Communication method and apparatus, terminal device, and network device

Abstract

This application discloses a communication method and apparatus, a terminal device, and a network device; the method includes: the network device sending indication information, the indication information being used to indicate K. i K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K i It is a positive integer greater than or equal to 1; the terminal device receives this indication information; the terminal device determines K... i The system sends a random access request message, where the SSB index i indicates the SSB selected by the terminal device from the monitored SSBs. Therefore, this application can indicate the number of repetitions of the random access request message corresponding to the SSB index through the indication information, and send random access request messages based on the number of repetitions to achieve coverage enhancement. This helps improve the transmission reliability of the random access request message and increases the probability of successful random access by the terminal device.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus, terminal equipment and network equipment. Background Technology

[0002] Compared to terrestrial network communication systems, non-terrestrial network (NTN) communication systems have greater propagation delays, therefore the communication methods used in terrestrial communication systems are no longer suitable for NTN communication systems.

[0003] In NTN communication systems, the 3rd Generation Partnership Project (3GPP) standard typically assumes that the antenna gain of the terminal device is 0 dBi. However, in actual communication, the antenna gain of the terminal device often fails to meet this requirement. Because the antenna gain of the terminal device cannot meet the requirements, the network device may be unable to successfully receive the random access request message (such as message 1 or Msg1) sent by the terminal device when it attempts to access the network. Summary of the Invention

[0004] This application provides a communication method and apparatus, a terminal device, and a network device, with the aim of enhancing coverage, improving the transmission reliability of random access request messages, and increasing the likelihood of successful random access by the terminal device.

[0005] Firstly, a communication method according to this application is applied in a terminal device; the method includes:

[0006] Receive indication information, the indication information being used to indicate K i The K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1;

[0007] According to the K i A random access request message is sent, wherein the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to.

[0008] In this embodiment of the application, by introducing indication information, the network device can indicate to the terminal device the number of repetitions of the random access request message for the SSB index or SSB configuration. Then, the terminal device can send the random access request message to the network device multiple times according to the number of repetitions of the random access request message corresponding to the selected SSB. This helps to achieve coverage enhancement, improve the transmission reliability of the random access request message, and increase the probability of successful random access by the terminal device.

[0009] In some possible implementations, the first cell is the serving cell of the terminal device. For example, for a terminal device in a connected, idle, or inactive state, the first cell is the serving cell of the terminal device. Alternatively, the first cell is the cell where the terminal device is camped. For example, for a terminal device initially accessing the network, the first cell is the cell where the terminal device is camped. It should be noted that, in the embodiments of this application, when a terminal device initially accesses the network, the cell where the terminal is camped can also be understood as the serving cell of the terminal device.

[0010] Secondly, this application provides a communication method applied in a network device; the method includes:

[0011] Send indication information, the indication information being used to indicate K i The K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1.

[0012] Thirdly, a communication device according to this application includes:

[0013] A receiving unit is configured to receive indication information, the indication information being used to indicate K. i The K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1;

[0014] The sending unit is configured to send according to the K i A random access request message is sent, wherein the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to.

[0015] Fourthly, a communication device according to this application includes:

[0016] A sending unit is configured to send indication information, the indication information being used to indicate K.i The K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1.

[0017] Fifthly, a terminal device according to this application includes a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps in the method designed in the first aspect above.

[0018] Sixthly, a network device according to this application includes a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps in the method designed in the second aspect above.

[0019] A seventh aspect is a chip according to this application, including a processor, wherein the processor performs the steps of the method designed in the first or second aspect described above.

[0020] Eighthly, a chip module according to this application includes a transceiver component and a chip, wherein the chip includes a processor, and the processor performs the steps in the method designed in the first or second aspect described above.

[0021] A ninth aspect is a computer-readable storage medium of this application, wherein the computer-readable storage medium stores a computer program or instructions, which, when executed, implement the steps in the method designed in the first or second aspect described above.

[0022] A tenth aspect is a computer program product of this application, comprising a computer program or instructions, wherein, when executed, the computer program or instructions implement the steps in the method designed in the first or second aspect described above. Exemplarily, the computer program product may be a software installation package.

[0023] The beneficial effects of the technical solutions in aspects two through ten can be found in the technical effects of the technical solution in aspect one, and will not be repeated here. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below.

[0025] Figure 1 This is a schematic diagram of the architecture of a wireless communication system according to an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of the architecture of a transparent satellite communication system according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of the structure of a beam generated by a satellite on the ground according to an embodiment of this application;

[0028] Figure 4 This is a schematic diagram illustrating the structure for comparing signal reception quality between a terrestrial network communication system and an NTN communication system according to an embodiment of this application.

[0029] Figure 5 This is a comparative architectural diagram of an NTN communication system according to an embodiment of this application;

[0030] Figure 6 This is a schematic diagram of a four-step random access process according to an embodiment of this application;

[0031] Figure 7 This is a schematic diagram of a two-step random access process according to an embodiment of this application;

[0032] Figures 8 to 10 This is a schematic diagram illustrating the mapping relationship between SSB and RO according to an embodiment of this application;

[0033] Figure 11 This is a schematic diagram illustrating a scenario in which the repetition count of Msg1 is configured in the SSB index according to an embodiment of this application;

[0034] Figures 12 to 31 This is a schematic diagram illustrating another mapping relationship between SSB and RO according to an embodiment of this application;

[0035] Figure 32 This is a schematic diagram illustrating another scenario in which the repetition count of Msg1 is configured in the SSB index according to an embodiment of this application;

[0036] Figures 33 to 36 This is a schematic diagram illustrating another mapping relationship between SSB and RO according to an embodiment of this application;

[0037] Figure 37 This is a schematic diagram illustrating another scenario in which the repetition count of Msg1 is configured in the SSB index according to an embodiment of this application;

[0038] Figures 38 to 47 This is a schematic diagram illustrating another mapping relationship between SSB and RO according to an embodiment of this application;

[0039] Figure 48 This is a flowchart illustrating a communication method according to an embodiment of this application;

[0040] Figure 49 This is a functional unit block diagram of a communication device according to an embodiment of this application;

[0041] Figure 50 This is a functional unit block diagram of another communication device according to an embodiment of this application;

[0042] Figure 51 This is a schematic diagram of the structure of a terminal device according to an embodiment of this application;

[0043] Figure 52 This is a schematic diagram of the structure of a network device according to an embodiment of this application. Detailed Implementation

[0044] It should be understood that the terms "first," "second," etc., used in the embodiments of this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, software, product, or device that includes a series of steps or units is not limited to the listed steps or units, but also includes steps or units not listed, or other steps or units inherent to these processes, methods, products, or devices.

[0045] The term "embodiment" as used in the embodiments of this application means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] In the embodiments of this application, "at least one" refers to one or more, and "multiple" refers to two or more.

[0047] In this application's embodiments, "and / or" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the following three cases: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. The character " / " can indicate that the preceding and following related objects are in an "or" relationship. Additionally, the symbol " / " can also represent a division sign, i.e., performing a division operation.

[0048] In the embodiments of this application, "at least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent the following seven cases: a, b, c, a and b, a and c, b and c, a, b, and c. Each of a, b, and c can be an element or a set containing one or more elements.

[0049] In the embodiments of this application, the terms "of," "corresponding (relevant)," "corresponding," "associated (related)," and "mapped" may sometimes be used interchangeably. It should be noted that when no distinction is emphasized, the concepts or meanings expressed are consistent.

[0050] In the embodiments of this application, "network" can be expressed as the same concept as "system," and a communication system is a communication network.

[0051] In this application, "connection" refers to various connection methods, such as direct connection or indirect connection, to achieve communication between devices, and is not specifically limited thereto.

[0052] The technical solutions of the embodiments of this application will be described in detail below.

[0053] 1. Wireless communication systems, terminal equipment, satellites, non-terrestrial network gateways and network equipment

[0054] 1) Wireless communication system

[0055] The technical solutions of this application embodiment can be applied to various wireless communication systems, such as: Long Term Evolution (LTE) systems, Advanced Long Term Evolution (LTE-A) systems, New Radio (NR) systems, evolution systems of NR systems, LTE-based Access to Unlicensed Spectrum (LTE-U) systems, NR-based Access to Unlicensed Spectrum (NR-U) systems, Non-Terrestrial Networks (NTN) systems, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), Wireless Fidelity (WiFi), 6th-Generation (6G) communication systems, or other communication systems, etc.

[0056] Traditional wireless communication systems support a limited number of connections and are easy to implement. With the development of communication technology, wireless communication systems can support not only traditional wireless communication systems, but also communication such as device-to-device (D2D), machine-to-machine (M2M), machine-type communication (MTC), vehicle-to-vehicle (V2V), vehicle-to-everything (V2X), and narrowband internet of things (NB-IoT). The technical solutions of this application embodiment can also be applied to the aforementioned wireless communication systems, or the aforementioned traditional wireless communication systems.

[0057] For example, embodiments of this application can be applied to beamforming, carrier aggregation (CA), dual connectivity (DC), or standalone (SA) deployment scenarios.

[0058] Alternatively, as another example, embodiments of this application can be applied to communication scenarios using unlicensed spectrum. In these embodiments, unlicensed spectrum can also be considered as shared spectrum. Alternatively, embodiments of this application can also be applied to licensed spectrum. In these embodiments, licensed spectrum can also be considered as non-shared spectrum.

[0059] In some embodiments, the technical solutions of this application can be applied to NTN communication systems, such as satellite communication systems. For satellite communication systems, network devices typically communicate with ground terminal devices via satellite.

[0060] Exemplary, an NTN communication system according to an embodiment of this application, such as Figure 1 As shown. The NTN communication system 10 may include terminal equipment 110, reference point 120, satellite 130, non-terrestrial network gateway (NTN gateway) 140, and network equipment 150. The terminal equipment 110, non-terrestrial network gateway 140, and network equipment 150 may be located on the Earth's surface, while the satellite 130 is located in Earth orbit. The satellite 130 can provide communication services to the geographical area covered by the signal and can communicate with the terminal equipment 110 located within the signal coverage area.

[0061] In this configuration, terminal device 110 is located within a cell or beam, and this cell includes a reference point 120. Furthermore, the wireless communication link between terminal device 110 and satellite 130 is called a service link. The wireless communication link between satellite 130 and non-terrestrial network gateway 140 is called a feeder link.

[0062] It should be noted that the non-terrestrial network gateway 140 and the network device 150 can be integrated into the same device or they can be separate devices; there are no specific restrictions on this.

[0063] 2) Terminal equipment

[0064] In this embodiment, the terminal device can be a device with transceiver capabilities, and may also be referred to as user equipment (UE), remote terminal equipment (relay UE), relay equipment (relay UE), access terminal equipment, user unit, user station, mobile station, mobile station, remote station, mobile device, user terminal equipment, smart terminal equipment, wireless communication equipment, user agent, or user device. It should be noted that a relay equipment is a terminal device capable of providing relay forwarding services to other terminal devices (including remote terminal devices).

[0065] In addition, the terminal device can also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, in-vehicle device, wearable device, terminal device in next-generation communication systems (such as NR communication systems, 6G communication systems), or terminal device in a future public land mobile network (PLMN), etc., without specific limitations.

[0066] In this embodiment of the application, the terminal device can be deployed on land, including indoor or outdoor, handheld, wearable or vehicle-mounted; it can be deployed on water (such as a ship); or it can be deployed in the air (such as an airplane, balloon and satellite).

[0067] In this application embodiment, the terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in autonomous driving, a wireless terminal device in remote medical care, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, or a wireless terminal device in a smart home, etc.

[0068] In this embodiment, the terminal device may include a device with wireless communication functionality, such as a chip system, a chip, or a chip module. For example, the chip system may include a chip, and may also include other discrete devices.

[0069] 3) Satellite

[0070] In this embodiment of the application, the satellite may be a spacecraft carrying a transparent payload (or bent pipe payload) or a regenerative payload signal transmitter, that is, a transparent satellite or a regenerative satellite.

[0071] Specifically, satellites can be categorized according to their orbital altitude into low Earth orbit (LEO) satellites, medium Earth orbit (MEO) satellites, geostationary orbit (GEO) satellites, and highly elliptical orbit (HEO) satellites. For example, LEO satellites operate at altitudes between 300 km and 1500 km. MEO satellites operate at altitudes between 7000 km and 25000 km. GEO satellites operate at an altitude of 35786 km. HEO satellites operate at altitudes between 400 km and 50000 km.

[0072] 4) Non-terrestrial network gateway

[0073] In this embodiment, the non-terrestrial network gateway can be a ground-based earth station or gateway capable of providing sufficient radio frequency (RF) power and RF sensitivity to enable connectivity between ground equipment (such as network equipment) and satellites. The non-terrestrial network gateway is a node in the transport network layer (TNL).

[0074] 5) Network equipment

[0075] In this embodiment, the network device is a device with transceiver capabilities used for communication with terminal devices. For example, the network device can be responsible for radio resource management (RRM), quality of service (QoS) management, data compression and encryption, and data transmission and reception on the air interface side. The network device can be a base station (BS) in a communication system or a device deployed in a radio access network (RAN) to provide wireless communication functions. Examples include evolved node B (eNB or eNodeB) in an LTE communication system, next-generation evolved node B (ng-eNB) in an NR communication system, next-generation node B (gNB) in an NR communication system, master node (MN) in a dual-connectivity architecture, and secondary node (SN) in a dual-connectivity architecture; no specific limitations are imposed on this.

[0076] In this embodiment of the application, the network device may also be a device in the core network (CN), such as the access and mobility management function (AMF) and user plane function (UPF); it may also be an access point (AP) in a wireless local area network (WLAN), a relay station, a communication device in a future PLMN network, or a communication device in an NTN network.

[0077] In this embodiment of the application, the network device may include means for providing wireless communication functions for terminal devices, such as a chip system, a chip, or a chip module. For example, the chip system may include a chip, or it may include other discrete devices.

[0078] In this embodiment, the network device can communicate with an Internet Protocol (IP) network, such as the Internet, a private IP network, or other data networks.

[0079] In some possible network deployments, the network device can be a single node to implement the functions of the aforementioned base station, or the network device can include two or more independent nodes to implement the functions of the aforementioned base station. For example, the network device includes a centralized unit (CU) and a distributed unit (DU), such as gNB-CU and gNB-DU. Furthermore, in some embodiments of this application, the network device may also include an active antenna unit (AAU). The CU implements some of the functions of the network device, and the DU implements other functions. For example, the CU is responsible for handling non-real-time protocols and services, implementing the functions of the radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, and packet data convergence protocol (PDCP) layer. The DU is responsible for handling physical layer protocols and real-time services, implementing the functions of the radio link control (RLC) layer, medium access control (MAC) layer, and physical (PHY) layer. In addition, the AAU can implement some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this network deployment, higher-layer signaling (such as RRC signaling) can be considered to be sent by the DU, or jointly by the DU and AAU. It is understood that network devices can include at least one of CU, DU, and AAU. Furthermore, the CU can be classified as a network device in the RAN, or it can be classified as a network device in the core network; no specific limitations are imposed on this.

[0080] In this embodiment, the network device can provide services to a cell, and the terminal devices in the cell can communicate with the network device through transmission resources (such as spectrum resources). The cell can be a macro cell, small cell, metro cell, micro cell, pico cell, or femto cell, etc.

[0081] 6) Exemplary Description

[0082] For example, this application embodiment employs a transparent satellite communication system. The transparent satellite communication system uses a transparent payload. A schematic diagram of the transparent satellite communication system architecture is shown below. Figure 2 As shown in the diagram. The terminal equipment, non-terrestrial network gateway, and gNB are located on the Earth's surface, while the satellite is in Earth orbit. The satellite, non-terrestrial network gateway, and gNB together form the NG-radio access network (NG-RAN). The NG-RAN connects to the 5G core network via the NG interface.

[0083] 2. NTN Communication System

[0084] (1) NTN communication system and terrestrial network communication system

[0085] In NTN communication systems, satellites typically generate one or more beams (or beam footprints) within a given service area. The shape of these beams is usually elliptical; for example, relevant descriptions can be found in the 3GPP standard. Some satellites (e.g., LEO satellites) generate beams that move with their fixed orbits; conversely, some satellites (e.g., LEO or GEO satellites) generate beams on the ground that do not move with their fixed orbits.

