Random access method and apparatus

Abstract

The present application relates to the technical field of communications, and provides a random access method and apparatus, which improve the success rate of random access of a terminal. In this method, a terminal may send a message 1 (Msg1) N times when performing random access. For example, the terminal may send a preamble sequence N times on the basis of resources configured by a network device for sending the preamble sequence N times. In this way, the terminal may use more resources to send the Msg1, to improve an uplink channel coverage capability of initial access of the terminal, thereby improving the success rate of the random access of the terminal.

Description

Random access method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on November 30, 2023, with application number 202311637433.3 and application name “Random Access Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a random access method and device. Background Art

[0003] In the fifth generation mobile communication technology (5G) new radio (NR), the terminal can access the 5G network through a random access process. For example, the network device (such as a base station) broadcasts synchronization signals and system messages on specific time-frequency resources. After the terminal is turned on or re-accesses the network, it scans the synchronization signal of the network device, performs downlink time and frequency synchronization, and receives the configuration information about the random access resource in the system message. Then, the terminal selects the random access resource associated with the SSB according to the random access resource configuration information and the received synchronization signal and physical broadcast channel block (SSB), and uses the random access resource to send a random access signal, that is, message (Msg) 1. Accordingly, the network device replies to the terminal with Msg2 based on the received Msg1. After receiving Msg2, the terminal sends Msg3 on the corresponding time-frequency resource according to the configuration in Msg2. After receiving Msg3, the network device replies to the terminal with Msg4, indicating that the terminal has successfully accessed. After the terminal is successfully connected, you can use the 5G network.

[0004] However, during the random access process of a terminal, random access may fail due to various reasons. Therefore, how to improve the success rate of random access of a terminal is a hot topic currently under discussion. Summary of the Invention

[0005] The embodiments of the present application provide a random access method and apparatus to improve the success rate of random access by a terminal.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, a random access method is provided. This method can be performed by a terminal, or by a component of the terminal, such as a processor, chip, or chip system, or by a logic module or software that implements all or part of the terminal device's functionality. The following description uses the method performed by a terminal as an example. The method includes: receiving configuration information, and transmitting a preamble sequence N times based on the configuration information; the configuration information indicates resources used to transmit the preamble sequence N times, where N is an integer greater than 1.

[0008] Currently, during the random access process, the terminal uses one antenna port to send Msg1 once. However, in cases where the signal is poor, the network device may not detect the Msg1, making it impossible for the network device to reply to Msg2 based on the Msg1. In this case, the terminal needs to send Msg1 again after the random access response window timing ends, that is, to re-perform random access. In other words, the terminal access fails at this time and needs to re-perform random access. Based on the method of the first aspect, it can be seen that the terminal can send Msg1 N times when performing random access. For example, the terminal can send the preamble sequence N times according to the resources configured by the network device for sending the preamble sequence N times. In this way, the terminal can use more resources to send Msg1, improve the uplink channel coverage capability of the terminal's initial access, and thus improve the success rate of the terminal's random access.

[0009] In one possible design, the configuration information includes at least one of the following: a first random access channel opportunity (RO) packet for transmitting N preamble sequences, a first synchronization signal and physical broadcast channel block (SSB) packet corresponding to the RO for transmitting N preamble sequences, or a first preamble sequence set for transmitting N preamble sequences. It is understood that the first SSB packet can be determined by the terminal based on the quality of each received SSB, such as including at least one SSB with good quality measured by the terminal; the first RO packet can include N ROs; and the first SSB packet has a mapping relationship with the first RO packet, and the first RO packet has a mapping relationship with the first preamble sequence set. In other words, after determining the first SSB packet, the terminal can determine the first RO packet and the first preamble sequence packet based on the first SSB packet, and transmit the preamble sequence N times based on the first RO packet and the first preamble sequence packet.

[0010] Optionally, the first preamble sequence set includes at least one preamble sequence, and any preamble sequence in the at least one preamble sequence is transmitted N times during the access process. In this way, the terminal can select a preamble sequence from the first preamble sequence set and transmit the preamble sequence N times. It will be appreciated that when any preamble sequence in the at least one preamble sequence is transmitted N times during the access process, the network devices can jointly detect the preamble sequence, thereby improving the success rate of random access by the terminal.

[0011] Optionally, the first SSB group includes M SSBs. When M is greater than 1, the index values ​​of the M SSBs are continuous, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in the same time slot, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in adjacent time slots, and M is an integer greater than 0 and less than N. That is, when the first SSB group includes multiple SSBs, these multiple SSBs are adjacent SSBs. It can be understood that the M SSBs can be multiple SSBs with better quality among the SSBs received by the terminal. Usually, the multiple SSBs with better quality detected by the terminal include the SSB whose position is covered by the beam and at least one SSB adjacent to the SSB. In this way, when the terminal uses the beams corresponding to these multiple SSBs to send the preamble sequence N times, the terminal's access success rate can be improved through the joint reception gain of multiple beams in a scenario with poor network quality.

[0012] Furthermore, the first RO group includes N ROs, and M SSBs are associated with N ROs. In other words, the first SSB group has a mapping relationship with the first RO group. In this way, after determining the first SSB group, the terminal can further determine the first RO group based on the first SSB group, thereby facilitating the terminal to determine the RO used to send the N preamble sequences.

[0013] Furthermore, when M is equal to 1, the N ROs are numbered adjacently, or the N ROs occupy adjacent time domain positions, or the N ROs occupy different frequency domain positions in the same time slot. That is, when the first SSB group includes one SSB, the N ROs included in the first RO group may be N consecutive ROs among the multiple ROs associated with the SSB. In this way, the network device can perform joint detection on the preamble sequences sent on these N ROs, thereby improving the success rate of terminal random access.

[0014] In one possible design, sending the preamble sequence N times according to configuration information includes sending the preamble sequence N times through different antenna ports according to the configuration information. This can enhance robust reception on the network device. It is understood that the preamble sequence can also be sent N times through the same antenna port, and the specific number can be flexibly configured based on actual circumstances.

[0015] In one possible design, the random access response window timing begins after the Nth preamble sequence transmission is completed. That is, the preamble sequence is transmitted N times between the terminal receiving each SSB and the RAR message. This reduces terminal overhead and avoids invalid detection by the terminal.

[0016] In one possible design, after sending preamble sequences N times according to configuration information, the method of the first aspect further includes: receiving a random access response (RAR) message, where a transmit beam of the RAR message is related to at least one SSB in the first SSB group. That is, after receiving N preamble sequences sent by the terminal, the network device may determine M SSBs included in the first SSB group based on resources from which the N preamble sequences were received, and determine a transmit beam for the RAR message based on the M SSBs.

[0017] Optionally, the RAR message includes scheduling information for indicating message 3, Msg3. The scheduling information includes at least one of the following: a transmission mode, a transmission port, or a repetition parameter. The transmission mode indicates whether Msg3 should be retransmitted. In other words, the RAR message can indicate the transmission mode of Msg3. In this way, the scheduling information for Msg3 can be determined based on actual conditions, thereby ensuring that the network device receives Msg3.

[0018] Optionally, after receiving the RAR message, the method of the first aspect further includes: sending Msg3 Y times according to the RAR message, and the antenna port for sending Msg3 Y times is at least partially the same as the antenna port for sending the preamble sequence N times, and Y is an integer greater than 0. It can be understood that the terminal can determine the antenna port for sending Msg3 Y times based on the antenna port for sending the preamble sequence N times. The terminal can also determine the antenna port for sending Msg3 Y times based on the sending method of Msg3 indicated by the network device through the RAR message. Because the network device determines the antenna port for sending Msg3 based on the antenna port for sending Msg1, the antenna port for sending Msg3 Y times by the terminal is at least partially the same as the antenna port for sending the preamble sequence N times.

[0019] In a second aspect, a random access method is provided. This method can be performed by a network device, or by a component of the network device, such as a processor, chip, or chip system of the network device. It can also be implemented by a logic module or software that implements all or part of the network device's functions, such as a distributed unit. The following description uses the method performed by a network device as an example. The method includes: sending configuration information indicating resources for sending N preamble sequences, where N is an integer greater than 1; receiving N preamble sequences, and sending a random access response (RAR) message based on the N preamble sequences.

[0020] In one possible design scheme, the configuration information includes at least one of the following: a first random access channel opportunity RO group for sending N preamble sequences, a first synchronization signal and physical broadcast channel block SSB group corresponding to the RO for sending N preamble sequences, or a first preamble sequence set for sending N preamble sequences.

[0021] Optionally, the first preamble sequence set includes at least one preamble sequence, and any preamble sequence of the at least one preamble sequence is sent N times during the access process.

