Satellite communication method and apparatus

Abstract

A satellite communication method and apparatus, which can be applied to the technical field of communications. The method comprises: a first communication apparatus sending first indication information and / or second indication information on the basis of channel information between the first communication apparatus and a second communication apparatus; if the channel information meets a first condition, the second communication apparatus using configuration information of a first reference signal to receive the first reference signal, and using the first reference signal to perform channel estimation, such that the accuracy of a channel estimation result can be effectively improved; and if the channel information meets a second condition, the second communication apparatus using configuration information of a second reference signal to receive the second reference signal, and using the second reference signal to perform channel estimation, such that pilot overheads can be effectively reduced. Therefore, the method can improve the accuracy of a channel estimation result on the basis of reducing pilot overheads.

Description

Satellite communication method and device

[0001] This application claims priority to the Chinese patent application with application number 202311803780.9 filed with the State Intellectual Property Office of China on December 25, 2023, and priority to the Chinese patent application with the invention name “Satellite Communication Method and Device”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a satellite communication method and device. Background Art

[0003] To achieve truly seamless global network coverage, the fifth generation (5G) mobile network proposes the construction of non-terrestrial networks (NTNs). In recent years, low Earth orbit (LEO) satellites, located between 200 kilometers (km) and 2000 km above the ground, have attracted widespread attention from academia and industry. In recent years, some companies have planned to build giant LEO constellations, including thousands or even tens of thousands of LEO satellites. As the size of satellite constellations increases, more than one satellite will be within the visual range of terminal devices. Single-satellite transmission has limited impact on system capacity. To effectively increase capacity in areas with overlapping satellite coverage, satellite systems are gradually evolving from single-satellite transmission to multi-satellite coordinated transmission.

[0004] In multi-satellite coordinated transmission, multiple satellites can communicate with terminal devices. For example, when signals transmitted by multiple satellites reach a terminal device, the corresponding time-frequency resources can overlap. However, due to the long communication distances between satellites and terminal devices, the signals transmitted between different satellites and the terminal device may be subject to significant interference, which can lead to inaccurate channel estimation results based on these heavily interfered signals.

[0005] Based on this, how to improve the accuracy of channel estimation results has become an urgent problem to be solved. Summary of the Invention

[0006] The embodiments of the present application provide a satellite communication method and apparatus, which can effectively improve the accuracy of channel estimation results.

[0007] In a first aspect, an embodiment of the present application provides a satellite communication method, which is applied to a first communication device, where the first communication device includes a satellite base station, or a chip or functional module that can be set in a satellite base station. The method includes:

[0008] Obtain channel information between a first communication device and a second communication device; if the channel information satisfies a first condition, send first indication information, where the first indication information is used to indicate configuration information of a first reference signal, where the configuration information includes time domain resources for transmitting the first reference signal, where the time domain resources include M time domain units, where M is an integer greater than or equal to 2; send the first reference signal, where the phase difference between signals transmitted on adjacent time domain units among the M time domain units for transmitting the first reference signal is a first phase offset value.

[0009] In an embodiment of the present application, when the channel information satisfies the first condition, the first communication device uses the configuration information of the first reference signal to send the first reference signal. Since the phase difference between the signals transmitted on adjacent time domain units in the M time domain units is the first phase offset value, when the second communication device performs channel estimation based on the first reference signal, the first phase offset value can be used to reduce the impact of interference to the signal during transmission on the accuracy of channel estimation, thereby improving the accuracy of the channel estimation result. And when the channel information satisfies the first condition, the first reference signal is used to perform channel estimation, so that the first reference signal can be reasonably utilized.

[0010] In a possible implementation manner, the first phase offset value is adjustable.

[0011] In an embodiment of the present application, by adjusting the first phase offset value, such as adjusting the phase of the first reference signal sent by the first communication device, the phase of inter-symbol interference (ISI) and inter-carrier interference (ICI) can be regulated, thereby improving the accuracy of the channel estimation result obtained when the second communication device performs channel estimation.

[0012] In a possible implementation manner, the first phase offset value is determined based on a frequency offset value that occurs when a signal from the first communication device is transmitted to the second communication device.

[0013] In a possible implementation, signals transmitted on the same frequency domain unit corresponding to any two time domain units among the M time domain units are generated based on the same sequence.

[0014] In the embodiment of the present application, the signals transmitted on any two of the M time domain units are generated based on the same sequence, which means that on any two time domain units, for the same frequency domain unit, the signals carried on the frequency domain unit are produced based on the same sequence. For the same frequency domain unit, the signals transmitted on each time domain unit are generated based on the same sequence (such as a generated sequence or an original sequence), thereby better eliminating interference during the channel estimation process and improving the accuracy of the channel estimation result.

[0015] In a possible implementation manner, the value of M is determined by the number of the first communication apparatuses serving the second communication apparatus for joint transmission.

[0016] In a possible implementation manner, the first indication information is used to indicate configuration information of the first reference signal, and includes: the first indication information is used to indicate configuration information for activating the first reference signal.

[0017] In the embodiment of the present application, the first indication information may indicate whether to activate the configuration information of the first reference signal through one bit. For another example, the first indication information may indicate whether to activate the configuration information of the first reference signal through one bit.

[0018] In a possible implementation manner, the first indication information is used to indicate configuration information of the first reference signal, including: the first indication information is used to indicate configuration information of the first reference signal within a first duration.

[0019] In this embodiment of the present application, the first indication information configures a first duration, which can cause the first communications device to transmit a first reference signal within the first duration, and to transmit a second reference signal by default after the first duration. This allows for automatic adjustment of the reference signal, thereby achieving a trade-off between pilot overhead and channel estimation accuracy.

[0020] In one possible implementation, the method further includes: when the channel information satisfies the second condition, sending second indication information, the second indication information being used to indicate configuration information of a second reference signal, the configuration information including time domain resources for transmitting the second reference signal, the time domain resources including N time domain units, where N is a positive integer less than or equal to 2; and sending the second reference signal.

[0021] In the embodiment of the present application, since N may be less than M, the pilot overhead of the second reference signal is small. Using the second reference signal can reduce the pilot overhead, and using the first reference signal can improve the accuracy of the channel estimation result. The first communication device sends different reference signals under different conditions satisfied by the channel information, such as sending the first reference signal when the channel information satisfies the first condition, and sending the second reference signal when the channel information satisfies the second condition. Thus, by fully considering the pilot overhead and the accuracy of the channel estimation result, balancing the pilot overhead and the accuracy of the channel estimation result, an accurate channel estimation result can be obtained with a smaller pilot overhead.

[0022] In a possible implementation manner, the second indication information is used to indicate configuration information of the second reference signal, and includes: the second indication information is used to indicate configuration information for activating the second reference signal.

[0023] In the embodiment of the present application, the second indication information may indicate whether to activate the configuration information of the second reference signal through one bit. For another example, the second indication information may indicate whether to activate the configuration information of the second reference signal through one bit.

[0024] In a possible implementation manner, the second indication information is used to indicate configuration information of the second reference signal, including: the second indication information is used to indicate configuration information of the second reference signal within a second duration.

[0025] In this embodiment of the present application, the second indication information configures a second duration, which can cause the second communication device to transmit the second reference signal within the second duration. After the second duration, the first reference signal can be transmitted by default. This allows for automatic adjustment of the reference signal, thereby achieving a trade-off between pilot overhead and channel estimation accuracy.

[0026] In one possible implementation, when the channel information satisfies the first condition, sending the first indication information includes: sending indication information, the indication information including first indication information and second indication information, the first indication information corresponding to the channel information satisfying the first condition, the second indication information corresponding to the channel information satisfying the second condition, the second indication information being used to indicate configuration information of a second reference signal, the configuration information including time domain resources for transmitting the second reference signal, the time domain resources including N time domain units, where N is a positive integer less than or equal to 2.

[0027] In the embodiment of the present application, the first communication device may simultaneously configure the first indication information and the second indication information based on different conditions that may be satisfied by the channel information. For example, the first indication information may be used to indicate the configuration information of the first reference signal within a first duration, and the second indication information may be used to indicate the configuration information of the second reference signal within a second duration. In this way, the first reference signal and the second reference signal are pre-configured using one piece of indication information.

[0028] In a possible implementation manner, the value of N is determined by the number of antenna ports used to send the second reference signal.

[0029] In one possible implementation, obtaining the channel information between the first communication device and the second communication device includes at least one of the following: receiving feedback information from the second communication device, where the feedback information is used to indicate the channel information; or obtaining the channel information based on position information and ephemeris information of the second communication device; or obtaining the channel information based on motion information and ephemeris information of the second communication device.

[0030] In one possible implementation, the channel information includes channel change information, and the channel information satisfies the first condition including: the channel change information satisfies at least one of the following: the posture change amount of the second communication device is greater than the change amount threshold; the reference signal receiving power (RSRP) change on different resources used for signal transmission is greater than the RSRP threshold; the reference signal receiving quality (RSRQ) on different resources used for signal transmission is greater than the RSRQ threshold; the signal to interference plus noise ratio (SINR) on different resources used for signal transmission is greater than the SINR threshold; the block error rate (BLER) on different resources used for signal transmission is greater than the BLER threshold; the throughput change on different resources used for signal transmission is greater than the throughput threshold.

[0031] In the embodiments of the present application, when channel information changes rapidly, using the first reference signal for channel estimation can effectively improve the accuracy of the channel estimation result. When channel information changes slowly, using the second reference signal for channel estimation can effectively improve the accuracy of the channel estimation result. Since the channel changes slowly, the second communication device can reuse the channel estimation result obtained based on the first reference signal to estimate the scalar channel estimation result. This not only improves the accuracy of the channel estimation result, but also achieves a trade-off between pilot overhead and channel estimation accuracy.

[0032] In a second aspect, an embodiment of the present application provides a satellite communication method, which is applied to a second communication device, where the first communication device includes a terminal device, or a chip or functional module that can be set in the terminal device, and the method includes:

[0033] Receive first indication information, where the first indication information is used to indicate configuration information of a first reference signal, where the configuration information includes time domain resources for transmitting the first reference signal, where the time domain resources include M time domain units, where M is an integer greater than or equal to 2; receive the first reference signal based on the first indication information, where the phase difference between signals transmitted on adjacent time domain units among the M time domain units for transmitting the first reference signal is a first phase offset value; and determine a channel estimation result between the first communication device and the second communication device based on the first reference signal.

[0034] In a possible implementation manner, the first phase offset value is adjustable.

[0035] In a possible implementation manner, the first phase offset value is determined based on a frequency offset value that occurs when a signal from the first communication device is transmitted to the second communication device.

[0036] In a possible implementation, signals transmitted on the same frequency domain unit corresponding to any two time domain units among the M time domain units are generated based on the same sequence.

[0037] In a possible implementation manner, the value of M is determined by the number of the first communication apparatuses serving the second communication apparatus for joint transmission.

[0038] In a possible implementation manner, the first indication information is used to indicate configuration information of the first reference signal, and includes: the first indication information is used to indicate configuration information for activating the first reference signal.

[0039] In a possible implementation manner, the first indication information is used to indicate configuration information of the first reference signal, including: the first indication information is used to indicate configuration information of the first reference signal within a first duration.

[0040] In one possible implementation, the method further includes: receiving second indication information, where the second indication information is used to indicate configuration information of a second reference signal, the configuration information including time domain resources for transmitting the second reference signal, the time domain resources including N time domain units, where N is a positive integer less than or equal to 2; and receiving the second reference signal.

[0041] In one possible implementation, the receiving of first indication information includes: receiving indication information, the indication information including first indication information and second indication information, the second indication information being used to indicate configuration information of a second reference signal, the configuration information including time domain resources for transmitting the second reference signal, the time domain resources including N time domain units, where N is a positive integer less than or equal to 2.

[0042] In a possible implementation manner, the value of N is determined by the number of antenna ports used to send the second reference signal.

[0043] In one possible implementation, the method further includes: sending feedback information, where the feedback information is used to indicate channel information between the first communication device and the second communication device; or, sending location information of the second communication device; or, sending motion information of the second communication device.

[0044] For the description of the second aspect, please refer to the first aspect and will not be repeated here.

[0045] In a third aspect, an embodiment of the present application provides a first communication device configured to execute the method in the first aspect or any possible implementation. The first communication device includes a module configured to execute the method in the first aspect or any possible implementation.

[0046] In a fourth aspect, embodiments of the present application provide a second communication device configured to execute the method in the second aspect or any possible implementation. The second communication device includes a module configured to execute the method in the second aspect or any possible implementation.