[0086] For example, such as Figure 3 As shown. In Figure 3 In (a), the beam generated by the satellite (e.g., a LEO or GEO satellite) does not move with the satellite's motion in a fixed orbit. Figure 3 In (b), the beam generated by the satellite moves with the satellite's motion in a fixed orbit. Furthermore, when the relative distance between the satellite and the beam it generates is fixed, the path loss varies little.

[0087] Because satellites are very far from the ground (e.g., GEO satellites are 35,786 km), within the coverage area of ​​the same beam or cell, the propagation distance between terminal devices (e.g., UEs) and satellites in different geographical locations is relatively small (i.e., the path loss of signals corresponding to terminal devices in different geographical locations within the coverage area of ​​the same beam / cell is relatively small). Consequently, within the coverage area of ​​the same beam, the difference in signal reception quality (including downlink signal reception quality of the terminal device or uplink signal reception quality of the base station) for terminal devices in different geographical locations is very small. Figure 4 As shown in (b).

[0088] exist Figure 4 In the terrestrial network communication system shown in (a), terminal equipment 4201 and terminal equipment 4202 with different geographical locations are within the coverage area of ​​the same beam / cell.

[0089] Because of the significant differences in the distances between network device 410 and terminal device 4201, and between network device 410 and terminal device 4202, there are substantial differences in the signal reception quality between terminal device 4201 and terminal device 4202. Figure 4 In the NTN communication system shown in (b), terminal devices 4401 and 4402 with different geographical locations are within the coverage area of ​​the same beam / cell.

[0090] Because the distance between satellite 430 and the ground is very far, there is a small difference between the distance between satellite 430 and terminal device 4401 and the distance between satellite 430 and terminal device 4402, resulting in a small difference between the signal reception quality of terminal device 4401 and the signal reception quality of terminal device 4402.

[0091] (2) Architecture of NTN communication system

[0092] The architecture of the NTN communication system in this application mainly includes an NTN communication architecture with a transparent satellite (i.e., using a transparent payload) and an NTN communication architecture with a regenerative satellite (i.e., using a regenerative payload). Please refer to [link to relevant documentation]. Figure 5 .in, Figure 5 Example (a) illustrates an NTN communication architecture with transparent satellites, while Figure 5 Example (b) illustrates an NTN communication architecture with regenerable satellites.

[0093] exist Figure 5In (a), the satellite 510 in transparent relay mode generates at least one beam 520, and the at least one beam 520 can form a cell. At this time, the terminal device 530 located in the cell can measure at least one beam of the cell, and select one beam from the at least one beam according to the beam measurement result, and establish a communication connection with the satellite 510 through the selected beam.

[0094] exist Figure 5 In (b), the satellite 540 in regenerated signal mode generates at least one beam 550, and the at least one beam 550 can form a cell. At this time, the terminal device 560 located in the cell can measure at least one beam of the cell, and select one beam from the at least one beam according to the beam measurement result, and establish a communication connection with the satellite 540 through the selected beam.

[0095] 3. Random access procedure

[0096] (1) 4-step random access process

[0097] like Figure 6 As shown, for a 4-step random access, the entire process includes 4 steps: transmission of the random access request message, transmission of the random access response (RAR) message, transmission of message 3 (Msg3), and transmission of message 4 (Msg4).

[0098] Step 1: Transmission of the random access request message, i.e., the terminal device sends a random access request message to the network device. This random access request message can also be referred to as message 1 (Msg1).

[0099] Specifically, the random access request message may include a random access preamble (RA preamble). The main function of the RA preamble is to request access from the network device, enabling the network device to estimate the transmission delay between itself and the terminal device based on the RA preamble and calibrate the uplink timing accordingly, and then instruct the terminal device through a RAR message.

[0100] Step 2: Transmission of RAR message. Upon receiving the Random Access Request message, the network device sends a RAR message to the terminal device. This RAR message can also be referred to as message 2 (Msg2).

[0101] Specifically, the network device sends a RAR message to the terminal device on the PDSCH (Physical Downlink Shared Channel) payload resource. For example, in this embodiment, the RAR message is obtained by scrambling with RA-RNTI (random access radio network temporary identifier). In some embodiments, the value of RA-RNTI is determined by the time-frequency resource location of the resource carrying the RA preamble.

[0102] For the terminal device, after sending the RApreamble, it can listen to the PDCCH within the RAR time window to obtain the DCI based on the RA-RNTI. Then, the terminal device uses the RA-RNTI to parse the PDSCH payload based on the DCI to receive the corresponding RAR message scrambled by the RA-RNTI. If no RAR message is received within the RAR time window, the random access procedure is considered to have failed.

[0103] RAR messages can include the time adjustment required for uplink synchronization, uplink resources required for the terminal device to send message 3, temporary C-RNTI, etc.

[0104] The first two steps of the random access procedure, Msg1 and Msg2, mainly complete the uplink time synchronization, while the main purpose of Msg3 and Msg4 is to assign a unique and legitimate identity, C-RNTI, to the terminal device for subsequent data transmission.

[0105] Step 3: Transmission of Message 3. Upon receiving the RAR message, the terminal device sends Message 3 to the network device. Message 3 is Msg3. For example, the terminal device sends Msg3 to the network device on the PUSCH (Physical Uplink Shared Channel). Further, in some embodiments, Msg3 contains a unique identifier for the terminal device. This identifier can be used for conflict resolution in Step 4. For example, for a terminal device in the RRC_CONNECTED state, the unique identifier is C-RNTI; for a terminal device not in the RRC_CONNECTED state, the unique identifier is a unique terminal device identifier from the core network (such as S-TMSI or a random number).

[0106] Step 4: Transmission of Message 4. The network device receives Msg3 and sends message 4 to the terminal device. Message 4 can also be referred to as Msg4.

[0107] In the conflict resolution mechanism, network devices carry a unique identifier for the terminal device in Msg4 to indicate the winning terminal device, while other terminal devices that do not win the conflict resolution will re-initiate random access. If the PDSCH received by the terminal device in Msg4 is scrambled with the TC-RNTI specified in the RAR message, then when the UE Contention Resolution Identity MAC control element contained in the successfully decoded MACPDU matches the CCCH SDU sent in Msg3, the terminal device will consider the random access successful and convert its TC-RNTI to C-RNTI.

[0108] (2) Two-step random access process

[0109] Compared to a 4-step random access procedure, a 2-step random access procedure helps reduce access latency for terminal devices.

[0110] like Figure 7 As shown, the two-step random access process mainly includes the following two steps:

[0111] Step 1: Transmission of MsgA, i.e., the terminal device sends MsgA to the network device. MsgA includes a random access request message.

[0112] In addition, MsgA also includes Msg3. Here, Msg3 refers to Msg3 in the above four-step random access process. That is to say, MsgA consists of two parts: the RA preamble and the PUSCH payload.

[0113] Step 2: Transmission of MsgB. This involves the network device receiving MsgA and sending MsgB to the terminal device. MsgB, also known as message B, includes Msg2 and Msg4. Here, Msg2 refers to Msg2 in the aforementioned four-step random access process, and Msg4 refers to Msg4 in the same process.

[0114] (3)RA preamble

[0115] 1) Composition, classification, and quantity of RA preamble

[0116] A RApreamble can consist of a cyclic prefix (CP) and a sequence.

[0117] RApreamble supports four long sequences of length 839 and nine short sequences of length 139. The length of the sequence formed by RApreamble can be indicated by the high-level parameter prach-RootSequenceIndex.

[0118] Each cell has 64 available RApreambles, forming an RApreamble sequence, and each RA preamble has a unique index within that sequence. The terminal device selects one RA preamble from this sequence (or it is specified by the network device) for transmission using a Physical Random Access Channel (PRACH) opportunity (RO), meaning the RA preamble is carried (or transmitted) by a PRACH opportunity.

[0119] The above RA preamble sequence can include the following two parts:

[0120] One part consists of contention-based random access preamble (CBRA) sequences and non-contention-based random access preamble (CFRA) sequences indicated by the higher-level parameter totalNumberOfRA-Preambles;

[0121] The other part consists of other RApreamble sequences besides those indicated by the high-level parameter totalNumberOfRA-Preambles. The RA preambles in these other RApreamble sequences are used for other purposes, such as requesting system information (SI).

[0122] It is worth noting that if the higher-level parameter totalNumberOfRA-Preambles does not indicate the specific number of RA preambles, then the above 64 RA preambles are used for both contention-based random access and non-contention-based random access.

[0123] In some embodiments, CBRA preambles can be divided into two groups: group A and group B. Group B may not necessarily exist and can be configured by the high-level parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB.

[0124] Network devices can configure the parameters required for contention-based random access via the higher-layer parameter RACH-ConfigCommon (carried by BWP-Common in SIB1), while network devices can configure the parameters required for non-contention-based random access via the higher-layer parameter RACH-ConfigDedicated.

[0125] (4) PRACH time and frequency resources

[0126] During random access, the transmission of PRACH messages requires time-frequency resources. These resources are divided to obtain at least one physical random access occasion (RO). The RO is used to transmit or carry random access request messages. The RO can include time-domain resources and frequency-domain resources. Specifically, time-domain resources can be indicated by their indexes, and frequency-domain resources can be indicated by their indexes.

[0127] The time-domain location or time-domain resource of RO, that is, the PRACH time-domain resource used to transmit / carry RApremble / Msg1, can be configured by the network device to the terminal device through the parameter prach-ConfigurationIndex in the higher-layer parameter RACH-ConfigGeneric. For example, the specific configuration method can be found in Table 1.

[0128] Table 1 defines the random access configuration for FR1 and paired spectrum / supplementary uplink. Where n f This indicates the system frame number, and x indicates the PRACH configuration period. The number of ROs in a PRACH slot This represents the time-domain symbol length of an RO.

[0129] Table 1

[0130]

[0131]

[0132] For example, when the PRACH Configuration Index is 109, the following exists:

[0133] ● The random access preamble format uses A1 / B1;

[0134] ● Every two system frames (i.e., system frame indices are even numbers 0, 2, 4…) contain temporal resources (i.e., n) of RO. f mod2 = 0);

[0135] ● The starting position of the temporal domain resources of RO is in the 4th subframe of the system frame, starting from the 0th OFDM symbol;

[0136] ●The fourth subframe contains two PRACH slots, and each PRACH slot contains Time-domain resource index of each RO;

[0137] ●The time-domain symbol length of RO is That is, it occupies 2 OFDM symbols.

[0138] It should be noted that, in the embodiments of this application, the time-domain resources identified by the indices of two adjacent time-domain resources can be continuous or non-contiguous. For example, when the indices of the time-domain resources are index 0 and index 1, the time-domain resource identified by index 0 is the 0th to 1st OFDM symbol under the 4th subframe in the system frame, and the time-domain resource identified by index 1 is the 2nd to 3rd OFDM symbol under the 4th subframe in the system frame.

[0139] The parameter msg1-FrequencyStart in the high-level parameter RACH-ConfigGeneric can be used to configure the offset of the starting frequency domain resource position of the RO to the starting frequency domain resource position of the initial BWP or the current active BWP.

[0140] The parameter msg1-FDM in the high-level parameter RACH-ConfigGeneric can be used to configure the number of frequency domain resource indexes for the RO.

[0141] (5) Synchronization Signal and PBCH block (SSB) corresponding (mapped / associated) beam

[0142] In 5G NR communication systems, as cell frequencies increase, coverage areas decrease accordingly. To increase cell coverage, some broadcast information can be transmitted using beam sweeping instead of coverage.

[0143] Beam scanning concentrates energy in one direction at a certain moment, allowing the signal to be transmitted further in that direction, while other directions cannot receive the signal; then, at the next moment, it is transmitted in another direction; ultimately, by continuously changing the beam direction, coverage of the entire cell is achieved.

[0144] In 5G NR, beams are used in the random access process, and SSB has multiple transmission opportunities within the time domain period, and there is a corresponding index, namely the SSB index.

[0145] Each beam can correspond to (map / associate) at least one SSB index, and the beams corresponding to different SSB indices may be the same (in the same direction) or different (in different directions).

[0146] SSBs are transmitted in units of 5ms half-frames, which is one SS burst set. All SSBs in an SS burst set must be periodically transmitted within the same half-frame. SSBs appear several times at intervals within a certain half-frame, and each of these SSBs corresponds to a beam scanning direction, so there will be one SSB in each direction.

[0147] For a terminal device, it only has the opportunity to send a beam mapping (RA) preamble when the SSB's beam scanning signal covers it. If the network device receives the terminal device's RA preamble, it can determine the optimal downlink beam. In other words, the network device knows which beam is pointing towards the terminal device.

[0148] Since the beam corresponds to the RA preamble, and the beam corresponds to the SSB, the SSB needs to be associated with (mapped) the RA preamble. Furthermore, since the RA preamble needs to be transmitted based on the RO, meaning the RA preamble needs to be carried (or transmitted) by the RO, the SSB needs to be associated with (mapped) the RO so that the network device knows under which beam to send Msg2 to the terminal device.

[0149] (6) SSB association (mapping / correspondence, etc.) RO and SSB association (mapping / correspondence, etc.) RA preamble

[0150] Network devices can configure N (where N is configured by the L1 parameter SSB-per-rach-occasion) SSBs associated (mapped / corresponded to) one RO (N≥1) for terminal devices through the higher-layer parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB. Alternatively, network devices can configure one SSB associated (mapped / corresponded to) 1 / N (where N is configured by the L1 parameter SSB-per-rach-occasion) ROs (N<1) for terminal devices through the higher-layer parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB, and each SSB associated (mapped / corresponded to) R (where R is configured by the L1 parameter CB-preambles-per-SSB) RA preamble index.

[0151] For example, the value of N can be {1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16}.

[0152] There are two configurations for N:

[0153] One scenario is where N < 1, in which case an SSB can be associated with 1 / N valid ROs. The preamble associated with this SSB starts from RA preamble index 0.

[0154] For example, if N = 1 / 8, then an SSB is associated with 8 ROs, and the preamble index of the starting point of these 8 ROs is 0.

[0155] Another scenario is where N ≥ 1, in which case N SSBs are associated with one RO. For example, SSB n can be selected from R preambles to send Msg1, 0 ≤ n ≤ N-1, where n refers to the SSB index, and the preamble associated with SSB n is from RA preamble index n*. The beginning. Among them, It is configured by the high-level parameter totalNumberOfRA-Preambles and is an integer multiple of N.

[0156] For example, with N=2, For example, in this case, two SSBs are associated with one RO. The RA preamble index associated with SSB0 starts from 0, and the RA preamble index associated with SSB1 starts from 32. That is, SSB0 is associated with RA preambles with indices from 0 to 31, and SSB1 is associated with RA preambles with indices from 32 to (the total number of corresponding RA preambles - 1).

[0157] It should be noted that for valid ROs, the relevant description can be found in the 3GPP standard. It can be understood that for FDD (Frequency Division Duplexing) mode or paired spectrum, all ROs are valid.

[0158] For TDD (Time Division Duplexing) mode or unpaired spectrum, if the network side does not configure higher-layer parameters (such as tdd-UL-DL-ConfigurationCommon), and the time-domain resource location of the RO is after the symbol location of the SSB, and the interval between the RO and the symbol location of the last SSB received by the terminal device is at least N, gap If N is a symbol, then the RO is valid, i.e., a valid RO. gap The relationship between the RA preamble subcarrier spacing and the RA preamble subcarrier spacing can be shown in Table 2.

[0159] If the network side configures higher-layer parameters (such as tdd-UL-DL-ConfigurationCommon), the RO should be configured in the uplink resources, and the temporal resource position of the RO should be after the symbol position of the SSB, and the interval between the RO and the symbol position of the last SSB received by the terminal device should be at least N. gap If a symbol is found, then the RO is valid, i.e., a valid RO.

