Method for Random Access, Satellite Base Station, Ground Terminal, and Storage Medium

Abstract

The present invention discloses a random access method, a satellite base station, a ground terminal and a storage medium for solving the technical problem that it is difficult for a ground terminal to access a satellite communication system. The method includes the steps of: acquiring a beam type of a current beam and a random access procedure of the current beam from received system broadcast information of a satellite base station; if the beam type of the current beam is an access beam, acquiring a location report mode of the ground terminal; and in the random access procedure of the current beam, reporting location information in the location report mode, where the beam type includes an access beam and a service beam, the location report mode is used to indicate a location report path of the ground terminal, and the location information is used to determine a service beam corresponding to the ground terminal.

Description

Technical Field

[0001] This application claims priority based on a Chinese patent application filed with the Chinese Patent Office on October 26, 2021, with an application number of 202111245889.6 and an invention title of "Method for Random Access, Satellite Base Station, Ground Terminal and Storage Medium", and incorporates all of its disclosures herein.

[0002] The present invention relates to the field of satellite communication, and in particular, to a method for random access, a satellite base station, a ground terminal and a storage medium.

Background Art

[0003] In a satellite communication system (Non-Terrestrial Networks, NTN), in order to improve the efficiency of beam application, the coverage of the access beam often becomes wider. The coverage of the service beam (also called the data service beam) that actually provides services is smaller than this.

[0004] For example, a typical satellite communication system includes two types of beams: an access beam and a service beam. Here, the access beam is used for scheduling the service beam. Since the coverage of a single beam of the satellite is wide, when the position of the NTN ground terminal cannot be obtained, it is difficult for the satellite network to perform beam tracking and scheduling. Under the condition that the coverage area of the initial access beam is wide but the actual coverage area of the service beam is small, the network needs to schedule the service beam to provide services to users. When the satellite cannot obtain the position information of the NTN ground terminal access beam, the satellite cannot accurately schedule a service beam suitable for the NTN ground terminal for subsequent uplink and downlink data transmission.

[0005] In an existing satellite communication system, there is still no regulation on how to notify the position information of an NTN terrestrial terminal. The potential position information reporting modes of an NTN terrestrial terminal may include a Global Navigation Satellite System (GNSS) position information reporting mode, a cell identification reporting mode, and a beam identification reporting mode. However, when the coverage of an access beam is wide and the coverage of a service beam is narrow, the above potential position information reporting modes cannot guarantee the accuracy and reliability of the position of the NTN terrestrial terminal. As a result, the NTN terrestrial terminal cannot accurately access an appropriate service beam, and ultimately leads to a failure in accessing the satellite communication system.

[0006] Therefore, how to enable the NTN terrestrial terminal to accurately access an appropriate service beam has become an urgent technical problem.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention provides a random access method, a satellite base station, a terrestrial terminal, and a storage medium for solving the above technical problems existing in the prior art.

Means for Solving the Problems

[0008] In a first aspect, in order to solve the above technical problems, the random access method provided by an embodiment of the present invention is applied to a terrestrial terminal in a satellite communication system, and the technical solution means of the method are as follows.

[0009] Obtaining a beam type of a current beam and a random access procedure of the current beam from system broadcast information received from a satellite base station; When the beam type of the current beam is an access beam, obtaining a position reporting mode of the terrestrial terminal; In the random access procedure of the current beam, it includes the step of reporting position information in the position reporting mode. The beam type includes an access beam and a service beam. The position reporting mode is used to indicate the position reporting path of the terrestrial terminal. The position information is used to determine the service beam corresponding to the terrestrial terminal.

[0010] In a possible embodiment, the method further includes the step of obtaining the beam configuration information of the current beam; when the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, determining the positioning information of the current position of the terrestrial terminal in another positioning mode other than the GNSS positioning function, and using the service beam index of the service beam corresponding to the index value of the subrange to which the positioning information in the beam configuration information belongs as the position information of the terrestrial terminal; when the terrestrial terminal has the GNSS positioning function, obtaining the GNSS positioning information of the current position of the terrestrial terminal based on the GNSS positioning function, and using the service beam index corresponding to the GNSS positioning information in the beam configuration information as the position information of the terrestrial terminal. When the beam type of the current beam is the access beam, the beam configuration information includes the subranges included in the coverage of the current beam, one or more subranges in the current beam correspond to one service beam in the current beam, and the subranges corresponding to different service beams are different.

[0011] In a possible embodiment, the step of obtaining the position reporting mode of the terrestrial terminal is the step of receiving the first information of the satellite base station; when the first information includes signaling directly indicating the position reporting mode, determining the position reporting mode based on the signaling. When the first information is the random access channel (RACH) configuration information of the current beam, determining the position reporting mode based on whether the RACH configuration parameters associated with the position information exist within the RACH configuration information.

[0012] In a possible implementation, the position reporting mode includes reporting the position in at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

[0013] In a possible implementation, when the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is Message (A-PUSCH) of the two-step random access procedure.

[0014] In a possible implementation, the signaling includes a Master Information Block (MIB) or a System Information Block 1 (SIB1).

[0015] In a possible implementation, the step of determining the position reporting mode based on whether the RACH configuration parameters associated with the position information exist in the RACH configuration information is When there is a RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in a message transmitted by a random access preamble corresponding to the current beam; When there is no RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in an uplink scheduling message corresponding to the current beam.

[0016] In a possible embodiment, the step of reporting the position information in the position reporting mode includes: When it is determined that the position reporting mode is transmission in a message transmitted by the random access preamble, in the random access procedure adopted by the current beam, reporting the position information via a message transmitted by the corresponding random access preamble; When it is determined that the position reporting mode is transmission in the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the position information via the corresponding uplink scheduling message; When it is determined that the position reporting mode is a mode transmitted in both the message transmitted by the random access preamble and the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the position information via each of the message transmitted by the corresponding random access preamble and the uplink scheduling message; When it is determined that the position reporting mode is a mode co-transmitted by a message transmitted by the random access preamble and the uplink scheduling message, the position information is divided into two parts, and in the random access procedure adopted by the current beam, each part of the position information is reported via a message transmitted by the corresponding random access preamble and the uplink scheduling message.

[0017] In a possible embodiment, the step of reporting the position information via a message transmitted by the corresponding random access preamble includes determining a current value of a RACH configuration parameter corresponding to the position information based on a correspondence between each bit or value occupied by the position information and a value of the RACH configuration parameter; and reporting the current value via a message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam.

[0018] In a possible embodiment, the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity (RO) resource, and a preamble index resource of the preamble.

[0019] In a possible embodiment, the preamble index resource includes a one-level preamble index and a multi-level preamble index. The multi-level preamble index includes a plurality of one-level preambles. Each level of the preamble index corresponds to a preamble index range. The preamble index ranges of two adjacent levels of the preamble index may be the same or different and take independent values from each other.

[0020] In a possible implementation, the total number of bits occupied by the position information is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0021] In a possible implementation, when the position information is indicated by the multi-level preamble index, the bits corresponding to the total number of bits or all values of the position information are divided into a plurality of sets based on a preset order, and the plurality of sets correspond one-to-one with the multi-level preamble index. Bits or values of the position information within each set correspond one-to-one with the preamble index among the preamble indexes of the corresponding levels.

[0022] In a possible implementation, the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0023] In a possible implementation, when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries one level of preamble index.

[0024] In a possible implementation, the step of reporting the position information via a corresponding uplink scheduling message is at least one of, or both, the data part of the PUSCH carrying the uplink scheduling message and the PUSCH demodulation reference signal (DMRS) jointly report the position information.

[0025] In a possible implementation, when reporting the position information with the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with all bits occupied by the position information, When the PUSCH DMRS and the data part jointly report the position information, all bits occupied by the position information are divided into two parts based on a preset order, the PUSCH DMRS and the data part respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with the bits occupied by the corresponding part, and the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0026] In a second aspect, an embodiment of the present invention provides a random access method applied to a satellite base station in a satellite communication system, and the method includes: transmitting a system broadcast message so that a ground terminal can determine a beam type of a current beam and a random access procedure of the current beam based on the system broadcast message; when the beam type of the current beam is the access beam, notifying the ground terminal of a position reporting mode for reporting the current position, and the ground terminal adopts the random access method of the first aspect to perform random access to the satellite base station; receiving position information of the current position of the ground terminal in the position reporting mode in the random access procedure of the current beam; scheduling a corresponding service beam of the ground terminal based on the position information, generating and transmitting corresponding service beam configuration information, and controlling the ground terminal to complete a random access procedure within the service beam. The beam type includes an access beam and a service beam.

[0027] In a third aspect, an embodiment of the present invention also provides a ground terminal including a memory, a transceiver, and a memory, a transceiver, and a processor. The memory is configured to store a computer program, the transceiver is configured to transmit and receive data under the control of the processor, and the processor is configured to read the computer program in the memory and execute the following: Obtain the beam type of the current beam and the random access procedure of the current beam from the received system broadcast information of the satellite base station, where the beam type includes an access beam and a service beam. When the beam type of the current beam is an access beam, obtain the position reporting mode of the terrestrial terminal, where the position reporting mode is used to indicate the position reporting path of the terrestrial terminal. In the random access procedure of the current beam, report the position information in the position reporting mode, where the position information is used to determine the service beam corresponding to the terrestrial terminal.

[0028] In a possible embodiment, the processor further Obtain the beam configuration information of the current beam. When the beam type of the current beam is the access beam, the beam configuration information includes the sub-ranges included in the coverage of the current beam. One or more sub-ranges in the current beam correspond to one service beam in the current beam, and the sub-ranges corresponding to different service beams are different. When the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, determine the positioning information of the current position of the terrestrial terminal in another positioning mode other than the GNSS positioning function, and use the service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information belongs as the position information of the terrestrial terminal. When the terrestrial terminal has the GNSS positioning function, obtain the GNSS positioning information of the current position of the terrestrial terminal based on the GNSS positioning function, and use the service beam index corresponding to the GNSS positioning information in the beam configuration information as the position information of the terrestrial terminal.

[0029] In a possible embodiment, the processor further receives first information of the satellite base station, and when the first information includes signaling directly indicating the position reporting mode, determines the position reporting mode based on the signaling, and when the first information is the random access channel (RACH) configuration information of the current beam, determines the position reporting mode based on whether RACH configuration parameters associated with the position information exist within the RACH configuration information.

[0030] In a possible embodiment, the position reporting mode reports the position via at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

[0031] In a possible embodiment, when the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is Message (A-PUSCH) of the two-step random access procedure.

[0032] In a possible embodiment, the signaling includes a master information block MIB or a system message block SIB1.

[0033] In a possible implementation, the processor further When there are RACH configuration parameters associated with the location information in the RACH configuration information, report the location information in a message transmitted by a random access preamble corresponding to the current beam, When there are no RACH configuration parameters associated with the location information in the RACH configuration information, report the location information in an uplink scheduling message corresponding to the current beam.