[0022] Optionally, the first SSB group includes M SSBs, and when M is greater than 1, the index values ​​of the M SSBs are continuous, or the time-frequency domain resources of at least two of the M SSBs are located in the same time slot, or the time-frequency domain resources of at least two of the M SSBs are located in adjacent time slots, and M is an integer greater than 0 and less than N.

[0023] Furthermore, the first RO group includes N ROs, and M SSBs are associated with the N ROs.

[0024] Furthermore, when M is equal to 1, the numbers of the N ROs are adjacent, or the time domain positions occupied by the N ROs are adjacent, or the N ROs occupy different frequency domain positions in the same time slot.

[0025] In one possible design scheme, the transmission beam of the RAR message is related to at least one SSB in the first SSB group.

[0026] In one possible design, the RAR message includes scheduling information for indicating message three Msg3, where the scheduling information includes at least one of the following: a sending mode, a sending port, or a repeated sending parameter, where the sending mode is used to indicate whether to repeatedly send Msg3.

[0027] In addition, the technical effects of the method described in the second aspect can also refer to the technical effects of the method described in the first aspect, and will not be repeated here.

[0028] According to a third aspect, a communication device is provided. The communication device includes: a module configured to execute the method described in the first aspect, such as a transceiver module and a processing module. For example, the transceiver module is configured to receive configuration information indicating resources for transmitting a preamble sequence N times, where N is an integer greater than 1; and the processing module is configured to transmit the preamble sequence N times according to the configuration information.

[0029] Optionally, the transceiver module may include a sending module and a receiving module, wherein the sending module is used to implement the sending function of the communication device described in the third aspect, and the receiving module is used to implement the receiving function of the communication device described in the third aspect.

[0030] Optionally, the communication device described in the third aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device may execute the method described in the first aspect.

[0031] It can be understood that the communication device described in the third aspect can be a terminal, or a chip (system) or other parts or components that can be set in the terminal, or a device including a terminal, and this application does not limit this.

[0032] In a fourth aspect, a communication device is provided. The communication device includes: a module configured to execute the method described in the second aspect, such as a transceiver module and a processing module. For example, the processing module is configured to send configuration information indicating resources for sending N preamble sequences, where N is an integer greater than 1; the transceiver module is configured to receive N preamble sequences; and the processing module is further configured to send a random access response (RAR) message based on the N preamble sequences.

[0033] Optionally, the transceiver module may include a sending module and a receiving module, wherein the sending module is used to implement the sending function of the communication device described in the fourth aspect, and the receiving module is used to implement the receiving function of the communication device described in the fourth aspect.

[0034] Optionally, the communication device described in the fourth aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device may execute the method described in the second aspect.

[0035] It can be understood that the communication device described in the fourth aspect can be a network device, or a chip (system) or other parts or components that can be set in the network device, or a device that includes a network device. This application does not impose any restrictions on this.

[0036] In a fifth aspect, a communication device is provided, comprising: a processor configured to execute the method described in any possible implementation of the first aspect or the second aspect.

[0037] In one possible design solution, the communication device described in the fifth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fifth aspect to communicate with other communication devices.

[0038] In one possible design, the communication device described in the fifth aspect may further include a memory. The memory may be integrated with the processor or provided separately. The memory may be used to store the computer program and / or data involved in the method described in either the first aspect or the second aspect.

[0039] In an embodiment of the present application, the communication device described in the fifth aspect may be the terminal or network device described in any one of the first aspect or the second aspect, or a chip (system) or other parts or components that can be set in the terminal or the network device, or a device that includes the terminal or the network device.

[0040] In a sixth aspect, a communication device is provided, comprising: a processor coupled to a memory, the processor configured to execute a computer program stored in the memory, so that the communication device performs the method described in any possible implementation of the first aspect or the second aspect.

[0041] In one possible design solution, the communication device described in the sixth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the sixth aspect to communicate with other communication devices.

[0042] In an embodiment of the present application, the communication device described in the sixth aspect may be the terminal or network device described in any one of the first aspect or the second aspect, or a chip (system) or other parts or components that can be set in the terminal or the network device, or a device that includes the terminal or the network device.

[0043] In the seventh aspect, a communication chip includes: a logic circuit and a communication interface, the logic circuit is used to execute computer instructions, and the communication interface is used for the communication chip to communicate with other devices or chips, when the logic circuit executes the computer instructions, the method described in any one of the implementation methods of the first aspect or the second aspect is implemented.

[0044] In an eighth aspect, a communication system is provided, comprising: an apparatus for executing the method described in the first aspect, and / or an apparatus for executing the method described in the second aspect.

[0045] In a ninth aspect, a computer-readable storage medium is provided, comprising: a computer program or instructions; when the computer program or instructions are run on a computer, the computer is caused to execute the method described in any possible implementation of the first aspect or the second aspect.

[0046] In a tenth aspect, a computer program product is provided, comprising a computer program or instructions, which, when executed on a computer, causes the computer to execute the method described in any possible implementation of the first aspect or the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0048] FIG2 is a schematic diagram of a random access process according to an embodiment of the present application;

[0049] FIG3 is a schematic diagram of a mapping relationship between a synchronization signal block SSB and a random access opportunity RO provided in an embodiment of the present application;

[0050] FIG4 is a schematic diagram of the mapping relationship between SSB and preamble sequence provided in an embodiment of the present application;

[0051] FIG5 is a schematic diagram of a random access response message provided in an embodiment of the present application;

[0052] FIG6 is a schematic diagram of a flow chart of a random access method provided in an embodiment of the present application;

[0053] FIG7 is a first schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0054] FIG8 is a second schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0055] FIG9 is a third schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0056] FIG10 is a schematic diagram 1 of configuring RO groups corresponding to different transmission times when RO groups are provided in an embodiment of the present application;

[0057] FIG11 is a fourth schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0058] FIG12 is a fifth schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0059] FIG13 is a sixth schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0060] FIG14 is a seventh schematic diagram of configuring N ROs when grouping ROs according to an embodiment of the present application;

[0061] FIG15 is a second schematic diagram of configuring RO groups corresponding to different transmission times when RO groups are provided in an embodiment of the present application;

[0062] FIG16 is a third schematic diagram of configuring RO groups corresponding to different transmission times when RO groups are provided in an embodiment of the present application;

[0063] FIG17 is a first schematic diagram of an RO when grouping a leading sequence according to an embodiment of the present application;

[0064] FIG18 is a second schematic diagram of RO when grouping leading sequences according to an embodiment of the present application;

[0065] FIG19 is a third schematic diagram of RO when grouping a leading sequence according to an embodiment of the present application;

[0066] FIG20 is a fourth schematic diagram of RO when grouping leading sequences according to an embodiment of the present application;

[0067] FIG21 is a fifth schematic diagram of RO when grouping leading sequences according to an embodiment of the present application;

[0068] FIG22 is a sixth schematic diagram of RO when grouping leading sequences according to an embodiment of the present application;

[0069] FIG23 is a schematic diagram of the positional relationship between a terminal and an SSB according to an embodiment of the present application;

[0070] FIG24 is a schematic diagram of an antenna port for transmitting a preamble sequence according to an embodiment of the present application;

[0071] FIG25 is a first structural diagram of a communication device provided in an embodiment of the present application;

[0072] FIG26 is a second structural diagram of the communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0073] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first introduced.

[0074] The communication system includes: a terminal and a network device. The terminal device and the network device can be referred to in the following "terminal 120" and "network device 110" respectively, and will not be described in detail here.

[0075] To facilitate understanding of the embodiments of the present application, the application scenarios used in the present application are described using the communication system architecture shown in FIG1 as an example. FIG1 is a schematic diagram illustrating a possible, non-limiting system. As shown in FIG1 , a communication system 1000 includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN 100 includes at least one network device (such as 110a and 110b in FIG1 , collectively referred to as 110) and at least one terminal (such as 120a to 120j in FIG1 , collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG1 ). The terminal 120 is connected to the network device 110 wirelessly. The network device 110 is connected to the core network 200 wirelessly or wiredly. The core network device in the core network 200 and the network device 110 in the RAN 100 may be different physical devices, or they may be the same physical device that integrates the core network logical functions and the radio access network logical functions.

[0076] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), such as a fourth generation (4G) mobile communication system, such as the Long Term Evolution (LTE) system, a fifth generation (5G) mobile communication system, such as the NR system, and a communication system evolved after 5G, such as the sixth generation (6G) mobile communication system. It may also be applied to wireless fidelity (WiFi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, and Internet of Vehicles communication systems. The RAN 100 may also be an open radio access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a WiFi system. The RAN 100 may also be a communication system that integrates two or more of the above systems.