[0047] In a fifth aspect, an embodiment of the present application provides a first communication device, comprising a processor configured to execute the method described in the first aspect or any possible implementation. The processor is configured to execute a program stored in a memory, and when the program is executed, the method described in the first aspect or any possible implementation is executed.

[0048] In a possible implementation, the memory is located outside the first communication device.

[0049] In a possible implementation, the memory is located within the first communication device.

[0050] In the embodiment of the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together. For example, the first communication device may be a chip.

[0051] In a possible implementation, the first communication device further includes a transceiver, where the transceiver is configured to receive information or send information.

[0052] In a sixth aspect, an embodiment of the present application provides a second communication device, comprising a processor configured to execute the method described in the second aspect or any possible implementation. The processor is configured to execute a program stored in a memory, and when the program is executed, the method described in the second aspect or any possible implementation is executed.

[0053] In a possible implementation, the memory is located outside the second communication device.

[0054] In a possible implementation, the memory is located within the second communication device.

[0055] In the embodiment of the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together. Exemplarily, the second communication device may be a chip.

[0056] In a possible implementation, the second communication device further includes a transceiver, where the transceiver is configured to receive information or send information.

[0057] In the seventh aspect, an embodiment of the present application provides a first communication device, which includes a logic circuit and an interface, and the logic circuit and the interface are coupled; the interface is used to input and / or output information, and the logic circuit is used to execute the method described in the first aspect or any possible implementation method.

[0058] In an eighth aspect, an embodiment of the present application provides a second communication device, which includes a logic circuit and an interface, and the logic circuit and the interface are coupled; the interface is used to input and / or output information, and the logic circuit is used to execute the method described in the second aspect or any possible implementation method.

[0059] In the ninth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program. When the computer-readable storage medium is run on a computer, the method shown in any one of the above-mentioned first to second aspects or any possible implementation method is executed.

[0060] In a tenth aspect, an embodiment of the present application provides a computer program product, which, when executed on a computer, enables the method shown in any one of the first to second aspects or any possible implementation thereof to be executed.

[0061] In an eleventh aspect, an embodiment of the present application provides a computer program. When the computer program is run on a computer, the method shown in any one of the first to second aspects or any possible implementation is executed.

[0062] In the twelfth aspect, an embodiment of the present application provides a communication system, which includes a first communication device and / or a second communication device, the first communication device is used to execute the method shown in the above-mentioned first aspect or any possible implementation of the first aspect, and the second communication device is used to execute the method shown in the above-mentioned second aspect or any possible implementation of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG1 is a schematic diagram of a satellite communication system in a transparent transmission scenario provided by an embodiment of the present application;

[0064] FIG2 is a schematic diagram of a satellite communication system in a regeneration scenario provided by an embodiment of the present application;

[0065] FIG3a is a schematic structural diagram of a first reference signal provided in an embodiment of the present application;

[0066] FIG3b is a schematic structural diagram of a first reference signal provided in an embodiment of the present application;

[0067] FIG3c is a schematic structural diagram of a second reference signal provided in an embodiment of the present application;

[0068] FIG3 d is a schematic structural diagram of a second reference signal provided in an embodiment of the present application;

[0069] FIG4a is a schematic structural diagram of a first reference signal provided in an embodiment of the present application;

[0070] FIG4b is a schematic diagram of a first reference signal received by a second communication device according to an embodiment of the present application;

[0071] FIG5 is a schematic diagram of a flow chart of a satellite communication method provided in an embodiment of the present application;

[0072] FIG6 is a schematic diagram of a dynamic change of a reference signal provided in an embodiment of the present application;

[0073] FIG7a is a schematic diagram of a data detection process provided by an embodiment of the present application;

[0074] FIG7 b is a schematic diagram of a data detection process provided by an embodiment of the present application;

[0075] FIG8 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0076] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0077] FIG10 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0078] To facilitate understanding of the technical solution of the present application, the present application will be further described below with reference to the accompanying drawings.

[0079] The terms "first" and "second" in the specification, claims, and drawings of this application are used only to distinguish different objects and are not used to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to the process, method, product, or device.

[0080] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It will be understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0081] In this application, "at least one (item)" means one or more, "more than one" means two or more, "at least two (items)" means two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. "Or" means that two relationships can exist, such as only A exists, only B exists; when A and B are not mutually exclusive, it can also mean that three relationships exist, such as only A exists, only B exists, and A and B exist at the same time. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c".

[0082] In this application, "indication" may include direct indication, indirect indication, explicit indication, and implicit indication. When describing that a certain indication information is used to indicate A, it can be understood that the indication information carries A, directly indicates A, or indirectly indicates A.

[0083] In this application, the information indicated by the indication information is referred to as the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information can also be achieved with the help of the arrangement order of each information agreed in advance (for example, stipulated by the protocol), thereby reducing the indication overhead to a certain extent. In addition, the information to be indicated can be sent together as a whole, or it can be divided into multiple sub-information and sent separately, and the sending period and / or sending time of these sub-information can be the same or different.

[0084] In this application, "sending" and "receiving" indicate the direction of signal transmission. For example, "sending information to XX" can be understood as the destination of the information is XX, which can include direct sending through the air interface, and also include indirect sending through the air interface by other units or modules. "Receiving information from YY" can be understood as the source of the information is YY, which can include direct receiving from YY through the air interface, and also include indirect receiving from YY through the air interface from other units or modules. "Sending" can also be understood as the "output" of the chip interface, and "receiving" can also be understood as the "input" of the chip interface. In other words, sending and receiving can be carried out between devices, for example, between network devices and terminal devices, or can be carried out within a device, for example, sending or receiving between components, modules, chips, software modules or hardware modules within the device through a bus, trace or interface.

[0085] In terrestrial cellular mobile communication systems, the collaboration of multiple base stations can significantly improve the data rate performance of users at the cell edge. This technology, also known as coordinated multi-point (CoMP), allows multiple base stations to collaborate and jointly provide services to certain terminal devices. CoMP has various implementation methods, including dynamic point selection (DPS), coordinated scheduling (CS), coordinated beamforming (CBF), and joint transmission (JT).

[0086] DPS means that different base stations use different time resources to provide services to terminal devices, allowing the terminal devices to dynamically select different base stations for communication. CS means that different base stations use different frequency resources to provide services to terminal devices at the same time, allowing the terminal devices to communicate with different base stations on different subcarriers. Furthermore, CoMP also supports different base stations providing services to terminal devices on the same time-frequency resources. In CBF, only one base station in a cell transmits a useful signal to a terminal device. Base stations in adjacent coordinated cells adjust beamforming vectors to reduce interference to the terminal device. In JT, multiple base stations are allowed to transmit useful signals to terminal devices. There are two transmission modes: coherent JT (CJT) and non-coherent JT (NCJT). In CJT, multiple base stations transmit the same useful signal to terminal devices, achieving the best system performance, but requiring ideal backhaul between base stations, making the system more challenging to implement. In NCJT, multiple base stations transmit different useful signals to terminal devices, allowing for non-ideal backhaul between base stations. This reduces system implementation complexity, but at the cost of some performance loss compared to CJT.

[0087] In satellite communications, due to the long distance between satellites, it is difficult to ensure ideal inter-satellite backhaul, which makes the implementation of CJT more difficult. Compared with CJT, NCJT relaxes the requirements for ideal inter-satellite backhaul and is easier to implement in actual systems. Therefore, the focus of the embodiments of this application is on multi-satellite NCJT scenarios. Of course, without considering the ideal inter-satellite backhaul (or relaxing the requirements for ideal inter-satellite backhaul), the embodiments of this application can also be applied to multi-satellite CJT scenarios. With the advancement of standards, if other similar technologies appear in the future, the methods provided in the embodiments of this application are also applicable to other technologies that appear later.

[0088] However, there are significant differences between multi-satellite NCJT in satellite communications and multi-base station NCJT in land mobile communications. The following uses the orthogonal frequency division multiplexing (OFDM) modulation scheme, which is used in both land mobile communications and NTN, as an example to illustrate the differences between multi-satellite NCJT in satellite communications and multi-base station NCJT in land mobile communications.

[0089] For terrestrial mobile communications, due to the short distances between ground base stations, the time delay difference between signals sent from different base stations reaching the terminal device is small, and this time delay difference can be protected by the cyclic prefix (CP). In addition, because ground base stations are stationary, terminal devices can move at relatively low speeds (relative to NTN), and the Doppler shift difference between signals sent from different base stations reaching the terminal device is small, and this Doppler shift difference can be protected by the subcarrier spacing. In this way, when signals from different base stations reach the terminal device, there will be no inter-subcarrier interference, and the terminal device can use a frequency domain receiver to process signals from different base stations.

[0090] However, for NTN communications, due to the long distance between satellites and the ground and the fact that satellites are always in high-speed motion, the time delay difference between signals sent by different satellites (or satellite base stations) reaching the terminal device side may far exceed the CP. The Doppler frequency shift difference between signals sent by different satellites reaching the terminal device side is on the same order of magnitude as the subcarrier spacing. This causes inter-symbol interference (ISI) in the time domain and inter-carrier interference (ICI) in the frequency domain when signals sent by different satellites reach the terminal device side. Therefore, when the terminal device determines the channel estimation result between the terminal device and the satellite based on the signal sent by a certain satellite, the signals sent by other satellites will interfere with the signal of the aforementioned satellite, resulting in inaccurate channel estimation results. The terminal device needs to use the channel estimation results to calculate the spatial receiver to receive signals from multiple satellites. Therefore, inaccurate channel estimation results will lead to inaccurate calculations of the spatial receiver on the terminal device side, which in turn will reduce the terminal device's ability to suppress interference signals between satellites and lead to reduced system throughput performance.

[0091] In view of this, embodiments of the present application provide a satellite communication method and apparatus that can effectively improve the accuracy of channel estimation results. For example, channel estimation results for multiple satellites can be obtained with a relatively low pilot overhead, achieving a compromise between pilot overhead and the accuracy of the channel estimation results. For example, the first reference signal involved in embodiments of the present application can effectively improve the accuracy of channel estimation, and the second reference signal can effectively reduce pilot overhead. For example, the phase of the first reference signal involved in embodiments of the present application is adjustable, and by adjusting the phase of the first reference signal, the accuracy of the channel estimation results can be effectively improved.

[0092] The following introduces the communication system involved in the embodiments of the present application.

[0093] The method provided in the embodiment of the present application can be applied to non-terrestrial networks (NTN) communication systems. The method provided in the embodiment of the present application can be applied to the Internet of Things (IoT) system, the Internet of Vehicles such as vehicle-to-everything (V2X, X can represent anything), and the narrowband Internet of Things (NB-IoT) system; for example, it can be applied to the LTE frequency division duplex (FDD) system, the LTE time division duplex (TDD), the long term evolution (LTE) system, or future communication systems, etc., which are not specifically limited in the embodiment of the present application. For example, V2X may include: vehicle to vehicle (V2V) communication, vehicle to infrastructure (V2I) communication, vehicle to pedestrian (V2P) communication, or vehicle to network (V2N) communication, etc. For example, terminal devices can communicate with each other through device-to-device (D2D) technology, machine-to-machine (M2M) technology, or V2X technology.

[0094] The following introduces the communication device involved in the embodiments of the present application.

[0095] (1) Terminal equipment

[0096] A terminal device is a device with wireless transceiver functions. The terminal device can communicate with an access network device (or also referred to as an access device) in a radio access network (RAN). The terminal device can also be referred to as user equipment (UE), access terminal, terminal, subscriber unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, user agent or user device, etc. In one possible implementation, the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or it can also be deployed on the water surface, including ships, etc.; or it can also be deployed in the air, such as on airplanes, balloons or satellites, etc. In another possible implementation, the terminal device can be a handheld device with wireless communication function, a vehicle-mounted device, a wearable device, a sensor, a terminal in the Internet of Things, a terminal in the Internet of Vehicles, a drone, and any form of terminal device in future networks, etc., and the embodiments of the present application are not limited to this. In another possible implementation, the terminal device may also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in a smart city, or a wireless terminal in a smart home, etc.

[0097] In the embodiments of the present application, the device for realizing the function of the terminal device may be the terminal device; or it may be a device capable of supporting the terminal device to realize the function, such as a chip system or a functional module. The device may be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices. For ease of description, when referring to some examples below, the technical solution provided in the embodiments of the present application will be described by taking the device for realizing the function of the terminal device as a UE as an example.

