna ports to obtain an adjusted vector; converting the adjusted vector into a radio frequency signal to obtain the target signal.

[0099] Optionally, at the transmitting end (the first device, for example, a satellite), the transmission power of the precoded signal vector is adjusted according to the number of antenna ports deployed in the receiving end (the second device). This adjustment is based on the channel amplitude matrix and the gain adjustment matrix. The gain adjustment matrix reflects the power allocation strategy of the transmitting end antenna ports in order to match the specific receiving end antenna configuration.

[0100] This embodiment forms the channel of MIMO through the gain adjustment operation, improving the spatial multiplexing capability and signal reception quality of the MIMO system.

[0101] In this embodiment, a data receiving method is provided, Figure 5 is a flowchart of the data receiving method according to an embodiment of the present application, as Figure 5 shown, the flow includes the following steps:

[0102] Step S502, receiving a target signal sent by a first device through an antenna port deployed in a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, the target signal is a signal determined based on Q pieces of data sent by the first device to the second device, and Q is a natural number less than or equal to the number of antennas deployed in the first device;

[0103] Optionally, the embodiments can be applied in a satellite communication system, where multiple transmit antennas and multiple receive antennas are used at the transmitter and receiver respectively, and the signals are transmitted and received through multiple antennas at the transmitter and receiver. Spatial resources can be fully utilized, and multiple transmission and multiple reception can be achieved through multiple antennas, which can multiply the system channel capacity without increasing the spectrum resources and antenna transmit power. For example, as shown in FIG. 1, the embodiments can be applied in a scenario where a satellite has two or more independent antenna ports, and a terminal has two or more independent antenna ports, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing in a low-orbit single-satellite beam coverage range. Figure 3 For another example, as shown in FIG. 2, the embodiments can be applied in a scenario where a satellite has one or more independent antenna ports, and a terminal has two or more independent antenna ports, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing in a low-orbit single-satellite or adjacent-satellite multi-beam overlapping coverage range. Figure 4 For another example, as shown in FIG. 2, the embodiments can be applied in a scenario where a satellite has one or more independent antenna ports, and a terminal has two or more independent antenna ports, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing in a low-orbit single-satellite or adjacent-satellite multi-beam overlapping coverage range.

[0104] Optionally, the satellite communication system in the embodiments refers to data transmission using artificial satellites, and can be applied in fields such as civilian and commercial communication. For example, a MIMO-based communication system.

[0105] Optionally, the first device in the embodiments refers to a device for transmitting data, which can be a communication payload on a satellite or other transmitting terminal. The second device refers to a device for receiving data, which can be a ground station, other satellite or mobile terminal (for example, a user equipment).

[0106] Optionally, the Q streams of data in the embodiments refer to the number of data streams to be transmitted, and the value of Q is a natural number and is less than or equal to the number of antennas configured at the first device (transmitter). The value of Q corresponds to the number of data streams in the MIMO technology. For example, in a MIMO (Multiple Input Multiple Output) system, the value of Q is usually related to the antenna configuration and channel conditions in the system, and it represents the number of independent data streams that can be simultaneously transmitted by the transmitter. The value of Q depends on several key factors: the number of transmitter antennas, the number of receiver antennas, channel conditions, precoding and signal processing, system design and resource allocation. Therefore, the value of Q is a dynamically adjusted parameter, which is jointly affected by the hardware configuration of the transmitter and receiver, the channel state, the signal processing strategy and the system resource allocation strategy. In the optimal case, Q can be equal to the number of transmitter antennas N_t, but in actual application, Q is usually less than N_t, depending on the comprehensive influence of the above factors.

[0107] For example, in the scenario of the MIMO system described above, if the transmitting end (the first device, such as a satellite) has 4 antenna ports, theoretically Q can take a value of 4. However, if the receiving end (the second device, such as a ground station) only has 2 antenna ports, and the channel condition (such as the LOS channel) limits the rank of the channel, Q can only take a value of 2 or less, even if the transmitting end has additional antenna ports available. In this case, the transmitting end can only utilize part of the antenna ports for spatial multiplexing, and the remaining antenna ports can be used to provide additional spatial diversity or for other purposes.

[0108] At step S504, a phase rotation operation is performed on the target signal to obtain a third vector;

[0109] Optionally, the phase rotation operation in this embodiment is a matrix multiplication of the target signal (received radio frequency signal vector) using a phase rotation matrix to adjust the phase of the signal. In a satellite communication system, the phase rotation matrix is usually a diagonal matrix, where the elements on the diagonal are complex numbers representing the phase rotation factors of the signals of each antenna port.

[0110] At step S506, a demodulation operation and a decoding operation are performed on the third vector to recover a data vector from the third vector, where the data vector is used to represent a set of data streams of Q-way data;

[0111] Optionally, the demodulation operation is the process of converting the modulated radio frequency signal back to its original baseband signal form. In satellite communication, the transmitting end can use various modulation techniques, such as QPSK (Quadrature Phase Shift Keying), QAM (Quadrature Amplitude Modulation), BPSK (Binary Phase Shift Keying), etc., to improve data transmission rate and efficiency.