[0077] The terminal and network device provided in the embodiment of the present application can be applied to the network device 110 or to the terminal 120. It is understood that FIG1 only shows a possible communication system architecture that can be applied in the embodiment of the present application. In other possible scenarios, the communication system architecture can also include other devices.

[0078] The network device 110 is a node in the RAN, which can also be called an access network device or a RAN node (or device). The network device 110 is used to help terminals achieve wireless access. The multiple network devices 110 in the communication system 1000 can be nodes of the same type or different types. In some scenarios, the roles of the network device 110 and the terminal 120 are relative. For example, the network element 120i in Figure 1 can be a helicopter or a drone, which can be configured as a mobile base station. For the terminal 120j that accesses the RAN 100 through the network element 120i, the network element 120i is a base station; but for the base station 110a, the network element 120i is a terminal. The network device 110 and the terminal 120 are sometimes referred to as communication devices. For example, the network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and the network elements 120a to 120j can be understood as communication devices with terminal functions.

[0079] In one possible scenario, a network device can be a base station, an evolved NodeB (eNodeB), a transmitting and receiving point (TRP), a transmitting point (TP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, a satellite, or an access point (AP) in a WiFi system, such as a home gateway, router, server, switch, bridge, etc., an integrated access and backhaul (IAB) node, a mobile switching center, or a network device in a non-terrestrial network (NTN) communication system, i.e., it can be deployed on a high-altitude platform or satellite. The network device can be a macro base station (such as 110a in Figure 1), a micro base station or an indoor station (such as 110b in Figure 1), a relay node or a donor node, or a wireless controller in a CRAN scenario. The network device can also be a device that functions as a base station in device-to-device (D2D) communication, vehicle-to-vehicle communication, drone communication, or machine communication. Optionally, the network device may also be a server, a wearable device, a vehicle or an onboard device, etc. For example, the access network device in vehicle to everything (V2X) technology may be a road side unit (RSU).

[0080] In another possible scenario, multiple network devices collaborate to assist the terminal in achieving wireless access, and different network devices respectively implement part of the functions of the base station. For example, the network device can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). It can be understood that the network device can be a CU node, a DU node, or a device including a CU node and a DU node. In addition, the CU can be divided into a network device in the access network RAN, or the CU can be divided into a network device in the core network CN, which is not limited here.

[0081] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (Open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0082] In the embodiments of the present application, the form of the network device is not limited. The device used to implement the function of the network device can be a network device; it can also be a device that can support the network device to implement the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device.

[0083] Terminal 120, which may also be referred to as user equipment (UE), mobile station (MS), mobile terminal (MT), user device, terminal equipment, access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device, may be a device for providing voice or data connectivity to a user, or may be an IoT device. For example, terminal equipment includes handheld devices with wireless connectivity, vehicle-mounted devices, and the like. Currently, terminal devices can be: mobile phones, tablet computers, computers with wireless transceiver functions, laptops, PDAs, mobile internet devices (MIDs), wearable devices (such as smart watches, smart bracelets, pedometers, etc.), vehicle-mounted equipment (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), satellite terminals, virtual reality (VR) devices, augmented reality (AR) devices, smart point of sale (POS) machines, customer-premises equipment (CPE), wireless terminals in industrial control, smart home devices (such as refrigerators, televisions, air conditioners, electricity meters, etc.), intelligent robots, robotic arms, workshop equipment, wireless terminals in unmanned driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, flying equipment (such as intelligent robots, hot air balloons, drones, airplanes), etc. The terminal device may also be other devices with terminal functions. For example, the terminal device may also be a device that serves as a terminal in D2D communication.

[0084] The embodiments of this application do not limit the device form factor of the terminal. The device used to implement the functions of the terminal device can be the terminal device; it can also be a device that supports the terminal device to implement the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of this application, the chip system can be composed of chips or include chips and other discrete devices.

[0085] It should be noted that the solutions in the embodiments of the present application can also be applied to other communication systems, and the corresponding names can also be replaced by the names of corresponding functions in other communication systems. The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0086] In a communication system, a terminal can send N preamble sequences based on the configuration information of resources (such as RO, preamble sequence, etc.) configured by a network device for sending N preamble sequences. In this way, the terminal can use more resources to send Msg1, that is, enhance Msg1, thereby improving the uplink channel coverage capability of the terminal's initial access, and further improving the success rate of the terminal's random access.

[0087] For ease of understanding, the technical terms involved in the embodiments of this application are introduced below.

[0088] 1. Beam

[0089] Beamforming is a special, directional transmission or reception effect created by the antenna array of a network device or terminal's transmitter or receiver, similar to the beam formed by a flashlight that focuses light in a single direction. Transmitting and receiving signals using beamforming can effectively increase signal transmission distance.

[0090] The beam can be a wide beam, a narrow beam, or other types of beams. The beam forming technology can be beamforming technology or other technologies. The beamforming technology can specifically be digital beamforming technology, analog beamforming technology, or hybrid digital / analog beamforming technology.

[0091] Beams generally correspond to resources. For example, when performing beam measurement, the network device measures different beams using different resources, and the terminal feeds back the measured resource quality, allowing the network device to know the quality of the corresponding beam. During data transmission, beams can also be indicated by their corresponding resources. For example, the network device indicates a transmission configuration indication-state through the transmission configuration index (TCI) field in the downlink control information (DCI), and the terminal determines the beam corresponding to the reference resource based on the reference resource contained in the TCI-state.

[0092] In communication protocols, beams can be specifically characterized as digital beams, analog beams, spatial domain filters, spatial filters, spatial parameters, TCIs, and TCI-states. A beam used to transmit signals can be called a transmission beam (or Tx beam), a spatial domain transmission filter, a spatial transmission filter, a spatial domain transmission parameter, or a spatial transmission parameter. A beam used to transmit signals can be understood as the distribution of signal strength in different directions in space after the signal is transmitted by an antenna. A beam used to receive signals can be called a reception beam (or Rx beam), a spatial domain reception filter, a spatial reception filter, a spatial domain reception parameter, or a spatial reception parameter. The beam used to receive signals can be understood as the signal strength distribution of the wireless signal received from the antenna in different directions in space.

[0093] It is understood that in the embodiments of the present application, unless otherwise specified, a beam refers to the transmit beam of a network device. In beam measurement, each beam of a network device corresponds to a resource, so the beam corresponding to the resource can be uniquely identified by the resource index or number. The embodiments of the present application uniformly use the term beam for description, but beam can be replaced by other equivalent concepts, such as antenna port, receive quasi-colocation, transmit quasi-colocation, spatial filtering transmission, or spatial filtering reception, and is not limited to the concepts mentioned above.

[0094] 2. Antenna port

[0095] An antenna port is a logical concept and does not directly correspond to a physical antenna. An antenna port is typically associated with a reference signal and can be understood as a transceiver interface on the channel through which the reference signal travels. For low-frequency systems, an antenna port may correspond to one or more antenna elements, which jointly transmit reference signals. The receiver can treat them as a whole without distinguishing between the elements. For high-frequency systems, an antenna port may correspond to a beam. Similarly, the receiver only needs to treat the beam as an interface, without distinguishing between individual elements.

[0096] 3. Port Group

[0097] A port group can be understood as a collection of multiple antenna ports. Specifically, multiple digital ports of a base station can be grouped to form multiple port groups. Alternatively, a port group can be multiple digital ports corresponding to the same analog beam, also referred to as a port group or a digital-analog port group. Alternatively, a port group can be a collection of digital ports corresponding to multiple analog beams, also referred to as a port group or a digital-analog port group. Alternatively, multiple digital ports of the same analog beam can be divided into multiple subsets, each of which is called a port group or a digital-analog port group.

[0098] 4. Random access channel (RA)

[0099] The terminal can access the network through the random access process, thereby achieving uplink and downlink synchronization with network devices. The random access process refers to the process from the terminal sending a random access preamble to attempt to access the network to the establishment of a basic signaling connection with the network. In other words, the terminal can access the network through the random access process. The random access process can be triggered by certain events, for example, the terminal device can perform initial access from the idle state, or perform the radio resource control layer (RRC) connection recovery process from the inactive state, or perform the RRC connection re-establishment process, etc.

[0100] As shown in Figure 2, the 5G NR random access process mainly includes the following five steps, namely S201 to S205. They are introduced below.

[0101] S201, a network device broadcasts a synchronization signal and system information at a specific time and frequency position.