[0160] Table 2

[0161] 1.25kHz or 5kHz 0 15kHz or 30kHz or 60kHz or 120kHz 2

[0162] In Table 2, for RApreamble sequences with a subcarrier spacing (SCS) of 1.25 kHz / 5 kHz, N gap The value of is 0; for RA preamble sequences with subcarrier spacing (SCS) of 15kHz / 30kHz / 60kHz / 120kHz, N gap The value of is 2.

[0163] In summary, the mapping relationship between SSB and RO can be mapped sequentially as follows:

[0164] First, in a RO, the order of the RApreamble indexes is increasing;

[0165] Secondly, the frequency resource index of a frequency-multiplexed operating system (RO) is in ascending order;

[0166] Furthermore, the order of the time resource indexes of the time-multiplexed RO within a PRACH time slot is increasing;

[0167] Finally, the PRACH slot indexes are ordered in ascending order.

[0168] The following example illustrates the mapping relationship between SSB and RO.

[0169] Example 1:

[0170] Taking a cell with 8 SSBs configured, each with indices from 0 to 7, and parameters msg1-FDM = 4 and ssb-perRACH-Occasion = 1 / 4 as an example, the mapping relationship between SSBs and ROs in this case is as follows: Figure 8 As shown.

[0171] exist Figure 8 In this context, the parameter msg1-FDM=4 indicates that the frequency domain resource index of RO is index 0, index 1, index 2, index 3 on one time domain resource of RO.

[0172] The parameter ssb-perRACH-Occasion = 1 / 4 (i.e., N = 1 / 4) means that 1 SSB maps to 4 ROs.

[0173] Therefore, following the ascending order of the frequency domain resource indexes, SSB 0 is mapped sequentially to four ROs. That is, the time domain resource index of the RO is index 0, and the frequency domain resource indexes are index 0, index 1, index 2, and index 3 of the RO.

[0174] Since there are 8 SSBs, and the SSBs have not yet been mapped, according to the above "mapping principle", SSB 1 is mapped to the 4 ROs in the order of increasing frequency domain resource index. That is, when the time domain resource index of the RO is index1, the frequency domain resource indexes are index0, index1, index2, and index3 of the RO, and so on.

[0175] Example 2:

[0176] Taking a cell with 8 SSBs configured, each with indices from 0 to 7, and parameters msg1-FDM = 4 and ssb-perRACH-Occasion = 1 as an example, the mapping relationship between SSBs and ROs in this case is as follows: Figure 9 As shown.

[0177] exist Figure 9 In this context, the parameter msg1-FDM=4 indicates that the frequency domain resource index of RO is index 0, index 1, index 2, index 3 on one time domain resource of RO.

[0178] The parameter ssb-perRACH-Occasion=1 indicates that one SSB maps to one RO. Therefore, following the ascending order of the frequency domain resource index, SSBs 0 to 3 are sequentially mapped to ROs with time domain resource index 0 and frequency domain resource indices of index 0, index 1, index 2, and index 3. That is, when SSB 0 maps to RO with time domain resource index index 0, it is mapped to RO with frequency domain resource index index 0, and so on.

[0179] Since there are 8 SSBs, and the SSBs have not yet been mapped, according to the above "mapping principle", SSBs 4 to 7 are mapped sequentially to the ROs with time domain resource index 2 and frequency domain resource indices index 0, index 1, index 2, and index 3 in ascending order of frequency domain resource index, and so on.

[0180] Example 3:

[0181] Taking a cell with 8 SSBs configured, each with indices from 0 to 7, parameters msg1-FDM = 4 and ssb-perRACH-Occasion = 2 as an example. In this case, the mapping relationship between SSBs and ROs is as follows: Figure 10 As shown.

[0182] exist Figure 10In this context, the parameter msg1-FDM=4 indicates that the frequency domain resource index of RO is index 0, index 1, index 2, index 3 on one time domain resource of RO.

[0183] The parameter ssb-perRACH-Occasion=2 indicates that 2 SSBs are mapped to 1 RO.

[0184] The specific mapping is as follows:

[0185] SSB 0 / 1 maps to RO with time-domain resource index 0 and frequency-domain resource index 0 on RO. SSB 2 / 3 maps to RO with time-domain resource index 0 and frequency-domain resource index 1 on RO. SSB 4 / 5 maps to RO with time-domain resource index 0 and frequency-domain resource index 2 on RO. SSB 6 / 7 maps to RO with time-domain resource index 0 and frequency-domain resource index 3 on RO.

[0186] The same logic applies to the rest.

[0187] (7) CSI-RS Association (or Mapping) RO

[0188] Similar to SSB, CSI-RS IDs correspond to beams. If the random access procedure is triggered by a higher layer request and the CSI-RS index is associated with an RO, then if the parameter ra-PreambleIndex is not 0, the parameter ra-OccasionList indicates the set of ROs associated with that CSI-RS index.

[0189] (8) Transmission of Msg1

[0190] During random access, the terminal device can use RO to transmit (bear) Msg1. There are three ways to trigger the random access process:

[0191] ●PDCCH order trigger: The network device notifies the terminal device through a special DCI format 1_0 that a random access procedure needs to be initiated, and informs the terminal device of the ra-PreambleIndex, SSB Index, PRACH MaskIndex, and UL / SUL Indicator indicating whether UL or SUL should be used.

[0192] ●MAC layer trigger: The terminal device selects RApreamble to initiate a random access procedure.

[0193] ●RRC layer triggers: such as initial access, re-establishment, handover, RRC_INACTIVE to RRC_CONNECTED state transition, requests to other SIs, and requests during RRC synchronization reconfiguration.

[0194] When a terminal device needs to transmit Msg1, it needs to perform the following operations:

[0195] 1) Select SSB or CSI-RS

[0196] It should be noted that the range of values ​​for the RApreamble index is associated (mapped / corresponding) with the SSB index or CSI-RS index, and the SSB index or CSI-RS index is mapped to the RO.

[0197] ① Select SSB

[0198] The terminal device can obtain the SS-RSRP of an SSB through channel estimation, and then compare the SS-RSRP of the SSB with the parameter rsrp-ThresholdSSB. If there is an SSB whose SS-RSRP is greater than the parameter rsrp-ThresholdSSB, the terminal device selects that SSB; otherwise, the terminal device arbitrarily selects an SSB.

[0199] If multiple SSBs have an SS-RSRP greater than the parameter rsrp-ThresholdSSB, the terminal device may arbitrarily select one SSB from among these multiple SSBs.

[0200] The above is merely an example of a strategy for selecting an SSB, and the embodiments of this application do not limit the strategy for selecting an SSB.

[0201] ② Select CSI-RS

[0202] When selecting a CSI-RS, the CSI-RSRP of the CSI-RS is compared with the parameter rsrp-ThresholdCSI-RS. If there is a CSI-RS whose CSI-RSRP is greater than the parameter rsrp-ThresholdCSI-RS, the terminal device selects that CSI-RS.

[0203] 2) Select RA preamble index

[0204] The RA preamble index can be selected by the terminal device or indicated by the network device.

[0205] 3) Select the PRACH resource to carry (transmit) the RApreamble.

[0206] 4) Determine the corresponding RA-RNTI

[0207] The time-frequency resource location of the RO determines the RA-RNTI value. After transmitting the RA preamble, the terminal device calculates the RA-RNTI based on the time-frequency resource location of the RO in order to receive the RAR scrambled with the RA-RNTI. The RA-RNTI calculation formula is as follows (not applicable to contention-free random access preambles for beam failure recovery requests):

[0208] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0209] Wherein, s_id is the index of the first OFDM symbol of RO (0≤s_id<14), t_id is the index of the first slot of RO in the system frame (0≤t_id<80), f_id is the index of RO in the frequency domain (0≤f_id<8), and ul_carrier_id is the UL carrier used for RA preamble transmission (0 indicates normal uplink carrier, 1 indicates SUL carrier).

[0210] 5) Determine the target received power of the RA preamble.

[0211] 4. A communication method

[0212] 3GPP standards typically assume that the antenna gain of terminal devices in NTN communication systems is 0 dBi. However, in actual communication, the antenna gain of terminal devices often falls short of this requirement. Because the antenna gain of the terminal device cannot meet the requirements, the network device may fail to successfully receive the random access request message (such as message 1 or Msg1) sent by the terminal device during random access. Therefore, it is necessary to enhance the coverage of the NTN communication system to ensure the successful transmission of random access request messages.

[0213] Based on this, in this embodiment of the application, by introducing indication information, the network device can indicate to the terminal device the number of repetitions of the random access request message for the SSB index or SSB configuration. Then, the terminal device can send the random access request message to the network device multiple times (or repeatedly) according to the number of repetitions of the random access request message corresponding to the selected SSB. This helps to achieve coverage enhancement, improve the transmission reliability of the random access request message, and increase the probability of successful random access by the terminal device.

[0214] The specific implementation is as follows:

[0215] ●For network devices

[0216] Network devices can send indication information that indicates the number of times a random access request message is repeated, and the number of repetitions of the random access request message corresponds to (is associated with or mapped to) the SSB index.

[0217] It should be noted that, in the embodiments of this application, the indication information can be used to indicate the number of times the random access request message is repeated, or it can be replaced by the following description: the indication information can be used to configure the number of times the random access request message is repeated.

[0218] ●For terminal devices

[0219] The terminal device can receive the indication information and send a random access request message according to the number of times the random access request message is repeated.

[0220] The following explanation uses Msg1 as an example of a random access request message.

[0221] It should be noted that the number of repetitions of Msg1 configured for different SSB indexes on network devices can vary because:

[0222] Within the same cell, different beams correspond to different antenna elevation angles, and the distance between the coverage area of ​​each beam and the satellite also varies. Therefore, the signal strength of different beams also differs; for example, the signal strength at the center of the satellite coverage is greater than the signal strength at the edge. Since random access uses beams, the number of Msg1 repetitions required may differ when a terminal device performs random access in the coverage area of ​​different beams.

[0223] Since each beam can correspond to at least one SSB, network devices can configure the number of times Msg1 is repeated for the SSB index in a cell. During random access, the number of times Msg1 is repeated for the SSB index corresponding to the beam can be used. This can also be understood as the number of times Msg1 is repeated for the SSB index in the cell.

[0224] When the beam scanning signal of the SSB covers the terminal device, the terminal device has the opportunity to transmit Msg1. Since the SSB associated with the beam corresponds to the number of repetitions of Msg1, the terminal device can transmit according to the number of repetitions of Msg1 corresponding to the selected SSB, thereby facilitating coverage enhancement.

[0225] Furthermore, since the beam corresponds to the RA preamble, and the beam corresponds to the SSB, the SSB needs to correspond to the RA preamble. In addition, since the RA preamble needs to be carried (or transmitted) by the RO, the SSB corresponding to the number of repetitions of Msg1 needs to be associated with the RO.

[0226] Additionally, in some embodiments, the network device selects the value of the number of repetitions of Msg1 configured for the SSB index from a set of candidate values ​​for the number of repetitions of Msg1.

[0227] The number of repetitions of Msg1 corresponding to different SSB indices can be different or the same, mainly determined by the specific implementation of the network device. In some embodiments of this application, the SSBs corresponding to the same number of repetitions of Msg1 belong to an SSB group. That is, each SSB index belonging to the same SSB group corresponds to the same number of repetitions of Msg1.

[0228] To achieve the above technical solution, the following provides further explanations of other content, concepts, and meanings that may be involved.

[0229] (1) Number of repetitions of the random access request message

[0230] It should be noted that the number of repetitions of the random access request message can be used to indicate the number of times the random access request message is transmitted multiple times (or repeatedly). For example, the number of repetitions of Msg1.

[0231] (2) First Community

[0232] The first cell in this application embodiment may be the cell where the terminal device is camped, the cell selected by the terminal device in the cell search, or the serving cell of the terminal device, etc., and there are no specific limitations on this.

[0233] In some possible implementations, the first cell can be the serving cell of the terminal device.

[0234] For example, for a terminal device in a connected state, an idle state, or an inactive state, the first cell is the serving cell of the terminal device.

[0235] In some possible implementations, the first cell can be the cell where the terminal device resides.

[0236] For example, for a terminal device initially accessing the network or a terminal device accessing the network for the first time, the first cell is the cell where the terminal device camps. It should be noted that, in this embodiment, when a terminal device initially accesses the network, the cell where the terminal camps can also be understood as the terminal device's serving cell.

[0237] For example, in response to turning off airplane mode or powering on, the terminal device initiates an initial network access process to the network device.

[0238] It should be noted that the first cell refers to the cell used to provide services to terminal devices, or it can be the cell used for terminal devices to access the network, or other terms such as target cell. As long as they have the same meaning / function / interpretation, they are all within the scope of protection claimed in the embodiments of this application.

[0239] (3) Instruction information

[0240] In order to indicate to the terminal device the number of times Msg1 is configured by the network device for the SSB index in the first cell, this application embodiment introduces indication information, through which the network device indicates or configures the number of times Msg1 is repeated for the terminal device.

[0241] It should be noted that the correspondence between the number of repetitions of Msg1 and the SSB index can be network-configured, pre-configured, protocol-specified, or explicitly or implicitly indicated, without specific restrictions.

[0242] For example, network devices can directly indicate this correspondence to terminal devices.

[0243] For example, network devices can indicate the repetition count of Msg1 according to the order of the SSB indices indicated to the terminal devices, thus implicitly indicating the correspondence to the terminal devices and helping to reduce signaling overhead. For instance, the network device sequentially indicates SSB0, SSB1, and SSB2 to the terminal devices, and then indicates the repetition count of Msg1 as 1, 2, and 3 through the indication information. In this case, the repetition count of Msg1 corresponding to SSB0 is 1, the repetition count of Msg1 corresponding to SSB1 is 2, and the repetition count of Msg1 corresponding to SSB2 is 3.

[0244] In addition, the instruction information may also be described using other terms, such as first information, configuration information, etc. As long as they have the same meaning / function / interpretation, they are all within the scope of protection claimed in the embodiments of this application.

[0245] In some possible implementations, the indication information may be sent or received during processes such as cell search, cell reselection, uplink / downlink synchronization, cell access, cell camping, initial access, or uplink / downlink resource scheduling.

[0246] In some possible implementations, the indication information can be carried by system information (SI), higher-layer signaling (such as RRC signaling), terminal device-specific signaling, etc.

[0247] For example, a network device can broadcast system information that carries the instruction information, thereby configuring the number of repetitions of Msg1 through broadcasting.

[0248] (4) SSB Index and SSB Group

[0249] In this embodiment, the SSB index can be indicated to the terminal device by the network device through system information or higher-layer parameters, thereby enabling the network device to configure the SSB for the terminal device. For example, the network device can indicate the SSB index to the terminal device during processes such as cell search, cell reselection, uplink / downlink synchronization, cell access, cell camping, initial access, or uplink / downlink resource scheduling.

[0250] For example, network devices can indicate the SSB index of multiple SSBs in a first cell to terminal devices through system information or higher-level parameters.

[0251] For example, during cell search, network devices indicate the first cell to the terminal device via SIB1 or the ssb-PositionsInBurst parameter in ServingCellConfigCommon. The SSB index of each SSB enables the configuration of SSBs on the terminal device.

[0252] Furthermore, in some embodiments, the network device of this application can configure the repetition count of Msg1 corresponding to an SSB for the terminal device according to SSB groups. For example, if the indication information indicates P0, where P0 is a positive integer greater than or equal to 1, and P0 corresponds to SSB group 1, which includes SSB1, SSB2, and SSB3, then the repetition count of Msg1 corresponding to SSB1, SSB2, and SSB3 is all P0. In this case, P0 corresponds to the repetition count of Msg1 for SSB1, SSB2, and SSB3. This method helps to save signaling overhead. It should be noted that in the embodiments of this application, the number of SSBs in different SSB groups can be the same or different, and this is not limited.