[0034] In a possible implementation, the processor further When it is determined that the location reporting mode is transmission in a message transmitted by the random access preamble, report the location information via a message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam, When it is determined that the location reporting mode is transmission in the uplink scheduling message, report the location information via the corresponding uplink scheduling message in the random access procedure adopted by the current beam, When it is determined that the location reporting mode is a mode transmitted in a message transmitted by the random access preamble and the uplink scheduling message respectively, report the location information via a message transmitted by the corresponding random access preamble and the uplink scheduling message respectively in the random access procedure adopted by the current beam, When it is determined that the position reporting mode is a mode co-transmitted by a message transmitted by the random access preamble and the uplink scheduling message, the position information is divided into two parts, and in the random access procedure adopted by the current beam, each part of the position information is reported via a message transmitted by the corresponding random access preamble and the uplink scheduling message respectively.

[0035] In a possible implementation, the processor further determines a current value of a RACH configuration parameter corresponding to the position information based on a correspondence between each bit or value occupied by the position information and a value of the RACH configuration parameter, and reports the current value via a message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam.

[0036] In a possible implementation, the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity RO resource, and a preamble index resource of the preamble.

[0037] In a possible implementation, the preamble index resource includes a one-level preamble index and a multi-level preamble index, the multi-level preamble index includes a plurality of one-level preambles, each level of the preamble index corresponds to a preamble index range, and the preamble index ranges of two adjacent levels of the preamble index are the same or different and take independent values from each other.

[0038] In a possible implementation, the position reporting mode of the bits occupied by the position information is that the total number transmitted by the random access preamble is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0039] In a possible implementation, when the position information is indicated by the multi-level preamble index, the bits corresponding to the total number of the bits or all values of the position information are divided into a plurality of sets based on a preset order, and the plurality of sets correspond one-to-one to the multi-level preamble index, and the bits or the values of the position information within each set correspond one-to-one to the preamble index among the preamble indexes of the corresponding level.

[0040] In a possible implementation, the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0041] In a possible implementation, when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries one level of preamble index.

[0042] In a possible implementation, the processor further reports the position information by at least one of the data part of the PUSCH carrying the uplink scheduling message and the PUSCH demodulation reference signal DMRS.

[0043] In a possible implementation, the processor further When reporting the position information by the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one to all the bits occupied by the position information, When the PUSCH DMRS and the data part jointly report the position information, all the bits occupied by the position information are divided into two parts based on a preset order, the PUSCH DMRS and the data part respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one to the bits occupied by the corresponding part, and the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0044] In a fourth aspect, an embodiment of the present invention provides a satellite base station, and the satellite base station includes a memory, a transceiver, and a processor, the memory is configured to store a computer program, the transceiver is configured to transmit and receive data under the control of the processor, and the processor is configured to read the computer program in the memory and execute the following: Transmit a system broadcast message so that the terrestrial terminal can determine the beam type of the current beam and the random access procedure of the current beam based on the system broadcast message, and the beam type includes an access beam and a service beam, When the beam type of the current beam is the access beam, notify the terrestrial terminal of a position reporting mode for reporting the current position, and the terrestrial terminal accesses the satellite base station by the random access method on the terrestrial terminal side, In the random access procedure of the current beam, receive the position information of the current position of the terrestrial terminal in the position reporting mode, Schedule the corresponding service beam of the terrestrial terminal based on the position information, generate and transmit the corresponding service beam configuration information, and control the terrestrial terminal to complete the random access procedure within the service beam.

[0045] In a fifth aspect, an embodiment of the present invention further provides a terrestrial terminal, and the terrestrial terminal is A receiving unit configured to obtain, from the system broadcast information of the received satellite base station, the beam type of the current beam and the random access procedure of the current beam; A transmitting unit configured to report position information in the position reporting mode in the random access procedure of the current beam, and including: The beam type includes an access beam and a service beam; When the beam type of the current beam is an access beam, the receiving unit further obtains the position reporting mode of the terrestrial terminal, and the position reporting mode is used to indicate the position reporting path of the terrestrial terminal; The position information is used to determine a service beam corresponding to the terrestrial terminal.

[0046] In a possible implementation, the receiving unit further: Obtains the beam configuration information of the current beam. When the beam type of the current beam is the access beam, the beam configuration information includes a sub-range included in the coverage of the current beam, and one or more sub-ranges in the current beam correspond to one service beam in the current beam, and sub-ranges corresponding to different service beams are different; When the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, determines positioning information of the current position of the terrestrial terminal in another positioning mode other than the GNSS positioning function, and uses the service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information belongs as the position information of the terrestrial terminal; When the terrestrial terminal has the GNSS positioning function, obtains GNSS positioning information of the current position of the terrestrial terminal based on the GNSS positioning function, and uses the service beam index corresponding to the GNSS positioning information in the beam configuration information as the position information of the terrestrial terminal.

[0047] In a possible implementation, the receiving unit further: Receive the first information of the satellite base station, When the first information includes signaling directly indicating the position reporting mode, determine the position reporting mode based on the signaling, When the first information is the random access channel (RACH) configuration information of the current beam, determine the position reporting mode based on whether the RACH configuration parameters associated with the position information exist within the RACH configuration information.

[0048] In a possible implementation, the position reporting mode reports the position via at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

[0049] In a possible implementation, when the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is Message (A-PUSCH) of the two-step random access procedure.

[0050] In a possible implementation, the signaling includes a master information block MIB or a system message block SIB1.

[0051] In a possible implementation, determining the location reporting mode based on whether there is a RACH configuration parameter associated with the location information in the RACH configuration information specifically includes: When there is a RACH configuration parameter associated with the location information in the RACH configuration information, reporting the location information in a message transmitted by a random access preamble corresponding to the current beam; When there is no RACH configuration parameter associated with the location information in the RACH configuration information, reporting the location information in an uplink scheduling message corresponding to the current beam.

[0052] In a possible implementation, the transmitting unit further When it is determined that the location reporting mode is transmission in a message transmitted by the random access preamble, in the random access procedure adopted by the current beam, reporting the location information via a message transmitted by the corresponding random access preamble; When it is determined that the location reporting mode is transmission in the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the location information via the corresponding uplink scheduling message; When it is determined that the location reporting mode is a mode of being transmitted in both the message transmitted by the random access preamble and the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the location information via the message transmitted by the corresponding random access preamble and the uplink scheduling message respectively; When it is determined that the position reporting mode is a mode co-transmitted by a message transmitted by the random access preamble and the uplink scheduling message, the position information is divided into two parts, and in the random access procedure adopted by the current beam, each part of the position information is reported via a message transmitted by the corresponding random access preamble and the uplink scheduling message respectively.

[0053] In a possible implementation, the transmitting unit further determines a current value of a RACH configuration parameter corresponding to the position information based on a correspondence between each bit or value occupied by the position information and a value of the RACH configuration parameter, and reports the current value via a message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam.

[0054] In a possible implementation, the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity RO resource, and a preamble index resource of the preamble.

[0055] In a possible implementation, the preamble index resource includes a one-level preamble index and a multi-level preamble index, the multi-level preamble index includes a plurality of one-level preambles, each level of the preamble index corresponds to a preamble index range, and the preamble index ranges of two adjacent levels of the preamble index are the same or different and take independent values from each other.

[0056] In a possible implementation, the total number of bits occupied by the position information is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0057] In a possible implementation, when the position information is indicated by the multi-level preamble index, the bits corresponding to the total number of bits or all values of the position information are divided into a plurality of sets based on a preset order, and the plurality of sets correspond one-to-one with the multi-level preamble index, and the bits or the values of the position information within each set correspond one-to-one with the preamble index among the preamble indexes of the corresponding levels.

[0058] In a possible implementation, the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0059] In a possible implementation, when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries one level of preamble index.

[0060] In a possible implementation, the transmitting unit further reports the position information by at least one of the data part of the PUSCH carrying the uplink scheduling message and the PUSCH demodulation reference signal DMRS.

[0061] In a possible implementation, the transmitting unit further when reporting the position information by the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with all the bits occupied by the position information, When the PUSCH DMRS and the data part jointly report the position information, all the bits occupied by the position information are divided into two parts based on a preset order, the PUSCH DMRS and the data part respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with the bits occupied by the corresponding part, and the preset order includes the order from the higher bits to the lower bits of the position information or the order from the lower bits to the higher bits of the position information.

[0062] In a sixth aspect, a satellite base station provided by an embodiment of the present invention A transmission unit 2101 configured to transmit a system broadcast message so that a ground terminal can determine a beam type of a current beam and a random access procedure of the current beam based on the system broadcast message; A receiving unit configured to receive position information of a current position of the ground terminal in the position reporting mode in the random access procedure of the current beam; The beam type includes an access beam and a service beam; When the beam type of the current beam is the access beam, the transmission unit further notifies the ground terminal of a position reporting mode for reporting the current position, and the ground terminal accesses the satellite base station by the random access method on the ground terminal side; The transmission unit further schedules a corresponding service beam of the ground terminal based on the position information, generates and transmits corresponding service beam configuration information, and controls the ground terminal to complete a random access procedure within the service beam.

[0063] In a seventh aspect, an embodiment of the present invention further provides a processor-readable storage medium, on which a computer program is stored, and the computer program is configured to cause the processor to execute the method according to the first aspect or the second aspect.

Advantages of the Invention

[0064] Through the technical solution means in one or more of the above embodiments of the embodiments of the present invention, the embodiments of the present invention have at least the following technical effects.

[0065] According to the embodiment of the present invention, when the current beam received by the ground terminal is an access beam, in the random access procedure of the access beam, the ground terminal reports its position information to the satellite base station according to the mode specified by the satellite base station, and the satellite base station can quickly and accurately obtain the position information of the ground terminal, and allocate an appropriate service beam to the ground terminal according to the position information of the ground terminal, so that the ground terminal can normally access the satellite communication system.

Brief Description of the Drawings

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Embodiments for Carrying out the Invention

[0067] The term "and / or" in the embodiments of the present invention describes the relationship of related objects. For example, A and / or B indicates that there may exist three types of objects: A alone, A and B together, and B alone. The symbol " / " usually indicates that the related objects are in an "or" relationship.

[0068] The term "a plurality" in the embodiments of the present invention refers to two or more, and the same applies to other quantifiers.

[0069] Hereinafter, with reference to the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. It is obvious that the described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are included within the protection scope of the present invention.

[0070] The technical solution provided by the embodiments of the present invention can be applied to various systems, especially 5G systems. For example, applicable systems include global system of mobile communication (GSM) systems, code division multiple access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) general packet radio service (GPRS) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, long term evolution advanced (LTE-A) systems, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) systems, 5G New Radio (NR) systems, and the like. These various systems include terminal devices and network devices. This system can also include a core network part such as an evolved packet system (EPS), 5G system (5GS), and the like.

[0071] The terrestrial terminal included in the embodiments of the present invention is a device with a wireless transceiver function, which can be deployed on land including indoors or outdoors, handheld, wearable, or in-vehicle. Also, the terrestrial terminal can be deployed on water such as a ship. Further, it can also be deployed in the air such as an aircraft, a balloon, or a satellite. The terrestrial terminal may be a mobile phone, a tablet computer (Pad), a computer with a wireless function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal for industrial control, a wireless terminal for self-driving, a wireless terminal for remote medical, a wireless terminal for smart grid, a wireless terminal for transportation safety, a wireless terminal for smart city, or a wireless terminal for smart home that can communicate with a satellite base station.