[0102] Synchronization signals and system information are periodically sent by network devices based on their configuration. After powering on or reconnecting to the network, a terminal scans for synchronization signals sent by network devices to synchronize downlink time and frequency, while also receiving random access resource configuration information from system information.

[0103] S202, the terminal sends Msg1 to the network device according to the configuration information and the received SSB (denoted as SSB#102).

[0104] SSB#102 is an SSB selected by the terminal from multiple received SSBs, which may be the SSB with the best quality among the multiple SSBs detected by the terminal.

[0105] Msg1 includes a preamble sequence, also known as a preamble code. The preamble sequence notifies the network device of a random access request and enables it to calculate the transmission delay between itself and the terminal. This allows the network device to calibrate the uplink timing and communicate this calibration information to the terminal via timing advance (TA) adjustment information.

[0106] After the terminal determines SSB#102, it can select the random access resources corresponding to SSB#102, such as time resources, frequency resources, code domain resources, etc., and use the random access resources to send Msg1. It can be understood that there is a mapping relationship between SSB and random access resources, that is, there is a mapping relationship between SSB and RO / preamble code. This mapping relationship is configured by the network device. For example, as shown in Figure 3, one SSB can be associated with multiple random access channel occasions (RO); as shown in Figure 4, SSB0 and SSB1 in the figure are both associated with RO#0, that is, multiple SSBs can also be associated with one RO. At this time, these multiple SSBs can correspond to different preamble sequences. Based on the mapping relationship between SSB and random access resources, the network device can obtain the downlink beam for sending Msg2 (described below) after detecting the random access preamble. RO is sometimes also called physical random access channel opportunity.

[0107] S203: The network device sends Msg2 to the terminal according to Msg1.

[0108] Based on the received Msg1, the network device estimates the terminal's timing advance and sends Msg2 to the terminal. Msg2 is a response message to Msg1, which can also be called a random access response (RAR). As shown in Table 1 and Figure 5, Msg2 can include a frequency hopping flag, a physical uplink shared channel (PUSCH) frequency resource allocation, an uplink grant, and a temporary cell wireless network equipment temporary identifier. The uplink grant is used to indicate the transmission resources for Msg3.

[0109] Table 1

[0110] S204: The terminal sends Msg3 to the network device according to Msg2.

[0111] After receiving Msg2, the terminal may send Msg3 on the transmission resources indicated by the uplink grant. Msg3 may include layer 2 information and / or layer 3 information, such as an RRC setup request message, an RRC recovery request, a beam failure recovery, or a media access control element.

[0112] S205: The network device sends Msg4 to the terminal according to Msg3.

[0113] After receiving Msg3, the network device sends Msg4 to the terminal to indicate that the terminal has successfully accessed. Msg4 may include a contention resolution message, which includes the terminal device identifier. If the random access is determined to be contention-based random access from Msg3, the information of the terminal devices that need to compete is saved. When resolving contention through Msg4, the terminal devices that need to compete, as determined by Msg3, are processed to resolve the contention problem.

[0114] In 5G NR, terminals can access the 5G network through the random access process. However, during the random access process, random access may fail due to various reasons. For example, during the random access process, the terminal will use one antenna port to send a Msg1. However, in situations such as poor signal, the network device may not detect this Msg1, causing the network device to not reply to Msg2 based on this Msg1. In this case, after the random access response window expires, the terminal needs to send Msg1 again, that is, to perform the random access operation again. Therefore, how to improve the success rate of terminal random access is currently a hot topic of discussion.

[0115] In response to the above technical problems, the embodiments of the present application propose the following technical solutions to improve the success rate of random access of terminals.

[0116] The technical solution in this application will be described below with reference to the accompanying drawings.

[0117] Figure 6 is a flow chart of a random access method provided in an embodiment of the present application. This method can be applied to communication between a terminal and a network device in the above communication system.

[0118] S601: The network device sends configuration information. Correspondingly, the terminal receives the configuration information from the network device.

[0119] S602: The terminal sends N preamble sequences according to the configuration information. Correspondingly, the network device receives N preamble sequences from the terminal.

[0120] S603: The network device sends a RAR message according to the N preamble sequences.

[0121] S601 to S603 are introduced below respectively.

[0122] For S601:

[0123] The configuration information indicates resources for transmitting preamble sequences N times, where N is an integer greater than 1. Transmitting preamble sequences N times can be understood as transmitting one preamble sequence each time, for a total of N times. For information about preamble sequences, refer to the aforementioned "4. Random Access S202" and are not further described here. The resources may be an RO and / or a preamble sequence, meaning that a preamble sequence can be transmitted N times on the RO. The preamble sequence can be transmitted N times.

[0124] The configuration information may include at least one of the following: a first RO packet for transmitting the preamble sequence N times, a first SSB packet corresponding to the RO for transmitting the preamble sequence N times, or a first preamble sequence set for transmitting the preamble sequence N times.

[0125] The first RO group may include N ROs, i.e., a preamble sequence may be sent on each of the N ROs, thereby transmitting the preamble sequence N times. For example, if N is 4, the first RO group may include four ROs, namely RO#1 to RO#4, i.e., a preamble sequence may be sent on each of RO#1 to RO#4. It will be understood that, in different situations, the preamble sequences sent on the N ROs may be the same or different (described below).

[0126] The first SSB group may include M SSBs, where M is a positive integer. When M is greater than 1, the index values ​​of the M SSBs are continuous, or the time-frequency domain resources of at least two of the M SSBs are located in the same time slot, or the time-frequency domain resources of at least two of the M SSBs are located in adjacent time slots.

[0127] The first preamble set may include at least one preamble sequence. The at least one preamble sequence may be used to transmit N times. For example, a preamble sequence #1 may be selected from the first preamble set and transmitted N times. Alternatively, multiple preamble sequences may be selected from the first preamble set, such as preamble sequences #1 to #3, and transmitted N times using preamble sequences #1 to #3, where N is greater than or equal to 3. It is understood that in different situations, the terminal may select one or more preamble sequences from the first preamble set and transmit them N times (described below).

[0128] There is a mapping relationship (denoted as mapping relationship #1) between the first RO group, the first SSB group, and the first preamble sequence set, that is, the first SSB group has a mapping relationship with the first RO group, and the first RO group has a mapping relationship with the first preamble sequence set. Mapping relationship #1 can be configured by a network device. That is, the network device can first determine the mapping relationship between SSB, RO, and the preamble sequence (denoted as a mapping relationship set), and then configure the mapping relationship set to the terminal through signaling, so that the terminal can select a mapping relationship from the mapping relationship set according to actual conditions, and send N preamble sequences based on the resources corresponding to the mapping relationship. In this case, mapping relationship #1 can be a mapping relationship in the mapping relationship set. For ease of understanding, the mapping relationship set is first introduced below, and then the first RO group, the first SSB group, and the first preamble sequence set are introduced.

[0129] The mapping relationship set may include a mapping relationship between SSB and RO, and a mapping relationship between RO and a preamble sequence. All SSBs sent by the network device may be divided into multiple SSB groups, i.e., the mapping relationship between SSB and RO may be a mapping relationship between multiple different SSB groups and RO. At least some of the multiple SSB groups may include M SSBs. For example, if there are 8 SSBs in total and M is 1, then the group may be divided into 8 SSB groups, i.e., each SSB group includes 1 SSB; or, if M is 2, then the group may be divided into 4 SSB groups, each of which includes 2 SSBs with consecutive index values, such as SSB#1 and SSB#2, SSB#3 and SSB#4, SSB#5 and SSB#6, and SSB#7 and SSB#8. It is understood that the multiple SSB groups may also include groups with other different numbers of SSBs, without limitation.

[0130] By setting a mapping relationship set, after receiving a preamble sequence from a terminal, the network device can determine the downlink beam based on the preamble sequence and / or the RO receiving the preamble sequence. And when the terminal device sends N preamble sequences, the network device can jointly detect the N preamble sequences to improve the success rate of random access of the terminal. It can be understood that the network device can agree with the terminal on how to send the preamble sequence N times through the mapping relationship set, thereby realizing joint detection of the N preamble sequences sent by the terminal. The mapping relationship set can be grouped by RO, that is, configuring which ROs are ROs that can be used to send preamble sequences N times, or grouped by preamble sequences, that is, configuring which preamble sequences are preamble sequences used to send N times. The following is an introduction to each case.

[0131] Case 1: Group by RO and determine the mapping relationship set.

[0132] RO grouping can be understood as dividing each RO associated with M SSBs into RO groups for transmitting preamble sequences with different transmission frequencies. That is, different RO groups support preamble sequence transmission methods corresponding to different transmission frequencies. Because there are multiple mapping relationships between an SSB and an RO, such as one SSB associated with n ROs and at least one SSB associated with one RO, where n is an integer greater than 1, the division of ROs varies under different SSB-RO mapping relationships. This is explained in detail below.