[0112] Optionally, the decoding operation is a key step to recover the original data, which involves converting the demodulated baseband signal back to the original data stream. Forward error correction (FEC) encoding techniques, such as Turbo code, convolutional code, or LDPC code, etc., are usually used in the decoding process to correct errors that may occur during transmission.

[0113] After the above demodulation and decoding operations, the receiving end can recover the data vector from the third vector, where the data vector contains a set of Q-way data streams. The recovery of the data vector ensures that the receiving end can obtain the original information sent by the transmitting end, even under complex channel conditions, maintaining the accuracy and integrity of data transmission.

[0114] For example, in a low earth orbit satellite communication system, the ground receiver receives the radio frequency signals from the satellite and compensates for the phase variations of the LOS channel through a phase rotation operation. Subsequently, a demodulation operation is performed to recover the baseband signals, and a decoding operation is performed to correct possible transmission errors, ultimately recovering the original set of data streams, i.e., the data vector, that was originally transmitted by the satellite. The recovery of the set of data streams is the foundation of efficient and reliable data transmission in satellite communication MIMO systems. Through accurate demodulation and decoding, the ground receiving equipment can ensure the recovery of the original data from the received signals, even under conditions of high satellite mobility and complex channels, achieving the gains of spatial diversity and spatial multiplexing, and improving the system capacity and transmission quality.

[0115] At step S508, the set of data streams of the Q paths of data are merged to obtain the original data.

[0116] Optionally, in a satellite communication system, after the receiving end (second device) receives the data streams through the multiple antenna ports deployed thereby, it needs to merge them into the original data. This process is referred to as data stream merging.

[0117] After the receiving end decodes and demodulates each path of data streams, it will obtain Q independent digital signal data streams. These data streams are originally transmitted in parallel, and thus need to be converted from parallel format to serial format, i.e., recombined in the order of the original data. This process is commonly referred to as parallel / serial conversion (P / S conversion), which is a key step in merging data streams.

[0118] Data stream recombination involves the inverse operation of the data stream mapping performed by the transmitting end. When performing data stream mapping, the transmitting end may use layer mapping, spatial multiplexing, or spatial diversity to split the original data stream into Q independent data streams. The receiving end needs to perform the opposite operation to recombine these independent data streams into the original continuous data stream or data block.

[0119] In the data stream merging process, error detection and correction operations may also need to be performed. Because in satellite communication, the signal may be affected by channel noise, interference, and fading, resulting in errors in the data during transmission. The receiving end detects and corrects these errors through forward error correction (FEC) techniques, such as convolutional codes, Turbo codes, or LDPC codes, to ensure the integrity of the data.

[0120] The merged data stream needs to be unpacked to remove any additional encapsulation added at the transmitting end, such as frame headers, packet headers, or modulation and coding information, to recover the original data information. Unpacking is the final step in data recovery, ensuring that the receiving end can correctly parse and use the received data.

[0121] After all the above steps, the receiving end will obtain the original data, which can be further processed or directly passed to the application. The format and content of the original data are exactly the same as the data originally sent by the transmitting end, except that it has undergone a series of signal processing and recovery operations.

[0122] For example, in a 2x2 MIMO low-orbit satellite communication system, the transmitting end divides the original data into two independent data streams and transmits them through two antennas. After receiving these data streams through two antennas, the receiving end performs demodulation, decoding and phase rotation operations to recover the two data streams. Then, the receiving end serializes the two data streams, i.e. recombines them according to the original data stream mapping order, removes any errors, and unpacks to recover the original data, so that user equipment or ground stations can process and use it.

[0123] Through this series of data processing and recovery operations, the satellite communication system can effectively recover the data originally sent by the transmitting device in the ground receiving device, ensuring the accuracy and integrity of data transmission even in the presence of various channel challenges, thereby improving the communication efficiency and user experience of the system.

[0124] The execution subject of the above steps in this embodiment can be a terminal, a server, a specific processor arranged in the terminal or server, or a processor or processing device arranged independently of the terminal or server, but is not limited thereto. For example, a user equipment receiving data sent by a satellite in a MIMO system.

[0125] Through the above steps, since the target signal sent by the first device is received through the antenna port deployed in the second device, a phase rotation operation is performed on the target signal to obtain a third vector; a demodulation operation and a decoding operation are performed on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a set of Q-way data stream; and the set of Q-way data stream is merged to obtain the original data. The frequency spectrum can be more effectively utilized, and the data stream on each subcarrier is independently modulated and transmitted through the precoding matrix, so that even in a severe multi-path propagation and channel interference environment, high spectral efficiency can be maintained. Moreover, through dynamic adjustment of the precoding matrix, the transmission of signals in the channel can be optimized, the interference between signals can be reduced, and the utilization rate of the channel can be improved. Therefore, the problems of limited data transmission rate, low spectral efficiency and insufficient channel utilization in satellite communication in the related art can be solved, and the effects of improving the utilization rate and transmission rate of the channel can be achieved.