[0253] (5)K i and K j

[0254] Of course, in this embodiment, the repetition count of Msg1 corresponding to an SSB can also be configured for the terminal device according to the SSB. For example, the indication information indicates P1 and P2, where P1 corresponds to SSB1 and P2 corresponds to SSB2. In this case, the repetition count of Msg1 corresponding to SSB1 is P1, and the repetition count of Msg1 corresponding to the SSB index of SSB2 is P2. P1 and P2 can be the same or different. Both P1 and P2 are positive integers greater than or equal to 1. It should be understood that in this embodiment, the indication information can indicate only the repetition count of one Msg1 or the repetition count of multiple Msg1s, and there is no limitation on this.

[0255] For example, the indication information is used to indicate K. i Ki This represents the number of repetitions of Msg1 corresponding to SSB index i, where the SSB identified by SSB index i is the SSB in the first cell, 1 ≤ i ≤ M, i is a positive integer, and M is the total number of SSBs in the first cell. For example, the indication information is used to indicate K. i and K j Regarding K i Please refer to the above-mentioned introduction; it will not be repeated here. K j Msg1 represents the number of repetitions of Msg1 corresponding to SSB index j, where the SSB identified by SSB index j is the SSB in the first cell, and the SSB identified by SSB index j is different from the SSB identified by SSB index i, that is, j and i are different values. 1≤j≤M, and j is a positive integer.

[0256] Furthermore, in some embodiments, the number of repetitions of Msg1 corresponding to different SSB indices is different. Take SSB index i and SSB index j as examples. SSB index i corresponds to K... i SSB index j corresponds to K j When the number of repetitions of Msg1 corresponding to different SSB indices is different, K i With K j They are different. Or, the number of repetitions of Msg1 corresponding to different beams' SSBs is different. Take SSB index i and SSB index j as examples. SSB index i corresponds to K... i SSB index j corresponds to K j If the beam corresponding to the SSB identified by SSB index i is different from the beam corresponding to the SSB identified by SSB index j, then K i With K j Different. In some embodiments, if the beam corresponding to the SSB identified by SSB index i and the beam corresponding to the SSB identified by SSB index j are the same, then K i With K j They can be different, or they can be the same.

[0257] In other embodiments of this application, the network device can select the number of repetitions of Msg1 corresponding to the SSB index from the candidate value set of Msg1 repetition counts, as indicated by the terminal device. The candidate value set of Msg1 repetition counts can be predefined by a protocol, determined by the network device based on an algorithm or strategy, or indicated by other devices or servers; there is no limitation on this. For example, the candidate value set of Msg1 repetition counts may include at least one candidate value. For instance, each candidate value is a power of 2. In this case, the candidate value set of Msg1 repetition counts is the set {1, 2, 4, 8, 16, ..., 2}. nFor example, the value of n can be predefined, predefined by the protocol, determined by the network device based on a certain algorithm or policy, or indicated by other devices or servers; there are no specific restrictions on this.

[0258] For example, consider SSB index i. SSB index i corresponds to K. i K i =2 a , where a is a positive integer greater than or equal to 0.

[0259] Alternatively, in some other embodiments of this application, the number of repetitions of Msg1 corresponding to the SSB index is a power of 2. For example, consider SSB index i. SSB index i corresponds to K i K i =2 a 'a' is a positive integer greater than or equal to 0. For example, consider SSB index j. SSB index j corresponds to K. j K j =2 b b is a positive integer greater than or equal to 0.

[0260] (6) PRACH time and frequency resources

[0261] When a terminal device performs random access, it needs to use the corresponding PRACH time-frequency resources. These resources are then divided to obtain at least one RO (Redirect Access Request). The RO is used to transmit or carry random access request messages. ROs include time-domain resources and frequency-domain resources. Specifically, time-domain resources can be indicated by their indexes, and frequency-domain resources can be indicated by their indexes.

[0262] PRACH time-frequency resources can be configured by network devices to terminal devices through higher-layer parameters. For example, network devices can configure these resources to terminal devices during processes such as cell search, cell reselection, uplink / downlink synchronization, cell access, cell camping, initial access, or uplink / downlink resource scheduling.

[0263] For example, in conjunction with the content of “(4) PRACH time and frequency resources” above, it can be seen that in this embodiment of the application, the network device can configure the time domain location or time domain resources of the RO through the parameter prach-ConfigurationIndex in the higher layer parameter RACH-ConfigGeneric, and configure the frequency domain location or the number of frequency domain resource indices of the RO through the parameters msg1-FrequencyStart and msg1-FDM in the higher layer parameter RACH-ConfigGeneric, thereby realizing the configuration of PRACH time and frequency resources.

[0264] (7) Mapping relationship between SSB index and RO

[0265] In existing 3GPP standards, the mapping relationship between SSB and RO is not applicable to multiple (or repeated) transmissions of Msg1. If the terminal device needs to transmit Msg1 multiple times (or repeatedly), the existing standard protocol specified by 3GPP will no longer be applicable. Therefore, this application embodiment needs to re-examine the mapping relationship between SSB index and RO corresponding to the number of repetitions of Msg1.

[0266] Based on this, in this embodiment of the application, the mapping between the SSB index and RO can be specifically implemented as follows:

[0267] ◆Determine the mapping order of SSB index mapping RO in the first cell.

[0268] The network device can indicate (configure) the SSBs of the first cell to the terminal device, for example, indicating M SSBs of the first cell to the terminal device. In this embodiment, the terminal device can sequentially map the ROs corresponding to the SSBs according to the following mapping order.

[0269] For example, the mapping order can be as follows:

[0270] ◆One approach is to sort SSB indexes in descending order based on the number of times Msg1 is repeated, and to sort SSB indexes with the same number of repetitions in ascending order.

[0271] For example, the network device indicates to the terminal device via system information the number of repetitions (K) of Msg1 corresponding to the SSB index (SSBi, i = 0, 1, 2, ..., 5) used to identify the SSB in the first cell. i For example, the correspondence between the SSB index and the number of repetitions of Msg1 is as follows: That is, the number of repetitions of Msg1 corresponding to SSB0 is 8, the number of repetitions of Msg1 corresponding to SSB1 is 2, and so on.

[0272] Then, sort the SSB indexes in descending order based on the number of times Msg1 is repeated, with SSB indexes having the same number of Msg1 repetitions sorted in ascending order. The correspondence between the reordered SSB indexes and the number of Msg1 repetitions is as follows: Therefore, the mapping order is as follows: SSB0→SSB4→SSB5→SSB1→SSB2→SSB3.

[0273] ◆Another method is to sort the SSB indexes in ascending order based on the number of times Msg1 is repeated, with SSB indexes having the same number of repetitions being sorted in ascending order.

[0274] ◆Another method is to sort the SSB indexes in descending order based on the number of times Msg1 is repeated, with SSB indexes having the same number of repetitions being sorted in descending order.

[0275] ◆Another method is to sort the SSB indexes in ascending order based on the number of times Msg1 is repeated, and then sort the SSB indexes with the same number of repetitions in descending order.

[0276] Alternatively, embodiments of this application can also map ROs corresponding to SSBs sequentially at the SSB group level. Specifically, the mapping order can be as follows:

[0277] ◆One approach is to sort in descending order based on the number of times Msg1 is repeated in each SSB group, and in ascending order based on the SSB index within the same SSB group.

[0278] ◆Another method is to sort in descending order based on the number of times Msg1 is repeated in each SSB group, and also sort in descending order based on the SSB index within the same SSB group.

[0279] ◆Another method is to sort in ascending order based on the number of times Msg1 is repeated in each SSB group, and also sort in ascending order based on the SSB index within the same SSB group.

[0280] ◆Another method is to sort in ascending order based on the number of times Msg1 is repeated in each SSB group, and in descending order based on the SSB index within the same SSB group.

[0281] etc.

[0282] ◆The temporal resource index of RO is divided into RO groups based on the maximum number of repetitions of Msg1 corresponding to each SSB index in the first cell. In other words, an RO group includes K ROs in the temporal domain, where K is the maximum number of repetitions of at least one Msg1 indicated by the network device to the terminal device.

[0283] This application embodiment requires partitioning the time-domain resource index of RO in the PRACH time-frequency resources.

[0284] Taking the example of a network device indicating the temporal resource indexes of multiple Resource Objects (ROs) to a terminal device via the higher-layer parameter `prach-ConfigurationIndex`, when the maximum value of the repetition count of Msg1 corresponding to the SSB index in the first cell is K, RO groups are obtained by dividing the data into groups based on the temporal resource indexes of these K ROs, so that the SSB indexes can be mapped sequentially within each RO group. For example, if the maximum value of the repetition count of Msg1 corresponding to the SSB index in the first cell is K=8, the temporal resource indexes of the ROs in the first RO group are index 0, index 1, index 2, index 3, index 4, index 5, index 6, and index 7, and the temporal resource indexes of the ROs in the second RO group are index 8, index 9, index 10, index 11, index 12, index 13, index 14, and index 15, and so on.

[0285] Network devices can indicate the number of frequency domain resource indices of a Resource Oriented (RO) to the terminal device through the msg1-FDM parameter in the higher-layer parameter RACH-ConfigGeneric. For example, msg1-FDM=4 indicates that the frequency domain resource indices of the RO are index 0, index 1, index 2, and index 3 for one time domain resource of the RO.

[0286] ◆The mapping relationship between the SSB index and RO in the first cell can be determined by the high-layer parameters.

[0287] It should be noted that, in conjunction with the above content of "(6) SSB association (mapping / correspondence, etc.) RO and SSB association (mapping / correspondence, etc.) RA preamble", the higher layer can configure N (e.g., N is configured by the L1 parameter SSB-per-rach-occasion) SSB association (mapping / correspondence) to one RO, and each of the N SSBs associates (mapping / corresponds) R (e.g., R is configured by the L1 parameter CB-preambles-per-SSB) RA preamble index.

[0288] The N SSBs are selected from the SSBs in the first cell.

[0289] In some possible implementations, N can take the value of 1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, or 16.

[0290] If N < 1, it means that one SSB can be mapped to N ROs; if N = 1, it means that one SSB can be mapped to one RO; if N > 1, it means that one RO can be mapped to at most N SSBs.

[0291] For example, when N>1, the mapping rules for the SSB index are as follows.

[0292] In some possible implementations, when N > 1, the N SSBs mapped by the same RO are distinguished by the RA preamble index. The following mapping rules may exist:

[0293] ◆T is the number of time-domain resource indexes of RO, that is, the time-domain resource indexes of T RO in the RO group, where T is the maximum value of the repetition count of Msg1 corresponding to each of the N SSB indexes, and the N SSBs are mapped according to the time-domain resource indexes of the T ROs.

[0294] If there is an SSB index in the time domain resource index of the T ROs that maps to one of the N SSB indexes, then the RA preamble index associated with the one SSB mapped by the RO starts from 0;

[0295] If there are two SSB indices in the time domain resource index of the T ROs that are mapped to the N SSB indices, then the two SSBs mapped by the ROs are distinguished by the RA preamble index.

[0296] If there are S (2≤S≤N) SSB indices in the time-domain resource indexes of the T ROs that are mapped to the N SSB indices, then the S S SSBs mapped by the ROs are distinguished by the RA preamble index.

[0297] In summary, the ROs mapped by the N SSB indices may be the same or different.

[0298] If N SSB indices each map to the same RO, then the N SSB indices are distinguished by the RApreamble index in the same (identical) RO.

[0299] For example, when N=2, it means that 2 SSBs are mapped to 1 RO. If SSB0 and SSB1 need to be mapped to the same RO, and the Msg1 corresponding to SSB0 has a repetition count of 8, and the Msg1 corresponding to SSB1 has a repetition count of 4, then 8 is used as the number of time-domain resource indices of the RO, that is, the time-domain resource indices of the 8 ROs in the RO group, and the 2 SSBs are mapped according to the time-domain resource indices of the 8 ROs.

[0300] In the time-domain resource index of the eight ROs, the first four ROs are mapped to SSB0 and SSB1, and are distinguished by RA preambleindex. The latter four ROs are mapped to only SSB0, and the RA preambleindex associated with the SSB0 mapped by the latter four ROs starts from 0.

[0301] ◆SSB index maps RO in ascending order according to the RA preamble index.

[0302] It is understandable that the mapping relationship between SSB and RO can follow the following: the order of RA preamble index in an RO is increasing, and SSB is mapped according to the increasing order (ascending order) of RA preamble index in the RO.

[0303] ◆The SSB index is mapped to ROs, with mapping done at the granularity of RO groups. Each RO group comprises K ROs in the time domain, where K is the maximum number of repetitions of Msg1. First, mapping is performed sequentially within the RO groups with the smallest time-domain resource index (index 0 to K-1), following the ascending order of time-domain resource index. Next, after all ROs in the RO groups with the smallest frequency-domain resource index (index 0 to K-1) have been mapped, a new frequency-domain resource index and / or time-domain resource index are added to obtain the next RO group. Mapping continues sequentially within these RO groups, following the ascending order of time-domain resource index, and so on. The repetition counts of Msg1 corresponding to the SSB index are packaged and mapped across the time domain.

[0304] For example, if the repetition count of Msg1 corresponding to SSB0 is 8, and N = 1 / 2, it means that 1 SSB is mapped to 2 ROs. The parameter msg1-FDM = 4 indicates that the frequency domain resource indices of the ROs are index 0, index 1, index 2, and index 3 on one time-domain resource of the RO. First, on the RO group with the smallest frequency domain resource index (index 0-7), i.e., the RO group with the smallest frequency domain resource index (index 0), the ROs corresponding to SSB0 are mapped sequentially in ascending order of time domain resource index. After all the ROs in the RO group with the smallest frequency domain resource index are mapped, a frequency domain resource index is added to obtain the RO group with the frequency domain resource index index 1. Then, the ROs corresponding to SSB0 are mapped sequentially in ascending order of time domain resource index. After the ROs corresponding to SSB0 are mapped, if all the RO groups with the frequency domain resource index index 1 are mapped, the frequency domain resource index is continued to be added.

[0305] It is understood that, in this embodiment of the application, the mapping between the SSB index and the RO is performed sequentially at the RO group level.

[0306] (8) Send Msg1

[0307] It should be noted that, in this embodiment of the application, Msg1 can be sent according to the number of repetitions of Msg1 to achieve coverage enhancement.

[0308] The following example demonstrates configuring K from a network device to a terminal device. i Let's take an example to illustrate this in detail.

[0309] In practical implementation, the terminal device can determine K... i Send Msg1.

[0310] Furthermore, since Msg1 needs to be carried (or transmitted) by RO, in order to achieve repeated transmission of Msg1, this embodiment of the application also needs to be based on K. i Multiple Return Entities (ROs) are identified, and Msg1 is transmitted through at least one of the ROs to achieve multiple (or repeated) transmissions of Msg1.

[0311] For example, according to K i Determine M i One RO, K i ≤M i ≤K i *L; where L = N, N > 1; or, L = 1 / N, N ≤ 1; N can be used to indicate the mapping relationship between the SSB indicated by SSB index i and RO; select M i K in RO i One RO sends Msg1.

[0312] It should be noted that, in conjunction with the content of “(7) Mapping relationship between SSB index and RO” above, N can be configured by high-level parameters (such as the L1 parameter SSB-per-rach-occasion).

[0313] In some embodiments, the terminal device may determine Mi ROs based on Ki in the following manner:

[0314] ◆If K i =K, and N≤1, then M i Each RO is divided into 1 / N RO groups. Each RO group includes K ROs in the time domain, where K can be the maximum number of repetitions of the random access request message indicated by the indication information.

[0315] It should be noted that the RO group includes the ROs whose time-domain resources are identified by the time-domain resource indexes of K ROs. In other words, the RO group includes K ROs in the time domain.

[0316] In addition, K i =K, indicating the number of times Msg1 corresponding to SSB index i is repeated (i.e., K). i The maximum value is ). Additionally, N ≤ 1, indicating that one SSB can map N ROs. Since this embodiment requires dividing the temporal resource index of ROs using the maximum repetition count of Msg1 corresponding to each SSB index in the first cell as the granularity, this embodiment can divide the temporal resource index of ROs based on K. i Identify 1 / N RO groups, each of which includes K ROs in the time domain. Select one RO group from these 1 / N RO groups to obtain K ROs, so that Msg1 can be transmitted multiple times (or repeatedly).