[0133] Case 1.1: 1 SSB associated with n ROs

[0134] When M is equal to 1, for any SSB, if n is equal to N, then these n ROs can be used to transmit the preamble sequence N times, that is, the preamble sequence can be transmitted once on each of these n ROs. In this case, these n ROs can be a group of ROs used to transmit the preamble sequence N times. If n is greater than N, and n is greater than q×N, then p groups of ROs can be set on the n ROs, each of the p groups of ROs can include N ROs, and these N ROs are consecutive, with p being an integer less than or equal to q. If n is less than N, the preamble sequence can be transmitted n times by default, that is, in this case, N is equal to n. It can be understood that N consecutive ROs can be understood as the N ROs being adjacent or consecutive in number, or the N ROs occupying adjacent time domain positions, or the N ROs occupying different frequency domain positions in the same time slot.

[0135] For example, as shown in Figure 7 , when N is 2 and n is 4, that is, when one SSB is associated with four ROs, RO#a0 and RO#a1 can be a group of RO packets used to transmit two preamble sequences, and / or RO#a2 and RO#a3 can be a group of RO packets used to transmit two preamble sequences; alternatively, RO#a1 and RO#a2 can be a group of RO packets used to transmit two preamble sequences. It will be understood that the multiple ROs (RO#a0 to RO#a3) in Figure 7 are numbered consecutively, and these multiple ROs can occupy different time domain locations and / or frequency domain locations.

[0136] When M is greater than 1, for any M SSBs, the M SSBs correspond to M×n ROs. These M×n ROs are jointly grouped, with each SSB group containing N ROs, and these N ROs are associated with at least two SSBs. For example, N / M ROs can be selected from the n ROs corresponding to each SSB of the M SSBs and grouped into the same RO group; the N / M ROs associated with each SSB in the same group are numbered adjacent or consecutive, or occupy adjacent time domain positions, or occupy different frequency domain positions in the same time slot; and the ROs associated with different SSBs in the same group have the same local number. The local number can be understood as the number of the n ROs corresponding to each SSB, arranged starting from a preset value, where the preset value can be any integer. In other words, the relative continuity of the N ROs in each group of ROs after division can be understood as that, for the n ROs associated with each SSB in the M SSBs, the multiple ROs selected for sending N preamble sequences are continuous, that is, the numbers of these multiple ROs are adjacent or continuous, or the time domain positions they occupy are adjacent, or they occupy different frequency domain positions in the same time slot, and the multiple ROs selected from the M SSBs are sorted by number, such as sorted from small to large, and correspond in position.

[0137] For example, as shown in FIG8 , N is 2, M is 2, and n is 4, i.e., 2 SSBs are associated with 8 SSBs. The RO packet used to transmit the preamble sequence twice may include at least one of the following: RO#b0 and RO#b4, RO#b1 and RO#b5, RO#b2 and RO#b6, or RO#b3 and RO#b7. Alternatively, the RO packet used to transmit the preamble sequence four times may include at least one of the following: RO packet #b1, RO packet #b2, or RO packet #b3. RO packet #b1 includes RO#b0, RO#b1, RO#b4, and RO#b5. RO packet #b2 includes RO#b2, RO#b3, RO#b6, and RO#b7. RO packet #b3 includes RO#b1, RO#b2, RO#b5, and RO#b6. As can be seen, each RO group corresponds in position, such as RO#b0 and RO#b4, RO#b1 and RO#b5, RO#b2 and RO#b6, and RO#b3 and RO#b7. It can be understood that the ROs (RO#b0 to RO#b7) in Figure 8 are numbered consecutively, and these ROs can occupy different time domain positions and / or frequency domain positions.

[0138] For another example, as shown in FIG9 , N is 4, M is 3, and n is 4, i.e., 3 SSBs are associated with 12 SSBs. The RO group used to transmit the preamble sequence three times may include at least one of the following: RO group #c1, RO group #c2, RO group #c3, or RO group #c4. RO group #c1 includes RO#c0, RO#c4, and RO#c8. RO group #c2 includes RO#c1, RO#c5, and RO#c9. RO group #c3 includes RO#c2, RO#c6, and RO#c10. RO group #c4 includes RO#c3, RO#c7, and RO#c11. It will be understood that the multiple ROs (RO#c0 to RO#c11) in FIG9 are numbered consecutively, and these multiple ROs may occupy different time domain locations and / or frequency domain locations.

[0139] It is understood that the above content describes how to configure N ROs for transmitting N preamble sequences on multiple ROs associated with M SSBs, when one SSB is associated with n ROs. It is also understood that when grouping ROs, RO grouping can also be performed based on various transmission times. For example, multiple ROs associated with M SSBs can be divided into RO groups for transmitting a preamble sequence once, RO groups for transmitting a preamble sequence twice, and RO groups for transmitting a preamble sequence three times. In this case, the ROs included in each RO group are continuous or relatively continuous.

[0140] For example, as shown in Figure 10, when n is 4, meaning one SSB is associated with four ROs, the transmission times are one and two, meaning a preamble sequence is transmitted once and twice. In this case, RO#aa0 and RO#aa1 can be a group of RO packets used to transmit a preamble sequence twice, while RO#aa2 and RO#aa3 can be two groups of RO packets used to transmit a preamble sequence once. Alternatively, RO#aa1 and RO#aa2 can be a group of RO packets used to transmit a preamble sequence twice, while RO#aa0 and RO#aa3 can be two groups of RO packets used to transmit a preamble sequence once. RO#aa2 and RO#aa3 can be a group of RO packets used to transmit a preamble sequence twice, while RO#aa0 and RO#aa1 can be two groups of RO packets used to transmit a preamble sequence once. It will be understood that the multiple ROs (RO#aa0 to RO#aa3) in Figure 10 are numbered consecutively, and these multiple ROs can occupy different time domain locations and / or frequency domain locations.

[0141] For another example, M is 2 and n is 4, that is, 2 SSBs are associated with 8 SSBs, and the number of transmissions is 1 and 2, that is, the preamble sequence is sent once and twice. In this case, the RO group used to send the preamble sequence twice can include at least one of the following: RO#bb0 and RO#bb4, RO#bb1 and RO#bb5, RO#bb2 and RO#bb6, or RO#bb3 and RO#bb7. After the RO group used to send the preamble sequence twice is determined, each of the remaining SSBs in the 8 SSBs is a group of RO groups used to send the preamble sequence once.

[0142] Case 1.2: At least one SSB is associated with one RO

[0143] When M is equal to 1, any SSB is associated with one RO within one RO association cycle. When transmitting preamble sequences N times, ROs with different RO association cycles can be grouped. For example, ROs associated with the same SSB in N consecutive RO association cycles can be configured as a group of RO groups and used to transmit preamble sequences N times. That is, the preamble sequences are transmitted separately on each RO in this group of RO groups.

[0144] For example, as shown in Figure 11, N is 2, and one SSB is associated with one RO. In this case, for SSB#dx, RO#dx in RO association period #d1 and RO#dx in RO association period #d2 can be configured as one RO packet, which is used to send two preamble sequences, where x is an integer greater than or equal to 0.

[0145] For another example, as shown in FIG12 , N is 2, and two SSBs are associated with one RO. In this case, RO#ex in RO association period #e1 and RO#ex in RO association period #e2 can be configured as one RO group, which is used to send two preamble sequences, where x is an integer greater than or equal to 0.

[0146] When M is greater than 1, for any M SSBs, the M SSBs are associated with M ROs within one RO association cycle. When transmitting preamble sequences N times, the ROs within the same RO association cycle can be grouped. For example, the M ROs associated with M SSBs within the same RO association cycle are grouped into one RO group. It will be appreciated that in this case, M equals N, meaning that when the terminal transmits preamble sequences N times, the network device requires beams corresponding to N SSBs to receive the N preamble sequences.

[0147] For example, as shown in Figure 13, there are a total of 6 SSBs, N is 3, and 1 SSB is associated with 1 RO. In this case, 3 consecutive ROs within the same RO association period can be grouped into a group of RO packets. That is, the RO packet used to transmit the preamble sequence three times can include at least one of the following: RO packet #f1, RO packet #f2, RO packet #f3, or RO packet #f4. RO packet #f1 includes RO#f0, RO#f1, and RO#f2; RO packet #f2 includes RO#f1, RO#f2, and RO#f3; RO packet #f3 includes RO#f2, RO#f3, and RO#f4; and RO packet #f4 includes RO#f3, RO#f4, and RO#f5.