[0126] In one example embodiment, performing a phase rotation operation on the target signal to obtain a third vector comprises: obtaining coordinates of the first device and coordinates of the second device; calculating a relative position between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating phase rotation adjustment values of a plurality of antenna ports deployed in the second device using the relative position and a number of antennas deployed in the second device; constructing a phase rotation matrix based on the plurality of phase rotation adjustment values, wherein diagonal elements of the phase rotation matrix are phase rotation factors of the plurality of antenna ports; and performing a phase rotation operation on the target signal using the phase rotation matrix to compensate for phase differences between the plurality of antenna ports to obtain the third vector.

[0127] Optionally, in a satellite communication system, the receiving end (second device) first needs to obtain the coordinate information of the transmitting end (first device, usually a satellite) and its own coordinate information. These coordinate information is usually obtained through GNSS (Global Navigation Satellite System) such as GPS, GLONASS, Galileo or Beidou system, or determined through ephemeris information and other satellite positioning technologies.

[0128] Optionally, according to the coordinate information of the first device (satellite) and the second device (ground receiving device), the relative position between them is calculated. This relative position information is crucial for calculating the phase difference caused by the relative motion of the satellite and the receiving end.

[0129] Optionally, using the calculated relative position information and the number of antennas of the receiving end, the phase rotation adjustment value of each antenna port is calculated according to a specific algorithm. These adjustment values aim to compensate for the phase changes in the LOS channel transmission, ensuring that the signal can be correctly decoded and processed at the receiving end.

[0130] Optionally, based on the calculated plurality of phase rotation adjustment values, a phase rotation matrix is constructed. In a satellite communication MIMO system, this matrix is a diagonal matrix, where the elements on the diagonal are the phase rotation factors calculated according to the antenna ports.

[0131] Optionally, the receiving end performs a phase rotation operation on the target signal (received radio frequency signal vector) using the constructed phase rotation matrix. This operation is completed through matrix multiplication, multiplying the target signal with the phase rotation matrix to obtain a third vector, where the phase of the signal has been adjusted to compensate for the phase changes in the LOS channel. The third vector contains the phase-compensated signals, which can be further demodulated and decoded to recover the original data stream sent by the transmitting end.

[0132] Through the above steps, even in the case of high-speed relative motion between the satellite and the receiving device, the satellite communication system recovers the original data, thereby improving the stability and reliability of the communication.

[0133] In one example embodiment, the demodulation operation and the decoding operation are performed on the third vector to recover the data vector from the third vector, including: performing the demodulation operation on the third vector to recover a demodulated data stream from the third vector; and performing the decoding operation on the demodulated data stream using a decoding matrix corresponding to a precoding matrix used by the second device to obtain the data vector, wherein the precoding matrix is a matrix used by the first device to perform the precoding operation on the data vector.

[0134] Optionally, the demodulation operation first needs to perform carrier synchronization and bit synchronization to ensure the timing and frequency alignment of the received signal and the transmitted signal. The receiving end needs to recover the carrier frequency of the received signal and demodulate using the same modulation scheme as the transmitting end to extract the bit stream of the digital signal from the third vector. After the demodulation operation, the third vector is converted into a set of demodulated data streams, which contain the original bit information of the Q-path data stream sent by the transmitting end, but may also be affected by channel noise and interference.

[0135] Optionally, the decoding operation aims to correct errors in the demodulated data stream and recover the originally transmitted data vector. In a MIMO system, the transmitting end performs a precoding operation on the data vector using a precoding matrix to achieve spatial diversity and spatial multiplexing. Therefore, the receiving end needs to use a decoding matrix corresponding to the precoding matrix (inverse matrix of the precoding matrix) to perform the decoding operation.

[0136] Optionally, the receiving end constructs the corresponding decoding matrix based on the channel matrix estimation and the precoding matrix used by the transmitting end. The receiving end uses the decoding matrix to perform matrix multiplication on the demodulated data stream to eliminate channel effects and recover the data vector before transmission:

[0137] Optionally, after the decoding operation, the receiving end may use forward error correction (FEC) techniques such as Turbo code, LDPC code, or convolutional code to detect and correct errors that may be introduced during signal transmission to improve data reliability.

[0138] Optionally, the receiving end recombines and encapsulates the Q-path data stream to recover the original data transmitted by the transmitting end.

[0139] This embodiment can effectively recover the data vector transmitted by the transmitting end through demodulation and decoding operations, ensuring accurate data transmission even in complex channel environments, achieving performance gain in spatial diversity and spatial multiplexing in MIMO communication systems, and improving system capacity and spectral efficiency. This process is an integral part of satellite communication MIMO system design, ensuring high-quality data transmission and service.

[0140] In one example embodiment, a set of data streams comprising Q parallel data streams are merged to obtain original data, including: serially mapping a plurality of parallel data streams in the set of data streams to convert the plurality of data streams in the set of data streams into serial data streams; and merging the serial data streams to obtain the original data.