[0072] The satellite base station according to the embodiments of the present invention can provide a wireless access service to a terrestrial terminal, schedule wireless resources for the accessed terrestrial terminal, and provide a highly reliable wireless transmission protocol and a data encryption protocol.

[0073] Please refer to FIG. 1. FIG. 1 is a diagram showing a four-step random access procedure in a 5G NR system.

[0074] Step 101: The terminal transmits Message 1 (random access preamble) to the base station.

[0075] In step 101, the terminal transmits a random access preamble, also referred to as Message 1 (Msg1), to the base station in the Physical Random Access Channel (PRACH) time-frequency resource. The function of the random access preamble is to notify the base station of a random access request and enable the base station to estimate the transmission delay between the terminal and itself. Thereby, the base station calibrates the uplink timing, and the calibration information is notified to the terminal through a Timing Advance command (TA command).

[0076] Step 102: The base station transmits Message 2 (random access response) to the terminal.

[0077] After detecting the random access preamble, the base station transmits a Random Access Response (RAR), called Message 2 (Msg2), to the terminal in the Physical Downlink Control Channel (PDCCH) / Physical Downlink Shared Channel (PDSCH). The random access response may include the sequence number of the random access preamble received in step 101 above, the TA command, uplink resource allocation information, and a Cell-Radio Network Temporary Identifier (C-RNTI), etc.

[0078] Step 103: The terminal transmits Message 3 (RRC connection request) to the base station.

[0079] After the terminal receives a random access response, if the random access preamble indicated by the sequence number of the random access preamble in the random access response is the same as the random access preamble transmitted by the terminal to the base station in step 101 above, the terminal considers this random access response to be a random access response for the terminal. Thereafter, the terminal transmits an uplink message (RRC connection request), also called message 3 (Msg3), on the uplink resource indicated by the random access response. Here, Msg3 can carry a unique user identifier.

[0080] Step 104: The base station transmits message 4 (contention resolution) to the terminal.

[0081] The base station receives the uplink data of the terminal and returns a contention resolution message, also called message 4 (Msg4), to the terminal that has successfully accessed on the PDSCH. The base station incorporates the unique user identifier included in Msg3 into the contention resolution message to indicate the terminal that has successfully accessed, and other terminals that have not successfully accessed resume random access.

[0082] To reduce access delay and signaling overhead, a two-step random access procedure has also been proposed in the 5G NR system. Figure 2 is a diagram showing the two-step random access procedure in the 5G NR system.

[0083] Step 201: The terminal transmits message A (preamble + data) to the base station.

[0084] Message A (MsgA) includes a MsgA preamble part and a MsgA data part. The preamble is transmitted on the MsgA PRACH physical channel, and the data part is transmitted on the MsgA PUSCH physical channel. The data part may include, for example, a terminal identifier, a Scheduling Request (SR), a small data packet, etc.

[0085] Step 202: The base station transmits Message B (Random Access Response) to the terminal.

[0086] The base station transmits a random access response called Message B (MsgB) to the terminal. The random access response includes a Random Access Preamble ID (RAPID), a TA command, a C-RNTI, etc.

[0087] Figure 3 is a diagram showing the beam coverage of a satellite. In Figure 3, the largest ellipse is the full coverage of the satellite base station, and the dotted ellipse is the coverage of the access beam of the satellite base station. The service beam (also called the data beam) shown in Figure 3 is a small beam directed at a ground terminal, which realizes a beam focusing function and performs data transmission with the ground terminal. Since the coverage of the access beam is larger than that of the service beam, when it is necessary for a ground terminal to transfer to a service beam during an initial access process such as Msg3, the network side cannot schedule and configure the service beam because it does not know the user's location information, the ground terminal cannot accurately access the appropriate service beam, and further cannot access the satellite communication system normally.

[0088] To solve the above technical problems, embodiments of the present invention provide a random access method, a satellite base station, a ground terminal, and a storage medium.

[0089] As shown in FIG. 4, an embodiment of the present invention provides a random access method applied to a ground terminal in a satellite communication system. The processing process of the method is as follows.

[0090] Step 401: Obtain the beam type of the current beam and the random access procedure of the current beam from the system broadcast information received from the satellite base station. Here, the beam type includes an access beam and a service beam.

[0091] The above random access procedure may be the aforementioned four-step random access procedure or a two-step random access procedure, which is specifically determined by the network side. The system broadcast message of the satellite base station includes the beam type of the current beam and the adopted random access procedure. The ground base station can obtain the above information through the obtained system broadcast information.

[0092] After the ground base station obtains the beam type to which the current beam belongs and the adopted random access procedure, step 402 can be executed.

[0093] Step 402: If the beam type of the current beam is an access beam, obtain the position reporting mode of the ground terminal. Here, the position reporting mode is used to indicate the position reporting path of the ground terminal.

[0094] Before or after obtaining the position reporting mode of the terminal, the ground terminal also needs to obtain its position information. This can be achieved by the following means.

[0095] Obtain the beam configuration information of the current beam. Here, when the beam type of the current beam is an access beam, the beam configuration information includes the sub-ranges included in the coverage of the current beam, and one or more sub-ranges in the current beam correspond to one service beam in the current beam, and the sub-ranges corresponding to different service beams are different.

[0096] FIG. 5 is a diagram showing the relationship between the coverage of an access beam and the coverage of a service beam provided according to an embodiment of the present invention.

[0097] FIG. 5 shows the coverage of the access beam (within the thick line). The coverage of the access beam is equally divided into 20 sub-ranges, and the network side can correspond each sub-range to one service beam. In this way, the size of the coverage of the service beam is the size of one sub-range (as shown in the lower left of FIG. 5). When the range that can be covered by the service beam is larger than the size of one sub-range, an area composed of a plurality of consecutive sub-ranges can be regarded as the coverage of one service beam (as shown in the range surrounded by the dotted line in the lower right of FIG. 5).

[0098] When the beam type of the current beam is an access beam, the relationship between the coverage of the access beam and the coverage of the service beam is included in the beam configuration information of the current beam. After acquiring the above beam configuration information, the terrestrial terminal can determine the position information of the terrestrial terminal by combining its positioning information. According to the accuracy of the position information, the terrestrial terminal can determine the position information in the following mode.

[0099] The first type of positioning mode: When the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function (that is, accurate positioning information cannot be obtained), the positioning information of the current position of the terrestrial terminal is determined in another positioning mode other than the GNSS positioning function. The service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information belongs is adopted as the position information of the terrestrial terminal.

[0100] The above-mentioned other positioning mode, for example, obtains position information with the help of sensors, WiFi, etc., and determines a sub-range corresponding to the positioning information based on the above beam configuration information. The service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information of the current beam belongs is adopted as the position information of the ground terminal for reporting.

[0101] Second positioning mode: When the ground terminal has a GNSS positioning function, based on the GNSS positioning function, the GNSS positioning information of the current position of the ground terminal is obtained, and from the beam configuration information, the service beam index corresponding to the GNSS positioning information is determined as the position information of the ground terminal.

[0102] In the embodiment provided by the present invention, the positioning information of the ground terminal is obtained, and based on the positioning information and the beam configuration information of the current beam, the service beam index of the service beam corresponding to the position of the ground terminal is determined, and the service beam index is used as the position information of the ground terminal for reporting, so that the data transmission volume can be reduced, which is suitable for reporting on the access beam, and the network side can accurately allocate an appropriate service beam to the ground terminal.

[0103] After or before the ground terminal determines its position information, the ground terminal obtains its position reporting mode of the position information in the following mode.

[0104] When receiving the first information of the satellite base station and the first information includes signaling directly indicating the position reporting mode, based on the signaling (corresponding to explicit signaling), the position reporting mode is determined. When the first information is the random access channel (RACH) configuration information of the current beam (corresponding to implicit signaling), the position reporting mode is determined based on whether there is a RACH configuration parameter associated with the position information in the RACH configuration information.

[0105] The above signaling includes a Master Information Block (MIB) or a System Information Block 1 (SIB1).

[0106] The above location reporting mode reports the location by at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by a Physical Uplink Shared Channel (PUSCH).

[0107] For example, the network side instructs the terrestrial terminal to report the address information in the message transmitted by the random access preamble via the MIB, and the terrestrial terminal determines, based on the obtained MIB, that the location reporting mode is a mode in which the address information is reported by the message transmitted by the random access preamble.

[0108] As another example, the network side instructs the terrestrial terminal to report the address information via the SIB by the message transmitted by the random access preamble and the uplink scheduling message carried by the PUSCH. Then, the terrestrial terminal determines, based on the obtained SIB, that the location reporting mode is a mode in which the address information is reported by the message transmitted by the random access preamble and the uplink scheduling message carried by the PUSCH.

[0109] In a possible implementation, based on whether there is a RACH configuration parameter associated with the location information in the RACH configuration information, the location reporting mode is determined in the following manner.

[0110] If there is a RACH configuration parameter associated with the location information in the RACH configuration information, the location information is reported by the message transmitted by the random access preamble corresponding to the current beam.

[0111] When there is no RACH configuration parameter associated with the location information in the RACH configuration information, the location information is reported in the uplink scheduling message corresponding to the current beam.

[0112] The RACH configuration parameter includes at least one of a Physical Random Access Channel (PRACH) format, a Random Access Opportunity (RO) resource, and a preamble index resource of a preamble.

[0113] The preamble index resource includes a single-level preamble index and a multi-level preamble index. Here, the multi-level preamble index includes a plurality of single-level preambles. Each level of the preamble index corresponds to a preamble index range. The preamble index ranges of two adjacent levels of preamble indexes may be the same or different and take independent values from each other.

[0114] For example, the network side includes a RACH configuration parameter associated with the location information in the RACH configuration information. The terrestrial terminal implicitly determines that the location reporting mode is a mode in which the location information is reported in a message transmitted by a random access preamble based on the RACH configuration information. When the RACH configuration information received by the terrestrial terminal does not include a RACH configuration parameter, it is implicitly / indirectly determined that the location reporting mode is a mode in which the location information is reported in an uplink scheduling message.

[0115] When the random access procedure corresponding to the current beam is a four-step random access procedure or a two-step random access procedure, the different location reporting modes use different messages in the random access procedure as follows.

[0116] When the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure.

[0117] For example, when the ground terminal determines that the beam type of the current beam is an access beam, the random access procedure used is a four-step random access procedure, the position reporting mode specified by the network side is the mode reported by the message transmitted by the random access preamble, and the ground terminal reports its position information in Message 1 of the four-step random access procedure.

[0118] When the random access procedure adopted by the current beam is a two-step random access procedure, the message carried by the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carried by the uplink scheduling is Message A - PUSCH of the two-step random access procedure.