[0148] For another example, as shown in Figure 14, there are a total of 6 SSBs, N is 2, and 2 SSBs are associated with one RO. In this case, two consecutive ROs within the same RO association period can be grouped into a group of RO packets. That is, the RO packet used to transmit the preamble sequence twice can include at least one of the following: RO packet #g1 or RO packet #g2. RO packet #g1 includes RO#g0 and RO#g1, and RO packet #g2 includes RO#g1 and RO#g2.

[0149] It is understood that the above content describes how to configure N ROs for transmitting N preamble sequences on multiple ROs associated with M SSBs, when at least one SSB is associated with one RO. It is also understood that when grouping ROs, RO grouping can also be performed based on various transmission times. For example, multiple ROs associated with M SSBs can be divided into RO groups for transmitting a preamble sequence once, RO groups for transmitting a preamble sequence twice, and RO groups for transmitting a preamble sequence three times. In this case, the ROs included in each RO group are continuous or relatively continuous.

[0150] For example, as shown in Figure 15, there are a total of four SSBs, two of which are associated with one RO. SSB#dd0 and SSB#dd1 are associated with RO#dd0, and SSB#dd2 and SSB#dd3 are associated with RO#dd1. In this case, RO#dd0 in association period #dd1 and RO#d0 in RO association period #dd2 can be configured as a group of RO packets for transmitting preamble sequences twice, and RO#dd1 can be a group of RO packets for transmitting preamble sequences once. Alternatively, RO#dd1 in association period #dd1 and RO#d1 in RO association period #dd2 can be configured as a group of RO packets for transmitting preamble sequences twice, and RO#dd0 can be a group of RO packets for transmitting preamble sequences once.

[0151] For another example, as shown in Figure 16, there are a total of 6 SSBs, 2 of which are associated with one RO. SSB#ff0 and SSB#ff1 are associated with RO#ff0, SSB#ff2 and SSB#ff3 are associated with RO#ff1, and SSB#ff4 and SSB#ff5 are associated with RO#ff2. In this case, RO#ff0 and RO#ff1 can be a group of RO packets used to send preamble sequences twice, and RO#ff2 can be a group of RO packets used to send preamble sequences once. Alternatively, RO#ff1 and RO#ff2 can be a group of RO packets used to send preamble sequences twice, and RO#ff0 can be a group of RO packets used to send preamble sequences once.

[0152] It can be understood that Case 1 uses M SSBs as an example to introduce RO grouping under different SSB-RO mapping relationships. For multiple ROs associated with M SSBs, each of the multiple ROs can only exist in one RO group. All SSBs can be divided into multiple SSB groups, each of which includes at least one SSB. The RO groups associated with each SSB group can be divided with reference to the aforementioned RO grouping, and there is no relationship between the different SSB groups. In other words, different SSB groups can be divided into the same or different RO groups.

[0153] Furthermore, each group of divided RO packets can be associated with at least one preamble sequence. That is, each group of RO packets has a mapping relationship with at least one preamble sequence. The same preamble sequence can be used to transmit the RO packets, or different preamble sequences can be used to transmit the packets, without limitation. It will be understood that regardless of whether the same or different preamble sequences are used to transmit the RO packets, each corresponds to a single random access request. For example, if N different preamble sequences are used and transmitted separately on N ROs in an RO packet used to transmit the preamble sequence N times, these N transmissions correspond to one random access request. For another example, if one preamble sequence is used and repeatedly transmitted on N ROs in an RO packet used to transmit the preamble sequence N times, these N transmissions correspond to one random access request.

[0154] Case 2: Group the leading sequence and determine the mapping relationship set.

[0155] Grouping preamble sequences can be understood as configuring preamble sequence sets corresponding to each transmission count based on the number of preamble sequence transmissions. That is, when M SSBs are associated with at least one RO, the multiple preamble sequences associated with the at least one RO are divided into different preamble sequence sets based on the number of transmissions. The different preamble sequence sets support preamble sequence transmission modes corresponding to different transmission counts. The preamble sequence set includes at least one preamble sequence, and the preamble sequences in the preamble sequence sets corresponding to different transmission counts are different. For example, M SSBs are associated with 4 ROs, and these 4 ROs are associated with 100 preamble sequences, which are sent 1 time and 2 times. Then, the 1st preamble sequence to the 50th preamble sequence can be configured as preamble sequence set #1, and the 51st preamble sequence to the 100th preamble sequence can be configured as preamble sequence set #2. Preamble sequence set #1 is used to send the preamble sequence once, and preamble sequence set #2 is used to send the preamble sequence twice. It can be understood that any preamble sequence in preamble sequence set #1 is sent once during the access process, and any preamble sequence in preamble sequence set #2 is sent twice during the access process.

[0156] It will be appreciated that after determining each preamble sequence set, the preamble sequence selected from the preamble sequence set needs to be transmitted on at least one RO associated with M SSBs. There are various mapping relationships between an SSB and an RO, such as one SSB associated with n ROs, or at least one SSB associated with one RO, where n is an integer greater than 1. Therefore, under different SSB-RO mapping relationships, the ROs that can be used to transmit preamble sequences with different transmission times also vary. This is described in detail below.

[0157] Case 2.1: One SSB is associated with n ROs

[0158] When M is 1, one SSB is associated with n ROs, each of which can be used to transmit the preamble sequence at different transmission times. When transmitting the preamble sequence at different transmission times, the multiple ROs used are consecutive, for example: N consecutive ROs used to transmit the preamble sequence N times; another example: S consecutive ROs used to transmit the preamble sequence S times, where S is an integer greater than 0 and different from N. It can be understood that multiple consecutive ROs can be understood as multiple ROs with adjacent or consecutive numbers, multiple ROs occupying adjacent time domain positions, or multiple ROs occupying different frequency domain positions in the same time slot.

[0159] For example, as shown in Figure 17, n is 4, M is 1, and one SSB is associated with 4 ROs, namely RO#h0 to RO#h3. These 4 ROs are associated with 100 preamble sequences, namely preamble sequence #h1 to preamble sequence #h100, and the number of transmission times is 1, 2, 3 and 4 times. At this time, the 100 preamble sequences can be divided into 4 preamble sequence sets, such as preamble sequence set #h0 to preamble sequence set #h3, where preamble sequence set #h0 includes 25 preamble sequences for sending a preamble sequence once, such as preamble sequence #h1 to preamble sequence #h25; preamble sequence set #h1 includes 25 preamble sequences for sending a preamble sequence twice, such as preamble sequence #h26 to preamble sequence #h50; preamble sequence set #h2 includes 25 preamble sequences for sending a preamble sequence three times, such as preamble sequence #h51 to preamble sequence #h75; and preamble sequence set #h3 includes 25 preamble sequences for sending a preamble sequence four times, such as preamble sequence #h76 to preamble sequence #h100. Any preamble sequence in preamble sequence set #h0 can be transmitted on any RO from RO#h0 to RO#h3. Any preamble sequence in preamble sequence set #h1 can be transmitted on two consecutive ROs among the four ROs, such as RO#h0 and RO#h1, RO#h1 and RO#h2, or RO#h2 and RO#h3. Any preamble sequence in preamble sequence set #h2 can be transmitted on three consecutive ROs among the four ROs, such as RO#h0, RO#h1, and RO#h2, or RO#h1, RO#h2, and RO#h3. Any preamble sequence in preamble sequence set #h3 can be transmitted on RO#h0 to RO#h3. It will be understood that the multiple ROs (RO#h0 to RO#h3) in FIG17 are numbered consecutively, and these multiple ROs can occupy different time domain locations and / or frequency domain locations.

[0160] When M is greater than 1, for any M SSBs, the M SSBs correspond to M×n ROs, each of which can be used to transmit preamble sequences with different transmission times. When transmitting preamble sequences with different transmission times, the relative continuity of the multiple ROs used can be referred to in the aforementioned "Case 1.1" and will not be repeated here. These multiple ROs are associated with at least two of the M SSBs.