[0141] Optionally, in a satellite communication MIMO system, a transmitter splits and maps original data into Q parallel data streams for transmission through multiple antenna ports. A receiver obtains the same number of parallel data streams after demodulation and decoding. To reassemble the original data, the receiver needs to perform a serial mapping operation to convert the parallel data streams back into serial data stream format.

[0142] This process requires the receiver to sort the decoded parallel data streams according to the original data stream mapping order of the transmitter, ensuring their correct sequence.

[0143] Optionally, the sorted parallel data streams are serially mapped, i.e., recombined in time sequence to form a continuous serial bit stream or byte stream. Serial mapping is a critical step to convert parallel data back into serial format. After serial mapping, the receiver obtains a continuous serial data stream composed of Q parallel data streams. To recover the complete original data, these serial data streams need to be merged. Based on serial mapping, the receiver further reassembles the data streams to remove any additional information that may have been added during parallel transmission, such as forward error correction (FEC) codes, control information, or channel coding information, ensuring the purity of the data streams. Finally, the reassembled serial data streams are used as input to perform packet reassembly, de-encapsulation, etc., to recover the original data originally sent by the transmitter. This process may involve removing packet headers, recombining data blocks, performing error detection and correction, etc.

[0144] For example, in a 2x2 MIMO low-orbit satellite communication system, a transmitter splits original data into two parallel data streams and transmits them through two antenna ports. A receiver obtains two parallel data streams after demodulation, decoding, and performing phase rotation operations. Next, the receiver serially maps the two data streams, recombining them in the original data stream mapping order of the transmitter to form a serial bit stream. Finally, through merging operations of the serial data streams, any additional coding information is removed, data packets are reassembled, and the original data sent by the transmitter is recovered, ensuring the integrity and accuracy of the information.

[0145] This embodiment ensures that the receiver can accurately recover the original data sent by the transmitter even in the complex environment of multi-antenna parallel transmission, improving communication efficiency and reliability.

[0146] In this embodiment, a satellite communication system is also provided,Figure 6 is a structural block diagram of a satellite communication system according to an embodiment of the present application, as Figure 6 illustrated, the apparatus comprises:

[0147] The transmitting device implements the steps of the method in the satellite when transmitting, and the receiving device implements the steps of the method of the user equipment in the second device when receiving.

[0148] The first device in the embodiment refers to a device transmitting data, which can be a communication payload on a satellite or other transmitting terminal. The second device refers to a device receiving data, which can be a ground station, other satellite or mobile terminal (for example, user equipment).

[0149] The satellite communication system in the embodiment uses multiple transmitting antennas and receiving antennas at the transmitting end and the receiving end respectively, and is used in a scenario where signals are transmitted and received through multiple antennas at the transmitting end and the receiving end. For example, as Figure 3 illustrated, the embodiment is applicable to a scenario where a satellite has two or more independent antenna ports, a terminal has two or more independent antenna ports, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing within the coverage range of a low-orbit single-satellite beam. Figure 4 For example, as illustrated, the embodiment is applicable to a scenario where a satellite has one or more independent antenna ports, a terminal has two or more independent antenna ports, and a MIMO communication system is constructed for spatial diversity and spatial multiplexing within the coverage range of a low-orbit single-satellite or adjacent-satellite multi-beam overlapping.

[0150] Figure 7 The embodiment needs to solve the problems of insufficient channel independence and channel matrix estimation when using MIMO technology in a satellite communication system. As illustrated, the left side is a schematic diagram of a channel without using the system channel of the embodiment, and the right side is a schematic diagram of a channel using the system channel of the embodiment. Under the channel structure on the left side, the channel matrix is Since the scattering and multipath effects of the satellite-ground link are small, and the phase changes cannot be fed back and tracked in time due to the long RTT time, if antennas 1 and 2 are located on the same satellite, the matrix is obviously not of rank 2, and cannot transmit independent data streams. Under the channel structure on the right side, the channel matrix is if antennas 1 and 2 are located on the same satellite, the matrix is obviously not of rank 2, and cannot transmit independent data streams.

[0151] ​​But by setting different gain adjustment and phase adjustment, the rank of channel matrix can be 2, and 2 independent data streams can be transmitted. If antenna 1 and 2 are located in different satellites, and by setting different phase adjustment, the rank of channel matrix can be 2, and 2 independent data streams can be transmitted. By superimposing controllable gain and phase adjustment at the transmitting end and the receiving end, a full rank channel matrix can be obtained.

[0152] The channel matrix estimation part, in this embodiment, the channel matrix is composed of three parts of influence, the path loss between the satellite and the terminal, the gain adjustment superimposed at the transmitting end, and the phase adjustment superimposed at the receiving end. In satellite communication, the terminal usually reports the position information obtained by GNSS to the satellite, and obtains the position information through the ephemeris information broadcast by the satellite. Therefore, based on the position information of the satellite and the terminal, the value of can be obtained. If antenna 1 and 2 are located in different satellites, there is no need to calculate and use If antenna 1 and 2 are located in the same satellite, the receiving sensitivity requirement can still be met after superimposing gain adjustment According to the design of the phase adjustment of the receiving end, wherein the function is a function of the initial value of the phase adjustment calculated according to the position information of the terminal and the satellite. The same function is used at the satellite and the terminal, and the terminal is used to perform the phase adjustment of the corresponding antenna port according to the calculation result, and the satellite is used to calculate the channel matrix.