[0119] For example, when the ground terminal determines that the beam type of the current beam is an access beam, the random access procedure used is a two-step random access procedure. The position reporting mode specified by the network side is the mode reported by the uplink scheduling message carried by the PUSCH, and the ground terminal reports its position information through Message A - PUSCH of the two-step random access procedure.

[0120] In the case of a ground terminal, the following cases can be considered for the position reporting mode of the ground terminal.

[0121] The first mode: The position information is reported in Message 1 (Msg1) of the four-step random access procedure.

[0122] Second mode: The location information is reported in Message 3 (Msg3) of the four-step random access procedure.

[0123] Third mode: The location information is reported in Message A-PRACH (MsgA-PRACH) of the two-step random access procedure.

[0124] Fourth mode: The location information is reported in Message A-PUSCH (MsgA-PUSCH) of the two-step random access procedure.

[0125] Fifth mode: The location information is reported in Msg1 and Msg3 of the four-step random access procedure respectively (i.e., the same location information is reported).

[0126] Sixth mode: The location information is reported in MsgA-PRACH and MsgA-PUSCH of the two-step random access procedure respectively (i.e., the same location information is reported).

[0127] Since the location information is reported in two different messages in the same random access procedure, the reliability of the location information reporting is improved, and the network side can obtain the location information of the terrestrial terminal.

[0128] Seventh mode: The location information is reported jointly by Msg1 and Msg3 of the four-step random access procedure (i.e., different parts of the location information are reported).

[0129] Eighth mode: The location information is reported jointly by MsgA-PRACH and MsgA-PUSCH of the two-step random access procedure (i.e., different parts of the location information are reported).

[0130] In the random access procedure, when reporting the location information jointly by two pieces of information, the location information data can be divided into two parts, and one part can be reported in each of the two pieces of information.

[0131] When notifying the location information of the terrestrial terminal in a batch using two messages, the location information may be divided into two parts, and may be divided at a preset ratio, or the network side may notify the ratio divided through the broadcast channel, and the terrestrial terminal divides the location information into two parts at the preset ratio or the notified ratio, and may notify each of the two messages.

[0132] For example, the instruction received by the terrestrial terminal is to report the location information using the case of the above seventh mode. The location information occupies a total of 10 bits, and the preset ratio is 0.6. And the bit data corresponding to the location information is divided into the data of the first 6 bits and the data of the last 4 bits. The first 6 bits of the data are reported through Msg1, and the last 4 bits of the data are reported through Msg3.

[0133] In the same random access procedure, in order to jointly report the location information using two messages, the amount of data transmitted by each message can be reduced, so that the network side can quickly obtain the location information of the terrestrial terminal. Also, by jointly reporting the location information with two messages, it is possible to report high-precision location information with a larger amount of data, and the network side can obtain more accurate location information.

[0134] After the terrestrial terminal obtains its location reporting mode and location information, the terrestrial terminal can execute step 403.

[0135] Step 403: In the random access procedure of the current beam, report the location information in the location reporting mode, and the location information is used to determine the service beam corresponding to the terrestrial terminal.

[0136] In an embodiment provided by the present invention, when the current beam received by the ground terminal is an access beam, in the random access procedure of the access beam, the ground terminal reports its location information to the satellite base station according to the mode specified by the satellite base station. Thereby, the satellite base station can quickly and accurately obtain the location information of the ground terminal, allocate an appropriate service beam to the ground terminal according to the location information of the ground terminal, enable the ground terminal to accurately access the appropriate service beam, and enable the ground terminal to normally access the satellite communication system.

[0137] The ground terminal uses the location reporting mode instructed by the satellite base station to report the location information as follows.

[0138] If it is determined that the location reporting mode is transmitted by a message carried by a random access preamble, the location information is reported by a message carried by the corresponding random access preamble in the random access procedure adopted by the current beam. If it is determined that the location reporting mode is transmitted by an uplink scheduling message, the location information is reported by the corresponding uplink scheduling message in the random access procedure adopted by the current beam. If it is determined that the location reporting mode is transmitted by a random access preamble message and an uplink scheduling message respectively, the location information is reported by the message carried by the corresponding random access preamble and the uplink scheduling message respectively in the random access procedure adopted by the current beam. When it is determined that the location reporting mode is a mode in which it is transmitted jointly with a random access preamble message and an uplink scheduling message, the location information is divided into two parts, and each part of the location information is reported by the message transmitted by the corresponding random access preamble and the uplink scheduling message, respectively, in the random access procedure adopted by the current beam.

[0139] For example, when the location reporting mode indicated by the satellite base station is the one transmitted by the uplink scheduling message, if the random access procedure used is a four-step random access procedure, the terrestrial terminal reports the address information with the address information in message 3 of the four-step random access procedure. If the random access procedure used is a two-step random access procedure, the terrestrial terminal reports the address information with the message A-PUSCH of the two-step random access procedure.

[0140] When the location reporting mode indicated by the satellite base station is a mode transmitted by the message transmitted by the random access preamble, if the random access procedure used is a four-step random access procedure, the terrestrial terminal reports the address information with message 1 of the four-step random access procedure. If the random access procedure used is a two-step random access procedure, the terrestrial terminal reports the address information with the message A-PRACH of the two-step random access procedure.

[0141] When the location reporting mode indicated by the satellite base station is a mode in which it is transmitted in each of the random access preamble message and the uplink scheduling message, if the random access procedure used is a four-step random access procedure, the terrestrial terminal reports the complete address information in message 1 and message 3 of the four-step random access procedure respectively. If the random access procedure used is a two-step random access procedure, the terrestrial terminal reports the complete address information in message A-PRACH and message A-PUSCH of the two-step random access procedure respectively.

[0142] When the location reporting mode indicated by the satellite base station is transmitted jointly in the random access preamble message and the uplink scheduling message, the terrestrial terminal divides the location information into two parts (part A and part B). If the random access procedure used is a four-step random access procedure, part A in the location information is reported in message 1 of the four-step random access procedure, and part B in the address information is reported in message 3. If the random access procedure used is a two-step random access procedure, the terrestrial terminal reports part A in the location information in message A-PRACH of the two-step random access procedure, and reports part B in the address information in message A-PUSCH.

[0143] When the terrestrial terminal reports the address information or a part of the information in message A-PUSCH, the address information may be directly reported in the data part of message A-PUSCH, or the address information may be indirectly reported in the PUSCH DMRS of message A-PUSCH. For example, among the bits corresponding to the location information, different bits correspond to different scrambling sequences of PUSCH DMRS.

[0144] In the above reporting mode, when the ground terminal reports using the data part of Message 3 and Message A-PUSCH, the reporting mode belongs to explicit reporting (i.e., the location information of the ground terminal is directly reported). Other modes belong to implicit reporting (i.e., the location information of the ground terminal is indirectly reported through other information). When implicit reporting is used, since the location information of the ground terminal is indirectly reported using other information without transmitting the bit data of the actual location information, the data transmission volume can be effectively saved.

[0145] In a possible embodiment, the location information is reported as follows via a message transmitted by a corresponding random access preamble.

[0146] Based on the correspondence between each bit or value occupied by the location information and the value of the RACH configuration parameter, determine the current value of the RACH configuration parameter corresponding to the location information, and report the current value in the message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam.

[0147] For example, when the RACH parameter is the RO resource and the total number of bits occupied by the location information is 10 bits, the network side pre-defines the correspondence between the 10 bits occupied by the location information and the RO resource as shown in FIG. 6. FIG. 6 is a diagram showing the correspondence between the bits of the location information and the RO resource provided by an embodiment of the present invention. The RO resource in FIG. 6 includes RO indexes RO#0 to RO#9 that correspond one-to-one with the 10 bits corresponding to the location information. When the binary data of the location information is 0000100100, it can be determined through the above correspondence that RO indexes: RO#4 and RO#7 (recorded as the current values corresponding to the RO resource) are required. And since RO#4 and RO#7 are used in Message 1 of the four-stage random access procedure of the current beam, the network side can determine that the location information of the ground terminal is 0000100100.

[0148] Also, the possible values of the location information include 0 to 7, and the RACH parameter is the RO resource (RO#0 to RO#7). FIG. 7 is a diagram showing the correspondence between the value of the location information and the RO resource provided according to an embodiment of the present invention. The RO resources in FIG. 7 include RO indexes: RO#0 to RO#7, and RO#0 to RO#7 correspond one-to-one with eight possible values (0 to 7, and these values are service beam indexes) corresponding to the location information. When the terrestrial terminal determines that the location information is 5, RO#5 is used in message 1 of the four-stage random access procedure of the current beam, and the satellite base station can determine that the location information of the terrestrial base station is 5.

[0149] In a possible embodiment, the total number of bits transmitted by the random access preamble for the location reporting mode occupied by the location information is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0150] In an embodiment of the present invention, since the service beam index used when the terrestrial terminal reports the location information and the total number of service beams included in one access beam are usually fixed, the total number of bits occupied by the location information is determined based on the total number of service beams included in the access beam. Assuming that the total number of service beams included in one access beam is R, the total number of bits (denoted as M) occupied by the location information is obtained by the following formula: M = log2(R).

[0151] For example, assuming that there are eight service beams in one access beam of the satellite base station, according to the above formula, it is obtained that the total number of bits occupied by the location information is M = log2(8) = 3.

[0152] Assuming that the RACH configuration parameter is a single-level preamble index, the network side can pre-define the correspondence between 3-bit location information and three single-level preamble indexes. FIG. 8 is a diagram showing the correspondence between the bits of the location information provided according to an embodiment of the present invention and the single-level preamble index. Preamble index 0 to preamble index 2 correspond one-to-one with bit0 to bit2 of the location information. The satellite base station notifies the terrestrial base station of the above correspondence through system broadcast or signaling, and when the terrestrial terminal reports location information, it can report the location information by using the single-level preamble index in Msg1 according to the above correspondence.

[0153] In a possible embodiment, when the location information is indicated by a multi-level preamble index, the bits corresponding to the total number of bits or all values of the location information are divided into multiple sets based on a pre-set order, and the multiple sets correspond one-to-one with the multi-level preamble index. The bits or the values of the location information within each subset correspond one-to-one with the preamble index among the preamble indexes of the corresponding level. Here, the pre-set order includes the order from the most significant bit to the least significant bit of the location information or the order from the least significant bit to the most significant bit of the location information.

[0154] For example, if the total number of bits occupied by the location information is 12 bits, the multi-level preamble index is a two-level preamble index, and the pre-set order is from the least significant bit to the most significant bit, the above 12 bits are divided into two sets in order from the least significant bit to the most significant bit, and each set contains 6 bits. The above two sets correspond one-to-one with the two single-level preamble indexes within the two-level preamble index. Since each single-level preamble index contains six preambles, the six bits within each set correspond one-to-one with the six preambles within the corresponding single-level preamble.

[0155] As another example, the possible values of the location information are from 1 to 8. Let 1 to 4 be set A and 5 to 8 be set B. Among the two-level preamble indexes, the four preamble indexes included in one-level preamble index correspond one-to-one to the four values in set A, and the four preamble indexes included in the other one-level preamble correspond one-to-one to the four values in set B, where set B corresponds one-to-one to the four values in set A.