[0161] For example, as shown in FIG18 , M is 2 and n is 4, i.e., 2 SSBs are associated with 8 ROs, namely RO#i0 to RO#i7, and 8 ROs are associated with 100 preamble sequences, namely preamble sequence #i1 to preamble sequence #i100, which are sent 2 times and 4 times. In this case, these 100 preamble sequences can be divided into two preamble sequence sets, namely preamble sequence set #i0 and preamble sequence set #i1. Preamble sequence set #i0 includes 50 preamble sequences for sending the preamble sequence twice, such as preamble sequence #i1 to preamble sequence #i50; preamble sequence set #i1 includes 50 preamble sequences for sending the preamble sequence four times, such as preamble sequence #i51 to preamble sequence #i100. Any preamble sequence in preamble sequence set #i0 can be transmitted on two relatively consecutive ROs among the eight ROs, such as RO#i0 and RO#i4, or RO#i1 and RO#i5, or RO#i2 and RO#i6, or RO#i3 and RO#i7. Any preamble sequence in preamble sequence set #i1 can be transmitted on four relatively consecutive ROs among the eight ROs, such as RO#i0, RO#i1, RO#i4, and RO#i5, or RO#i1, RO#i2, RO#i5, and RO#i6, or RO#i2, RO#i3, RO#i6, and RO#i7. It will be understood that the multiple ROs (RO#i0 to RO#i7) in FIG18 are numbered consecutively, and these multiple ROs can occupy different time domain positions and / or frequency domain positions.

[0162] Case 2.2: At least one SSB is associated with a RO

[0163] When M is 1, any SSB is associated with one RO within one RO association cycle. When the preamble sequence is sent N times, the preamble sequence can be sent once on the RO with the same number in N consecutive RO association cycles. It will be understood that for the terminal, this number can be the number of the RO associated with the SSB determined by the terminal.

[0164] For example, as shown in Figure 19, one SSB is associated with one RO. There are eight SSBs in total, namely SSB#j0 to SSB#j7. These eight ROs are associated with 100 preamble sequences, namely preamble sequence #j1 to preamble sequence #j50, which are sent once and twice. In this case, these 50 preamble sequences can be divided into two preamble sequence sets, namely preamble sequence set #j0 and preamble sequence set #j1. Preamble sequence set #j0 includes preamble sequences #1 to #25 for sending the preamble sequence once, and preamble sequence set #j1 includes preamble sequences #26 to #50 for sending the preamble sequence twice. SSB#jx is mapped to RO#jx, and x ranges from 0 to 7. When a preamble sequence from preamble sequence set #j0 (e.g., preamble sequence #j23) is used to transmit a preamble, it can be transmitted on each RO in RO association period #j1 or on each RO in RO association period #j2. Each transmission corresponds to a random access request. When a preamble sequence from preamble sequence set #j1 (e.g., preamble sequence #j48) is used to transmit a preamble, the same preamble sequence #48 can be transmitted on RO #jx1 in RO association period #j1 and RO #jx1 in RO association period #j2, where x1 is any integer between 0 and 7. This results in two preamble transmissions, each of which corresponds to one random access request.

[0165] For another example, as shown in Figure 20, two SSBs are associated with one RO, with a total of eight SSBs, namely SSB#k0 to SSB#k7. These eight ROs are associated with 20 preamble sequences, namely preamble sequence #k1 to preamble sequence #k20, which are sent once and twice. In this case, these 20 preamble sequences can be divided into two preamble sequence sets, namely preamble sequence set #k0 and preamble sequence set #k1. Preamble sequence set #k0 includes preamble sequences #k0 to #k9 for sending the preamble sequence once, and preamble sequence set #k1 includes preamble sequences #k10 to #k19 for sending the preamble sequence twice. Among them, SSB#kx has a mapping relationship with RO#kx, and x is 0 to 7 respectively. When a preamble sequence from preamble sequence set #k0 (e.g., preamble sequence #k8) is used to transmit the preamble, it can be transmitted on each RO in RO association period #k1 or on each RO in RO association period #k2, i.e., each transmission corresponds to a random access request. When a preamble sequence from preamble sequence set #k1 (e.g., preamble sequence #k18) is used to transmit the preamble, the same preamble sequence #18 can be transmitted on RO #kx1 in RO association period #k1 and RO #kx1 in RO association period #k2, where x1 is any integer between 0 and 3. This results in two preamble transmissions, and these two transmissions of preamble sequence #k18 correspond to one random access request.

[0166] When M is greater than 1, for any M SSBs, the M SSBs are associated with M ROs within one RO association cycle. When the preamble sequence is sent N times, the preamble sequence can be sent on each of the M ROs within the same RO association cycle. It can be understood that these M ROs are continuous.

[0167] For example, as shown in Figure 21, one SSB is associated with one RO, and there are a total of six SSBs, namely SSB#p0 to SSB#p5. These six SSBs are associated with 50 preamble sequences, namely preamble sequence #p1 to preamble sequence #p50, which are sent once and twice. In this case, these 50 preamble sequences can be divided into two preamble sequence sets, namely preamble sequence set #p0 and preamble sequence set #p1. Preamble sequence set #p0 includes preamble sequences #1 to #25 for sending the preamble sequence once, and preamble sequence set #p1 includes preamble sequences #26 to #50 for sending the preamble sequence twice. When the preamble sequence of preamble sequence set #p0 (such as preamble sequence #p23) is used to send the preamble sequence, it can be sent on any RO from RO#p0 to RO#p5, that is, each transmission corresponds to a random access request; when the preamble sequence of preamble sequence set #p1 (such as preamble sequence #p48) is used to send the preamble sequence, the same preamble sequence #48 can be sent on RO#p0 and RO#p1, RO#p1 and RO#p2, RO#p2 and RO#p3, RO#p3 and RO#p4, or RO#p4 and RO#p5, respectively, that is, the preamble sequence is sent twice. In this case, the two transmissions of preamble sequence #48 correspond to one random access request.

[0168] For another example, as shown in Figure 22, two SSBs are associated with one RO, and there are a total of six SSBs, namely SSB#q0 to SSB#q5. These six SSBs are associated with 20 preamble sequences, namely preamble sequence #q1 to preamble sequence #q20, which are sent once and twice. In this case, these 20 preamble sequences can be divided into two preamble sequence sets, namely preamble sequence set #q0 and preamble sequence set #q1. Preamble sequence set #q0 includes preamble sequences #1 to #10 for sending the preamble sequence once, and preamble sequence set #q1 includes preamble sequences #11 to #20 for sending the preamble sequence twice. When the preamble sequence of preamble sequence set #q0 (such as preamble sequence #q1) is used to send the preamble sequence, it can be sent on RO#q0, RO#q1 or RO#q2, that is, each transmission corresponds to a random access request; when the preamble sequence of preamble sequence set #q1 (such as preamble sequence #p48) is used to send the preamble sequence, the same preamble sequence #4 can be sent on RO#q0 and RO#q1 respectively, or the same preamble sequence #p4 can be sent on RO#q1 and RO#q2 respectively, that is, the preamble sequence is sent twice. In this case, the two transmissions of preamble sequence #4 correspond to one random access request.

[0169] It can be understood that Case 2 introduces the grouping of at least one preamble sequence associated with M SSBs. All SSBs can be divided into multiple SSB groups, each of which includes at least one SSB. The preamble sequence set associated with each SSB group and the RO used to send the preamble sequence can be configured with reference to the above content. There is no relationship between the different SSB groups. In other words, different preamble sequence sets and RO groupings can be configured for different SSB groups.

[0170] It will also be understood that the above content describes how to configure a mapping relationship set. The mapping relationship set may indicate resources used to send preamble sequences N times. The mapping relationship set may also indicate at least one resource used to send preamble sequences R times, where R is an integer greater than 0, and R is different from N. After configuring the mapping relationship set, the network device may send configuration information indicating the mapping relationship set to the terminal, so that the terminal can determine the preamble sequence and RO used to send the preamble sequence N times based on the configuration information and actual conditions. It will be understood that the configuration information may indicate the resources used to send the preamble sequence N times, and the configuration information may include: an SSB group set, an RO group set, or a total preamble sequence set.

[0171] An SSB grouping set may include at least one SSB grouping, and the SSB grouping set is related to how the SSBs are divided. When all SSBs are divided by M SSBs, the SSB grouping set may include at least one SSB grouping set (denoted as an SSB grouping subset) obtained by dividing all SSBs by M SSBs, with each SSB grouping in the SSB grouping subset including M SSBs. It will be appreciated that all SSBs may also be divided by at least one other number of SSBs. In this case, the SSB grouping set may further include at least one SSB grouping set obtained by dividing all SSBs by the at least one number of SSBs. For example, there are 4 SSBs, namely: SSB#0 to SSB#3, M is 3, and when all SSBs are divided into 3 SSBs, 4 groups of SSB groups can be obtained, namely: SSB group #1 to SSB group #4. SSB group #1 includes SSB#0, SSB#1 and SSB#2, SSB group #2 includes SSB#1, SSB#2 and SSB#3, SSB group #3 includes SSB#2, SSB#3 and SSB#0, and SSB group #4 includes SSB#3, SSB#0 and SSB#1.