[0153] Based on the above analysis, by knowing the position information of the satellite and the terminal, and the same phase adjustment initial value function, the satellite can obtain the complete channel matrix without relying on the channel estimation feedback link, and can calculate the invertible matrix for space-time precoding. The same design principle can be extended from a 2*2 MIMO system to an N*M MIMO system.

[0154] Optionally, as shown in Figure 7 the transmitting end (transmitting device) comprises a space-time precoding calculation module, a data stream mapping module, a space-time precoding module, and a modulation and coding module, wherein the space-time precoding calculation module is used to calculate the precoding matrix corresponding to the channel matrix according to the position information of the satellite and the terminal, and the phase adjustment initial value function. The data stream mapping module is used to map the sending data in parallel to the data that can be independently demodulated according to the rank of the channel matrix. The space-time precoding module is used to perform space-time precoding on the corresponding data stream according to the result of the space-time precoding calculation module. The modulation and coding module is used to perform gain control according to the gain modulation result to be performed at the transmitting end in different antenna ports.

[0155] The receiving end (receiving device) comprises a phase rotation calculation module for calculating phase rotation adjustment values of corresponding antenna ports according to position information of the satellites and the terminal and the number of receiving antennas, and a data merging module for serially mapping parallel data streams capable of independent demodulation to receiving data.

[0156] The application will be described in detail below with an example of data transmission from satellites to user equipment, and the specific work flow comprises the following steps:

[0157] Step S802, according to the known coordinates P sat,l (l=1,2...L) of L satellites and the coordinates P ue,k (k=1,2...K) of K user equipment, the distances d l,k (l=1,2...L k=1,2...K) between the L satellites and the K user equipment are calculated, and the path loss between the L satellites and the K user equipment is calculated according to the carrier frequency f c of the satellite communication system. .

[0158] Step S804, for user k, a path loss matrix is established:

[0159] ;

[0160] For the case of more than two antenna ports for the same satellite, the transmission gain is adjusted by the following formula.

[0161] .

[0162] Step S806, based on the adjusted matrix, a normalization operation is completed to form a channel amplitude matrix: .

[0163] Step S808, for user equipment k, a phase adjustment matrix is established: , wherein, . Then the channel matrix containing the amplitude and phase for user equipment k can be obtained as: .

[0164] Step S810, for K M*N K MIMO systems, the channel matrix is: .

[0165] The ZF, MMSE and other methods can be used to obtain the corresponding space-time precoding matrix, and here the MMSE is taken as an example, and the space-time precoding matrix is: , wherein, W k represents the precoding matrix of the Kth user.

[0166] Step S812, when the satellite transmits Q k path data to the user equipment k, wherein Q k has the following restrictions: .

[0167] Step S814, the transmitting end data stream mapping function maps the Q k path data to be transmitted in parallel to Q k path data streams, and the data vector is: .

[0168] The M path data vectors of all K terminal ends are: .

[0169] Step S816, in the transmitting end space-time precoding module, the satellite precodes S k with W k , and the sending vector is: ;

[0170] After the transmitting end gain adjustment, the sending vector is:

[0171] , wherein .

[0172] Step S818, after the spatial propagation and the receiving end phase adjustment, the total vector received by the user equipment k is: , wherein the first item on the right side is the signal required by the user k, the second item is the interference caused by other users, and the last item is the additive white Gaussian noise.

[0173] The matrix representation is: , and the second item is eliminated through the space-time precoding process.

[0174] Step S820, after the receiving end passes through the normal demodulation and decoding process, the Qk path data is serially mapped through the data stream merging module, and the transmitting end sending data stream is recovered.

[0175] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be realized by means of software and the necessary general hardware platform, of course, it can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes a plurality of instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device) to execute the method described in each embodiment of the present application.

[0176] A data sending apparatus is also provided in the embodiments, which is configured to implement the above-mentioned embodiments and preferred embodiments, and will not be described here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

[0177] Figure 8 is a structural block diagram of a data sending apparatus according to an embodiment of the present application, as shown in Figure 8 the apparatus comprises:

[0178] a first memory 82, a first processor 84, and a first computer program 86 stored in the first memory 82 and executable on the first processor 84, wherein the first processor 84 implements the following operations when executing the first computer program 86:

[0179] determining Q pieces of data to be sent by a first device to a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, and the Q is a natural number less than or equal to a number of antennas deployed in the first device;

[0180] performing a data stream mapping operation on the Q pieces of data to obtain a data vector, wherein the data vector is used to represent a data stream set of the Q pieces of data;

[0181] performing a precoding operation on the data vector by using a precoding matrix of the second device to obtain a first vector;

[0182] performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal;

[0183] sending the target signal to the second device.