[0317] ◆If N>1, or if N≤1 and K i / N≤K, then M i Each RO is located in the same RO group, and the RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

[0318] It should be noted that the RO group includes time-domain resource indices for K ROs. In other words, the RO group includes K ROs in the time domain. Each RO includes both time-domain and frequency-domain resources; time-domain resources can be indicated by their time-domain resource indices, and frequency-domain resources by their frequency-domain resource indices.

[0319] Furthermore, N>1 indicates that one RO can map N SSBs. In this case, the embodiments of this application can be based on K. i The determined M i If ROs are located in the same RO group, then K can be selected from the same RO group. i There are ROs to allow for multiple (or repeated) transmissions of Msg1. The RO group is divided into time-domain resource indexes of the ROs based on the maximum number of repetitions of Msg1.

[0320] Similarly, N≤1 means that one SSB can map to N ROs. Additionally, K i / N≤K indicates the number of times Msg1 corresponding to SSB index i is repeated (i.e., K). i The value is not the maximum. In this case, the embodiments of this application can be based on K. i The determined M i If ROs are located in the same RO group, then K can be selected from the same RO group. i There are ROs to allow for multiple (or repeated) transmissions of Msg1. The RO group is divided into time-domain resource indexes of the ROs based on the maximum number of repetitions of Msg1.

[0321] ◆If N>1, then the same RO corresponds to N SSBs.

[0322] It should be noted that N>1 means that one RO can map N SSBs.

[0323] ◆The number of repetitions of Msg1 corresponding to the N SSBs of the same RO are either the same or different.

[0324] It should be noted that one RO can map to N SSBs, and the number of repetitions of Msg1 corresponding to each of the N SSBs can be the same or different.

[0325] ● One method is that the terminal device determines the ROs sequentially according to the descending order of the number of repetitions of Msg1 corresponding to the SSB index. For SSB indexes with the same number of repetitions of Msg1, the terminal device determines the ROs in ascending order.

[0326] It should be noted that, based on the content of “(7) Mapping relationship between SSB index and RO” above, the mapping order can be sorted in descending order according to the number of repetitions of Msg1 corresponding to each SSB index, wherein SSB indexes with the same number of repetitions are sorted in ascending order.

[0327] ●Another method is: The terminal device determines the ROs sequentially according to the ascending order of the number of repetitions of Msg1 corresponding to the SSB index. The terminal device determines the ROs for SSB indexes with the same number of repetitions of Msg1 in ascending order.

[0328] It should be noted that, based on the content of “(7) Mapping relationship between SSB index and RO” above, the mapping order can be sorted in ascending order according to the number of repetitions of Msg1 corresponding to each SSB index, wherein SSB indexes with the same number of repetitions are sorted in ascending order.

[0329] ●Another method is: The terminal device determines the ROs sequentially according to the number of repetitions of Msg1 corresponding to the SSB index in descending order. The terminal device determines the ROs for SSB indexes with the same number of repetitions of Msg1 in descending order.

[0330] It should be noted that, in conjunction with the above content on "(7) Mapping relationship between SSB index and RO", the mapping order can be sorted in descending order according to the number of repetitions of Msg1 corresponding to each SSB index, wherein SSB indexes with the same number of repetitions are sorted in descending order.

[0331] ●Another method is: The terminal device determines the ROs sequentially according to the number of repetitions of Msg1 corresponding to the SSB index in ascending order. For SSB indexes with the same number of repetitions of Msg1, the terminal device determines the ROs in descending order.

[0332] It should be noted that, based on the content of “(7) Mapping relationship between SSB index and RO” above, the mapping order can be sorted in ascending order according to the number of repetitions of Msg1 corresponding to each SSB index, and SSB indexes with the same number of repetitions are sorted in descending order.

[0333] (9) Examples

[0334] The following embodiments of this application will provide examples of the contents of “(7) Mapping relationship between SSB index and RO” and “(8) Sending Msg1”.

[0335] Example 1:

[0336] like Figure 11 As shown, the signal transmitted by satellite 1110 forms at least six beams in the cell: beams 1121, 1122, 1123, 1124, 1125, and 1126. Each of these six beams corresponds to a Special Service Bus (SSB): beam 1121 corresponds to SSB0, beam 1122 to SSB1, beam 1123 to SSB2, beam 1124 to SSB3, beam 1125 to SSB4, and beam 1126 to SSB5. Therefore, there are at least six SSB indices in the cell.

[0337] Network devices configure the number of repetitions (K) of Msg1 for each of the six SSB indices in the cell using system information. i ),Right now

[0338] The indices of the time-domain resources configured by the network device for the terminal device via higher-level parameters (such as SSB-per-rach-occasion) and via higher-level parameters (such as prach-ConfigurationIndex) are index 0, index 1, index 2, index 3, index 4, index 5, index 6, index 7, index 8, index 9, index 10, index 11, index 12, index 13, index 14, index 15, ..., and the indices of the frequency-domain resources configured by the network device for the terminal device via higher-level parameters (such as msg1-FDM=4) are index 0, index 1, index 2, index 3, respectively. The time-domain resources identified by two adjacent time-domain resource indices can be continuous or non-contiguous.

[0339] When these 6 SSB indexes are mapped to RO, the specific implementation is as follows:

[0340] ◆ Sort the Msg1 repetition counts of each of the 6 SSB indexes in descending order, and sort the SSB indexes with the same repetition count in ascending order. The sorted SSB indexes are as follows: Therefore, the mapping order is as follows: SSB0→SSB4→SSB5→SSB1→SSB2→SSB3.

[0341] ◆The maximum number of repetitions of Msg1 corresponding to each of the six SSB indices is 8. Therefore, the time-domain resource indices of the ROs are index0 to 15, etc. ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 0 to 7 belong to one RO group; ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 8 to 15 belong to another RO group, and so on. In other words, an RO group includes the time-domain resource indices of 8 ROs.

[0342] ◆The six SSB indices are first mapped sequentially within the RO group with the smallest frequency domain resource index (index 0-7) and time domain resource index (index 0). This mapping is performed in ascending order of time domain resource index. Next, after mapping all ROs within the RO group with the smallest frequency domain resource index (index 0-7), a new frequency domain resource index is added, resulting in the next RO group with index 1. Mapping is then continued sequentially within the RO group in ascending order of time domain resource index, and so on. The number of repetitions of Msg1 corresponding to the SSB index is packaged and mapped across the time domain range.

[0343] ◆The six SSB indices are mapped sequentially in ascending order of time-domain resource indexes, starting with indexes 0-7 and increasing the frequency-domain resource index to its maximum value (i.e., RO group with frequency-domain resource index index 3). Then, eight more ROs are added to the time-domain resource indexes to create the next RO group, with time-domain resource indices ranging from index 8 to index 15 and frequency-domain resource index index 0. Similarly, in the RO group with time-domain resource indices ranging from index 8 to index 15 and frequency-domain resource index index 0, mapping is performed sequentially in ascending order of time-domain resource indexes. After all ROs with time-domain resource indices ranging from index 8 to index 15 and frequency-domain resource index index 0 are mapped, a new frequency-domain resource index is added to create the next RO group (with frequency-domain resource index index 1). Mapping continues sequentially in ascending order of time-domain resource indexes, and so on. The repetition count of Msg1 corresponding to the SSB index is packaged and mapped across the time-domain range.

[0344] Case 1: N < 1

[0345] If N = 1 / 2, it means that each of the 6 SSBs is mapped to 2 ROs.

[0346] The specific mapping details are as follows:

[0347] 1) Mapping SSB0

[0348] Following the mapping order, SSB0 is mapped first. The number of repetitions (K0) of Msg1 corresponding to SSB0 is 8.

[0349] On the RO group with time-domain resource indices of index 0 to 7 and the smallest frequency-domain resource index, i.e., the RO group with frequency-domain resource index of index 0, the RO corresponding to SSB0 is mapped sequentially in ascending order of time-domain resource index. After all the ROs in the RO group with the smallest frequency-domain resource index are mapped, a frequency-domain resource index is added to obtain the RO group with frequency-domain resource index of index 1. Then, the RO corresponding to SSB0 is mapped sequentially in ascending order of time-domain resource index.

[0350] SSB0 maps all 8 ROs together on the RO group with frequency domain resource index index0. At this point, SSB0 maps all 8 ROs in this RO group, such as... Figure 12 As shown. Among them, Figure 12 The 8 ROs within the dashed box in the image form an RO group, which is the RO group with index 0 to 7 in the time domain and index 0 in the frequency domain.

[0351] Since N = 1 / 2, SSB0 needs to be mapped to 2 ROs. At this point, SSB0 is packaged and mapped again as a whole.

[0352] Additionally, since 8 SSB0s have already been mapped on the RO group with frequency domain resource index 0, a new frequency domain resource index is added for mapping, specifically mapping on the RO group with frequency domain resource index 1, as follows: Figure 13 As shown. Among them, Figure 13 The eight ROs within the dashed box represent a group of ROs after the addition of a frequency domain resource index, i.e., a group of ROs with index 0 to 7 in the time domain and index 1 in the frequency domain.

[0353] 2) Mapping SSB4

[0354] Following the mapping order, after SSB0 is mapped, SSB4 is mapped next. The number of repetitions (K4) of Msg1 corresponding to SSB4 is 4.

[0355] SSB4 maps the RO group with 4 ROs as a whole on the frequency domain resource index index2, such as Figure 14 As shown. Among them, Figure 14 The eight ROs within the dashed box form a group of ROs after the addition of a frequency domain resource index, i.e., the RO group with index 0 to 7 in the time domain and index 2 in the frequency domain.

[0356] Since N = 1 / 2, SSB4 needs to be mapped to 2 ROs. At this point, SSB4 is packaged and mapped again as a whole.

[0357] Additionally, since four SSB4s have already been mapped to the RO group with frequency domain resource index 2, and the RO group is not fully mapped, mapping will continue on this RO group, such as... Figure 15 As shown.

[0358] 3) Mapping SSB5

[0359] Following the mapping order, after SSB4 is mapped, SSB5 is mapped next. The number of repetitions (K5) of Msg1 corresponding to SSB5 is 4.

[0360] SSB5 maps the RO group with 4 ROs as a whole, with the frequency domain resource index being index 3. Figure 16 As shown. Among them, Figure 16 The eight ROs within the dashed box form a group of ROs after the addition of a frequency domain resource index, i.e., the RO group with index 0 to 7 in the time domain and index 3 in the frequency domain.

[0361] Since N = 1 / 2, SSB5 needs to be mapped to 2 ROs.

[0362] Similar to the above, such as Figure 17 As shown.

[0363] 4) Mapping SSB1

[0364] Following the mapping order, after SSB5 is mapped, SSB1 is mapped next. The number of repetitions (K1) of Msg1 corresponding to SSB1 is 2. Since N = 1 / 2, SSB1 needs to be mapped to 2 ROs.

[0365] Since the mapping of RO groups with time-domain resource indices of index 0 to 7 and frequency-domain resource index of index 3 is complete, the time-domain resource indices are increased in ascending order. The RO groups are then divided again with a granularity of 8 RO time-domain resource indices for mapping. Figure 18 As shown. Among them, Figure 18 The eight ROs within the dashed box represent a group of ROs after the addition of a time-domain resource index, i.e., the RO group with time-domain resource indexes of index 8 to 15 and frequency-domain resource index of index 0.

[0366] Similar to the above, such as Figure 19 As shown.

[0367] 5) Mapping SSB2

[0368] Following the mapping order, after SSB1 is mapped, SSB2 is mapped next. The number of repetitions (K2) of Msg1 corresponding to SSB2 is 2. Since N = 1 / 2, SSB2 needs to be mapped to 2 ROs.

[0369] Similar to the above, such as Figure 20 As shown. Among them, Figure 20 The eight ROs within the dashed box form one RO group, which is the RO group with index 8 to 15 in the time domain and index 0 in the frequency domain.

[0370] Similar to the above, such as Figure 21 As shown.

[0371] 5) Mapping SSB3

[0372] Following the mapping order, after SSB2 is mapped, SSB3 is mapped next. The number of repetitions (K3) of Msg1 corresponding to SSB3 is 2. Since N = 1 / 2, SSB3 needs to be mapped to 2 ROs.

[0373] Similar to the above, such as Figure 22 As shown. Among them, Figure 22 The eight ROs within the dashed box form a group of ROs after the addition of a frequency domain resource index, i.e., the RO group with indexes 8 to 15 in the time domain and index 1 in the frequency domain.

[0374] Similar to the above, such as Figure 23 As shown.

[0375] At this point, the mapping of the six SSB indices is complete.

[0376] Case 2: N=1

[0377] If N=1, it means that each of the 6 SSBs is mapped to 1 RO.

[0378] The specific mapping details are as follows:

[0379] 1) Mapping SSB0

[0380] Following the mapping order, SSB0 is mapped first. The number of repetitions (K0) of Msg1 corresponding to SSB0 is 8. Since N=1, SSB0 needs to be mapped to one RO.

[0381] On the RO group with time-domain resource indexes of index 0 to 7 and the smallest frequency-domain resource index, i.e., on the RO group with frequency-domain resource index of index 0, the RO corresponding to SSB0 is mapped sequentially in ascending order of time-domain resource index.

[0382] SSB0 is mapped as a whole in the time domain using 8 ROs, such as Figure 12 As shown.

[0383] 2) Mapping SSB4

[0384] Following the mapping order, after SSB0 is mapped, SSB4 is mapped next. The repetition count (K4) of Msg1 corresponding to SSB4 is 4. Since N=1, SSB4 needs to be mapped to one RO, such as... Figure 24 As shown. Among them, Figure 24 The eight ROs within the dashed box represent a group of ROs after the addition of a frequency domain resource index, i.e., a group of ROs with index 0 to 7 in the time domain and index 1 in the frequency domain.

[0385] 3) Mapping SSB5

[0386] Following the mapping order, after SSB4 is mapped, SSB5 is mapped next. The number of repetitions (K5) of Msg1 corresponding to SSB5 is 4. Since N=1, SSB5 needs to be mapped to one RO.

[0387] When mapping SSB5, the process is similar to the above, such as... Figure 25 As shown.

[0388] 4) Mapping SSB1

[0389] Following the mapping order, after SSB5 is mapped, SSB1 is mapped next. The number of repetitions (K1) of Msg1 corresponding to SSB1 is 2. Since N=1, SSB1 needs to be mapped to one RO.

[0390] When mapping SSB1, the process is similar to the above, such as... Figure 26 As shown. Among them, Figure 26 The eight ROs within the dashed box represent a group of ROs after the addition of a frequency domain resource index, i.e., the RO group with index 0 to 7 in the time domain and index 2 in the frequency domain.

[0391] 5) Mapping SSB2

[0392] Following the mapping order, after SSB1 is mapped, SSB2 is mapped next. The number of repetitions (K2) of Msg1 corresponding to SSB2 is 2. Since N=1, SSB2 needs to be mapped to one RO.

[0393] When mapping SSB2, the process is similar to the above, such as... Figure 27 As shown.

[0394] 5) Mapping SSB3

[0395] Following the mapping order, after SSB2 is mapped, SSB3 is mapped next. The number of repetitions (K3) of Msg1 corresponding to SSB3 is 2. Since N=1, SSB3 needs to be mapped to one RO.

[0396] When mapping SSB3, the process is similar to the above, such as... Figure 28 As shown.

[0397] At this point, the mapping of the six SSB indices is complete.

[0398] Case 3: N > 1

[0399] If N=2, it means that every 2 SSBs out of the 6 SSBs are mapped to 1 RO.

[0400] Based on the content of "① When N>1, the mapping rules of the SSB index", in addition to implementing the above, the following also needs to be implemented:

[0401] ◆The ROs mapped by each pair of SSB indices may be the same or different.

[0402] ◆If two SSB indexes map to the same RO, the two SSB indexes are distinguished by the RApreambleindex in the same RO.

[0403] The specific mapping details are as follows:

[0404] 1) Map SSB0 and SSB4

[0405] Following the mapping order, SSB0 and SSB4 are mapped first. Among them, the number of repetitions (K0) of Msg1 corresponding to SSB0 is 8, and the number of repetitions (K4) of Msg1 corresponding to SSB4 is 4.