[0098] (2) Network equipment

[0099] A network device can be a device deployed in a wireless access network to provide wireless communication services to terminal devices. This network device can also be referred to as an access network device, access device, or RAN device. For example, the network device can be a next-generation node B (gNB), a next-generation evolved node B (ng-eNB), or a network device in a future communication network. A network device can be any device with wireless transceiver capabilities, including but not limited to the base stations described above (including base stations deployed on satellites). As an example, the network device can be an access node, wireless relay node, or wireless backhaul node in a wireless local area network (Wi-Fi) system. As another example, the network device can be a wireless controller in a cloud radio access network (CRAN) scenario. As yet another example, the network device can be a wearable device or in-vehicle device capable of providing wireless communication services. As yet another example, the network device can be a small cell, a transmission reception point (TRP) (or also referred to as a transmission point), or the like. In systems with different wireless access technologies, the names of communication devices with network device functions may be different, and the embodiments of the present application will not list them one by one.

[0100] In some deployments of network devices, the network device may include a centralized unit (CU) and a distributed unit (DU). In other deployments of network devices, the CU may also be divided into a CU-control plane (CP) and a CU-user plane (UP). In still other deployments of network devices, the network device may also be an open radio access network (ORAN) architecture, etc. The embodiments of the present application do not limit the specific deployment method of the network device. For example, when the network device is an ORAN architecture, the network device shown in the embodiments of the present application may be an access network device in the ORAN, or a functional module, etc. In the ORAN system, the CU may also be referred to as an open (O)-CU, the DU may also be referred to as an O-DU, the CU-CP may also be referred to as an O-CU-CP, and the CU-UP may also be referred to as an O-CU-UP, etc. The deployment methods of the network devices listed here are only examples. With the evolution of standard technologies, network devices may have other deployment forms.

[0101] The network devices in the embodiments of the present application may include network devices deployed on satellites (such as satellite base stations), may also include network devices deployed on gateways, and may also include network devices deployed on the ground (such as ground base stations). In the embodiments of the present application, the device for implementing the function of the network device may be a network device; it may also be a device that can support the network device to implement the function, such as a chip system or a functional module. The device can be installed in the network device or used in combination with the network device. For ease of description, when referring to some specific examples below, the technical solution provided in the embodiments of the present application is described by taking the device for implementing the function of the network device as a satellite base station as an example.

[0102] (3) Ground Station

[0103] Ground stations can be used to connect satellites and base stations, or satellites and core networks. Ground stations can also be called gateways, earth stations, gateways, etc. One or more satellites can be connected to one or more ground-based network devices (such as ground base stations) through one or more gateways, without limitation. The link between the satellite and the terminal is called a service link, and the link between the satellite and the gateway is called a feeder link. Network devices can be deployed separately from the gateway, so the delay of the feeder link can include the delay from the satellite to the gateway and the delay from the gateway to the network device.

[0104] (4) Satellite

[0105] The satellite may be a geostationary earth orbit (GEO) satellite (as shown in FIG1 and FIG2 ), a non-geostationary earth orbit (NGEO) medium earth orbit (MEO) satellite or a low earth orbit (LEO) satellite (as shown in FIG1 and FIG2 ), or a high altitude platform station (HAPS). The embodiments of the present application do not limit the specific type of satellite.

[0106] Figure 1 is a schematic diagram of a satellite communication system in a transparent transmission scenario according to an embodiment of the present application. Figure 2 is a schematic diagram of a satellite communication system in a regeneration scenario according to an embodiment of the present application.

[0107] When the satellite operates in transparent transmission mode, it performs the transparent forwarding function of a relay. The gateway has the functions of a network device (such as a base station) or some of them. In this case, the gateway can be considered a network device (such as a base station). Alternatively, the network device (such as a base station) can be deployed separately from the gateway. In this case, the feeder link latency includes both the satellite-to-gateway and gateway-to-gNB delays. The transparent transmission mode discussed below is based on the case where the gateway and gNB are located together or close together. For cases where the gateway and gNB are farther apart, the feeder link latency is simply the sum of the satellite-to-gateway and gateway-to-gNB delays.

[0108] When the satellite operates in regenerative mode, it has data processing capabilities, the functions of a network device (such as a base station) or partial functions of a network device (such as a base station). At this time, the satellite can be regarded as a network device (such as a base station).

[0109] Satellites can wirelessly communicate with terminals by broadcasting communication and navigation signals. Optionally, each satellite can provide terminal devices with communication, navigation, and positioning services using multiple beams. For example, each satellite can use multiple beams to cover its service area, and the relationships between the beams can be one or more of time division, frequency division, and space division.

[0110] (5) Core network (CN).

[0111] Core network equipment is a device installed on the ground and capable of communicating with NTN equipment in the NTN system. CN equipment is a network element included in the CN portion of a mobile communication system. CN equipment can connect terminal devices to different data networks and perform services such as authentication, billing, mobility management, session management, policy control, and user plane forwarding. CN equipment can be CN equipment in current mobile communication systems or CN equipment in future mobile communication systems. In mobile communication systems of different standards, the names of CN equipment with the same function may vary. However, the embodiments of the present application do not limit the specific names of CN equipment with each function.

[0112] For example, in the 4th generation (4G) mobile communication system (i.e., long term evolution (LTE), the network element responsible for functions such as access control, security control and signaling coordination is the mobility management entity (MME); the network element serving as the local mobility management anchor point is the serving gateway (S-GW); the network element serving as the anchor point for switching to the external data network and responsible for allocating Internet protocol (IP) addresses is the packet data network (PDN) gateway (P-GW); the network element storing user-related data and subscription data is the home subscriber server (HSS); and the network element responsible for policy and billing functions is called the policy and charging rule function (PCRF) network element.

[0113] For example, in a 5G mobile communication system, the core network can be divided into a control plane (CP) and a user plane (UP) according to specific logical functional divisions. The network elements in the CN responsible for control plane functions can be collectively referred to as control plane network elements, and the network elements responsible for user plane functions can be collectively referred to as user plane network elements. Specifically, in the user plane, the network element that serves as the interface to the data network and is responsible for user plane data forwarding and other functions is the user plane function (UPF) network element. In the control plane, the network element responsible for access control and mobility management functions is called the access and mobility management function (AMF) network element; the network element responsible for session management and control policy execution is called the session management function (SMF) network element; the network element responsible for managing subscription data, user access authorization, and other functions is called the unified data management (UDM) network element; the network element responsible for billing and policy control functions is called the policy control function (PCF) network element; and the application function (AF) network element is responsible for transmitting the application side's requirements to the network side.

[0114] The following describes the method provided in an embodiment of the present application using a first communication device and a second communication device as examples. The first communication device may be a communication device that transmits a reference signal, and the second communication device may be a communication device that receives the reference signal. Alternatively, the first communication device may be referred to as a transmitter, which may be a communication device for transmitting a reference signal, and the second communication device may be referred to as a receiver, which may be a communication device for receiving a reference signal. The embodiments of the present application do not limit the specific names of the first communication device and the second communication device. As an example, in a satellite regeneration mode, the first communication device may be a satellite, and the second communication device may be a terminal device. As another example, in a satellite transparent transmission mode, the first communication device may be a ground base station, and the second communication device may be a terminal device. The specific forms of the first communication device and the second communication device are not listed here one by one. In an embodiment of the present application, the number of first communication devices serving the second communication device for joint transmission may be 2, 3, or more than 3.

[0115] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field will know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions and network architecture provided in the embodiments of the present application are also applicable to similar technical problems.

[0116] The following introduces the terms involved in the embodiments of this application.

[0117] 1. Reference signal

[0118] In order to obtain the channel estimation result, a classic method is that the transmitter periodically sends a pilot known to the receiver, and the receiver calculates the channel estimation value based on the received signal and the known pilot. Specifically, taking the physical downlink shared channel (PDSCH) in 5G NR as an example, the satellite sends a demodulation reference signal (DMRS) known to the UE to the UE, and the UE performs channel estimation based on the received signal and the known DMRS sequence. For example, in multi-satellite NCJT, satellite 1 sends DMRS1 to the UE, and satellite 2 sends DMRS2 to the UE. From the previous analysis, it can be seen that the DMRS sent by different satellites will still have time-frequency asynchrony when they reach the UE side, that is, ISI is generated in the time domain and ICI is generated in the frequency domain. During the channel estimation process, ISI and ICI will make the channel estimation result inaccurate, which will lead to inaccurate calculation of the spatial receiver. This will make the spatial receiver's (asynchronous) interference suppression capability of non-synchronous satellites worse, ultimately resulting in a decrease in system throughput performance. It can be seen that the acquisition of channel estimation results has become a bottleneck restricting the performance of multi-satellite transmission, and accurately obtaining channel estimation results is a necessary condition for reaping multi-satellite gains.

[0119] The reference signal in the embodiment of the present application can be used for channel estimation. The reference signal may include but is not limited to a demodulation reference signal (DMRS), a channel state information reference signal (CSI) reference signal (RS), a synchronization signal block (SSB) (or a synchronization signal / physical broadcast channel block (SS / PBCH block)), a tracking reference signal (TRS), a phase tracking reference signal (PTRS), a cell reference signal (CRS), a sounding reference signal (SRS), etc. As the standard progresses, other types of reference signals for channel estimation may appear in the future, and the embodiment of the present application does not limit this.

[0120] The first reference signal and the second reference signal mentioned below may be for the same type of reference signal, or the first reference signal and the second reference signal mentioned below may be for different types of reference signals. For example, the type of the first reference signal and the type of the second reference signal may both be DMRS. For another example, the type of the first reference signal may be DMRS, and the type of the second reference signal may be CSI-RS, etc., which are not listed here one by one. Regardless of whether the type of the first reference signal and the second reference signal is the same, the method shown below is applicable. For ease of description, when some examples are mentioned below, the reference signal is DMRS as an example for explanation, but it should not be understood as a limitation on the embodiments of the present application.

[0121] 2. Time-frequency resources

[0122] In a wireless communication system, resources used to transmit a reference signal may include time domain resources and frequency domain resources. The resources used to transmit a reference signal may also be referred to as resources occupied by the reference signal.

[0123] Generally speaking, the unit for measuring the size of time domain resources (or size) may include at least one of a radio frame, a subframe, a slot, a mini slot, or an orthogonal frequency division multiplexing (OFDM) symbol. Of course, other units may emerge as standards progress, and the embodiments of the present application are not limited thereto.

[0124] In an embodiment of the present application, the time domain resources used to transmit the first reference signal include M time domain units, and the time domain resources used to transmit the second reference signal may include N time domain units. The size of the time domain resource corresponding to one time domain unit in the M time domain units is the same as the size of the time domain resource corresponding to one time domain unit in the N time domain units. Exemplarily, the size of the time domain resource corresponding to the above-mentioned one time domain unit can also be replaced by the duration of a time domain unit, or the time length of a time domain unit, or the size of a time domain unit, etc., which are not listed here one by one. Exemplarily, a time domain unit may include one or more OFDM symbols. Of course, the OFDM symbols shown here are only examples, and the embodiment of the present application does not limit the size of the time domain resource corresponding to a time domain unit. For the convenience of description, when referring to specific examples below, the size of a time domain unit is equal to an OFDM symbol.

[0125] Generally speaking, the unit for measuring the size of frequency domain resources may include at least one of a resource element (RE), a resource block (RB), a channel, a subchannel, a subcarrier, or a bandwidth part (BWP). Of course, other units may emerge as standards progress, and the embodiments of the present application are not limited thereto.

[0126] The frequency domain unit shown below may include one or more REs, or one or more RBs, etc. For ease of description, when referring to specific examples below, the size of one frequency domain unit is equal to one RE.

[0127] Exemplarily, the specific sizes of the time domain unit and the frequency domain unit can be determined in conjunction with the reference signal generation process. As shown below, when the first communication device uses RE as a unit to carry the signal when generating the reference signal, the size of the time domain unit can be equal to one OFDM symbol (for example only), and the size of the frequency domain unit can be equal to one subcarrier (for example only). The RE shown here is only an example. In a specific implementation, the minimum unit for carrying the signal can also be other units, which are not listed here one by one.

[0128] 3. First reference signal and second reference signal

[0129] Generally speaking, when sending a reference signal, the first communication device can combine the generation sequence of the reference signal and the time-frequency resources used to transmit the reference signal to generate signals carried on different REs, such as complex numbers (including real numbers). For example, after the first communication device generates multiple complex numbers, different complex numbers can be carried on corresponding REs. When the signal carried on the RE is a complex number, the phase of the complex number is involved. Therefore, the following will introduce the difference between the first reference signal and the second reference signal from the following aspects: the time domain resources used to transmit the reference signal, the generation sequence of the reference signal, and the phase difference of the signals transmitted on adjacent time domain units. It can be understood that the complex numbers shown here are not only generated based on the generation sequence, and the first communication device can also combine other parameters to ultimately generate the signal carried on the RE.