[0156] FIG. 9 is a diagram showing the correspondence between the bits of the location information provided according to an embodiment of the present invention and the two-level preamble index. The 12 bits occupied by the location information in FIG. 9 are divided into two sets (set 1 and set 2). Set 1 includes bit0 to bit5, and set 2 includes bit6 to bit11. Set 1 and set 2 respectively correspond one-to-one to two one-level preamble indexes in the two-level preamble index. The 6 bits (bit0 to bit5) in set 1 correspond one-to-one to the six preamble indexes (preamble index 0 to preamble index 5) in one-level preamble index 1, and the six bits (bit6 to bit11) in set 2 correspond one-to-one to the six preamble indexes (preamble index 0 to preamble index 5) in one-level preamble index 2.

[0157] In the embodiment provided by the present invention, the preamble indexes belonging to different one-level preamble indexes in the multi-level preamble index may be the same or different, and the details are not limited.

[0158] In the embodiment provided by the present invention, in addition to the indirect indication via a single RACH configuration parameter, the location information can also be jointly indicated via a plurality of RACH configuration parameters. When the location information is jointly indicated by the RO resource and the preamble index resource, one RO carries one-level preamble index.

[0159] The location information may be jointly indicated by the RO resource and the preamble index resource, or by the RO resource and the one-level preamble index, or by the RO resource and the multi-level preamble index.

[0160] FIG. 10 is a diagram showing the correspondence between the RO resource provided by an embodiment of the present invention and the one-level preamble index jointly indicating the location information.

[0161] FIG. 10 shows two ROs (RO#0, RO#1), each RO carrying six preamble indexes. The six preamble indexes carried by RO#0 correspond one-to-one to bits 0 to 5 of the location information, and the six preamble indexes carried by RO#1 correspond one-to-one to bits 6 to 11 of the location information.

[0162] Using the correspondence shown in FIG. 10, the ground terminal can jointly indicate the location information with RO#0, RO#1 (RO resources) and the one-level preamble index.

[0163] FIG. 11 is a diagram showing the correspondence between the RO resource provided by an embodiment of the present invention and the two-level preamble index jointly indicating the location information.

[0164] FIG. 11 shows two ROs (RO#0, RO#1), each RO carrying a two-level preamble index. The two preamble indexes (index0, index1) at each level of the preamble index in the two-level preamble index carried by RO#0 correspond one-to-one to two bits of the location information. When the ground terminal reports the location information, the network side can notify the ground terminal of the correspondence formed in FIG. 11. In this case, the above correspondence is jointly reported by the RO and the two-level preamble index.

[0165] In a possible embodiment, the location information is reported as follows via a corresponding uplink scheduling message.

[0166] Report the location information in at least one of the data part of the PUSCH carrying the uplink scheduling message and the PUSCH demodulation reference signal DMRS, or jointly report the location information in both.

[0167] When the location information is reported terrestrially through an uplink scheduling message, the random access procedure used by the current beam may be a four-step random access procedure or a two-step random access procedure. Thus, the above reporting modes are as follows.

[0168] Mode 1: In a four-step random access procedure, use the data part of the PUSCH in Msg3 to carry the above location information (explicit reporting mode).

[0169] Mode 2: In a four-step random access procedure, use the PUSCH DMRS in Msg3 to carry the above location information (implicit reporting mode).

[0170] Mode 3: In a four-step random access procedure, jointly report the above location information with the data part of the PUSCH and the PUSCH DMRS in Msg3. That is, use the data part of the PUSCH to explicitly report the data corresponding to some bits of the location information, and use the PUSCH DMRS to implicitly report the data corresponding to the remaining bits of the location information.

[0171] Mode 4: In a two-step random access procedure, use the data part of the PUSCH in MsgB to carry the above location information (explicit reporting mode).

[0172] Mode 5: In a two-step random access procedure, use the PUSCH DMRS in MsgB to carry the above location information (implicit reporting mode).

[0173] Mode 6: In the two-step random access procedure, the above location information is jointly reported using the data part of the PUSCH of MsgB and the PUSCH DMRS. The data part of the PUSCH is used to explicitly report the data corresponding to some bits of the location information, and the PUSCH DMRS is used to implicitly report the data corresponding to the remaining bits of the location information.

[0174] For example, taking the four-step random access procedure adopted by the current beam as an example, the above location information can be used as data. In the four-step random access procedure, it may be reported in the data part of the PUSCH of Msg3 or implicitly reported in the PUSCH DMRS of Msg3.

[0175] FIG. 12 is a diagram showing the correspondence between the bits of the location information provided by an embodiment of the present invention and the scrambling sequence of the PUSCH DMRS.

[0176] In FIG. 12, taking the case where the total number of bits of the location information is 8 as an example, the eight bits (bit0 to bit7) correspond one-to-one to the eight scrambling sequences (S0 to S7) of the PUSCH DMRS. When the terrestrial terminal reports the location information, based on the above correspondence, the indirect reporting of the location information can be completed by scrambling using the corresponding scrambling sequence.

[0177] When jointly reporting the location information using the PUSCH DMRS and the data part, all the bits occupied by the location information are divided into two parts based on a preset order. The PUSCH DMRS and the data part respectively correspond to one of the two parts, and the scrambling sequence of the PUSCH DMRS corresponds one-to-one to the bits occupied by the corresponding part. Here, the preset order includes the order from the higher bits to the lower bits of the location information or the order from the lower bits to the higher bits of the location information.

[0178] FIG. 13 is a diagram showing the correspondence between the bits of the position information provided by an embodiment of the present invention, the bits of the data part of the PUSCH, and the scrambling sequences of the PUSCH DMRS.

[0179] Taking the case where the total number of bits of the position information is 8 as an example, the terrestrial terminal divides the 8 bits into two sets. For the specific division method, the aforementioned division method can be referred to. Two sets (Set 1: bit0~bit1, Set 2: bit2~bit7) are obtained. Among them, the 2 bits of Set 1 correspond one-to-one to the 2 bits of the data part of the PUSCH, and the 6 bits of Set 2 correspond one-to-one to the 6 scrambling sequences (S0~S5) of the PUSCH DMRS. When reporting the position information, the terrestrial terminal can perform scrambling using the 2 bits of the data part of the PUSCH and the corresponding scrambling sequences of the PUSCH DMRS based on the above correspondence relationship, and jointly report the position information.

[0180] It should be understood that in the embodiment provided by the present invention, the bits corresponding to the bits of the position information in the data part of the PUSCH may be continuous or discontinuous. The scrambling sequences corresponding to the bits of the position information in the scrambling sequences of the PUSCH DMRS may be continuous or discontinuous, but are not limited here.

[0181] When the random access procedure adopted by the current access beam is a two-stage random access procedure, since the corresponding modes of Mode 4~Mode 6 are the same as those of Mode 1~Mode 3, the details will not be repeated.

[0182] After the terrestrial terminal has completed reporting the location information according to any of the above modes, the satellite base station receives the above location information in the corresponding message of the corresponding random access procedure, and then adapts the service beam corresponding to the terrestrial terminal based on the received location information of the terrestrial terminal. The satellite base station transmits the relevant configuration information of the service beam to the terrestrial terminal in Msg2 or Msg4 or MsgA, and the terrestrial terminal completes the random access procedure of the service beam based on the relevant configuration information of the service beam.

[0183] The correspondence between the bits of the location information shown in FIGS. 8 to 13 and each RACH configuration parameter can be changed to the correspondence between the value of the location information and each RACH configuration parameter, which is similar to FIG. 7 as follows, and the details will not be repeated.

[0184] In the embodiments provided by the present invention, in addition to the correspondence between the value of the location information and the value of the RACH configuration parameter, the positioning information of the terrestrial terminal is used to determine the location information of the terrestrial terminal, and the location information is implicitly reported using minimal resources during reporting.

[0185] The above mainly describes the random access method of the terrestrial terminal side to the satellite communication system. Next, the satellite base station side will be described.

[0186] Based on the same inventive concept, embodiments of the present invention provide a random access method applicable to a satellite base station of a satellite communication system. As shown in FIG. 14, this method includes the following steps.

[0187] Step 1401: Transmit a system broadcast message so that the terrestrial terminal determines the beam type of the current beam and the random access procedure of the current beam based on the system broadcast message. Here, the beam type includes an access beam and a service beam.

[0188] Step 1402: If the beam type of the current beam is an access beam, notify the terrestrial terminal to report the location reporting mode of the current position. Here, the terrestrial terminal accesses the satellite base station by adopting the above random access method on the terrestrial terminal side.

[0189] Step 1403: In the random access procedure of the current beam, receive the location information of the current position of the terrestrial terminal in the location reporting mode.

[0190] Step 1404: Schedule the corresponding service beam for the terrestrial terminal based on the location information, generate and send the corresponding service beam configuration information, and control the terrestrial terminal to complete the random access procedure in the service beam.

[0191] In the current beam, the broadcast information transmitted by the satellite base station includes the beam type of the current beam and the adopted random access procedure. The random access procedure may be a four-step random access procedure or a two-step random access procedure.

[0192] The above beam type can be an access beam or a service beam. If the beam type of the current beam is an access beam, the satellite base station further notifies the terrestrial terminal of the location reporting mode to be used for reporting the location information of the current position of the terrestrial terminal. The notification may be directly performed through signaling directly indicating an unknown reporting mode, or indirectly performed through implicit signaling (for example, whether there are RACH configuration parameters associated with the location information in the RACH configuration information). For the specific solution means of the above location reporting mode, reference can be made to the relevant description of the terrestrial terminal mentioned above, and it will not be repeated here.

[0193] The terrestrial terminal determines that the beam type of the current beam is an access beam, determines the adopted random access procedure and the position reporting mode, and uses the random access method on the terrestrial base station side to complete the position information reporting. The satellite base station receives the position information of the current position of the terrestrial terminal in the position reporting mode in the random access procedure of the current beam, schedules the corresponding service beam for the terrestrial terminal based on the position information, generates and transmits the corresponding service beam configuration information, and controls the terrestrial terminal to complete the random access procedure in the service beam.

[0194] In order for those skilled in the art to fully understand the solution, the following examples are shown.

[0195] Assume that the current beam A transmitted by the satellite base station is an access beam, the adopted random access procedure is a four-step random access procedure GA4, and the specified position reporting mode is the mode of reporting the message transmitted by the random access preamble. FIG. 15 is a schematic diagram of the interaction between the satellite base station and the terrestrial terminal in the four-step random access procedure provided by the embodiment of the present invention.

[0196] Step 1501: Transmit a system broadcast message.

[0197] The satellite base station transmits system broadcast information including the beam type of the current beam, which is an access beam, and the adopted random access procedure, which is a four-step random access procedure, and the position reporting mode (reported in Msg1) of the position information of the terrestrial terminal is further included in the system broadcast information.

[0198] Based on the system broadcast information, determine that the beam type of the current beam is an access beam, use the four-step random access procedure, report the position information in Msg1, and obtain the position information.