[0406] On the RO group with time-domain resource indices of index 0 to 7 and the smallest frequency-domain resource index, i.e., on the RO group with frequency-domain resource index of index 0, the ROs corresponding to SSB0 and SSB4 are mapped sequentially in ascending order of time-domain resource index.

[0407] like Figure 29 As shown, in the RO group with time-domain resource indices of index 0 to 7 and frequency-domain resource index of index 0, SSB0 and SSB4 are mapped on ROs with time-domain resource indices of index 0 to 3, and are distinguished by the RA preamble index. Among them, the RA preamble index associated with SSB0 ranges from 0 to 31, while the RA preamble index associated with SSB4 ranges from 32 to 63.

[0408] Only SSB0 is mapped on ROs with time-domain resource indices 4 to 7, and the RA preamble index associated with the SSB0 mapped on ROs with indices 4 to 7 is from 0 to 31, while the remaining RA preamble indexes are not mapped.

[0409] 2) Map SSB5 and SSB1

[0410] Following the mapping order, after SSB0 and SSB4 are mapped, SSB5 and SSB1 are mapped next. Specifically, the number of repetitions (K5) of Msg1 corresponding to SSB5 is 4, and the number of repetitions (K1) of Msg1 corresponding to SSB1 is 2.

[0411] Since the ROs in the RO group with time-domain resource indices 0-7 and frequency-domain resource index 0 have already been mapped, a new frequency-domain resource index is added for mapping. The first four ROs in the RO group with time-domain resource indices 0-7 and frequency-domain resource index 1 (i.e., ROs with time-domain resource indices 0-3) are selected, and SSB5 and SSB1 are mapped, as follows: Figure 30 As shown.

[0412] In the RO group, SSB5 and SSB1 are mapped to ROs with time-domain resource indices of index 0 to 1, and are distinguished by RApreamble index. Among them, the RApreamble index associated with SSB5 ranges from 0 to 31, while the RA preamble index associated with SSB1 ranges from 32 to 63.

[0413] Only SSB5 is mapped on ROs with time-domain resource indices of index 2 to 3, and the RApreamble index associated with the SSB5 mapped on ROs with indices of index 2 to 3 is from 0 to 31, while the remaining RApreamble indexes are not mapped.

[0414] 3) Map SSB2 and SSB3

[0415] Following the mapping order, after SSB5 and SSB1 are mapped, SSB2 and SSB3 are mapped next. Specifically, the number of repetitions (K2) of Msg1 corresponding to SSB2 is 2, and the number of repetitions (K3) of Msg1 corresponding to SSB3 is 2.

[0416] Select time-domain resource indices 0-7, frequency-domain resource indices 2 ROs from RO group 1, and time-domain resource indices 4-5, and map SSB2 and SSB3 as follows: Figure 31As shown. Among them, the RA preamble index associated with SSB2 ranges from 0 to 31, while the RA preamble index associated with SSB3 ranges from 32 to 63.

[0417] At this point, the mapping of the six SSB indices is complete.

[0418] Example 2:

[0419] like Figure 32 As shown, the signal transmitted by satellite 3210 has at least six beams in the cell, namely beams 3221, 3222, 3223, 3224, 3225, and 3226. Each of these six beams corresponds to a SSB: beam 3221 corresponds to SSB0, beam 3222 to SSB1, beam 3223 to SSB2, beam 3224 to SSB3, beam 3225 to SSB4, and beam 3226 to SSB5.

[0420] The network device configures a Msg1 repetition number (K) for each of the six beams using system information. i And the SSB indices corresponding to the same Msg1 repetition count are grouped together to obtain 3 SSB groups, namely Among them, SSB Group 0 includes SSB0, SSB Group 1 includes SSB1, SSB2 and SSB3, SSB Group 2 includes SSB4 and SSB5, the number of repetitions of Msg1 corresponding to SSB Group 0 is 8, the number of repetitions of Msg1 corresponding to SSB Group 1 is 2, and the number of repetitions of Msg1 corresponding to SSB Group 2 is 4.

[0421] The network device configures N for the terminal device via higher-level parameters (such as SSB-per-rach-occasion), and the RO time-domain resource indices configured for the terminal device via higher-level parameters (such as prach-ConfigurationIndex) are index0, index1, index2, index3, index4, index5, index6, index7, index8, index9, index10, index11, index12, index13, index14, index15, ... , and the frequency-domain resource indices of the RO configured via higher-level parameters (such as msg1-FDM=4) are index0, index1, index2, index3. When mapping SSBs and ROs in the three SSB groups, the specific implementation is as follows:

[0422] ◆ Sort the frequency of Msg1 in each of the three SSB groups in descending order, and sort the SSB indices within the same SSB group in ascending order. The resulting SSB indices in the sorted SSB groups are: Therefore, the mapping order is as follows: SSB group 0 → SSB group 2 → SSB group 1.

[0423] ◆The maximum number of repetitions of Msg1 for each of the three SSB groups is 8. Therefore, the time-domain resource indices of the ROs are sequentially numbered from index 0 to 15, etc. ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 0 to 7 form one RO group; ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 8 to 15 form another RO group, and so on. In other words, an RO group includes the time-domain resource indices of 8 ROs.

[0424] ◆The SSB indices of the three SSB groups are first mapped sequentially in the RO group with the smallest time-domain resource index (index 0-7) and frequency-domain resource index (index 0). Next, after mapping all ROs in the RO group with the smallest frequency-domain resource index (index 7), a new frequency-domain resource index is added, resulting in the RO group with the next frequency-domain resource index (index 1). This mapping process is then repeated sequentially in the RO group, following the same sequence of time-domain resource indexes. The number of repetitions of Msg1 corresponding to the SSB index is packaged and mapped across the time-domain range.

[0425] ◆The SSB indices of the three SSB groups are mapped sequentially in ascending order of time-domain resource index (index 0-7) to the RO group with the frequency-domain resource index increased to its maximum (index 3). Then, eight more RO time-domain resource indices are added to obtain the RO group with time-domain resource indices of index 8-15 and frequency-domain resource index of index 0. Similarly, mapping is performed sequentially in the RO group with time-domain resource indices of index 8-15 and frequency-domain resource index of index 0, following the ascending order of time-domain resource index. After all ROs with time-domain resource indices of index 8-15 and frequency-domain resource index of index 0 are mapped, a frequency-domain resource index is added to obtain the RO group with frequency-domain resource index of index 1. Mapping is then continued sequentially in the RO group with time-domain resource indices of index 1-15, and so on. The repetition count of Msg1 corresponding to the SSB index is packaged and mapped across the time-domain range.

[0426] Case 1: N < 1

[0427] If N = 1 / 2, it means that each SSB in the three SSB groups is mapped to two ROs.

[0428] 1) Map SSB0 in SSB group 0

[0429] Similar to "Example 1" above, such as Figure 12 and Figure 13 As shown.

[0430] 2) Map SSB4 in SSB group 2

[0431] Similar to "Example 1" above, such as Figure 14 and Figure 15 As shown.

[0432] 3) Map SSB5 in SSB group 2

[0433] Similar to "Example 1" above, such as Figure 16 and Figure 17 As shown.

[0434] 4) Map SSB1 in SSB group 1

[0435] Similar to "Example 1" above, such as Figure 18 and Figure 19 As shown.

[0436] 5) Map SSB2 in SSB group 1

[0437] Similar to "Example 1" above, such as Figure 20 and Figure 21 As shown.

[0438] 6) Map SSB3 in SSB group 1

[0439] Similar to "Example 1" above, such as Figure 22 and Figure 23 As shown.

[0440] At this point, the mapping of the six SSB indices is complete.

[0441] Case 2: N=1

[0442] If N=1, it means that each SSB in the three SSB groups is mapped to one RO.

[0443] The specific mapping details are as follows:

[0444] 1) Map SSB0 in SSB group 0

[0445] Similar to "Example 1" above, such as Figure 12 As shown.

[0446] 2) Map SSB4 in SSB group 2

[0447] Similar to "Example 1" above, such as Figure 24 As shown.

[0448] 3) Map SSB5 in SSB group 2

[0449] Similar to "Example 1" above, such as Figure 25 As shown.

[0450] 4) Map SSB1 in SSB group 1

[0451] Similar to "Example 1" above, such as Figure 26 As shown.

[0452] 5) Map SSB2 in SSB group 1

[0453] Similar to "Example 1" above, such as Figure 27 As shown.

[0454] 6) Map SSB3 in SSB group 1

[0455] Similar to "Example 1" above, such as Figure 28 As shown.

[0456] At this point, the mapping of the six SSB indices is complete.

[0457] Case 3: N > 1

[0458] If N=2, it means that 2 SSBs in each SSB group are mapped to 1 RO.

[0459] Based on the above content regarding "the mapping rules of the SSB index when N>1", in addition to implementing the above, the following also needs to be implemented:

[0460] ◆The two SSB indices in each SSB group have the same RO mapped to each other.

[0461] ◆The two SSB indexes in each SSB group are distinguished by the RA preamble index in the same RO.

[0462] The specific mapping details are as follows:

[0463] 1) Map SSB0 in SSB group 0

[0464] Following the mapping order, SSB group 0 is mapped first. The number of repetitions (K0) of Msg1 corresponding to SSB group 0 is 8.

[0465] On the RO group with time-domain resource indices of index 0 to 7 and the smallest frequency-domain resource index (i.e., the RO group with frequency-domain resource index index 0), SSB0 in SSB group 0 is mapped sequentially in ascending order of time-domain resource indices. Since SSB group 0 contains only one SSB index, SSB0 only occupies the first 32 RA preambles during mapping; the remaining RA preambles are not mapped. Figure 33 As shown.

[0466] 2) Map SSB4 and SSB5 in SSB group 2

[0467] Following the mapping order, after mapping SSB group 0, continue mapping SSB group 2. The number of repetitions (K2) of Msg1 corresponding to SSB group 2 is 4.

[0468] Since the ROs in the RO group with time-domain resource indices 0-7 and frequency-domain resource index 0 have already been mapped, a new frequency-domain resource index is added for mapping. The first four ROs in the RO group with time-domain resource indices 0-7 and frequency-domain resource index 1 (i.e., ROs with time-domain resource indices 0-3) are selected. SSB4 and SSB5 in SSB group 2 are mapped sequentially according to their time-domain resource indices, from smallest to largest, and distinguished by the RA preamble index. Figure 34 As shown. Among them, the RA preamble index associated with SSB4 ranges from 0 to 31, while the RA preamble index associated with SSB5 ranges from 32 to 63.

[0469] 3) Map SSB1 and SSB2 in SSB group 1

[0470] Following the mapping order, after mapping SSB group 2, continue mapping SSB group 1. The number of repetitions (K1) of Msg1 corresponding to SSB group 1 is 2.

[0471] Select time-domain resource indices 0-7, frequency-domain resource indices 2 ROs in RO group 1, and time-domain resource indices 4-5. Map SSB1 and SSB2 in SSB group 1 sequentially according to the ascending order of time-domain resource indices, and distinguish them by RA preamble index, such as... Figure 35 As shown. Among them, the RApreamble index associated with SSB1 ranges from 0 to 31, while the RApreamble index associated with SSB2 ranges from 32 to 63.

[0472] 4) Map SSB3 in SSB group 1

[0473] Following the mapping order, after mapping SSB1 and SSB2, SSB3 is mapped. The number of repetitions (K1) of Msg1 corresponding to SSB group 1 is 2.

[0474] Select two ROs from the RO group with time-domain resource indices of 0-7 and frequency-domain resource indices of 1, and ROs with time-domain resource indices of 6-7. Map SSB3 in SSB group 1 sequentially according to the ascending order of time-domain resource indices. When mapping SSB3, only the first 32 RA preambles are used; the remaining RA preambles are not mapped. Figure 36 As shown.

[0475] At this point, the mapping of the six SSB indices is complete.

[0476] Example 3:

[0477] like Figure 37 As shown, the signal transmitted by satellite 3710 forms at least three beams in the cell: beams 3721, 3722, and 3723. Each of these three beams corresponds to a Special Service Bus (SSB): beam 3721 corresponds to SSB0, beam 3722 to SSB1, and beam 3723 to SSB2. Therefore, there are at least three SSB indices in the cell.

[0478] The network device configures the number of repetitions (K) of Msg1 for each of the three SSB indices using system information. i ),Right now

[0479] The network device configures N for the terminal device through higher-level parameters (such as SSB-per-rach-occasion), and the time-domain resource indices of the RO configured for the terminal device through higher-level parameters (such as prach-ConfigurationIndex) are index0, index1, index2, index3, index4, index5, index6, index7, index8, index9, index10, index11, index12, index13, index14, index15, ... and the time-domain resource index of an RO configured through higher-level parameters (such as msg1-FDM=1) has one frequency domain resource with index 0.

[0480] When these three SSB indexes are mapped to RO, the specific implementation is as follows:

[0481] ◆ Sort the Msg1 repetition counts of each of the three SSB indexes in descending order, and sort the SSB indexes with the same repetition count in ascending order. The sorted SSB indexes are as follows: Therefore, the mapping order is: SSB0→SSB2→SSB1.

[0482] ◆The maximum number of repetitions of Msg1 corresponding to each of the three SSB indices is 4. Therefore, the time-domain resource indices of the ROs are sequentially numbered from index 0 to 15. ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 0 to 3 form one RO group; ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 4 to 7 form another RO group; ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 8 to 11 form another RO group; ROs with the same frequency-domain resource index and whose time-domain resources are identified by indices 12 to 15 form another RO group, and so on. In other words, an RO group includes the time-domain resource indices of four ROs.

[0483] ◆ First, map these three SSB indices sequentially within the RO group (time-domain resource indexes 0-3, frequency-domain resource index 0), following the ascending order of their time-domain resource indices. Next, after all ROs in this RO group have been mapped, add a time-domain resource index, resulting in another RO group with time-domain resource indices 4-7 and frequency-domain resource index 0. Continue mapping within this RO group in ascending order of their time-domain resource indices, and so on.

[0484] Case 1: N < 1

[0485] If N = 1 / 2, it means that each of the three SSBs is mapped to two ROs.

[0486] The specific mapping details are as follows:

[0487] 1) Mapping SSB0

[0488] Following the mapping order, SSB0 is mapped first. The number of repetitions (K0) of Msg1 corresponding to SSB0 is 4.

[0489] In the RO group with time-domain resource indices of index 0 to 3 and frequency-domain resource index of index 0, the ROs corresponding to SSB0 are mapped sequentially in ascending order of time-domain resource index. After all the ROs in this RO group have been mapped, a time-domain resource index is added to obtain the RO group with time-domain resource indices of index 4 to 7 and frequency-domain resource index of index 0. The ROs corresponding to SSB0 are mapped sequentially in ascending order of time-domain resource index.

[0490] SSB0 maps all four ROs together on the RO group with frequency domain resource index index0. At this point, SSB0 maps the four ROs in this RO group, as follows: Figure 38 As shown. Among them, Figure 38 The four ROs within the dashed box form an RO group, which is the RO group with index 0 to 3 in the time domain and index 0 in the frequency domain.

[0491] Since N = 1 / 2, SSB0 needs to be mapped to 2 ROs. At this point, SSB0 is packaged and mapped again as a whole.

[0492] Additionally, since the time-domain resource indices are index 0 to 3, and the frequency-domain resource index is index 0, four SSB0s have already been mapped on the RO group. Higher-level parameters (such as msg1-FDM=1) configure one frequency-domain resource on the time-domain resource index of an RO. Therefore, an additional time-domain resource index is needed for mapping, such as... Figure 39 As shown. Among them, Figure 39 The four ROs within the dashed box form an RO group, which is the RO group with index 4 to 7 in the time domain and index 0 in the frequency domain.

[0493] 2) Mapping SSB2

[0494] Following the mapping order, after SSB0 is mapped, SSB2 is mapped next. The number of repetitions (K2) of Msg1 corresponding to SSB2 is 2.