[0184] In one example embodiment, the apparatus determines the Q pieces of data to be sent by the first device to the second device by: obtaining original data to be sent to the second device; and dividing the original data into the Q pieces of data in a case where a rank of a channel matrix of the satellite communication system is the Q.

[0185] In one example embodiment, the apparatus performs the data stream mapping operation on the Q pieces of data to obtain the data vector by: mapping the Q pieces of data onto Q transmit antennas respectively to obtain a plurality of mapping data streams, wherein the transmit antennas are used to represent signal transmission paths corresponding to the antennas deployed in the first device; and converting the plurality of mapping data streams into a vector representation to obtain the data vector, wherein one element in the data vector represents data of one data stream.

[0186] In one example embodiment, before performing the precoding operation on the data vector by using the precoding matrix of the second device to obtain the first vector, the apparatus is further configured to obtain the coordinate of the first device and the coordinate of the second device; calculate the distance between the first device and the second device according to the coordinate of the first device and the coordinate of the second device; calculate the path loss of the data signal transmitted between the first device and the second device according to the carrier frequency of the satellite communication system and the distance between the first device and the second device; and determine the precoding matrix by using the path loss, wherein the precoding matrix is used to represent the adjustment of the signal transmission between the first device and the second device.

[0187] In one example embodiment, the apparatus determines the precoding matrix by using the path loss in the following manner: constructs a path loss matrix of the second device by using the path loss; constructs a gain adjustment matrix of the first device by using the path loss matrix in the case that the first device is determined to have multiple antenna ports, wherein the gain adjustment matrix is used to control the intensity of the signal transmission between the first device and the second device; performs normalization processing on the gain adjustment matrix to obtain a channel amplitude matrix; and determines the precoding matrix by using the channel amplitude matrix.

[0188] In one example embodiment, the apparatus determines the precoding matrix by using the channel amplitude matrix in the following manner: constructs a phase adjustment matrix of the second device by using the coordinate of the first device, the coordinate of the second device, and the number of antennas configured in the second device; constructs a channel matrix between the second device and the first device by using the phase adjustment matrix, wherein the channel matrix includes the amplitude and the phase of the signal transmitted between the first device and the second device; and constructs the precoding matrix according to the channel matrix between the second device and the first device.

[0189] In one example embodiment, the apparatus performs the precoding operation on the data vector by using the precoding matrix of the second device to obtain the first vector in the following manner: calculates the product between each element in the precoding matrix and each element in the data vector; and calculates the first vector by using the product result.

[0190] In one example embodiment, the apparatus performs the gain adjustment operation on the first vector according to the antenna port deployed in the second device to obtain a target signal in the following manner: adjusts the transmission power of the first vector according to the number of the antenna ports to obtain an adjusted vector; and converts the adjusted vector into a radio frequency signal to obtain the target signal.

[0191] Figure 9 is a structural block diagram of a data receiving device according to an embodiment of the present application, as shown in the figure, the device comprises: Figure 9

[0192] a second memory 92, a second processor 94, and a second computer program 96 stored on the second memory 92 and executable on the second processor 94, when the second processor 94 executes the second computer program 96, the following operations are implemented:

[0193] receive a target signal sent by a first device through an antenna port deployed in a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, the target signal is a signal determined based on Q pieces of data sent by the first device to the second device, and Q is a natural number less than or equal to the number of antennas deployed in the first device;

[0194] perform a phase rotation operation on the target signal to obtain a third vector;

[0195] perform demodulation and decoding operations on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a data stream set of Q pieces of data;

[0196] merge the data stream set of Q pieces of data to obtain original data.

[0197] In an exemplary embodiment, the device performs a phase rotation operation on the target signal to obtain a third vector in the following manner: obtaining coordinates of the first device and coordinates of the second device; calculating a relative position between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating phase rotation adjustment values of multiple antenna ports deployed in the second device by using the relative position and the number of antennas deployed in the second device; constructing a phase rotation matrix based on multiple phase rotation adjustment values, wherein diagonal elements of the phase rotation matrix are phase rotation factors of multiple antenna ports; performing the phase rotation operation on the target signal by using the phase rotation matrix to compensate for phase differences between multiple antenna ports to obtain the third vector.

[0198] ​In an example embodiment, the apparatus recovers the data vector from the third vector by performing the demodulation operation on the third vector to recover a demodulated data stream from the third vector, and performing the decoding operation on the demodulated data stream using a decoding matrix corresponding to a precoding matrix of the second device, wherein the precoding matrix is a matrix used by the first device when performing the precoding operation on the data vector, to obtain the data vector.

[0199] In an example embodiment, the apparatus combines the set of data streams of the Q data to obtain the original data by serial mapping a plurality of parallel data streams in the set of data streams to convert the plurality of data streams in the set of data streams into a serial data stream, and combining the serial data stream to obtain the original data.

[0200] It should be noted that each of the above modules can be implemented by software or hardware, and for the latter, the following implementation manners can be used, but are not limited thereto: all of the modules are located in the same processor; or each of the modules is located in a different processor in any combination.