[0199] After receiving the system broadcast information, the terrestrial terminal determines that the beam type of the current beam is an access beam based on the system broadcast information, and uses a four-step random access procedure to confirm that it reports the location information in Msg1.

[0200] Also, if the beam configuration information of the current beam is stored in the terrestrial terminal, there is no need to obtain it again. If the beam configuration information of the current beam is not stored, it is necessary to obtain it. When the satellite base station notifies the terrestrial terminal through signaling directly indicating the location reporting mode, the terrestrial terminal directly obtains the location reporting mode through the signaling. When the satellite base station notifies the terrestrial terminal through implicit signaling indirectly indicating the location reporting mode, the terrestrial terminal obtains the location reporting mode through the implicit signaling. The above beam configuration information includes all sub-ranges included in the coverage of the current beam. One or more sub-ranges within the current beam correspond to one service beam of the current beam, and the sub-ranges corresponding to different service beams are different.

[0201] Assuming that the terrestrial terminal has a GNSS positioning function, the terrestrial terminal obtains the GNSS location information of its current location, determines the service beam index corresponding to the GNSS location information based on the above beam configuration information, and uses the determined service beam index as the location information of the terrestrial terminal.

[0202] According to the correspondence relationship between the location information and the preamble index resource, the preamble index corresponding to the location information is determined.

[0203] Step 1503: Transmit the preamble index corresponding to the location information in Msg1.

[0204] The terrestrial terminal transmits the determined preamble index to the satellite base station in Msg1.

[0205] Step 1504: Determine the location information corresponding to the received preamble index, allocate a service beam corresponding to the location information to the ground terminal, and generate corresponding service beam configuration information.

[0206] After receiving the preamble index, the satellite base station determines the corresponding location information based on the correspondence between the location information and the preamble index resource, allocates a service beam corresponding to the ground terminal based on the location information, and generates corresponding service beam configuration information.

[0207] Step 1505: Transmit the service beam configuration information in Msg2.

[0208] The satellite base station transmits the service beam configuration information to the ground terminal in Msg2 (or Msg4).

[0209] In addition, the ground terminal also needs to complete the four-step random access procedure (Msg3, Msg4) of the access beam.

[0210] Step 1506: Receive the downlink SSB signal of the service beam based on the service beam configuration information.

[0211] After the ground terminal completes the four-step random access procedure of the access beam and obtains the service beam configuration information, the ground terminal can receive the downlink synchronization signal block (Synchronization Signal and PBCH block, SSB) signal of the service beam based on the service beam configuration information and complete the four-step random access procedure (Msg1~Msg4) of the service beam.

[0212] Assume that the current beam transmitted by the satellite base station is the access beam, the adopted random access procedure is a two-step random access procedure, the specified position reporting mode is the mode reported by the uplink scheduling message carried by the PUSCH, and the RACH configuration parameter used is the RO resource. FIG. 16 is a schematic diagram of the interaction between the satellite base station and the terrestrial terminal in the two-step random access procedure provided by an embodiment of the present invention.

[0213] Step 1601: Transmit a system broadcast message.

[0214] The satellite base station transmits system broadcast information including the beam type of the current beam, which is the access beam, and the adopted random access procedure, which is a two-step random access procedure, to the terrestrial terminal. The system broadcast information further includes the position reporting mode (reported by MsgA PUSCH) of the position information of the terrestrial terminal.

[0215] Step 1602: Based on the system broadcast information, determine that the beam type of the current beam is the access beam, 2 Use the two-step random access procedure, report the position information by MsgA PUSCH, and obtain the position information.

[0216] After receiving the above system broadcast information, the terrestrial terminal determines, based on the system broadcast information, that the beam type of the current beam is the access beam, adopts a two-step random access procedure, and reports the position information by the uplink scheduling message corresponding to MsgA PUSCH.

[0217] In the two-step random access procedure, the method for the terrestrial terminal to obtain its position information is similar to that in the case of the two-step random access procedure, so it will not be repeated here.

[0218] The terrestrial terminal determines the RO corresponding to the location information based on the correspondence between the location information and the RO resources.

[0219] Step 1603: Msg A PUSCH and transmits the RO corresponding to the location information.

[0220] The terrestrial terminal transmits the determined preamble index to the satellite base station in Msg1.

[0221] Step 1604: Determine the RO corresponding location information, allocate a service beam corresponding to the location information to the terrestrial terminal, and generate corresponding service beam configuration information.

[0222] After receiving the above preamble index, the satellite base station determines the corresponding location information based on the correspondence between the location information and the preamble index resources, allocates a service beam corresponding to the terrestrial terminal based on the location information, and generates corresponding service beam configuration information.

[0223] Step 1605: Msg B and transmits the service beam configuration information.

[0224] The satellite base station transmits the above service beam configuration information to the terrestrial terminal in MsgB.

[0225] The terrestrial terminal completes the two-step random access procedure of the access beam.

[0226] Step 1606: Receive the downlink SSB signal of the service beam based on the service beam configuration information.

[0227] After completing the two-step random access procedure of the access beam and obtaining the service beam configuration information, the terrestrial terminal receives the SSB signal of the service beam based on the service beam configuration information, and can complete the two-step random access procedure of the service beam.

[0228] As shown in FIG. 17, the ground terminal provided by the embodiment of the present invention includes a memory 1701, a transceiver 1702, and a processor 1703.

[0229] The memory 1701 is configured to store a computer program. The transceiver 1702 is configured to transmit and receive data under the control of the processor 1703.

[0230] The processor 1703 is configured to read the computer program in the memory 1701 and execute the following: Obtain the beam type of the current beam and the random access procedure of the current beam from the received system broadcast information of the satellite base station. The beam type includes an access beam and a service beam. When the beam type of the current beam is an access beam, obtain the position reporting mode of the ground terminal. The position reporting mode is used to indicate the position reporting path of the ground terminal. In the random access procedure of the current beam, report the position information in the position reporting mode. The position information is used to determine the service beam corresponding to the ground terminal.

[0231] In a possible implementation, the processor 1703 further Obtain the beam configuration information of the current beam. When the beam type of the current beam is the access beam, the beam configuration information includes the sub-ranges included in the coverage of the current beam. One or more sub-ranges in the current beam correspond to one service beam in the current beam, and the sub-ranges corresponding to different service beams are different. When the ground terminal does not have a Global Navigation Satellite System (GNSS) positioning function, determine the positioning information of the current position of the ground terminal in another positioning mode other than the GNSS positioning function, and use the service beam index of the service beam corresponding to the index value of the subrange to which the positioning information in the beam configuration information belongs as the position information of the ground terminal. When the ground terminal has the GNSS positioning function, obtain the GNSS positioning information of the current position of the ground terminal based on the GNSS positioning function, and use the service beam index corresponding to the GNSS positioning information in the beam configuration information as the position information of the ground terminal.

[0232] In a possible embodiment, the processor 1703 further receives the first information of the satellite base station, When the first information includes signaling directly indicating the position reporting mode, determine the position reporting mode based on the signaling, When the first information is the random access channel (RACH) configuration information of the current beam, determine the position reporting mode based on whether the RACH configuration parameters associated with the position information exist in the RACH configuration information.

[0233] In a possible embodiment, the position reporting mode includes a mode of reporting the position through at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

[0234] In a possible embodiment, when the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is message (A-PUSCH) of the two-step random access procedure.

[0235] In a possible embodiment, the signaling includes a Master Information Block MIB or a System Message Block SIB1.

[0236] In a possible embodiment, the processor 1703 further When there is a RACH configuration parameter associated with the position information in the RACH configuration information, report the position information in the message transmitted by the random access preamble corresponding to the current beam, When there is no RACH configuration parameter associated with the position information in the RACH configuration information, report the position information in the uplink scheduling message corresponding to the current beam.

[0237] In a possible embodiment, the processor 1703 further When it is determined that the position reporting mode is transmission in the message transmitted by the random access preamble, report the position information via the message transmitted by the corresponding random access preamble in the random access procedure adopted by the current beam, When it is determined that the position reporting mode is transmission in the uplink scheduling message, report the position information via the corresponding uplink scheduling message in the random access procedure adopted by the current beam, When it is determined that the position reporting mode is the mode transmitted by the message transmitted by the random access preamble and the uplink scheduling message respectively, in the random access procedure adopted by the current beam, report the position information through the message transmitted by the corresponding random access preamble and the uplink scheduling message respectively. When it is determined that the position reporting mode is the mode jointly transmitted by the message transmitted by the random access preamble and the uplink scheduling message, divide the position information into two parts, and in the random access procedure adopted by the current beam, report each part of the position information through the message transmitted by the corresponding random access preamble and the uplink scheduling message respectively.

[0238] In a possible embodiment, the processor 1703 further Determine the current value of the RACH configuration parameter corresponding to the position information based on the correspondence between each bit or value occupied by the position information and the value of the RACH configuration parameter. In the random access procedure adopted by the current beam, report the current value through the message transmitted by the corresponding random access preamble.

[0239] In a possible embodiment, the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity RO resource, and a preamble index resource of the preamble.

[0240] In a possible embodiment, the preamble index resource includes a one-level preamble index and a multi-level preamble index. The multi-level preamble index includes a plurality of one-level preambles. Each level of the preamble index corresponds to a preamble index range. The preamble index ranges of two adjacent levels of preamble indexes may be the same or different and take independent values from each other.

[0241] In a possible embodiment, the total number of bits occupied by the position information and transmitted by the random access preamble is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0242] In a possible embodiment, when the position information is indicated by the multi-level preamble index, the bits corresponding to the total number of bits or all values of the position information are divided into a plurality of sets based on a preset order. The plurality of sets correspond one-to-one with the multi-level preamble index. The bits or the values of the position information within each set correspond one-to-one with the preamble index of the corresponding level of the preamble index.

[0243] In a possible embodiment, the preset order includes the order from the most significant bit to the least significant bit of the position information or the order from the least significant bit to the most significant bit of the position information.

[0244] In a possible embodiment, when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries a one-level preamble index.

[0245] In a possible implementation, the processor 1703 further reports the location information using at least one of a data portion of a PUSCH that carries the uplink scheduling message and the PUSCH demodulation reference signal DMRS.

[0246] In a possible implementation, the processor 1703 further When reporting the location information using the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one to all bits occupied by the location information. When the PUSCH DMRS and the data portion jointly report the location information, all bits occupied by the location information are divided into two parts based on a preset order, the PUSCH DMRS and the data portion respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one to the bits occupied by the corresponding part, and the preset order includes the order from the most significant bit to the least significant bit of the location information, or the order from the least significant bit to the most significant bit of the location information.

[0247] The transceiver 1702 is configured to transmit and receive data under the control of the processor 1703.

[0248] Here, in FIG. 17, the bus architecture may include any number of interconnected buses and bridges, and in particular, may link one or more processors 1703 represented by the processor 1703 and the memory represented by the memory 1701. The bus architecture can further link various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., all of which are well known in the art and thus will not be further described herein again. The bus interface provides an interface. The transceiver 1702 can be a plurality of elements, i.e., can include a transmitter and a receiver, and provides a unit for communicating with various other devices via a transmission medium. These transmission media include wireless channels, wired channels, optical fiber cables, etc. Similar to the user device, the user interface 1704 may be an interface that can be externally and internally connected to the required devices, and the connected devices include, but are not limited to, a keypad, a monitor, a speaker, a microphone, a joystick, etc.