[0130] (1) Differences in time domain resources

[0131] The time domain resources used to transmit the first reference signal may include M time domain units. The time domain resources used to transmit the second reference signal may include N time domain units. Both M and N are positive integers.

[0132] In an embodiment of the present application, the time domain resources used to transmit the first reference signal and the time domain resources used to transmit the second reference signal are different resources. For example, the starting position of the M time domain units is different from the starting position of the N time domain units. The ending position of the M time domain units is different from the ending position of the N time domain units. For another example, there is no intersection between the M time domain units and the N time domain units. That is, there is no overlap between the time domain resources corresponding to the M time domain units and the time domain resources corresponding to the N time domain units. However, the size of one time domain unit in the M time domain units is the same as the size of one time domain unit in the N time domain units. Exemplarily, the M time domain units are continuous and the N time domain units are continuous.

[0133] Difference 1a: M is greater than or equal to N. Exemplarily, M is an integer greater than or equal to 2. N is a positive integer less than or equal to 2.

[0134] For example, the time domain resources used to transmit the first reference signal may include 3 OFDM symbols. Figures 3a and 3b are schematic diagrams of the structure of a first reference signal provided in an embodiment of the present application. Figure 3a exemplarily shows the situation of a signal transmitted within a time slot. Figure 3b exemplarily shows the situation of a signal transmitted within two time slots. The horizontal axis represents time, and the vertical axis represents frequency. A square in Figures 3a and 3b can represent an RE. As shown in Figures 3a and 3b, the first two OFDM symbols in each time slot can be used to transmit the PDCCH. The third to fourteenth OFDM symbols in the time slot can be used to transmit the PDSCH. The third to fifth OFDM symbols in the time slot can be used to transmit the first reference signal. The black squares in the third to fifth OFDM symbols in the time slot indicate that the corresponding RE carries a signal, and the white squares in the third to fifth OFDM symbols in the time slot indicate that the corresponding RE does not carry a signal. As shown in Figures 3a and 3b, the time domain resources used to transmit the first reference signal may include 3 OFDM symbols. The white squares shown in Figures 3a and 3b are only examples. In a specific implementation, the M time domain units used to transmit the first reference signal can also transmit valid data. For example, the white squares on the third OFDM symbol in a time slot in Figures 3a and 3b can carry valid data. At this time, the data carried on the fourth OFDM symbol and the fifth OFDM symbol in the time slot can be obtained after phase rotation based on the valid data carried on the third OFDM symbol. Exemplarily, the phase rotation method can refer to the first phase offset value shown below, such as the phase relationship between the data carried on different OFDM symbols can be similar to the phase difference of the first reference signal on different time domain units.

[0135] Generally speaking, the first reference signal can have the same configuration in each time slot in which it is transmitted. As shown in Figure 3b, in time slot i and time slot i+1, during which the first reference signal is transmitted, the number of time domain units used to transmit the first reference signal is three. The offset of the first reference signal relative to the starting OFDM symbol of a time slot is two OFDM symbols.

[0136] For another example, the time domain resources used to transmit the second reference signal may include 2 OFDM symbols, or 1 OFDM symbol. Figure 3c and Figure 3d are schematic diagrams of the structure of a second reference signal provided in an embodiment of the present application. Figure 3c exemplarily shows the situation of a signal transmitted in one time slot. Figure 3d exemplarily shows the situation of a signal transmitted in two time slots. As shown in Figures 3c and 3d, the time domain resources used to transmit the second reference signal in one time slot may include 1 OFDM symbol. Figures 3a to 3d are shown as an example of a time slot including 14 OFDM symbols, but they should not be understood as a limitation on the embodiments of the present application. For other explanations about Figures 3c and 3d, please refer to Figure 3a or Figure 3b, which will not be described in detail here.

[0137] For current standards, N=1 or N=2. Therefore, the following description of the second reference signal uses N=1 or N=2 as an example. However, as standards evolve, N=3 or N=4 may appear, and this is not limited in the present embodiment. Regardless of how the value of N changes, any value of N that meets the characteristics of the second reference signal described in the present embodiment falls within the scope of protection of the present embodiment.

[0138] Difference 1b: The value of M is related to the number of first communication devices serving the second communication device for joint transmission, and the value of N is related to the number of antenna ports for transmitting the second reference signal.

[0139] As shown above, the method shown in the embodiment of the present application can be applied to the scenario of joint transmission. Therefore, the value of M can be determined by the number of first communication devices for joint transmission serving the second communication device. Exemplarily, taking one time domain unit as an OFDM symbol as an example, the number of first communication devices is m, then M can be equal to m or m+1. m is an integer greater than or equal to 2. Of course, when the method provided in the embodiment of the present application is applied to other applicable scenarios (such as scenarios other than joint transmission), the value of M may not be limited thereto. In this case, the value of M may be greater than or equal to N.

[0140] The value of N may be determined by the number of antenna ports used to send the second reference signal. The value of N may depend on the number of antenna ports used by the first communication device to send the second reference signal. For ease of description, the following description takes the number of antenna ports as x and a time domain unit as an OFDM symbol as an example. As an example, 1≤x≤4, N=1. As another example, 5≤x≤8, N=2. As another example, 1≤x≤6, N=1. As another example, 7≤x≤12, N=2. Generally speaking, an antenna port can be defined as a channel experienced by an OFDM symbol sent on an antenna port that can be inferred from the channel experienced by another OFDM symbol sent on the same antenna port. Alternatively, an antenna port can be defined as when an OFDM symbol is transmitted through an antenna port, the channel it experiences is the same as the channel experienced by other OFDM symbols transmitted by the antenna port. If two OFDM symbols are sent on the same antenna port, the two OFDM symbols need to use the same beam, otherwise the channels experienced by the two OFDM symbols will be different. For example, an antenna port may represent a beam used by a transmitting end (eg, a first communication device). The above definition of an antenna port is merely an example, and descriptions of an antenna port may refer to standards or protocols, etc., which are not limited here.

[0141] (2) Difference in phase difference

[0142] The phase difference refers to the phase difference between signals transmitted on adjacent time domain units. Therefore, when describing the phase difference, M may be greater than or equal to 2, and N may be greater than or equal to 2.

[0143] Difference 2: The phase difference between signals transmitted in adjacent time domain units in the M time domain units used to transmit the first reference signal can be the first phase offset value. It can be understood that the phase difference between signals transmitted in adjacent time domain units in the N time domain units used to transmit the second reference signal does not exist.

[0144] The phase difference shown in the embodiment of the present application may also be referred to as a phase offset, a phase offset, or a time phase factor (TPF), etc. The embodiment of the present application does not limit the specific name.

[0145] Figure 4a is a schematic diagram of the structure of a first reference signal provided by an embodiment of the present application. Figure 4a exemplarily illustrates the structure of the first reference signals transmitted by two satellites. However, regardless of whether it is satellite 1 or satellite 2, the characteristics of the first reference signal meet the characteristics of difference 2.

[0146] For example, taking satellite 1 in FIG4a as an example, if the signal carried by the first OFDM symbol is X DMRS,1 , the signal carried by the second OFDM symbol is The signal carried by the third OFDM symbol is * represents multiplication. For satellite 1, the above ψ1 may be the first phase offset value.

[0147] For example, take satellite 2 in FIG4a as an example, if the signal carried by the first OFDM symbol is X DMRS,2 , the signal carried by the second OFDM symbol is The signal carried by the third OFDM symbol is For satellite 2, the above ψ2 may be the first phase offset value.

[0148] For satellite 1, the above X DMRS,1 Refers to the set of signals carried by satellite 1 on different frequency domain units corresponding to an OFDM symbol used to transmit the first reference signal, or a multidimensional vector corresponding to different frequency domain units corresponding to an OFDM symbol. For satellite 2, the above X DMRS,2 It refers to a set of signals carried on different frequency domain units corresponding to an OFDM symbol used by satellite 2 to transmit the first reference signal, or a multidimensional vector corresponding to different frequency domain units corresponding to an OFDM symbol.

[0149] In an embodiment of the present application, the phase difference between signals transmitted on adjacent time domain units is a first phase offset value, so that when the terminal device performs channel estimation, the first phase offset value can be set to reduce the impact of interference received during signal transmission on the accuracy of channel estimation, thereby improving the accuracy of the channel estimation result obtained by channel estimation. For example, by adjusting the phase of the signal transmitted on different time domain units, or by adjusting the first phase offset value, the terminal device can reduce or eliminate the interference part in the channel estimation formula when performing channel estimation based on the first reference signal, thereby improving the accuracy of the channel estimation, and then improving the accuracy of the channel estimation result obtained by channel estimation.

[0150] Exemplarily, the first phase offset value is adjustable, so that the first communication device can adjust the first phase offset value according to actual needs, and then reduce the impact of interference during the channel estimation process through the first phase offset value, thereby improving the accuracy of the channel estimation result obtained through the channel estimation.

[0151] The following uses DMRS as an example to illustrate the difference in signals carried on different frequency domain units corresponding to the second time domain unit. For example, in 5G NR, the time-frequency domain resource position of DMRS can satisfy the following formula:

[0152] Among them, k represents the frequency domain resource index, Indicates the time domain resource index, Indicates the index of the starting OFDM symbol of DMRS in a time slot, r(2n+k′) represents the generated sequence (or original sequence) associated with k′, where n=0, 1, ….

[0153] For example, the value of k can satisfy the following formula:

[0154] w f (k′), The values ​​of and are shown in Table 1 and Table 2. In Table 1 and Table 2, p represents the antenna port number, w f (k′) represents a value related to the frequency domain resource index, such as a fixed coefficient multiplied by the original sequence in the frequency domain. Indicates a value related to the time domain resource index, such as a fixed coefficient multiplied by the original sequence in the time domain. For example, when p = 1001 and k′ = 0, w f (k′)=+1;When k′=1,w f (k′)=−1. That is, when the time domain resource index is fixed, the phases of signals carried on different frequency domain resources are different.

[0155] Table 1

[0156] Table 2

[0157] In an embodiment of the present application, for a certain time domain unit among the N time domain units, the phases of the signals transmitted on different frequency domain units may not be the same, so the phase difference of the signals transmitted on adjacent time domain units among the N time domain units can be understood to be non-existent. Taking Tables 1 and 2 as an example, when p=1004, for the same frequency domain resource (such as k′=0), the signals carried on different time domain resources are obtained based on the following parameters: +1 and the generated sequence, -1 and the generated sequence. For another example, when p=1003, for the same frequency domain resource (such as k′=0), the signals carried on different time domain resources are obtained based on the following parameters: +1 and the generated sequence, +1 and the generated sequence. Since r(2n+k′) represents a generated sequence related to k′, for the same frequency domain unit, the phase difference of the signals carried on adjacent time domain units does not exist.

[0158] (3) Differences in generated sequences

[0159] Distinction 3: The signals transmitted on the same frequency domain unit corresponding to any two time domain units in the M time domain units are generated based on the same sequence. For the relevant description of the generation sequence of the second reference signal, please refer to the above formula (1) or Distinction 2, which will not be detailed here.

[0160] For the first reference signal, the same sequence description can refer to the above X DMRS,1 or X DMRS,2 The description is not detailed here.

[0161] In an embodiment of the present application, the signals transmitted on the same frequency domain unit corresponding to any two time domain units are generated based on the same sequence. Therefore, when the first communication device generates the first reference signal, it can combine the first phase offset value to reduce or eliminate interference in the channel estimation formula, thereby improving the accuracy of the channel estimation result.

[0162] In the embodiments of the present application, the difference between the first reference signal and the second reference signal can satisfy at least one of the aforementioned differences. The first reference signal can also be referred to as an asynchronous (Async) reference signal, and the second reference signal can also be referred to as a normal (Normal) reference signal. For example, using a DMRS as the reference signal, the first reference signal can be referred to as an asynchronous DMRS, and the second reference signal can be referred to as a normal DMRS. The embodiments of the present application do not limit the specific names of the first reference signal and the second reference signal.

[0163] In the embodiments of the present application, the value of M may be included in the configuration information of the first DMRS, or the value of M may be determined by both communicating parties based on a predetermined rule. If the predetermined rule may be a method for determining M, the relevant description of M can refer to Difference 1b above and will not be further described here. The embodiments of the present application do not limit the specific method for setting the value of N.