[0201] Embodiments of the present application also provide a computer readable storage medium, which stores a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when running.

[0202] In an example embodiment, the computer readable storage medium can include, but is not limited to, a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store computer programs.

[0203] Embodiments of the present application also provide an electronic device, which includes a memory storing a computer program and a processor configured to execute the computer program to perform the steps in any of the above method embodiments.

[0204] In an example embodiment, the electronic device can further include a transmission device connected to the processor and an input / output device connected to the processor.

[0205] Embodiments of the present application also provide a computer program product, which includes a computer program, and the computer program is executed by a processor to implement the steps in any of the above method embodiments.

[0206] The embodiment of the present application further provides another computer program product, comprising a nonvolatile computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps in any of the method embodiments.

[0207] The embodiment of the present application further provides a computer program, which comprises computer instructions stored in a computer readable storage medium; a processor of a computer device reads the computer instructions from the computer readable storage medium, and executes the computer instructions, so that the computer device executes the steps in any of the method embodiments.

[0208] The specific examples in the embodiment can refer to the examples described in the above embodiments and exemplary embodiments, and the embodiment will not be described here again.

[0209] Obviously, those skilled in the art should understand that each module or each step of the present application described above can be realized by using a general computing device, which can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, which can be realized by using program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described can be executed in an order different from here, or they can be manufactured into each integrated circuit module respectively, or multiple modules or steps among them can be manufactured into a single integrated circuit module to realize. Thus, the present application is not limited to any specific combination of hardware and software.

[0210] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A data transmission method, characterized by, The method comprises the following steps: determining Q pieces of data to be sent to a second device by a first device, wherein the first device and the second device are both devices deployed in a satellite communication system, and Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a data stream mapping operation on the Q pieces of data to obtain a data vector, wherein the data vector is used to represent a data stream set of the Q pieces of data; performing a precoding operation on the data vector by using a precoding matrix of the second device to obtain a first vector; performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal; sending the target signal to the second device; before performing the precoding operation on the data vector by using the precoding matrix of the second device to obtain the first vector, the method further comprises the following steps: obtaining coordinates of the first device and coordinates of the second device; calculating a distance between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating a path loss of a data signal transmitted between the first device and the second device according to a carrier frequency of the satellite communication system and the distance between the first device and the second device; and determining the precoding matrix by using the path loss, wherein the precoding matrix is used to adjust signal transmission between the first device and the second device.

2. The method of claim 1, wherein, determining Q pieces of data to be sent to a second device by a first device, comprising: obtaining original data to be sent to the second device; in a case where a rank of a channel matrix of the satellite communication system is Q, segmenting the original data into the Q pieces of data.

3. The method of claim 1, wherein, performing a data stream mapping operation on the Q pieces of data to obtain a data vector, comprising: mapping the Q pieces of data to Q pieces of transmitting antennas respectively to obtain a plurality of mapping data streams, wherein the transmitting antennas are used to represent signal transmission paths corresponding to antennas deployed in the first device; converting the plurality of mapping data streams into a vector representation to obtain the data vector, wherein one element in the data vector represents data of one data stream.

4. The method of claim 1, wherein, determining the precoding matrix by using the path loss, comprising: constructing a path loss matrix of the second device by using the path loss; in a case where it is determined that the first device has a plurality of antenna ports, constructing a gain adjustment matrix of the first device by using the path loss matrix, wherein the gain adjustment matrix is used to control the intensity of signal transmission between the first device and the second device; performing a normalization processing on the gain adjustment matrix to obtain a channel amplitude matrix; determining the precoding matrix by using the channel amplitude matrix.

5. The method of claim 4, wherein, determining the precoding matrix by using the channel amplitude matrix, comprising: constructing a phase adjustment matrix of the second device by using the coordinates of the first device, the coordinates of the second device and the number of antennas configured in the second device; constructing a channel matrix between the second device and the first device by using the phase adjustment matrix, wherein the channel matrix comprises amplitudes and phases of signals transmitted between the first device and the second device; constructing the precoding matrix according to the channel matrix between the second device and the first device.

6. The method of claim 1, wherein, performing a precoding operation on a data vector by using the precoding matrix of the second device to obtain a first vector, comprising: calculating a product between each element in the precoding matrix and each element in the data vector; calculating the first vector by using the product result.

7. The method of claim 1, wherein, performing a gain adjustment operation on the first vector according to an antenna port deployed in the second device to obtain a target signal, comprising: adjusting a transmission power of the first vector according to a number of the antenna port to obtain an adjusted vector; converting the adjusted vector into a radio frequency signal to obtain the target signal.