[0249] The processor 1703 is responsible for the management of the bus architecture and general processing, and the memory 1701 can store the data used when the processor 1703 operates.

[0250] Optionally, the processor 1703 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). Also, the processor 1703 can adopt a multi-core architecture. Also, the processor 1703 can adopt a multi-core architecture.

[0251] The processor 1703 is configured to execute any method provided by the embodiments of the present invention based on the obtained executable instructions by calling a computer program stored in the memory. The processor 1703 and the memory may be physically separately arranged.

[0252] As shown in FIG. 18, the satellite base station provided by the embodiment of the present invention includes a memory 1801, a transceiver 1802, and a processor 1803.

[0253] The memory 1801 is configured to store a computer program. The transceiver 1802 is configured to transmit and receive data under the control of the processor 1803. The processor 1803 is configured to read the computer program in the memory 1801 and execute the following: In order to enable the terrestrial terminal to determine the beam type of the current beam and the random access procedure of the current beam based on the system broadcast message, a system broadcast message is transmitted, and the beam type includes an access beam and a service beam. When the beam type of the current beam is the access beam, a position reporting mode for reporting the current position to the terrestrial terminal is notified, and the terrestrial terminal accesses the satellite base station by the random access method on the terrestrial terminal side. In the random access procedure of the current beam, position information of the current position of the terrestrial terminal is received in the position reporting mode. Based on the position information, the corresponding service beam of the terrestrial terminal is scheduled, corresponding service beam configuration information is generated and transmitted, and the terrestrial terminal is controlled to complete the random access procedure within the service beam.

[0254] The transceiver 1802 is configured to transmit and receive data under the control of the processor 1803.

[0255] Here, in FIG. 18, the bus architecture may include any number of interconnected buses and bridges, and in particular, can link one or more processors represented by processor 1803 and the memory represented by memory 1801. The bus architecture can further link various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., all of which are well known in the art and thus will not be further described herein again. The bus interface provides an interface. The transceiver 1802 can be a plurality of elements, i.e., can include a transmitter and a receiver, and provides a unit for communicating with various other devices via a transmission medium. These transmission media include wireless channels, wired channels, optical fiber cables, etc. The processor 1803 is responsible for the management of the bus architecture and general processing, and the memory 1801 can store the data used when the processor 1803 operates.

[0256] The processor 1803 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a complex programmable logic device (CPLD). Also, the processor 1703 can adopt a multi-core architecture. Also, the processor 1803 can adopt a multi-core architecture.

[0257] Here, the above device provided by the embodiments of the present invention can implement all the method steps implemented by the embodiments of the above method, can achieve the same technical effects, and it should be noted that some of the embodiments are the same as those of the method embodiments. The beneficial effects will not be described in detail.

[0258] Based on the same inventive concept, embodiments of the present invention provide a terrestrial terminal. For the specific implementation of the random access method of the terrestrial terminal in the satellite communication system, reference can be made to the description of the embodiments of the method on the terrestrial terminal side, and the description will not be repeated. As shown in FIG. 19, the terrestrial terminal includes a receiving unit 1901 and a transmitting unit 1902.

[0259] The receiving unit 1901 is configured to obtain, from the received system broadcast information of the satellite base station, the beam type of the current beam and the random access procedure of the current beam, and the beam type includes an access beam and a service beam.

[0260] The receiving unit 1901 is further configured to obtain the position reporting mode of the terrestrial terminal when the beam type of the current beam is an access beam, and the position reporting mode is used to indicate the position reporting path of the terrestrial terminal.

[0261] The transmitting unit 1902 is configured to report position information in the position reporting mode in the random access procedure of the current beam, and the position information is used to determine the service beam corresponding to the terrestrial terminal.

[0262] In a possible embodiment, the receiving unit 1901 is further configured to obtain the beam configuration information of the current beam, and when the beam type of the current beam is the access beam, the beam configuration information includes the sub-ranges included in the coverage of the current beam, and one or more sub-ranges in the current beam correspond to one service beam in the current beam, and the sub-ranges corresponding to different service beams are different. When the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, the positioning information of the current position of the terrestrial terminal is determined in another positioning mode other than the GNSS positioning function, and the service beam index of the service beam corresponding to the index value of the subrange to which the positioning information in the beam configuration information belongs is used as the position information of the terrestrial terminal. When the terrestrial terminal has the GNSS positioning function, GNSS positioning information of the current position of the terrestrial terminal is acquired based on the GNSS positioning function, and the service beam index corresponding to the GNSS positioning information in the beam configuration information is used as the position information of the terrestrial terminal.

[0263] In a possible embodiment, the receiving unit 1901 further receives the first information of the satellite base station, when the first information includes signaling directly indicating the position reporting mode, the position reporting mode is determined based on the signaling, when the first information is the random access channel (RACH) configuration information of the current beam, the position reporting mode is determined based on whether the RACH configuration parameters associated with the position information exist in the RACH configuration information.

[0264] In a possible embodiment, the position reporting mode includes a mode of reporting the position via at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

[0265] In a possible embodiment, when the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is the message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is the message (A-PUSCH) of the two-step random access procedure.

[0266] In a possible embodiment, the signaling includes a Master Information Block MIB or a System Message Block SIB1.

[0267] In a possible embodiment, determining the position reporting mode based on whether there is a RACH configuration parameter associated with the position information in the RACH configuration information specifically includes: When there is a RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in the message transmitted by the random access preamble corresponding to the current beam; When there is no RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in the uplink scheduling message corresponding to the current beam.

[0268] In a possible embodiment, the transmitting unit 1902 further When it is determined that the position reporting mode is transmission in the message transmitted by the random access preamble, in the random access procedure adopted by the current beam, reporting the position information via the message transmitted by the corresponding random access preamble, When it is determined that the position reporting mode is transmission in the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the position information via the corresponding uplink scheduling message, When it is determined that the position reporting mode is a mode transmitted by the message transmitted by the random access preamble and the uplink scheduling message respectively, in the random access procedure adopted by the current beam, the position information is reported via the message transmitted by the corresponding random access preamble and the uplink scheduling message respectively. When it is determined that the position reporting mode is a mode jointly transmitted by the message transmitted by the random access preamble and the uplink scheduling message, the position information is divided into two parts, and in the random access procedure adopted by the current beam, each part of the position information is reported via the message transmitted by the corresponding random access preamble and the uplink scheduling message respectively.

[0269] In a possible embodiment, the transmitting unit 1902 further determines the current value of the RACH configuration parameter corresponding to the position information based on the correspondence between each bit or value occupied by the position information and the value of the RACH configuration parameter. In the random access procedure adopted by the current beam, the current value is reported via the message transmitted by the corresponding random access preamble.

[0270] In a possible embodiment, the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity RO resource, and a preamble index resource of the preamble.

[0271] In a possible embodiment, the preamble index resource includes a one-level preamble index and a multi-level preamble index. The multi-level preamble index includes a plurality of one-level preambles. Each level of the preamble index corresponds to one preamble index range. The preamble index ranges of two adjacent levels of the preamble index may be the same or different and take independent values from each other.

[0272] In a possible implementation, the total number of bits occupied by the position information is log2(R), where R is the size of the value range of the RACH configuration parameter, and log2() represents the logarithm with base 2.

[0273] In a possible implementation, when the position information is indicated by the multi-level preamble index, the bits corresponding to the total number of bits or all values of the position information are divided into a plurality of sets based on a preset order. The plurality of sets correspond one-to-one with the multi-level preamble index, and the bits or the values of the position information within each set correspond one-to-one with the preamble index of the corresponding level of the preamble index.

[0274] In a possible implementation, the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

[0275] In a possible implementation, when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries one level of the preamble index.

[0276] In a possible implementation, the transmission unit 1902 further reports the position information by at least one of the data part of the PUSCH that carries the uplink scheduling message and the PUSCH demodulation reference signal DMRS.

[0277] In a possible implementation, the transmission unit 1902 further When reporting the location information using the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with all the bits occupied by the location information, When the PUSCH DMRS and the data part jointly report the location information, all the bits occupied by the location information are divided into two parts based on a preset order, the PUSCH DMRS and the data part respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with the bits occupied by the corresponding part, and the preset order includes the order from the most significant bit to the least significant bit of the location information, or the order from the least significant bit to the most significant bit of the location information.

[0278] Based on the same inventive concept, an embodiment of the present invention provides a satellite base station. For the specific implementation of the random access method of the satellite base station, reference can be made to the description of the embodiment of the method on the satellite base station side, and the description will not be repeated. As shown in FIG. 20, the satellite base station includes a transmission unit 2001 and a reception unit 2002.

[0279] The transmission unit 2001 is configured to transmit a system broadcast message so that a ground terminal can determine the beam type of the current beam and the random access procedure of the current beam based on the system broadcast message, and the beam type includes an access beam and a service beam.

[0280] When the beam type of the current beam is the access beam, the transmission unit 2001 further notifies the ground terminal of a location reporting mode for reporting the current location, and the ground terminal accesses the satellite base station by using the random access method on the ground terminal side.

[0281] The receiving unit 2002 is configured to receive the location information of the current location of the terrestrial terminal in the location reporting mode in the random access procedure of the current beam.

[0282] The transmitting unit 2001 further schedules the corresponding service beam of the terrestrial terminal based on the location information, generates and transmits the corresponding service beam configuration information, and controls the terrestrial terminal to complete the random access procedure within the service beam.

[0283] It should be noted that the division of units in the embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. Also, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0284] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit can be stored in a processor-readable storage medium. Based on this understanding, the technical solution means in the present invention can essentially, or as a contribution to the prior art, or in the form of a software product, embody all or part of the technical solution means. The computer software product includes several instructions stored in a storage medium that enables a computer device (personal computer, server, network device, etc.) or a processor to execute all or part of the steps of the methods in various embodiments of the present invention. The aforementioned storage medium includes a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, an optical disk, and other media capable of storing program code.

[0285] It should be noted that the above device provided by the embodiment of the present invention can realize all method steps realized by the embodiment of the above method and can achieve the same technical effects. For the parts and beneficial effects of this embodiment that are the same as those of the method embodiment, no detailed description will be given.

[0286] Based on the same inventive concept, the embodiment of the present invention also refers to a processor-readable storage medium, which stores a computer program, and the computer program is used to cause a processor to execute the random access method on the ground terminal side or the satellite base station side as described above.

[0287] The processor-readable storage medium may be any usable medium or data storage device accessible by the processor, such as magnetic memory (e.g., floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical memory (e.g., CD, DVD, BD, HVD, etc.), semiconductor memory (e.g., ROM, EPROM, EEPROM), non-volatile memory (NAND FLASH), solid state drive (SSD), etc., but not limited thereto.