[0164] 4. First phase offset value

[0165] The first phase offset value may be related to the value of the frequency offset that occurs when the signal from the first communication device is transmitted to the second communication device. For example, the first phase offset value may be determined based on the value of the frequency offset that occurs when the signal from the first communication device is transmitted to the second communication device. Thus, when the terminal device performs channel estimation, the satellite can reduce the impact of the signal frequency offset on the channel estimation accuracy by setting the first phase offset value, thereby improving the accuracy of the channel estimation result.

[0166] Exemplarily, the embodiments of the present application can be applied to joint transmission, such as the number of first communication devices serving the terminal equipment can be m. For example, the m first communication devices can all send useful signals to the terminal equipment. For example, there may be overlap between the time domain resources occupied by the useful signals respectively sent by the m first communication devices, or there may be overlap between the frequency domain resources when the signals respectively sent by the m first communication devices arrive at the second communication device side. For example, m=2, then the time domain resources occupied by the useful signal sent by the first communication device #1 and the time domain resources occupied by the useful signal sent by the first communication device #2 at least partially overlap, or the frequency domain resources when the useful signal sent by the first communication device #1 arrives at the second communication device side and the frequency domain resources when the useful signal sent by the first communication device #2 arrives at the second communication device side at least partially overlap.

[0167] As described above, when signals sent by different first communication devices reach the terminal device, ISI is generated in the time domain and ICI is generated in the frequency domain. Therefore, when the signal sent by the first communication device reaches the terminal device, the frequency domain resources of the signal may be sent offset, and the time domain resources may also be sent offset. For example, when the signal sent from the first communication device reaches the terminal device, the time-frequency resources corresponding to the time-frequency resources occupied by the signal at the transmitting end may not completely overlap, and may partially overlap or not overlap.

[0168] In an embodiment of the present application, by adjusting the first phase offset value, such as adjusting the phase of the first reference signal sent by the first communication device, the phase of ISI and ICI is regulated, thereby improving the accuracy of the channel estimation result obtained when the terminal device performs channel estimation.

[0169] The first phase offset value may be related to a frequency offset generated when a signal from the first communication device is transmitted to the second communication device, including: the first phase offset value being related to a first frequency difference, where the first frequency difference is the difference in frequency offsets generated when signals from different first communication devices are respectively transmitted to the second communication device. For example, the first frequency difference may be the difference in frequency offsets generated when signals from two of the m first communication devices are respectively transmitted to the second communication device.

[0170] Exemplarily, the first phase offset value ψ may satisfy the following formula:

[0171] Where m represents the number of first communication devices serving the terminal equipment. π is a constant. β D2,1 It can be calculated based on the first frequency difference. For example, β D2,1 It can be calculated based on the Doppler effect, β D2,1It can be the difference in phase offset values ​​that occur when signals from two different first communication devices are respectively transmitted to the terminal device, and q1 can be a positive integer.

[0172] For example, when m=2, q1 can be an odd number, such as +1, -1, +3, -3, +5, or -5. D2,1 +π.

[0173] β D2,1 The following formula can be satisfied: β D2,1 =2πf D2,1 ·T sym (4)

[0174] Where π is a constant, f D2,1 is the first frequency difference, T sym is the duration of a time domain unit. For example, where N c is the number of subcarriers, N g is the CP length, Δf is the subcarrier spacing, T sym It can be the duration of a time domain unit including the CP.

[0175] Furthermore, when m=2, for example, for the first communication device #1, the first communication device #1 may send a first reference signal #1 to the second communication device, where the phase difference between signals transmitted in adjacent time domain units among the M time domain units used to transmit the first reference signal #1 is ψ1. For example, for the first communication device #2, the first communication device #2 may send a first reference signal #2 to the second communication device, where the phase difference between signals transmitted in adjacent time domain units among the M time domain units used to transmit the first reference signal #2 is ψ2. Exemplarily, ψ1 and ψ2 satisfy the following formula:

[0176] In an embodiment of the present application, since the setting of ψ1 corresponding to the first communication device #1 takes into account the impact of the frequency offset of the signal of the first communication device #2 during the transmission process on the signal of the first communication device #1, the setting of the first phase offset value can be more reasonable, and then in the subsequent channel estimation process, the interference caused by the signal of the first communication device #2 can be better eliminated, thereby improving the accuracy of the channel estimation result.

[0177] 5. Channel Estimation

[0178] The following example illustrates the process of obtaining a channel estimation result using the first reference signal by the second communication device. Of course, the channel estimation method shown below is only an example and should not be understood as limiting the embodiments of this application. In a specific implementation, the method for channel estimation using the first reference signal or the formula satisfied can also be other similar methods or formulas, and the embodiments of this application do not limit this. For ease of description, the following specific examples are described using m=2 and M=3 as an example.

[0179] Figure 4b is a schematic diagram of the first reference signal received by the second communication device provided in an embodiment of the present application. Each box in Figure 4b can represent a time domain unit, and Figure 4b exemplarily shows three time domain units. The signal received by the second communication device from the first communication device #1 is the first reference signal #1, and the signal received by the second communication device from the first communication device #2 is the first reference signal #2. During the transmission of the first reference signal #1, part of the signal carried on the third time domain unit is not affected by the first communication device #2. Taking Figure 4b as an example, the signals sent by the first communication device #1 on different time domain units can be X DMRS,1 , The signals sent by the first communication device #2 in different time domain units can be X DMRS,2 , Since the transmission process of the first reference signal #1 and the first reference signal #2 may be affected by some factors, such as Doppler effect, the signal received by the second communication device may be phase-shifted.

[0180] Exemplarily, the channel estimation result between the first communication device #1 and the second communication device may satisfy the following formula:

[0181] in, is the channel estimation result on a certain frequency domain unit between the first communication device #1 and the second communication device. Formula (6) and Formula (7) are channel estimation methods using a certain frequency domain unit as an example, but they should not be understood as limitations on the embodiments of the present application. DMRS1 is the signal sequence used to generate the first reference signal #1, r 1,0 is the signal carried on the first time domain unit among the three time domain units, r 1,0 The corresponding signal can be expressed as DMRS1, r 1,1 is the signal carried on the second time domain unit among the three time domain units, For r 1,1 The corresponding correction value, r 1,1 The corresponding signal can be expressed as ψ1 is the first phase offset value of the first communication device #1, r 1,0 The corresponding correction value is 1.

[0182] Formula (6) is analyzed below to illustrate how the method provided in the embodiment of the present application improves the accuracy of the channel estimation result.

[0183] Since the first reference signal #1 received by the second communication device from the first communication device #1 corresponds to signals carried on three time domain units, as shown below: Since these signals are subject to some influences during transmission, such as Doppler effects, the signals received by the second communication device may be phase-shifted. The first reference signal #2 received by the second communication device from the first communication device #2 corresponds to the signals carried on the three time domain units, as shown below: The meaning of the relevant parameters can be found in the descriptions of the above formulas and will not be repeated here. 1,1 The interference W r1,1 and r 1,0 The interference W r1,0 Can satisfy Transform the formula, such as multiplying both sides of the formula by Then you can get: Also because therefore therefore +W r1,0 =0.

[0184] The above formula (6) can be further transformed into: Among them, P r1,0 Can be regarded as r 1,0 The effective signal in P r1,1 Can be regarded as r 1,1 The effective signal in . And because therefore Also because r 1,1 The corresponding signal is therefore Can P r1,1 phase compensation.

[0185] Exemplarily, the channel estimation result between the first communication device #2 and the second communication device may satisfy the following formula:

[0186] Among them, r 2,1 is the signal carried on the second time domain unit among the three time domain units, r 2,2The signal carried by the third of the three time domain units is used here to calculate the channel estimation result using the signals in the second and third time domain units because the signal transmitted by first communication device #2 in the first of the three time domain units is partially affected by the influence of first communication device #1. The specific process of channel estimation is not further described here.

[0187] It can be seen from the above analysis that by applying the solution provided in the embodiments of the present application, the interference to the signal can be eliminated in the subsequent channel estimation process, thereby improving the accuracy of the channel estimation result.

[0188] The following describes the methods involved in the embodiments of the present application.

[0189] FIG5 is a flow chart of a satellite communication method provided by an embodiment of the present application. The various communication devices or terms involved in FIG5 can be referred to above and will not be described in detail here. As shown in FIG5, the method includes:

[0190] 501. A first communication device obtains channel information between the first communication device and a second communication device.

[0191] As an example, the channel information may be information about channel changes between the first and second communications devices. The channel change information can be used to measure the speed of channel changes, or the magnitude of channel changes. The speed of channel changes may be changes in the channel between the first and second communications devices over a certain period of time.

[0192] As another example, the channel information may be channel quality information between the first communication device and the second communication device. The channel quality information may be used to measure the quality of the channel. The channel quality may be the quality of the channel between the first communication device and the second communication device at different times.

[0193] For the relevant description of the channel information, please refer to the description of step 502 below, which will not be described in detail here. The following describes a method for the first communication device to obtain channel information.

[0194] As an example, a second communication device may send feedback information to a first communication device, and the first communication device may receive feedback information from the second communication device. The feedback information may be used to indicate channel information. For example, the feedback information may be used to provide channel change information or channel quality information. In another example, the feedback information may be used to indicate whether the channel information meets a first condition. In another example, the feedback information may be used to indicate whether the channel information meets the first condition or the second condition. The specific form of the channel information indicated by the feedback information is not limited in the embodiments of the present application.

[0195] As another example, the first communication device may acquire channel information based on the location information and ephemeris information of the second communication device.

[0196] As another example, the first communication device may acquire channel information based on the motion information and ephemeris information of the second communication device.

[0197] For example, the second communication device may report location information or motion information to the first communication device, and the first communication device may then determine channel information between the first communication device and the second communication device based on the location information or motion information and the ephemeris information.

[0198] For related descriptions on the first communication device acquiring the channel information, please refer to Examples 1 to 3 below, which will not be described in detail here.

[0199] 502. When the channel information satisfies a first condition, the first communication device sends first indication information. The first indication information may be used to indicate configuration information of a first reference signal. Correspondingly, the second communication device receives the first indication information.

[0200] The channel information satisfying the first condition may include: channel change information satisfying the first condition, or channel quality information satisfying the first condition. Of course, the first condition may also be different when the channel information is different. For example, the first condition satisfied by the channel change information may be different from the first condition satisfied by the channel quality information.

[0201] As an example, the channel change information meeting the first condition may include at least one of the following:

[0202] 1A. The attitude change of the second communication device is greater than the change threshold. Generally speaking, when the attitude changes, it means that the direction of the beam sent by the antenna panel of the terminal device will also change, which may cause the signal of the beam to change. Therefore, when the attitude change of the terminal device is greater than the change threshold, it means that the channel between the second communication device and the first communication device will also change rapidly, such as greater than a certain threshold. For example, the UE can obtain the attitude change D through the gyroscope. att =(D x ,D y ,D z ), when the change ‖D att ‖>D th,1 When , it is considered that the posture changes greatly.

[0203] 1B. The variation of the reference signal receiving power (RSRP) on different resources used for signal transmission is greater than the RSRP threshold. For example, the above-mentioned resources may include beams. For example, the UE measures the variation of RSRP on different beams. RSRP =(p PSRP1 ,p RSRP2 ), when ‖P PSRP ‖>P th,1 When P RSRP =p PSRP1 -p RSRP2 , or, P RSRP =p PSRP2 -p RSRP1 Among them, p PSRP1 represents the RSRP on the first beam, p PSRP2 Indicates the RSRP on the second beam. For example, the feedback information reported by the UE may indicate the RSRP of the second beam. RSRP For another example, the feedback information reported by the UE may indicate ‖P PSRP ‖>P th,1 The specific forms of the feedback information are not listed here one by one. The first beam and the second beam may be beams sent by the UE at different times.

[0204] 1C. The reference signal receiving quality (RSRQ) on different resources used for signal transmission is greater than the RSRQ threshold. For example, the UE measures the RSRQ variation P on different beams. RSRQ =(p PSRQ1 ,p RSRQ2 ), when ‖P PSRQ ‖>P th,2 When P RSRQ =p PSRQ1 -p RSRQ2 , or, P RSRQ =p PSRQ2 -p RSRQ1 Among them, p PSRQ1 represents the RSRQ on the first beam, p PSRQ2 Indicates the RSRQ on the second beam.