[0495] SSB2 is mapped as a whole in the time domain using two ROs, such as Figure 40 As shown. Among them, Figure 40 The four ROs within the dashed box represent a group of ROs after the addition of a time-domain resource index, i.e., the RO group with time-domain resource indexes of index 8 to 11 and frequency-domain resource index of index 0.

[0496] Since N = 1 / 2, SSB2 needs to be mapped to 2 ROs. At this point, SSB2 is packaged and mapped again as a whole, as follows: Figure 41 As shown.

[0497] 3) Mapping SSB1

[0498] Following the mapping order, after SSB2 is mapped, SSB1 is mapped next. The number of repetitions (K1) of Msg1 corresponding to SSB1 is 1. Since N = 1 / 2, SSB1 needs to be mapped repeatedly to 2 ROs.

[0499] Similar to the above, such as Figure 42 As shown. Among them, Figure 42 The four ROs within the dashed box form one RO group, which is the RO group with index 12 to 15 in the time domain and index 0 in the frequency domain.

[0500] Similar to the above, such as Figure 43 As shown.

[0501] At this point, the mapping of the three SSB indices is complete.

[0502] Case 2: N=1

[0503] If N=1, it means that each of the three SSBs is mapped to one RO.

[0504] The specific mapping details are as follows:

[0505] 1) Mapping SSB0

[0506] Following the mapping order, SSB0 is mapped first. The number of repetitions (K0) of Msg1 corresponding to SSB0 is 4.

[0507] In the RO group with time-domain resource indexes of index 0 to 3 and frequency-domain resource index of index 0, the ROs corresponding to SSB0 are mapped sequentially in ascending order of time-domain resource index.

[0508] Since N=1, SSB0 needs to be mapped to 1 RO.

[0509] SSB0 is mapped as a whole in the time domain using 4 ROs, such as Figure 38 As shown.

[0510] 2) Mapping SSB2

[0511] Following the mapping order, after SSB0 is mapped, SSB2 is mapped next. The number of repetitions (K2) of Msg1 corresponding to SSB2 is 2. Since N=1, SSB2 needs to be mapped to one RO.

[0512] SSB2 is mapped as a whole in the time domain using two ROs, such as Figure 44 As shown. Among them, Figure 44 The four ROs within the dashed box represent a group of ROs after the addition of a time-domain resource index, i.e., the RO group with time-domain resource indexes of index 4 to 7 and frequency-domain resource index of index 0.

[0513] 3) Mapping SSB1

[0514] Following the mapping order, after SSB2 is mapped, SSB1 is mapped next. The repetition count (K1) of Msg1 corresponding to SSB1 is 1. Since N=1, SSB1 needs to be mapped to one RO.

[0515] When mapping SSB1, the process is similar to the above, such as... Figure 45 As shown.

[0516] At this point, the mapping of the three SSB indices is complete.

[0517] Case 3: N > 1

[0518] If N=2, it means that every 2 SSBs out of the 3 SSBs are mapped to 1 RO.

[0519] Based on the above content regarding "the mapping rules of the SSB index when N>1", in addition to implementing the above, the following also needs to be implemented:

[0520] ◆The ROs mapped by each pair of SSB indices may be the same or different.

[0521] ◆If two SSB indexes map to the same RO, the two SSB indexes are distinguished by the RApreambleindex in the same RO.

[0522] The specific mapping details are as follows:

[0523] 1) Map SSB0 and SSB2

[0524] Following the mapping order, SSB0 and SSB2 are mapped first. Among them, the number of repetitions (K0) of Msg1 corresponding to SSB0 is 4, and the number of repetitions (K2) of Msg1 corresponding to SSB2 is 2.

[0525] In the RO group with time-domain resource index 0 to 3 and frequency-domain resource index index 0, the ROs corresponding to SSB0 and SSB4 are mapped sequentially in ascending order of time-domain resource index.

[0526] like Figure 46 As shown, in the RO group with time-domain resource indices of 0-3 and frequency-domain resource index of index 0, SSB0 and SSB2 are mapped on ROs with time-domain resource indices of index 0-1, and are distinguished by the RA preamble index. Among them, the RA preamble index associated with SSB0 ranges from 0 to 31, while the RA preamble index associated with SSB2 ranges from 32 to 63.

[0527] Only SSB0 is mapped on ROs with time-domain resource indices 2 to 3, and the RA preamble index associated with the SSB0 mapped by the ROs with indices 2 to 3 is from 0 to 31, while the remaining RA preamble indexes are not mapped.

[0528] 2) Mapping SSB1

[0529] Following the mapping order, after SSB0 and SSB2 are mapped, SSB1 is mapped next. The number of repetitions (K1) of Msg1 corresponding to SSB1 is 1.

[0530] Since the ROs in the RO group with time-domain resource indices 0-3 and frequency-domain resource index 0 have already been mapped, and higher-level parameters (such as msg1-FDM=1) configure one RO with one frequency-domain resource on its time-domain resource index, a new time-domain resource index is added for mapping. The first RO in the RO group with time-domain resource indices 4-7 and frequency-domain resource index 0 (i.e., the RO with time-domain resource index 4) is selected, and SSB1 is mapped. The RA preamble indexes associated with SSB1 mapped to index 4 range from 0-31, while the remaining RA preamble indexes are not mapped. Figure 47 As shown.

[0531] At this point, the mapping of the three SSB indices is complete.

[0532] 5. An exemplary description of a communication method

[0533] In summary, the following description uses the interaction between a network device and a terminal device as an example to illustrate a communication method according to an embodiment of this application. The network device can also be a chip / chip module / device, etc., and the terminal device can also be a chip / chip module / device, etc., without specific limitations.

[0534] like Figure 48 The diagram shown is a flowchart of a communication method according to an embodiment of this application, which specifically includes the following steps:

[0535] S4810, The network device sends an indication message, which is used to instruct K. i .

[0536] Among them, K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K i It is a positive integer greater than or equal to 1.

[0537] Here, the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to.

[0538] Correspondingly, the terminal device receives this instruction information.

[0539] It should be noted that for "instruction information", "first community", and "K", i For details, please refer to the above content, and we will not repeat them here.

[0540] S4820, terminal equipment according to K i Send a random access request message.

[0541] Correspondingly, the network device receives the random access request message.

[0542] As can be seen, in this embodiment of the application, since the network device can indicate to the terminal device the number of repetitions of the random access request message corresponding to the SSB index through the indication information, the terminal device can send a random access request message after selecting a certain SSB, according to the number of repetitions of the random access request message corresponding to the SSB index used to identify the SSB, in order to achieve coverage enhancement, thereby improving the transmission reliability of the random access request message and increasing the probability of successful random access by the terminal device.

[0543] In this embodiment of the application, the terminal device according to K i When sending a random access request message, the terminal device sends the random access request message no more than K times. i For example, if the terminal device successfully accesses the network on the k-th random access request message, then random access will succeed. If k is less than K...i Then the terminal device will no longer need to repeatedly send random access request messages.

[0544] It should be noted that the embodiments of this application use instruction information for K. i Taking this application as an example, in this embodiment, the indication information can also indicate the number of repetitions of two or more random access request messages. The specific number of repetitions of which random access request message the terminal device sends depends on which SSB the terminal device selects. Taking SSB1 as an example, the terminal device sends a random access request message based on the number of repetitions of the random access request message corresponding to SSB1.

[0545] Network devices can use system information to indicate to terminal devices the number of repetitions of the random access request message corresponding to a SSB. After detecting at least one SSB, the terminal device selects one SSB from the at least one SSB to camp on in the cell, and sends the random access request message multiple times according to the number of repetitions of the random access request message corresponding to the selected SSB. For example, the number of repetitions of the random access request message indicated for different SSBs in the same cell can be the same or different. For example, the number of repetitions of the random access request message corresponding to SSB1 and the number of repetitions of the random access request message corresponding to SSB2 can be the same or different. In some possible implementations, the indication information can be sent or received during cell search, cell reselection, uplink / downlink synchronization, cell access, cell camping, initial access, or uplink / downlink resource scheduling, etc., and there is no limitation on this.

[0546] Furthermore, network devices can also indicate a random access request message corresponding to an SSB to terminal devices via higher-layer signaling (such as RRC signaling). In this case, the higher-layer signaling includes indication information. Of course, the embodiments of this application do not limit the message or signaling carrying indication information.

[0547] In some possible implementations, the indication information is used to indicate K. i K i Msg1 is the number of repetitions corresponding to SSB index i, where the SSB identified by SSB index i is the SSB in the first cell, 1≤i≤M, i is a positive integer, and M is the total number of SSBs in the first cell.

[0548] In some possible implementations, the indication information is also used to indicate K. j K jLet Msg1 be the number of repetitions corresponding to SSB index j, where the SSB identified by SSB index j is the SSB in the first cell, and the SSB identified by SSB index j is different from the SSB identified by SSB index i, that is, j and i are different values. 1≤j≤M, j is a positive integer, and M is the total number of SSBs in the first cell.

[0549] In some possible implementations, the number of repetitions of Msg1 corresponding to different SSB indices is different. Take SSB indices i and j as examples. SSB index i corresponds to K... i SSB index j corresponds to K j When the number of repetitions of Msg1 corresponding to different SSB indices is different, K i With K j different.

[0550] It should be noted that, since SSB index i and SSB index j are two different SSB indexes, the embodiments of this application can configure different repetition counts of Msg1, i.e., K, for different SSB indexes. i With K j Different, in order to improve configuration flexibility.

[0551] In some possible implementations, the number of repetitions of Msg1 corresponding to different beam SSBs varies. Take SSB index i and SSB index j as examples. SSB index i corresponds to K... i SSB index j corresponds to K j If the beam corresponding to the SSB identified by SSB index i is different from the beam corresponding to the SSB identified by SSB index j, then K i With K j Different. In some embodiments, if the beam corresponding to the SSB identified by SSB index i and the beam corresponding to the SSB identified by SSB index j are the same, then K i With K j They can be different, or they can be the same.

[0552] It should be noted that, since beams correspond to SSBs and different beams correspond to different SSBs, the embodiments of this application can configure different repetition numbers of Msg1 for different SSBs corresponding to different beams.

[0553] In other embodiments of this application, the network device can select the number of repetitions of Msg1 corresponding to the SSB index from the candidate value set of Msg1 repetition counts, as indicated by the terminal device. The candidate value set of Msg1 repetition counts can be predefined by a protocol, determined by the network device based on an algorithm or strategy, or indicated by other devices or servers; there is no limitation on this. For example, the candidate value set of Msg1 repetition counts may include at least one candidate value. For instance, each candidate value is a power of 2. In this case, the candidate value set of Msg1 repetition counts is the set {1, 2, 4, 8, 16, ..., 2}. n For example, consider SSB index i. SSB index i corresponds to K. i K i =2 a , where a is a positive integer greater than or equal to 0.

[0554] Alternatively, in some other embodiments of this application, the number of repetitions of Msg1 corresponding to the SSB index is a power of 2. For example, consider SSB index i. SSB index i corresponds to K i K i =2 a 'a' is a positive integer greater than or equal to 0. For example, consider SSB index j. SSB index j corresponds to K. j K j =2 b b is a positive integer greater than or equal to 0.

[0555] In some possible implementations, the S4820 according to K i Sending a random access request message may include the following steps:

[0556] Terminal equipment according to K i Determine M i One RO, K i ≤M i ≤K i *L; where L = N, N > 1; or, L = 1 / N, N ≤ 1; N is used to indicate the mapping relationship between the SSB and RO indicated by the SSB index i;

[0557] Terminal device selection M i K in RO i Each RO sends a random access request message.

[0558] It should be noted that, since Msg1 needs to be carried (or transmitted) by RO, in order to send Msg1, this embodiment of the application needs to be based on K. i Determine M i One RO, and through M i K in RO iOne RO is used to send Msg1 to achieve multiple (or repeated) transmissions of Msg1.

[0559] In some possible implementations, N takes the value of 1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, or 16.

[0560] In some possible implementations, if K i =K, and N≤1, then

[0561] M i Each RO is divided into 1 / N RO groups. Each RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

[0562] It should be noted that the RO group includes the ROs whose time-domain resources are identified by the time-domain resource indexes of K ROs. In other words, the RO group includes K ROs in the time domain.

[0563] In addition, K i =K, indicating the number of times Msg1 corresponding to SSB index i is repeated (i.e., K). i The maximum value is ). Additionally, N ≤ 1, indicating that one SSB can map N ROs. Since this embodiment requires dividing the temporal resource index of ROs using the maximum repetition count of Msg1 corresponding to each SSB index in the first cell as the granularity, this embodiment can divide the temporal resource index of ROs based on K. i Identify 1 / N RO groups, each of which includes K ROs in the time domain. Select one RO group from these 1 / N RO groups to obtain K ROs, so that Msg1 can be transmitted multiple times (or repeatedly).

[0564] In some possible implementations, if N>1, or if N≤1 and K i / N≤K, then

[0565] M i Each RO is located in the same RO group, and the RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

[0566] It should be noted that a RO group can include time-domain resource indexes of K ROs. In other words, an RO includes K ROs in the time domain.

[0567] Furthermore, N>1 indicates that one RO can map N SSBs. In this case, the embodiments of this application can be based on K. i The determined M i If ROs are located in the same RO group, then K can be selected from the same RO group. iThere are ROs to allow for multiple (or repeated) transmissions of Msg1. The RO group is divided into time-domain resource indexes of the ROs based on the maximum number of repetitions of Msg1.

[0568] Similarly, N≤1 means that one SSB can map to N ROs. Additionally, K i / N≤K indicates the number of times Msg1 corresponding to SSB index i is repeated (i.e., K). i The value is not the maximum. In this case, the embodiments of this application can be based on K. i The determined M i If ROs are located in the same RO group, then K can be selected from the same RO group. i There are ROs to allow for multiple (or repeated) transmissions of Msg1. The RO group is divided into time-domain resource indexes of the ROs based on the maximum number of repetitions of Msg1.

[0569] In some possible implementations, if N > 1, then the same RO corresponds to N SSBs.

[0570] It should be noted that N>1 means that one RO can map N SSBs.

[0571] In some possible implementations, the number of repetitions of random access request messages corresponding to the N SSBs of the same RO may be the same or different.

[0572] It should be noted that one RO can map to N SSBs, and the number of repetitions of Msg1 corresponding to each of the N SSBs can be the same or different.

[0573] In some possible implementations, the terminal device determines the RO in descending order of the number of repetitions of the random access request message corresponding to the SSB index.

[0574] In some possible implementations, the terminal device determines the RO in ascending order based on the SSB index for the number of times the same random access request message is repeated.

[0575] It should be noted that, based on the content of “(7) Mapping relationship between SSB index and RO” above, the mapping order can be sorted in descending order according to the number of repetitions of Msg1 corresponding to each SSB index, wherein SSB indexes with the same number of repetitions are sorted in ascending order.

[0576] In some possible implementations, the terminal device determines the ROs sequentially in ascending order of the number of repetitions of Msg1 corresponding to the SSB index. Specifically, the terminal device determines the ROs for SSB indexes with the same number of repetitions of Msg1 in ascending order.

[0577] In some possible implementations, the terminal device determines the ROs sequentially in descending order of the number of repetitions of Msg1 corresponding to the SSB index. Specifically, the terminal device determines the ROs for SSB indexes with the same number of repetitions of Msg1 in descending order.

[0578] In some possible implementations, the terminal device determines the ROs sequentially in ascending order of the number of repetitions of Msg1 corresponding to the SSB index. For SSB indexes with the same number of repetitions of Msg1, the terminal device determines the ROs in descending order.

[0579] The embodiments in this application can be used individually or in combination to achieve different technical effects.

[0580] 6. Exemplary Description of a Communication Device

[0581] The above primarily describes the solutions of the embodiments of this application from a methodological perspective. It is understood that, in order to achieve the above functions, terminal devices or network devices include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software-driven hardware manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0582] This application embodiment can divide terminal devices or network devices into functional units according to the above method examples. For example, each function can be divided into different functional units, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software program module. It should be noted that the unit division in this application embodiment is illustrative and only represents a logical functional division, while other division methods may be used in actual implementation.