[0288] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Further, the present invention may also take the form of a computer program product incorporated on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) in which computer-usable program code is incorporated.

[0289] The present invention is described by flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each flow and / or block of the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks of the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or another programmable data processing device to generate a machine that executes instructions for execution on the computer or other processor. The programmable data processing device creates means for performing the functions specified in the flow of the flowchart and / or the block of the block diagram.

[0290] These processor-executable instructions can also be stored in a processor-readable memory that can cause a computer or other programmable data processing device to operate in a particular mode, and the instructions stored in the processor-readable memory produce a product that includes a commander device. The commander device performs the functions specified in one or more flows of the flowchart and / or one or more blocks of the block diagram.

[0291] These processor-executable instructions can also be loaded onto a computer or other programmable data processing device, resulting in a series of operational steps being executed on the computer or other programmable device to generate a computer-implemented process. The commander executed on the computer or other programmable device performs the functions specified in one or more flows of the flowchart and / or one or more blocks of the block diagram.

[0292] Regardless, those skilled in the art can also improve the technical solutions described in the above-described embodiments or replace some of the technical elements therein. Such improvements and replacements are not considered to deviate from the technical scope of each embodiment of the present invention. All such improvements and replacements fall within the scope of the claims of the present invention.

Explanation of Reference Numerals

[0293] 1701 Memory 1702 Transceiver 1703 Processor 1704 User Interface 1801 Memory 1802 Transceiver 1803 Processor 1901 Receiver Unit 1902 Transmitter Unit 2001 Transmitter Unit 2002 Receiver Unit 2101 Transmitter Unit

Claims

1. A method of random access applied to a terrestrial terminal in a satellite communication system, comprising: obtaining, from the received system broadcast information of the satellite base station, the beam type of the current beam and the random access procedure of the current beam; when the beam type of the current beam is an access beam, obtaining the position reporting mode of the terrestrial terminal; reporting position information in the position reporting mode in the random access procedure of the current beam, wherein the beam type includes an access beam and a service beam, the position reporting mode is used to indicate the position reporting path of the terrestrial terminal, and the position information is used to determine a service beam corresponding to the terrestrial terminal.

2. obtaining the beam configuration information of the current beam, and when the beam type of the current beam is the access beam, the beam configuration information includes a sub-range included in the coverage of the current beam, and one or more sub-ranges in the current beam correspond to one service beam in the current beam, and sub-ranges corresponding to different service beams are different; when the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, determining the positioning information of the current position of the terrestrial terminal in another positioning mode other than the GNSS positioning function, and using the service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information belongs as the position information of the terrestrial terminal; when the terrestrial terminal has the GNSS positioning function, obtaining GNSS positioning information of the current position of the terrestrial terminal based on the GNSS positioning function, and using the service beam index corresponding to the GNSS positioning information in the beam configuration information as the position information of the terrestrial terminal.

3. The step of obtaining the position reporting mode of the ground terminal includes: receiving the first information of the satellite base station; when the first information includes signaling directly indicating the position reporting mode, determining the position reporting mode based on the signaling; when the first information is the random access channel (RACH) configuration information of the current beam, determining the position reporting mode based on whether the RACH configuration parameters associated with the position information exist in the RACH configuration information, and The position reporting mode includes a mode of reporting the position via at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH). The random access method according to claim 2 is characterized in that.

4. When the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is Message (A-PUSCH) of the two-step random access procedure. The signaling includes a master information block MIB or a system message block SIB1. The random access method according to claim 3 is characterized in that.

5. The step of determining the position reporting mode based on whether there is a RACH configuration parameter associated with the position information in the RACH configuration information is as follows: When there is a RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in a message transmitted by a random access preamble corresponding to the current beam; When there is no RACH configuration parameter associated with the position information in the RACH configuration information, reporting the position information in an uplink scheduling message corresponding to the current beam. The random access method according to claim 3 is characterized by including the above steps.

6. The step of reporting the position information in the position reporting mode is as follows: When it is determined that the position reporting mode is transmission in a message transmitted by the random access preamble, in the random access procedure adopted by the current beam, reporting the position information via a message transmitted by the corresponding random access preamble; When it is determined that the position reporting mode is transmission in the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the position information via the corresponding uplink scheduling message; When it is determined that the position reporting mode is a mode transmitted in both the message transmitted by the random access preamble and the uplink scheduling message, in the random access procedure adopted by the current beam, reporting the position information via each of the message transmitted by the corresponding random access preamble and the uplink scheduling message; When it is determined that the position reporting mode is a mode in which messages transmitted by the random access preamble and the uplink scheduling message are co-transmitted, the position information is divided into two parts, and in the random access procedure adopted by the current beam, each part of the position information is reported via a message transmitted by the corresponding random access preamble and the uplink scheduling message. The method for random access according to claim 3, characterized by including the step of

7. The step of reporting the position information via a message transmitted by the corresponding random access preamble includes determining a current value of a RACH configuration parameter corresponding to the position information based on a correspondence relationship between each bit or value occupied by the position information and a value of the RACH configuration parameter; in the random access procedure adopted by the current beam, reporting the current value via a message transmitted by the corresponding random access preamble, and the RACH configuration parameter includes at least one of a PRACH format, a random access opportunity RO resource, and a preamble index resource of the preamble; the preamble index resource includes a one-level preamble index and a multi-level preamble index; the multi-level preamble index includes a plurality of one-level preambles, each level of the preamble index corresponds to one preamble index range, and the preamble index ranges of two adjacent levels of the preamble index are the same or different and take independent values from each other; The total number of bits occupied by the position information and transmitted by the random access preamble is log2(R), where R is the size of the range of values of the RACH configuration parameter, and log2() represents the logarithm to the base 2. When the position information is indicated by the multi-level preamble index, divide the bits corresponding to the total number of bits or all values of the position information into a plurality of sets based on a preset order. The plurality of sets correspond one-to-one with the multi-level preamble index, and the bits or the values of the position information within each set correspond one-to-one with the preamble index among the preamble indexes of the corresponding level. The random access method according to claim 6, characterized in that the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information.

8. The random access method according to claim 7, characterized in that when the position information is jointly indicated by the RO resource and the preamble index resource, one RO carries one level of preamble index.

9. The step of reporting the position information via a corresponding uplink scheduling message includes: Reporting the position information by at least one of the data part of the PUSCH carrying the uplink scheduling message and the PUSCH demodulation reference signal DMRS. When reporting the position information by the PUSCH DMRS, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with all the bits occupied by the position information. When the PUSCH DMRS and the data part jointly report the position information, all the bits occupied by the position information are divided into two parts based on a preset order, the PUSCH DMRS and the data part respectively correspond to one of the two parts, the scrambling sequence of the PUSCH DMRS corresponds one-to-one with the bits occupied by the corresponding part, and the preset order includes the order from the most significant bit to the least significant bit of the position information, or the order from the least significant bit to the most significant bit of the position information. The random access method according to claim 6, characterized in that.

10. A random access method applied to a satellite base station in a satellite communication system, comprising: Transmitting a system broadcast message to cause a terrestrial terminal to determine a beam type of a current beam and a random access procedure of the current beam based on the system broadcast message; When the beam type of the current beam is the access beam, notifying the terrestrial terminal of a position reporting mode for reporting the current position, and causing the terrestrial terminal to perform random access to the satellite base station by the method according to any one of claims 1 to 9; In the random access procedure of the current beam, receiving position information of the current position of the terrestrial terminal in the position reporting mode; Scheduling a corresponding service beam of the terrestrial terminal based on the position information, generating and transmitting corresponding service beam configuration information, and controlling the terrestrial terminal to complete a random access procedure within the service beam. The random access method, characterized in that the beam type includes an access beam and a service beam.

11. A terrestrial terminal, comprising: A receiving unit configured to obtain, from the system broadcast information of the received satellite base station, the beam type of the current beam and the random access procedure of the current beam; A transmitting unit configured to report position information in a position reporting mode in the random access procedure of the current beam, and comprising: The beam type includes an access beam and a service beam; When the beam type of the current beam is an access beam, the receiving unit further obtains the position reporting mode of the terrestrial terminal, and the position reporting mode is used to indicate the position reporting path of the terrestrial terminal; The position information is used to determine a service beam corresponding to the terrestrial terminal. A terrestrial terminal characterized by this.

12. The receiving unit further obtains beam configuration information of the current beam. When the beam type of the current beam is the access beam, the beam configuration information includes a sub-range included in the coverage of the current beam. One or more sub-ranges in the current beam correspond to one service beam in the current beam, and sub-ranges corresponding to different service beams are different; When the terrestrial terminal does not have a Global Navigation Satellite System (GNSS) positioning function, the positioning information of the current position of the terrestrial terminal is determined in another positioning mode other than the GNSS positioning function, and the service beam index of the service beam corresponding to the index value of the sub-range to which the positioning information in the beam configuration information belongs is used as the position information of the terrestrial terminal; The terrestrial terminal according to claim 11, wherein when the terrestrial terminal has the GNSS positioning function, GNSS positioning information of the current position of the terrestrial terminal is obtained based on the GNSS positioning function, and the service beam index corresponding to the GNSS positioning information in the beam configuration information is used as the position information of the terrestrial terminal.

13. Obtaining the position reporting mode of the terrestrial terminal is receiving the first information of the satellite base station; when the first information includes signaling directly indicating the position reporting mode, determining the position reporting mode based on the signaling; when the first information is the random access channel (RACH) configuration information of the current beam, determining the position reporting mode based on whether RACH configuration parameters associated with the position information exist within the RACH configuration information; The ground terminal according to claim 12, wherein the position reporting mode includes a mode of reporting a position via at least one of a message transmitted by a random access preamble and an uplink scheduling message carried by an uplink physical shared channel (PUSCH).

14. When the random access procedure adopted by the current beam is a four-step random access procedure, the message transmitted by the random access preamble is Message 1 of the four-step random access procedure, and the uplink scheduling message is Message 3 of the four-step random access procedure. When the random access procedure adopted by the current beam is a two-step random access procedure, the message carrying the random access preamble is Message A - Physical Random Access Channel (PRACH) of the two-step random access procedure, and the message carrying the uplink scheduling message is Message (A - PUSCH) of the two-step random access procedure. The ground terminal according to claim 13, wherein the signaling includes a master information block MIB or a system message block SIB1.

15. A satellite base station, A transmitting unit configured to transmit a system broadcast message so that a terrestrial terminal can determine a beam type of a current beam and a random access procedure of the current beam based on the system broadcast message, and a receiving unit configured to receive position information of a current position of the terrestrial terminal in the position reporting mode in the random access procedure of the current beam. The beam type includes an access beam and a service beam. The transmitting unit further notifies the terrestrial terminal of a position reporting mode for reporting a current position when the beam type of the current beam is the access beam, and causes the terrestrial terminal to access the satellite base station by the method according to any one of claims 1 to 9. The transmitting unit further schedules a corresponding service beam of the terrestrial terminal based on the position information, generates and transmits corresponding service beam configuration information, and controls the terrestrial terminal to complete a random access procedure within the service beam. A satellite base station characterized by this.

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