[0205] 1D. The signal to interference plus noise ratio (SINR) on different resources used to transmit signals is greater than the SINR threshold. Of course, the SINR shown here can also be replaced by the signal-to-noise ratio (SNR). For example, the UE measures the SINR change P on different beams. SINR =(p SINR1 ,p SINR2 ), when ‖P SINR ‖>P th,3 When P SINR =p SINR1 -p SINR2 , or, P SINR =p SINR2 -p SINR1 Among them, p SINR1 represents the SINR on the first beam, p SINR2 represents the SINR on the second beam.

[0206] 1E. The block error rate (BLER) on different resources used for signal transmission is greater than the BLER threshold. For example, the UE measures the BLER variation B on different beams. d =(B1,B2), when ‖B d ‖>B th,1 When , it is considered that the channel changes rapidly.

[0207] 1F. The throughput variation on different resources used for signal transmission is greater than the throughput threshold. For example, the UE measures the throughput variation rate R on different beams. d =(R1,R2), when ‖R d ‖>R th,1 When , it is considered that the channel changes rapidly.

[0208] The above-mentioned channel changes faster refer to that the channel change of the channel between the first communication device and the second communication device within a certain time period is greater than a certain threshold. Similarly, the channel change shown below is smaller and refers to that the channel change of the channel between the first communication device and the second communication device within a certain time period is less than a certain threshold. The embodiment of the present application does not limit the specific value of the certain threshold. When the channel change is equal to a certain threshold, it can be considered that the channel change is smaller, or it can be considered that the channel change is faster. Of course, the threshold for judging that the channel change is faster and the threshold for judging that the channel change is slower can be the same or different, and the embodiment of the present application does not limit this.

[0209] In an embodiment of the present application, when the channel between a first communication device and a second communication device changes rapidly (e.g., the channel change is greater than a certain threshold), the first communication device may configure a first reference signal and transmit the first reference signal. Thus, after receiving the first reference signal, the second communication device may perform channel estimation in conjunction with the first phase offset value, thereby improving the accuracy of the channel estimation result.

[0210] As another example, the channel quality information change meeting the first condition may include:

[0211] 1G. The channel quality between the first communication device and the second communication device is less than a quality threshold.

[0212] In an embodiment of the present application, when the channel quality between a first communication device and a second communication device is less than a quality threshold, the first communication device may configure a first reference signal and transmit the first reference signal. Consequently, upon receiving the first reference signal, the second communication device may perform channel estimation in conjunction with the first phase offset value, thereby improving the accuracy of the channel estimation result.

[0213] When the channel information satisfies at least one of the above 1A to 1G, the first communication device may send the first indication information.

[0214] The specific manner in which the first communication device sends the first indication information is described below.

[0215] As an example, the first indication information may include configuration information of the first reference signal, such as time domain resources or frequency domain resources used to transmit the first reference signal.

[0216] As another example, the first indication information may include an index of the configuration information of the first reference signal. For example, the second communication device may store the configuration information of the first reference signal or the configuration information of the second reference signal. For example, before the first communication device sends the first indication information, the relationship between the configuration information of the first reference signal and the index, as well as the relationship between the configuration information of the second reference signal and the index, may be indicated to the second communication device. The second communication device then stores the relationship between the configuration information of the first reference signal and the index, as well as the relationship between the configuration information of the second reference signal and the index. Thus, after the second communication device receives the first indication information, it can obtain the configuration information of the first reference signal based on the above relationship and the first indication information.

[0217] As another example, the first indication information may be used to indicate configuration information for activating a first reference signal. For example, the first indication information may include an indication for activating the configuration information for the first reference signal. For example, the indication for activating the configuration information for the first reference signal may occupy one bit. For example, if the value of the indication is 1, it indicates that the configuration information for the first reference signal is activated. For another example, if the value of the indication is 0, it indicates that the configuration information for the second reference signal is activated. For example, the second communication device may store configuration information for the first reference signal or configuration information for the second reference signal.

[0218] As another example, the first indication information can be used to indicate the configuration information of the first reference signal within the first time period. For example, the first communication device predicts the channel information in combination with the UE's location information and ephemeris information, and then determines the first time period in combination with the channel information. Thus, the UE can use the configuration information of the first reference signal to receive the first reference signal within the first time period. The starting time of the first time period shown here can be the time when the first communication device sends the first indication information, or the time when the second communication device receives the first indication information, or the starting time of the first time period indicated by the first indication information, etc., and the embodiments of the present application are not limited to this.

[0219] As an example, the first indication information may be carried in RRC signaling.

[0220] As another example, the first indication information may be carried in DCI.

[0221] As another example, the first indication information may be carried in a MAC CE.

[0222] For other explanations about RRC signaling, DCI and MAC CE, please refer to Examples 1 to 3 below, which will not be described in detail here.

[0223] 503. The first communication device sends a first reference signal, and correspondingly, the second communication device receives the first reference signal.

[0224] Exemplarily, the first communication device may send the first reference signal based on the configuration information of the first reference signal. For example, the first communication device may send the first reference signal on a time-frequency resource used for transmitting the first reference signal.

[0225] 504. The second communication device determines a channel estimation result between the first communication device and the second communication device based on the first reference signal.

[0226] The method for the second communication device to perform channel estimation may refer to the description of the term channel estimation above.

[0227] In the embodiment of the present application, after the first communication device configures the first reference signal for the UE, the first communication device may send the first reference signal within a period of time.

[0228] As an example, when the first indication information indicates a first duration, the first communications apparatus may transmit the first reference signal within the first duration. After the first duration, the first communications apparatus may transmit the second reference signal. The second communications apparatus may automatically activate the configuration information for the second reference signal and receive the second reference signal based on the configuration information for the second reference signal.

[0229] As another example, the above-mentioned first indication information may be included in the indication information. The indication information may include first indication information and second indication information. For example, the indication information may indicate the configuration information for activating the first reference signal within the first duration and the configuration information for activating the second reference signal within the second duration; or, the indication information may indicate that the UE receives the first reference signal based on the configuration information of the first reference signal within the first duration, and receives the second reference signal based on the configuration information of the second reference signal within the second duration. Thus, the UE may adopt different configuration information to receive the reference signal in different time periods based on the indication information. The above-mentioned first indication information may correspond to the case where the channel information meets the first condition, and the second indication information may correspond to the case where the channel information meets the second condition.

[0230] As another example, the first communication device may send the first reference signal until the configuration information needs to be updated. The first communication device may send second indication information to the second communication device, as shown in steps 505 to 507 below.

[0231] In a possible implementation, the method shown in FIG5 may further include:

[0232] 505. If the channel information satisfies the second condition, the first communication device sends second indication information. The second indication information may be used to indicate configuration information of the second reference signal. Correspondingly, the second communication device receives the second indication information.

[0233] The channel information meeting the second condition may include: channel change information meeting the second condition, or channel quality information meeting the second condition.

[0234] Exemplarily, the channel information meeting the second condition may include at least one of the following:

[0235] 2A. The posture change of the second communication device is less than the change threshold.

[0236] 2B. The RSRP variation on different resources used for signal transmission is less than the RSRP threshold.

[0237] 2C. The RSRQ variation on different resources used for signal transmission is less than the RSRQ threshold.

[0238] 2D. The SINRs on different resources used for signal transmission are less than the SINR threshold.

[0239] 2E. The BLER on different resources used for signal transmission is less than the BLER threshold.

[0240] 2F. The throughput of different resources used for signal transmission is less than the throughput threshold.

[0241] 2G, the channel quality between the first communication device and the second communication device is greater than the quality threshold.

[0242] For the relevant description of 2A to 2G, please refer to the description of 1A to 1G above, which will not be described in detail here. It should be noted that the thresholds in 2A to 2G can be the same as or different from the corresponding thresholds in 1A to 1G, and this embodiment of the application does not limit this.

[0243] 506. The first communication device sends a second reference signal, and correspondingly, the second communication device receives the second reference signal.

[0244] Exemplarily, the first communication device may send the second reference signal based on the configuration information of the second reference signal. For example, the first communication device may send the second reference signal on the time-frequency resources used for transmitting the second reference signal.

[0245] In an embodiment of the present application, when the channel between the first communication device and the second communication device changes slowly (e.g., the channel change is less than a certain threshold), or the channel quality is greater than a quality threshold, the first communication device may configure a second reference signal and transmit the second reference signal. Because the time domain resources occupied by the second reference signal may be less than the time domain resources occupied by the first reference signal, pilot overhead may be reduced.

[0246] 507. The second communication device determines a channel estimation result between the first communication device and the second communication device based on the second reference signal.

[0247] Taking the reference signal as DMRS as an example, in an embodiment of the present application, the network device can configure different DMRSs as the UE posture or channel changes at different speeds. As shown in Figure 6, when the UE posture or channel changes quickly, the network device can send a first DMRS. When the UE posture or channel changes slowly, the network device can send a second DMRS. In this way, the accuracy of the channel estimation result and the pilot overhead can be balanced. Figure 6 uses the direction change of the panel to indicate the speed of the channel change. For example, the direction of the panel corresponding to the fast channel change has changed, and the direction of the panel corresponding to the slow channel change can be considered to have not changed.

[0248] Steps 501 to 504 can be combined with each other or separated into separate embodiments. For example, steps 501 to 504 can be separate embodiments, or steps 501 and 505 to 507 can be separate embodiments. These embodiments can be performed independently or in combination, and are not listed here one by one.

[0249] The following takes m=2 as an example to illustrate the method provided in an embodiment of the present application. When m=2, the network device performing joint transmission may include a primary network device and a secondary network device. Exemplarily, an RRC connection can be established between the primary network device and the UE, and the secondary network device can send an uplink signal to the UE. For ease of description, the following will be explained using a primary satellite (such as satellite 1) and a secondary satellite (such as satellite 2) as an example, and using a reference signal as DMRS as an example. In each of the examples below, an RRC connection is established between the primary satellite (such as satellite 1) and the UE, and the secondary satellite (such as satellite 2) and satellite 1 can collaborate to provide non-coherent joint transmission for the UE.

[0250] Example 1:

[0251] 11) When the UE detects that the attitude or channel changes significantly, the UE may send feedback information to satellite 1.

[0252] The manner in which the UE detects a large posture change or a large channel change may refer to the above 1A to 1G or 2A to 2G, which will not be described in detail here.

[0253] 12) After receiving the feedback information from the UE, satellite 1 notifies satellite 2 of the configuration information for enabling the first DMRS via the inter-satellite link and sends the configuration information of the first DMRS to the UE via RRC signaling.

[0254] For example, satellite 1 may send activation information to satellite 2, where the activation information may be used to instruct satellite 2 to activate the first DMRS configuration. For example, the activation information may be a 1-bit activation message. For another example, the activation information may indicate the configuration information used by satellite 2 when sending the first DMRS.

[0255] For example, the first DMRS configuration of satellite 1 may be the same as or different from the first DMRS configuration of satellite 2. For example, the generation sequence of the first DMRS generated by satellite 1 may be different from the generation sequence of the first DMRS generated by satellite 2.

[0256] 13) The UE receives the first DMRS from satellite 1 and satellite 2 respectively based on the configuration information of the first DMRS, estimates the channel estimation result based on the first DMRS, calculates the spatial receiver, and performs data detection.

[0257] Exemplarily, in order to improve the system performance of multi-satellite NCJT, the UE side can adopt the receiver architecture shown in Figure 7a. Figure 7a is a schematic diagram of a data detection process provided by an embodiment of the present application. As shown in Figure 7a, satellite 1 sends a single data stream x1 to the UE, and satellite 2 sends a single data stream x2 to the UE. The UE side is equipped with multiple antennas, and the signal received on each antenna is sampled by an analog-to-digital converter (ADC) and then connected to two synchronization modules, one synchronization module is synchronized with satellite 1, and the other synchronization module is synchronized with satellite 2. Assuming that the signal after synchronization with satellite 1 is r1, r1 is demodulated by OFDM to obtain the frequency domain received signal {y 1,k |k=0,1,…,N c -1}, where k is the subcarrier index, N c is the number of subcarriers. Next, 1,k Using the spatial receiver w 1,k After merging, we get signal d 1,k , and finally use d 1,k Perform data detection (such as recovering the data from satellite 1 and the data from satellite 2). Here, the spatial receiver w 1,k The role of is to suppress the interference from non-synchronous satellites, which plays an important role in multi-satellite NCJT. For example, the minimum mean square error (MMSE) spatial receiver can be expressed as in is the channel estimation value from satellite 1 to UE, λ1 is the weighting coefficient, is the estimated value of the covariance matrix of interference plus noise. It can be seen that the spatial receiver w 1,k The design depends on the channel estimation result h 1,k .