[0583] When using integrated units, Figure 49 This is a functional unit block diagram of a communication device according to an embodiment of this application. The communication device 4900 includes: a receiving unit 4901 and a transmitting unit 4902.

[0584] It should be noted that the receiving unit 4901 can be a module unit used for transmitting and receiving signals, data, information, etc.

[0585] The transmitting unit 4902 can be a module unit for processing signals, data, information, etc., and there are no specific limitations on it.

[0586] The communication device 4900 may further include a storage unit for storing computer program code or instructions executed by the communication device 4900. The storage unit may be a memory.

[0587] Additionally, it should be noted that the communication device 4900 can be a chip or a chip module.

[0588] In some possible implementations, the receiving unit 4901 and the transmitting unit 4902 can be integrated into one unit or separate units.

[0589] For example, the receiving unit 4901 and the transmitting unit 4902 can be integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

[0590] For example, the receiving unit 4901 and the transmitting unit 4902 can be integrated into the processing unit. The processing unit can be a processor or controller, such as a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processing unit can also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0591] In specific implementation, the receiving unit 4901 and the sending unit 4902 are used to perform any step as performed by the terminal device, chip, chip module, etc. in the above method embodiments, such as sending or receiving data transmission. A detailed description follows.

[0592] Receiving unit 4901 is used to receive indication information, which is used to indicate K. i K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K i It is a positive integer greater than or equal to 1;

[0593] Transmitting unit 4902, used according to K i Send a random access request message, where the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to.

[0594] As can be seen, by introducing indication information in this embodiment, the number of times the random access request message is repeated in the SSB index or SSB configuration can be indicated. Then, the communication device 4900 can send the random access request message to the network device multiple times (or repeatedly) according to the number of times the random access request message is repeated for the selected SSB. This helps to achieve coverage enhancement, improve the transmission reliability of the random access request message, and increase the probability of successful random access by the communication device 4900.

[0595] It should be noted that, Figure 49 The specific implementation of each operation in the embodiments can be found in the description of the above-described method embodiments, and will not be repeated here.

[0596] In some possible implementations, the indication information is used to indicate K. i K i Msg1 is the number of repetitions corresponding to SSB index i, where the SSB identified by SSB index i is the SSB in the first cell, 1≤i≤M, i is a positive integer, and M is the total number of SSBs in the first cell.

[0597] In some possible implementations, the indication information is also used to indicate K. j K j Let Msg1 be the number of repetitions corresponding to SSB index j, where the SSB identified by SSB index j is the SSB in the first cell, and the SSB identified by SSB index j is different from the SSB identified by SSB index i, that is, j and i are different values. 1≤j≤M, j is a positive integer, and M is the total number of SSBs in the first cell.

[0598] In some possible implementations, K i With K j different.

[0599] In some possible implementations, the beam corresponding to the SSB indicated by SSB index i is different from the beam corresponding to the SSB indicated by SSB index j.

[0600] In some possible implementations, according to K i Regarding sending random access request messages, the sending unit 3802 is used for:

[0601] Terminal equipment according to K i Determine M iOne RO, K i ≤M i ≤K i *L; where L = N, N > 1; or, L = 1 / N, N ≤ 1; N is used to indicate the mapping relationship between the SSB and RO indicated by the SSB index i;

[0602] Terminal device selection M i K in RO i Each RO sends a random access request message.

[0603] In some possible implementations, N takes the value of 1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, or 16.

[0604] In some possible implementations, if K i =K, and N≤1, then

[0605] M i Each RO is divided into 1 / N RO groups. Each RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

[0606] In some possible implementations, if N>1, or if N≤1 and K i / N≤K, then

[0607] M i Each RO is located in the same RO group, and the RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

[0608] In some possible implementations, if N > 1, then the same RO corresponds to N SSBs.

[0609] In some possible implementations, the number of repetitions of random access request messages corresponding to the N SSBs of the same RO may be the same or different.

[0610] In some possible implementations, the communication device 4900 determines the ROs sequentially in descending order of the number of repetitions of the random access request messages corresponding to the SSB index.

[0611] In some possible implementations, the communication device 4900 determines the RO in ascending order based on the SSB index of the number of repetitions of the same random access request message.

[0612] 7. Another exemplary description of a communication device

[0613] When using integrated units, Figure 50This is a functional unit block diagram of another communication device according to an embodiment of this application. The communication device 5000 includes: a transmitting unit 5001.

[0614] It should be noted that the transmitting unit 5001 can be a module unit used for transmitting and receiving signals, data, information, etc., and there are no specific restrictions on it.

[0615] The communication device 5000 may further include a storage unit for storing computer program code or instructions executed by the communication device 5000. The storage unit may be a memory.

[0616] Additionally, it should be noted that the communication device 5000 can be a chip or a chip module.

[0617] In some possible implementations, the transmitting unit 5001 is integrated into the processing unit. The processing unit can be a processor or controller, such as a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processing unit can also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0618] In some possible implementations, the transmitting unit 5001 is integrated into the communication unit. The communication unit can be a communication interface, transceiver, transceiver circuit, etc.

[0619] In specific implementation, the sending unit 5001 is used to perform any step as performed by the network device, chip, chip module, etc. in the above method embodiments, such as sending data / signals / information. A detailed explanation follows.

[0620] Transmitting unit 5001 is used to transmit indication information, which is used to indicate K. i K i Msg1 is the number of repetitions corresponding to SSB index i, where the SSB identified by SSB index i is the SSB in the first cell, 1≤i≤M, i is a positive integer, and M is the total number of SSBs in the first cell.

[0621] As can be seen, by introducing indication information in this embodiment, the communication device 5000 can indicate to the terminal device the number of repetitions of the random access request message for the SSB index or SSB configuration. Then, the terminal device can send the random access request message to the communication device 5000 multiple times (or repeatedly) according to the number of repetitions of the random access request message corresponding to the selected SSB. This helps to achieve coverage enhancement, improve the transmission reliability of the random access request message, and increase the probability of successful random access by the terminal device.

[0622] It should be noted that, Figure 50 The specific implementation of each operation in the embodiments can be found in the description of the above-described method embodiments, and will not be repeated here.

[0623] 8. An exemplary description of a terminal device

[0624] Please see Figure 51 , Figure 51 This is a schematic diagram of the structure of a terminal device according to an embodiment of this application. The terminal device 5100 includes a processor 5110, a memory 5120, and a communication bus for connecting the processor 5110 and the memory 5120.

[0625] The memory 5120 includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM). The memory 5120 is used to store program code executed by the terminal device 5100 and data transmitted.

[0626] The terminal device 5100 also includes a communication interface for receiving and sending data.

[0627] The processor 5110 can be one or more CPUs. When the processor 5110 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

[0628] The processor 5110 in the terminal device 5100 is used to execute the computer program or instructions 5121 stored in the memory 5120, and to perform the following operations: receive instruction information, the instruction information being used to instruct K. i K iLet Msg1 be the number of repetitions corresponding to SSB index i, where the SSB identified by SSB index i is the SSB in the first cell, 1 ≤ i ≤ M, i is a positive integer, and M is the total number of SSBs in the first cell. According to K... i Send a random access request message.

[0629] As can be seen, in this embodiment of the application, since the network device can indicate to the terminal device the number of repetitions of the random access request message corresponding to the SSB index through the indication information, the terminal device 5100 can send the random access request message multiple times after selecting a certain SSB according to the number of repetitions of the random access request message corresponding to the SSB index used to identify the SSB. This helps to achieve coverage enhancement, improve the transmission reliability of the random access request message, and increase the probability of successful random access by the terminal device.

[0630] It should be noted that the specific implementation of each operation can be described in the corresponding description of the method embodiments shown above. The terminal device 5100 can be used to execute the terminal device side method of the above method embodiments of this application, and will not be described in detail here.

[0631] 9. An exemplary description of a network device

[0632] Please see Figure 52 , Figure 52 This is a schematic diagram of the structure of a network device according to an embodiment of this application. The network device 5200 includes a processor 5210, a memory 5220, and a communication bus for connecting the processor 5210 and the memory 5220.

[0633] The memory 5220 includes, but is not limited to, RAM, ROM, EPROM or CD-ROM, and is used to store related instructions and data.

[0634] The network device 5200 also includes a communication interface for receiving and sending data.

[0635] Processor 5210 can be one or more CPUs. When processor 5210 is a CPU, the CPU can be a single-core CPU or a multi-core CPU.

[0636] The processor 5210 in network device 5200 is used to execute computer programs or instructions 5221 stored in memory 5220 to perform the following operations: send instruction information, the instruction information being used to instruct K i K i K represents the number of repetitions of the random access request message corresponding to the SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K i It is a positive integer greater than or equal to 1.

[0637] As can be seen, in order to enhance the coverage of the communication system, this application embodiment introduces the number of repetitions of the random access request message and uses indication information to configure the number of repetitions of the random access request message corresponding to the SSB index. Based on the number of repetitions of the random access request message, the random access request message is sent to achieve coverage enhancement, which in turn helps to improve the transmission reliability of the random access request message and increase the probability of successful random access by the terminal device.

[0638] It should be noted that the specific implementation of each operation can be described in the corresponding description of the method embodiments shown above. The network device 5200 can be used to execute the network device side method of the above method embodiments of this application, and will not be described in detail here.

[0639] 10. Other exemplary descriptions

[0640] This application also provides a chip, including a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps described in the above method embodiments.

[0641] This application also provides a chip module, including a transceiver component and a chip. The chip includes a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps described in the above method embodiments.

[0642] This application also provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

[0643] This application also provides a computer program product, including a computer program or instructions that, when executed, implement the steps described in the above method embodiments.

[0644] In the above embodiments, the descriptions of each embodiment in this application have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0645] The steps of the methods or algorithms described in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, read-only optical discs (CD-ROMs), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a terminal device or management device. Alternatively, the processor and storage medium can exist as discrete components in the terminal device or management device.

[0646] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in the embodiments of this application can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0647] The modules / units included in the various devices and products described in the above embodiments can be software modules / units, hardware modules / units, or a combination of both. For example, for devices and products applied to or integrated into a chip, all modules / units can be implemented using hardware methods such as circuits, or at least some modules / units can be implemented using software programs that run on a processor integrated within the chip, while the remaining (if any) modules / units can be implemented using hardware methods such as circuits. For devices and products applied to or integrated into a chip module, all modules / units can be implemented using hardware methods such as circuits. Different modules / units can be located in the same component (e.g., chip, circuit module, etc.) or different components of the chip module, or at least some modules / units can be implemented using hardware methods such as circuits. The implementation is achieved through a software program that runs on a processor integrated within the chip module. The remaining modules / units (if any) can be implemented using hardware methods such as circuits. For various devices and products applied to or integrated into terminal equipment, each of their modules / units can be implemented using hardware methods such as circuits. Different modules / units can be located in the same component (e.g., chip, circuit module, etc.) or different components within the terminal equipment. Alternatively, at least some modules / units can be implemented using a software program that runs on a processor integrated within the terminal equipment, while the remaining modules / units (if any) can be implemented using hardware methods such as circuits.

[0648] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above descriptions are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A communication method, characterized in that, The method is applied in terminal devices; the method includes: The system receives indication information, which indicates the number of repetitions of the random access request message corresponding to each of the M synchronization signal blocks (SSBs) in the first cell. The number of repetitions of the random access request message corresponding to each SSB includes K. i The K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i The SSB index i is a positive integer greater than or equal to 1, and the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to. According to the K i Send a random access request message.

2. The method according to claim 1, characterized in that, Ki is a candidate value from the set of candidate values ​​for the number of repetitions of the random access request message; and / or, K i =2 a , where a is a positive integer greater than or equal to 0.

3. The method according to claim 1 or 2, characterized in that, The number of repetitions of the random access request message corresponding to each SSB also includes K. j The K j Let be the number of times the random access request message corresponding to SSB index j in the first cell is repeated, 1≤j≤M, where j and i are different values.

4. The method according to claim 3, characterized in that, The K i With the K j different.

5. The method according to claim 4, characterized in that, The beam corresponding to the SSB indicated by SSB index i is different from the beam corresponding to the SSB indicated by SSB index j.

6. The method according to claim 1, characterized in that, According to the K i Send a random access request message, including: According to the K i Determine M i A random access opportunity RO, K i ≤M i ≤K i ·L; where L = N, N>1; or, L = 1 / N, N ≤ 1; N is used to indicate the mapping relationship between the SSB and RO indicated by the SSB index i; Select the M i K in RO i Each RO sends the random access request message.

7. The method according to claim 6, characterized in that, The value of N can be one of 1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, or 16.

8. The method according to claim 6 or 7, characterized in that, If K i = K, and N ≤ 1, then The M i Each RO is divided into 1 / N RO groups, and each RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

9. The method according to claim 6 or 7, characterized in that, If N>1, or if N≤1 and K i If / N ≤ K, then The M i ROs are located in the same RO group, and the RO group includes K ROs in the time domain, where K is the maximum number of repetitions of the random access request message indicated by the indication information.

10. The method according to claim 9, characterized in that, If N > 1, then the same RO corresponds to N SSBs.

11. The method according to claim 10, characterized in that, The number of times the random access request messages corresponding to the N SSBs of the same RO are repeated is either the same or different.

12. The method according to any one of claims 8-10, characterized in that, The terminal device determines the RO in descending order of the number of repetitions of the random access request message corresponding to the SSB index.

13. The method according to claim 12, characterized in that, The terminal device determines the RO in ascending order based on the SSB index of the number of times the same random access request message is repeated.

14. A communication method, characterized in that, Applied to network devices; the method includes: Sending indication information, the indication information being used to indicate the number of repetitions of the random access request message corresponding to each of the M synchronization signal blocks (SSBs) in the first cell, wherein the number of repetitions of the random access request message corresponding to each SSB includes K. i The K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1.

15. The method according to claim 14, characterized in that, Ki is a candidate value from the set of candidate values ​​for the number of repetitions of the random access request message; and / or, K i =2 a , where a is a positive integer greater than or equal to 0.

16. The method according to claim 14 or 15, characterized in that, The number of repetitions of the random access request message corresponding to each SSB also includes K. j The K j Let be the number of times the random access request message corresponding to SSB index j in the first cell is repeated, 1≤j≤M, where j and i are different values.

17. The method according to claim 16, characterized in that, The K i With the K j different.

18. The method according to claim 17, characterized in that, The beam corresponding to the SSB indicated by SSB index i is different from the beam corresponding to the SSB indicated by SSB index j.

19. A communication device, characterized in that, The device includes: The receiving unit is configured to receive indication information, which indicates the number of repetitions of the random access request message corresponding to each of the M synchronization signal blocks (SSBs) in the first cell. The number of repetitions of the random access request message corresponding to each SSB includes K. i The K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i The SSB index i is a positive integer greater than or equal to 1, and the SSB index i indicates the SSB selected by the terminal device from the SSBs it has been listening to. The sending unit is configured to send according to the K i Send a random access request message.

20. A communication device, characterized in that, The device includes: The transmitting unit is used to transmit indication information, which indicates the number of repetitions of the random access request message corresponding to each of the M synchronization signal blocks (SSBs) in the first cell. The number of repetitions of the random access request message corresponding to each SSB includes K. i The K i K represents the number of repetitions of the random access request message corresponding to SSB index i in the first cell, 1 ≤ i ≤ M, where M is the total number of SSBs in the first cell, and K... i It is a positive integer greater than or equal to 1.

21. A terminal device, comprising a processor, a memory, and a computer program or instructions stored in the memory, characterized in that, The processor executes the computer program or instructions to implement the steps of the method according to any one of claims 1-13.

22. A network device, comprising a processor, a memory, and a computer program or instructions stored in the memory, characterized in that, The processor executes the computer program or instructions to implement the steps of the method according to any one of claims 14-18.

23. A computer-readable storage medium, characterized in that, It stores a computer program or instructions that, when executed, implement the steps of the method described in any one of claims 1-13 or 14-18.

24. A chip, comprising a processor, characterized in that, The processor performs the steps of the method according to any one of claims 1-13 or 14-18.

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