8. A data receiving method characterized by comprising: comprising: receiving a target signal sent by a first device through an antenna port deployed in a second device, wherein the first device and the second device are devices deployed in a satellite communication system, the target signal is a signal determined based on Q pieces of data sent by the first device to the second device, and Q is a natural number less than or equal to a number of antennas deployed in the first device; performing a phase rotation operation on the target signal to obtain a third vector; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a data stream set of the Q pieces of data; merging the data stream set of the Q pieces of data to obtain original data; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, comprising: performing the demodulation operation on the third vector to recover a demodulated data stream from the third vector; and performing the decoding operation on the demodulated data stream by using a decoding matrix corresponding to a precoding matrix of the second device to obtain the data vector, wherein the precoding matrix is a matrix used by the first device when performing a precoding operation on the data vector; wherein the first device is further configured to: obtain a coordinate of the first device and a coordinate of the second device; calculate a distance between the first device and the second device according to the coordinate of the first device and the coordinate of the second device; calculate a path loss of a data signal transmitted between the first device and the second device according to a carrier frequency of the satellite communication system and the distance between the first device and the second device; and determine the precoding matrix by using the path loss, wherein the precoding matrix is used to adjust signal transmission between the first device and the second device.

9. The method of claim 8, wherein, performing a phase rotation operation on the target signal to obtain a third vector, comprising: obtaining a coordinate of the first device and a coordinate of the second device; calculating a relative position between the first device and the second device according to the coordinate of the first device and the coordinate of the second device; calculating phase rotation adjustment values of a plurality of antenna ports deployed in the second device by using the relative position and the number of antennas deployed in the second device; constructing a phase rotation matrix based on the plurality of phase rotation adjustment values, wherein diagonal elements of the phase rotation matrix are phase rotation factors of the plurality of antenna ports; performing the phase rotation operation on the target signal by using the phase rotation matrix to compensate for phase differences between the plurality of antenna ports, to obtain the third vector.

10. The method of claim 8, wherein, merging the set of data streams of the Q paths of data to obtain original data, comprising: serially mapping a plurality of parallel data streams in the set of data streams to convert the plurality of data streams in the set of data streams into a serial data stream; merging the serial data stream to obtain the original data.

11. A data transmission device, characterized in that, comprising a first memory, a first processor, and a first computer program stored on the first memory and executable on the first processor, wherein the first processor implements the following operations when executing the first computer program: determining Q paths of data to be sent by a first device to a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, and the Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a data stream mapping operation on the Q paths of data to obtain a data vector, wherein the data vector is used to represent a set of data streams of the Q paths of data; performing a precoding operation on the data vector by using a precoding matrix of the second device to obtain a first vector; performing a gain adjustment operation on the first vector according to antenna ports deployed in the second device to obtain a target signal; sending the target signal to the second device; before performing the precoding operation on the data vector by using the precoding matrix of the second device, further comprising: obtaining coordinates of the first device and coordinates of the second device; calculating a distance between the first device and the second device according to the coordinates of the first device and the coordinates of the second device; calculating a path loss of a data signal transmitted between the first device and the second device according to a carrier frequency of the satellite communication system and the distance between the first device and the second device; and determining the precoding matrix by using the path loss, wherein the precoding matrix is used to adjust signal transmission between the first device and the second device.

12. A data receiving apparatus characterized by comprising: comprising a second memory, a second processor, and a second computer program stored on the second memory and executable on the second processor, wherein the second processor implements the following operations when executing the second computer program: receiving a target signal sent by a first device through antenna ports deployed in a second device, wherein the first device and the second device are both devices deployed in a satellite communication system, and the target signal is a signal determined based on Q paths of data sent by the first device to the second device, and the Q is a natural number less than or equal to the number of antennas deployed in the first device; performing a phase rotation operation on the target signal to obtain a third vector; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, wherein the data vector is used to represent a data stream set of the Q-path data; merging the data stream set of the Q-path data to obtain original data; performing a demodulation operation and a decoding operation on the third vector to recover a data vector from the third vector, comprises: performing the demodulation operation on the third vector to recover a demodulated data stream from the third vector; performing the decoding operation on the demodulated data stream by using a decoding matrix corresponding to a precoding matrix of the second device to obtain the data vector, wherein the precoding matrix is a matrix used by the first device when performing a precoding operation on the data vector; wherein the first device is further configured to obtain a coordinate of the first device and a coordinate of the second device; calculate a distance between the first device and the second device according to the coordinate of the first device and the coordinate of the second device; calculate a path loss of a data signal transmitted between the first device and the second device according to a carrier frequency of the satellite communication system and the distance between the first device and the second device; and determine the precoding matrix by using the path loss, wherein the precoding matrix is used to represent adjustment of signal transmission between the first device and the second device.

13. A satellite communication system, characterized by The sending device, when executed, implements the steps of the method in any one of claims 1 to 7, and the receiving device, when executed, implements the steps of the method in any one of claims 8 to 10.

14. A computer-readable storage medium, characterized in that, The computer program is stored in the computer readable storage medium, and when executed by a processor, implements the steps of the method in any one of claims 1 to 7, or when executed by a processor, implements the steps of the method in any one of claims 8 to 10.

15. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor, when executing the computer program, implements the steps of the method in any one of claims 1 to 7, or when executing the computer program, implements the steps of the method in any one of claims 8 to 10.

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