[0258] Therefore, using the first DMRS to improve the accuracy of the channel estimation result can further improve the processing accuracy of the spatial domain receiver, thereby improving the accuracy of data detection performed by the UE.

[0259] For the relevant descriptions of serial-to-parallel conversion (S / P), CP removal (-CP), fast Fourier transform (FFT), and parallel-to-serial conversion (P / S) in Figure 7a, please refer to relevant standards (such as the processing process in the OFDM standard), etc., and will not be described in detail here.

[0260] 14) When the UE detects that the attitude or channel change is small, the UE can send feedback information to satellite 1.

[0261] 15) After receiving the feedback information from the UE, satellite 1 notifies satellite 2 to enable the second DMRS configuration via the inter-satellite link and sends the configuration information of the second DMRS to the UE via RRC signaling.

[0262] 16) The UE receives the second DMRS from satellite 1 and satellite 2 respectively based on the configuration information of the second DMRS, and uses the previously obtained spatial receiver to estimate scalar channel information and perform data detection.

[0263] The previously obtained spatial domain receiver shown here may be the spatial domain receiver obtained through the above step 13).

[0264] Exemplarily, after the UE uses the first DMRS for channel estimation, it can obtain the channel estimation results on multiple antennas, and then use the channel estimation results on the multiple antennas to calculate the spatial receiver. If the role of the spatial receiver is to combine the multi-dimensional signals on multiple antennas into a one-dimensional scalar signal, the UE can reuse the channel estimation results obtained based on the first DMRS, or reuse the spatial receiver obtained based on the first DMRS, so that the channel after passing through the spatial receiver can be regarded as an equivalent channel, and the equivalent channel can be expressed as a one-dimensional scalar. Figure 7b is a schematic diagram of another data detection process provided by the application embodiment. As shown in Figure 7b, the UE can reuse the spatial receiver obtained using the first DMRS, and then use the signal processed by the spatial receiver to estimate the scalar channel information, and use it for the channel equalizer to perform data detection. For relevant instructions on Figure 7b, please refer to Figure 7a, which will not be described in detail here.

[0265] In an embodiment of the present application, in a subsequent process, when the UE again detects a significant attitude change or a significant channel change and sends feedback information to satellite 1, satellite 1 may instruct the UE to reactivate the configuration information of the first DMRS through DCI or MAC CE signaling. For example, the configuration information instructing the UE to reactivate the first DMRS may occupy one bit.

[0266] In the embodiment of the present application, satellite 1 configures different DMRSs based on the speed of channel changes, thereby balancing the accuracy of channel estimation results and pilot overhead.

[0267] Example 2:

[0268] 21) Satellite 1 sends the configuration information of the first DMRS and the configuration information of the second DMRS to the UE through RRC signaling.

[0269] 22) When the UE detects a significant change in attitude or channel, the UE may send feedback information to satellite 1.

[0270] 23) After receiving the feedback information from the UE, satellite 1 notifies satellite 2 to activate the first DMRS configuration via the inter-satellite link and notifies the UE of the configuration information of activating the first DMRS via MAC CE signaling.

[0271] Exemplarily, satellite 1 may also inform the UE of the configuration information of activating the first DMRS through DCI.

[0272] 24) The UE receives the first DMRS from satellite 1 and satellite 2 respectively based on the configuration information of the first DMRS, estimates the satellite channel based on the first DMRS, calculates the spatial receiver, and performs data detection.

[0273] 25) When the UE detects that the attitude or channel change is small, the UE can send feedback information to satellite 1.

[0274] 26) After receiving the feedback information from the UE, satellite 1 notifies satellite 2 to activate the second DMRS configuration via the inter-satellite link and notifies the UE of the configuration information of activating the second DMRS via MAC CE signaling.

[0275] Exemplarily, satellite 1 may also inform the UE of the configuration information of activating the first DMRS through DCI.

[0276] 27) The UE receives the second DMRS of satellite 1 and satellite 2 respectively based on the configuration information of the second DMRS, and uses the previously obtained spatial receiver to estimate scalar channel information and perform data detection.

[0277] For relevant descriptions of Example 2, please refer to Figure 5 or the above Example 1, which will not be described in detail here.

[0278] Example 3:

[0279] 31) When the UE position or motion trajectory is determined, the UE reports the position information or motion trajectory information to satellite 1.

[0280] 32) After receiving the location information or motion trajectory information of the UE, satellite 1 can determine the configuration information of satellite 1 and satellite 2 in the subsequent period [T1, T2] in combination with the ephemeris information.

[0281] For example, satellite 1 may determine a time within a time period [T1, T2] to use the configuration information of the first DMRS and a time within a time period [T1, T2] to use the configuration information of the second DMRS. For example, within the time period [T1, T2], the configuration information of the first DMRS is used during a first time period, and the configuration information of the second DMRS is used during a second time period. As described above, the first time period may be a continuous time period or multiple continuous time periods. As described above, the second time period may be a continuous time period or multiple continuous time periods.

[0282] 33) Send indication information to satellite 2 through the inter-satellite link, and send indication information to the UE.

[0283] The indication information may be used to indicate a time period for using the configuration information of the first DMRS and a time period for using the configuration information of the second DMRS. For example, the indication information may be sent by satellite 1 to the UE via RRC.

[0284] As an example, the indication information may include at least one of the following: the number of continuous time slots of the first DMRS, the number of continuous time slots of the second DMRS, the period during which the first DMRS appears, and the period during which the second DMRS appears. The number of continuous time slots of the first DMRS may be the number of time slots occupied by the first DMRS. As shown in FIG3b , the number of continuous time slots of the first DMRS may be 2 time slots. The number of continuous time slots of the second DMRS may be the number of time slots occupied by the second DMRS. As shown in FIG3d , the number of continuous time slots of the second DMRS may be 2 time slots.

[0285] The first DMRS period can be understood as the number of time domain units between satellites 1 and 2 that transmit the first DMRS, e.g., the number of time slots between satellites 1 and 2 that transmit the first DMRS. The second DMRS period can be understood as the number of time domain units between satellites 1 and 2 that transmit the second DMRS. Taking Figure 6 as an example, the first DMRS period can be four time slots, and the second DMRS period can be two time slots.

[0286] 34) The UE receives DMRSs from satellite 1 and satellite 2 respectively within time [T1, T2] based on the configuration information of the first DMRS and the configuration information of the second DMRS.

[0287] For example, the satellite channel is estimated at the time of the configuration information of the first DMRS, the spatial receiver is calculated, and data detection is performed.

[0288] For another example, at the time of the second DMRS configuration information, the spatial domain receiver obtained by previous calculation is used to estimate the scalar channel information and perform data detection.

[0289] For relevant descriptions of Example 3, please refer to Figure 5 or the above Example 1, which will not be described in detail here.

[0290] The following describes a communication device according to an embodiment of the present application.

[0291] The present application divides the functional modules of the communication device according to the above-mentioned method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in this application is schematic and is only a logical functional division. There may be other division methods in actual implementation. The communication device of the embodiment of the present application will be described in detail below with reference to Figures 8 to 10.

[0292] Figure 8 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. As shown in Figure 8, the communication device includes a processing module 801 and a transceiver module 802. The transceiver module 802 can implement corresponding communication functions, and the processing module 801 is used to implement corresponding processing functions. For example, the transceiver module 802 can also be referred to as an interface, a communication interface, or a communication module.

[0293] In some embodiments of the present application, the communication device may be used to perform the actions performed by the first communication device in the above method embodiments. In this case, the first communication device may be the network device itself, or a chip or functional module configurable in the device. The transceiver module 802 is used to perform the transceiver-related operations of the first communication device in the above method embodiments, and the processing module 801 is used to perform the processing-related operations of the first communication device in the above method embodiments.

[0294] Exemplarily, the processing module 801 may be used to obtain channel information; the transceiver module 802 may be used to send or output first indication information, and send or output a first reference signal.

[0295] Exemplarily, the transceiver module 802 may also be configured to send or output second indication information. Exemplarily, the transceiver module 802 may also be configured to send or output a second reference signal. Exemplarily, the transceiver module 802 may also be configured to receive or input feedback information, location information, or motion information.

[0296] Referring to Figure 8 , in some other embodiments of the present application, the communication device can be used to perform the actions performed by the second communication device in the above method embodiments. In this case, the communication device can be the terminal device itself, or a chip or functional module configurable in the device. The transceiver module 802 is used to perform the transceiver-related operations of the second communication device in the above method embodiments, and the processing module 801 is used to perform the processing-related operations of the second communication device in the above method embodiments.

[0297] Exemplarily, the transceiver module 802 can be used to receive or input first indication information, and receive or input a first reference signal; the processing module 801 can be used to perform channel estimation based on the first reference signal to obtain a channel estimation result between the first communication device and the second communication device.

[0298] Exemplarily, the transceiver module 802 may also be configured to receive or input second indication information. Exemplarily, the transceiver module 802 may also be configured to receive or input a second reference signal. Exemplarily, the processing module 801 may perform channel estimation based on the second reference signal.

[0299] Optionally, in each of the above embodiments, the communication device may further include a storage module, which may be used to store instructions and / or data. The processing module 801 may read the instructions and / or data in the storage module to enable the communication device to implement the above method embodiments. Exemplarily, the storage module may also store the configuration information of the reference signal described above, etc.

[0300] In the above embodiments, the specific descriptions of terms or steps such as the first reference signal, the second reference signal, M time domain units, N time domain units, the first offset value, the configuration information, the first indication information, and the second indication information can be referred to the introduction in the above method embodiments and will not be described in detail here.

[0301] The specific descriptions of the transceiver module and the processing module shown in the above embodiments are only examples. For the specific functions or execution steps of the transceiver module and the processing module, please refer to the above method embodiments and will not be described in detail here.

[0302] The above describes the communication device according to the embodiment of the present application. The following describes possible product forms of the communication device. Any product having the functions of the communication device described in FIG8 falls within the scope of protection of the embodiment of the present application. The following description is for illustrative purposes only and does not limit the product forms of the communication device according to the embodiment of the present application to these examples.

[0303] In one possible implementation, in the communication device shown in Figure 8, processing module 801 may be one or more processors, and transceiver module 802 may be a transceiver. Alternatively, transceiver module 802 may be a transmitting module and a receiving module, where the transmitting module may be a transmitter and the receiving module may be a receiver, with the transmitting module and receiving module being integrated into a single device, such as a transceiver. In embodiments of the present application, the processor and transceiver may be coupled, and the connection method between the processor and transceiver is not limited in embodiments of the present application. During the execution of the above-described method, the process of sending information in the above-described method may be the process of the processor outputting the above-described information. When outputting the above-described information, the processor outputs the above-described information to the transceiver for transmission by the transceiver. After being output by the processor, the above-described information may require further processing before reaching the transceiver. Similarly, the process of receiving information in the above-described method may be the process of the processor receiving the above-described information. When the processor receives the input information, the transceiver receives the above-described information and inputs it into the processor. Furthermore, after the transceiver receives the above-described information, the above-described information may require further processing before being input into the processor.

[0304] As shown in FIG. 9 , the communication device 90 includes one or more processors 920 and a transceiver 910 .

[0305] In some embodiments of the present application, the communication device may be configured to execute the steps, methods, or functions performed by the first communication device described above. For example, the processor 920 may be configured to execute the functions or steps implemented by the processing module 801 shown in FIG8 , and the transceiver 910 may be configured to execute the functions or steps implemented by the transceiver module 802 shown in FIG8 . For detailed descriptions of the processor 920 and the transceiver 910 , reference may be made to FIG8 or the method embodiments shown above and will not be described in detail here.

[0306] In other embodiments of the present application, the communication device is used to execute the steps, methods, or functions performed by the second communication device described above. For example, the processor 920 can be used to execute the functions or steps implemented by the processing module 801 shown in Figure 8, and the transceiver 910 can be used to execute the functions or steps implemented by the transceiver module 802 shown in Figure 8. For detailed descriptions of the processor 920 and the transceiver 910, please refer to Figure 8 or the method embodiment shown above and will not be described in detail here.

[0307] In various implementations of the communication device shown in FIG9 , the transceiver may include a receiver and a transmitter, wherein the receiver is configured to perform a receiving function (or operation) and the transmitter is configured to perform a transmitting function (or operation). The transceiver is configured to communicate with other devices / devices via a transmission medium.

[0308] Optionally, the communication device 90 may further include one or more memories 930 for storing program instructions and / or data. The memory 930 is coupled to the processor 920. The coupling in the embodiment of the present application is an indirect coupling or communication connection between the communication devices, units or modules, which may be electrical, mechanical or other forms, and is used for information exchange between the communication devices, units or modules. The processor 920 may operate in conjunction with the memory 930. The processor 920 may execute program instructions stored in the memory 930. Optionally, at least one of the above-mentioned one or more memories may be included in the processor.

[0309] The specific connection medium between the transceiver 910, processor 920, and memory 930 is not limited in the embodiments of the present application. In Figure 9, the memory 930, processor 920, and transceiver 910 are connected via a bus 940. The bus is represented by a bold line in Figure 9. The connection methods between other components are only for illustrative purposes and are not limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, Figure 9 only uses a single bold line, but this does not mean that there is only one bus or only one type of bus.

[0310] In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of the present application may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor, etc.

[0311] In the embodiment of the present application, memory may include but is not limited to non-volatile memories such as hard disk drive (HDD) or solid-state drive (SSD), random access memory (RAM), erasable programmable read-only memory (EPROM), read-only memory (ROM) or portable read-only memory (CD-ROM), etc. Memory is any storage medium that can be used to carry or store program code in the form of instructions or data structures, and can be read and / or written by a computer (such as the communication device shown in the present application), but is not limited thereto. The memory in the embodiment of the present application can also be a circuit or other arbitrarily capable of realizing a storage function, for storing program instructions and / or data.

[0312] The processor 920 is primarily used to process communication protocols and communication data, control the entire communication device, execute software programs, and process software program data. The memory 930 is primarily used to store software programs and data. The transceiver 910 may include control circuitry and an antenna. The control circuitry is primarily used to convert baseband signals into radio frequency signals and process radio frequency signals. The antenna is primarily used to transmit and receive radio frequency signals in the form of electromagnetic waves. Input / output devices, such as a touch screen, display, and keyboard, are primarily used to receive user input and output data to the user.

[0313] When the communication device is powered on, the processor 920 can read the software program in the memory 930, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor 920 performs baseband processing on the data to be sent and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 920. The processor 920 converts the baseband signal into data and processes the data.

[0314] In another implementation, the RF circuit and antenna may be provided independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be remotely arranged independent of the communication device.

[0315] The communication device shown in the embodiment of the present application may also have more components than those in Figure 9, and the embodiment of the present application is not limited to this. The method performed by the processor and transceiver shown above is only an example. For the specific steps performed by the processor and transceiver, please refer to the method described above.

[0316] In another possible implementation, in the communication device shown in FIG8 , the processing module 801 may be one or more logic circuits, and the transceiver module 802 may be an input / output interface, or may be called a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver module 802 may be a sending module and a receiving module, the sending module may be an output interface, the receiving module may be an input interface, and the sending module and the receiving module may be integrated into one module, such as an input / output interface. As shown in FIG10 , the communication device shown in FIG10 includes a logic circuit 1001 and an interface 1002. That is, the processing module 801 may be implemented using a logic circuit 1001, and the transceiver module 802 may be implemented using an interface 1002. The logic circuit 1001 may be a chip, a processing circuit, an integrated circuit, or a system-on-chip (SoC) chip, etc., and the interface 1002 may be a communication interface, an input / output interface, a pin, etc. For example, FIG10 is illustrated using the communication device as a chip, and the chip includes a logic circuit 1001 and an interface 1002.

[0317] In the embodiment of the present application, the logic circuit and the interface may also be coupled to each other. The embodiment of the present application does not limit the specific connection method of the logic circuit and the interface. For example, the logic circuit 1001 can be used to perform the functions or steps implemented by the processing module 801 shown in Figure 8, and the interface 1002 can be used to perform the functions or steps implemented by the transceiver module 802 shown in Figure 8. For a specific description of the logic circuit 1001 and the interface 1002, please refer to Figure 8 or the method embodiment shown above, and will not be described in detail here.

[0318] The communication device shown in the embodiment of the present application can implement the method provided in the embodiment of the present application in the form of hardware, or can implement the method provided in the embodiment of the present application in the form of software, etc., and the embodiment of the present application is not limited to this.

[0319] An embodiment of the present application further provides a communication system, which includes a first communication device and a second communication device. The first communication device and the second communication device can be used to execute the method in any of the aforementioned embodiments.

[0320] In addition, the present application also provides a computer program, which is used to implement the operations and / or processing performed by each communication device in the method provided by the present application.

[0321] The present application also provides a computer-readable storage medium having computer code stored therein. When the computer code is run on a computer, the computer executes the operations and / or processing performed by each communication device in the method provided by the present application.

[0322] The present application also provides a computer program product, which includes computer code or computer program. When the computer code or computer program is run on a computer, the operations and / or processes performed by the method provided in the present application are executed.

[0323] In the several embodiments provided in this application, it should be understood that the disclosed systems, communication devices, and methods can be implemented in other ways. For example, the communication device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, communication devices or modules, or can be electrical, mechanical or other forms of connection.

[0324] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of the present application.

[0325] In addition, the functional modules in the various embodiments of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into a single module. The above-mentioned integrated modules may be implemented in the form of hardware or software functional modules.

[0326] If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned readable storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0327] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A satellite communication method, characterized in that, The method is applied to a first communication device, and the method includes: Obtaining channel information between the first communication device and a second communication device; When the channel information meets a first condition, sending first indication information, where the first indication information is used to indicate configuration information of a first reference signal, and the configuration information includes time-domain resources for transmitting the first reference signal, and the time-domain resources include M time-domain units, and M is an integer greater than or equal to 2; Sending the first reference signal, where the phase difference between signals transmitted on adjacent time-domain units among the M time-domain units for transmitting the first reference signal is a first phase offset value.

2. The method according to claim 1, characterized in that, The first phase offset value is adjustable.

3. The method according to claim 1 or 2, characterized in that, The first phase offset value is determined based on the value of the frequency offset that occurs when the signal of the first communication device is transmitted to the second communication device.

4. The method according to any one of claims 1 to 3, characterized in that, Signals transmitted on the same frequency-domain unit corresponding to any two of the M time-domain units are all generated based on the same sequence.

5. The method according to any one of claims 1-4, characterized in that The value of M is determined by the number of first communication devices serving the second communication device for joint transmission.

6. The method according to any one of claims 1-5, characterized in that, That the first indication information is used to indicate the configuration information of the first reference signal includes: the first indication information is used to indicate activating the configuration information of the first reference signal.

7. The method according to any one of claims 1-5, characterized in that, That the first indication information is used to indicate the configuration information of the first reference signal includes: the first indication information is used to indicate the configuration information of the first reference signal within a first time period.

8. The method according to any one of claims 1 to 7, characterized in that, The method further includes: When the channel information meets a second condition, sending second indication information, where the second indication information is used to indicate configuration information of a second reference signal, and the configuration information includes time-domain resources for transmitting the second reference signal, and the time-domain resources include N time-domain units, and N is a positive integer less than or equal to 2; Sending the second reference signal.

9. The method according to claim 8, characterized in that, That the second indication information is used to indicate the configuration information of the second reference signal includes: the second indication information is used to indicate activating the configuration information of the second reference signal.

10. The method according to claim 8, characterized in that That the second indication information is used to indicate the configuration information of the second reference signal includes: the second indication information is used to indicate the configuration information of the second reference signal within a second time period.

11. The method according to any one of claims 1 to 10, characterized in that, When the channel information meets the first condition, sending the first indication information includes: Sending indication information, where the indication information includes the first indication information and the second indication information, the first indication information corresponds to the channel information meeting the first condition, the second indication information corresponds to the channel information meeting the second condition, and the second indication information is used to indicate the configuration information of the second reference signal, and the configuration information includes time-domain resources for transmitting the second reference signal, and the time-domain resources include N time-domain units, and N is a positive integer less than or equal to 2.

12. The method according to any one of claims 8-11, characterized in that, The value of N is determined by the number of antenna ports for sending the second reference signal.

13. The method according to any one of claims 1 to 12, characterized in that The obtaining the channel information between the first communication device and the second communication device includes at least one of the following: Receiving feedback information from the second communication device, where the feedback information is used to indicate the channel information; or, Obtain the channel information based on the location information of the second communication device and the ephemeris information; Or, Obtain the channel information based on the motion information of the second communication device and the ephemeris information.

14. The method according to any one of claims 1 to 13, characterized in that, The channel information includes channel change information, and the channel information satisfying the first condition includes: the channel change information satisfies at least one of the following: The attitude change amount of the second communication device is greater than the change amount threshold; The change in the reference signal received power (RSRP) on different resources for transmitting signals is greater than the RSRP threshold; The reference signal received quality (RSRQ) on different resources for transmitting signals is greater than the RSRQ threshold; The signal-to-noise ratio (SINR) on different resources for transmitting signals is greater than the SINR threshold; The block error rate (BLER) on different resources for transmitting signals is greater than the BLER threshold; The change in throughput on different resources for transmitting signals is greater than the throughput threshold.

15. A satellite communication method, characterized in that, The method is applied to a second communication device, and the method includes: Receive first indication information, where the first indication information is used to indicate the configuration information of a first reference signal, and the configuration information includes the time-domain resources for transmitting the first reference signal. The time-domain resources include M time-domain units, and M is an integer greater than or equal to 2; Receive the first reference signal based on the first indication information. The phase difference between the signals transmitted on adjacent time-domain units among the M time-domain units for transmitting the first reference signal is a first phase offset value; Determine the channel estimation result between the first communication device and the second communication device based on the first reference signal.

16. The method according to claim 15, wherein The first phase offset value is adjustable.

17. The method according to claim 15 or 16, characterized in that, The first phase offset value is determined based on the value of the frequency offset that occurs when the signal of the first communication device is transmitted to the second communication device.

18. The method according to any one of claims 15-17, characterized in that, The signals transmitted on the same frequency-domain unit corresponding to any two of the M time-domain units are all generated based on the same sequence.

19. The method according to any one of claims 15 - 18, characterized in that, The value of M is determined by the number of first communication devices for joint transmission serving the second communication device.

20. The method according to any one of claims 15 - 19, characterized in that, The first indication information for indicating the configuration information of the first reference signal includes: the first indication information is used to indicate the configuration information for activating the first reference signal.

21. The method according to any one of claims 15 - 19, characterized in that, The first indication information for indicating the configuration information of the first reference signal includes: the first indication information is used to indicate the configuration information of the first reference signal within a first time period.

22. The method according to any one of claims 15 - 21, characterized in that, The method further includes: Receive second indication information, where the second indication information is used to indicate the configuration information of a second reference signal, and the configuration information includes the time-domain resources for transmitting the second reference signal. The time-domain resources include N time-domain units, and N is a positive integer less than or equal to 2; Receive the second reference signal.

23. The method according to claim 22, wherein The second indication information for indicating the configuration information of the second reference signal includes: the second indication information is used to indicate the configuration information for activating the second reference signal.

24. The method according to claim 22, wherein The second indication information for indicating the configuration information of the second reference signal includes: the second indication information is used to indicate the configuration information of the second reference signal within a second time period.

25. The method according to any one of claims 15 - 24, characterized in that, The receiving of the first indication information includes: Receive indication information, where the indication information includes first indication information and second indication information, and the second indication information is used to indicate configuration information of a second reference signal. The configuration information includes time-domain resources for transmitting the second reference signal, and the time-domain resources include N time-domain units, where N is a positive integer less than or equal to 2.

26. The method according to any one of claims 22-25, characterized in that, The value of N is determined by the number of antenna ports for transmitting the second reference signal.

27. The method according to any one of claims 15-26, characterized in that, The method further includes: Transmit feedback information, where the feedback information is used to indicate channel information between the first communication device and the second communication device; or, Transmit location information of the second communication device; or, Transmit motion information of the second communication device.

28. A communication device, characterized in that, Includes a module for performing the method according to any one of claims 1-27.

29. A communication device, characterized in that, Includes a processor for performing the method according to any one of claims 1-27.

30. A communication device, characterized in that, Includes a logic circuit and an interface, and the logic circuit and the interface are coupled; The interface is used to input and / or output information, and the logic circuit is used to perform the method according to any one of claims 1-14, or the logic circuit is used to perform the method according to any one of claims 15-27.

31. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program, and when the computer program is executed, the method according to any one of claims 1-27 is executed.

32. A computer program product, characterized in that, When the computer program product is executed, the method according to any one of claims 1-27 is executed.

33. A communication system, characterized in that, The communication system includes a first communication device and a second communication device. The first communication device is used to perform the method according to any one of claims 1-14, and the second communication device is used to perform the method according to any one of claims 15-27.

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