[0172] It can be understood that the SSB group set may include the above-mentioned first SSB group, that is, the first SSB group may belong to the SSB group set. Specifically, the first SSB group may be any SSB group set in the SSB group subset. Continuing with the above example, when the above SSB group subset includes: SSB group #1 to SSB group #4, the first SSB group may be any SSB group from SSB group #1 to SSB group #4.

[0173] An RO group set may include at least one group of RO groups, and the RO group set is related to the configuration of a mapping relationship set. When the mapping relationship set is configured by grouping ROs, the RO group set may include at least one group of RO groups (denoted as an RO group subset) associated with each SSB group in the SSB group subset for transmitting N preamble sequences. For example, the SSB group subset includes two SSB groups, namely SSB group #11 and SSB group #22. SSB group #11 is associated with three groups of RO packets for transmitting N preamble sequences, and SSB group #22 is associated with four groups of RO packets for transmitting N preamble sequences. In this case, the RO group subset includes five groups of RO groups. When the mapping relationship set is grouped according to the preamble sequence, the RO group set may include at least one group of RO groups (recorded as RO group subset) associated with each SSB group in the SSB group subset for sending the preamble sequence N times; or, the RO group set may include at least one group of RO groups (recorded as RO group subset) of all ROs associated with each SSB group in the SSB group subset. For example: continuing the above example, all ROs associated with SSB group #11 are a group of RO groups, and all ROs associated with SSB group #22 are a group of RO groups. At this time, the RO group subset includes 2 groups of RO groups.

[0174] It can be understood that when the mapping relationship set is grouped and configured using the leading sequence, the RO group set may include at least one group of RO groups consisting of all ROs associated with each SSB group in the SSB group subset. In this case, a rule for selecting N ROs from all the ROs can be pre-configured, that is, these N ROs are continuous or relatively continuous.

[0175] It is also understood that the RO group set may include the first RO group, that is, the first RO group may belong to the RO group set. Specifically, the first RO group may be any RO group set in the RO group subset. It is also understood that the first RO group is associated with the first SSB, that is, the N ROs included in the first RO group are associated with the M SSBs included in the first SSB. When M is equal to 1, the N ROs included in the first RO group are continuous, that is, the N ROs are numbered adjacently, or the N ROs occupy adjacent time domain positions, or the N ROs occupy different frequency domain positions in the same time slot. When M is greater than 1, the N ROs included in the first RO group are relatively continuous.

[0176] The total set of preamble sequences may include at least one preamble sequence set, and the total set of preamble sequences is related to the configuration of the mapping relationship set. When the mapping relationship set is configured by grouping ROs, the total set of preamble sequences may include at least one preamble sequence set (referred to as a preamble sequence subset) associated with each RO group in the RO group subset for transmitting N preamble sequences. For example, the RO group subset includes two RO groups, namely RO group #1 and RO group #2. RO group #1 is associated with one preamble sequence set, and RO group #2 is associated with one preamble sequence set. In this case, the preamble sequence set subset includes two preamble sequence sets. When the mapping relationship set is configured by grouping preamble sequences, the total set of preamble sequences may include at least one preamble sequence set (referred to as a preamble sequence subset) for transmitting N preamble sequences.

[0177] It is understood that the total preamble sequence set may include the first preamble sequence set, that is, the first preamble sequence set may belong to the total preamble sequence set. Specifically, the first preamble sequence set may be any preamble sequence set in the preamble sequence subset. It is understood that when the mapping relationship set is configured by grouping preamble sequences, the first preamble sequence set includes at least one preamble sequence, and any preamble sequence of the at least one preamble sequence is transmitted N times during the access process.

[0178] It will also be appreciated that the above content describes the relationship between the first SSB group, the SSB group subset, and the SSB group set; the relationship between the first RO group, the RO group subset, and the RO group set; and the relationship between the first preamble sequence set, the preamble sequence subset, and the total preamble sequence set. It can be seen that mapping relationship #1 can be one mapping relationship in the mapping relationship set. Furthermore, the first SSB group, the first RO group, and the first preamble sequence set can be determined by the terminal based on actual conditions (described below).

[0179] For S602:

[0180] The terminal may determine, based on the configuration information, resources for transmitting the N preamble sequences, such as the RO for transmitting the N preamble sequences and / or the preamble sequences for transmitting the N preamble sequences. In other words, the terminal may determine, based on actual circumstances, the first SSB group, the first RO group, and the first preamble sequence set from the configuration information. This will be described in detail below.

[0181] After receiving all the SSBs sent by the network device, the terminal can measure the signal quality of each received SSB, and determine the sending method of sending N preamble sequences based on the measured signal quality of each SSB. When the signal quality of each SSB is less than the signal quality threshold, the terminal can determine to send the preamble sequence N times. The signal quality threshold can be preset or predefined by the protocol, and can also be configured through a system message (such as system message block 1) without restriction. It can be understood that when the signal quality of each SSB is lower than the signal quality threshold, it can be characterized as poor network quality at this time. In this case, the sending method of sending N preamble sequences can improve the uplink channel coverage capability of the terminal. It can also be understood that when the signal quality of each SSB is greater than or equal to the signal quality threshold, it can be characterized as good network quality at this time. In this case, the sending method of sending 1 preamble sequence can be adopted.

[0182] After determining to send the preamble sequence N times, the terminal can determine the M SSBs corresponding to the N-times sent preamble sequence, that is, it can determine one or more SSBs corresponding to the N-times sent preamble sequence. The determination of the first SSB group is related to the signal quality of the SSB received by the terminal. When M is equal to 1, the M SSBs can be the SSB with the best signal quality measured by the terminal from the multiple SSBs periodically sent by the network device, that is, the first SSB group includes the SSB with the best measured signal quality. When M is greater than 1, the M SSBs can be multiple SSBs with good signal quality measured by the terminal from all SSBs periodically sent by the network device, and these multiple SSBs are adjacent, that is, the first SSB group includes multiple SSBs with good measured signal quality. It can be understood that the above-mentioned SSB with the best signal quality can be the SSB covering the area where the terminal is located; the above-mentioned multiple SSBs with good signal quality can be the SSB covering the area where the terminal is located, and at least one SSB adjacent to the SSB. For example, as shown in Figure 23, when the terminal is located in the coverage area of ​​SSB#3, SSB#3 can be the SSB with the best signal quality measured by the terminal, and SSB#2 to SSB#4 can be multiple SSBs with good quality measured by the terminal. Adjacent SSBs can be understood as SSBs with continuous index values, or SSBs whose time-frequency domain resources are located in the same time slot, or SSBs whose time-frequency domain resources are located in adjacent time slots. It can also be understood that all SSBs periodically sent by the network device are pre-divided into multiple groups of SSB groups, and the terminal can select the first SSB from these multiple groups of SSB groups according to actual conditions. The division of all SSBs into multiple groups of SSB groups can refer to the above-mentioned related introduction and will not be repeated here.

[0183] After the first SSB group is determined, the first RO group can be determined based on the first SSB group, and the first preamble sequence set can be determined based on the first RO group.

[0184] When configuring a mapping relationship set in groups using RO, the terminal can determine the first RO group from at least one RO group associated with the first SSB group, that is, the first RO group can be any RO group in the at least one RO group. Furthermore, the terminal can determine the first preamble sequence set associated with the first RO group. It is understood that in this case, the preamble sequences sent N times can be the same or different. In other words, the terminal can determine at least one preamble sequence for N transmissions from the first preamble sequence set, that is, the terminal can select a preamble sequence from the first preamble sequence and send the preamble sequence N times; or the terminal can select F preamble sequences from the first preamble sequence and use these F preamble sequences to send the preamble sequence N times, where F is an integer greater than 1 and less than or equal to N.

[0185] When preambles are grouped and configured with a mapping relationship set, the terminal can determine the first RO group from at least one RO group associated with the first SSB group, and determine the first preamble set for transmitting preambles N times. It will be understood that in this case, any preamble in the first preamble set is transmitted N times during the access process. In other words, the terminal can select a preamble from the first preamble set and transmit the preamble N times, i.e., the preamble sequence transmitted N times is the same preamble.

[0186] After determining the first SSB group, the first RO group, the first preamble sequence set, and the preamble sequences used for N transmissions, the terminal may respectively transmit the preamble sequences on the N ROs included in the first RO group.

[0187] After the terminal completes the Nth preamble transmission, it can start the random access response window timing. In other words, the terminal does not receive the RAR message (described below) before completing the Nth preamble transmission. In other words, the Nth preamble transmission occurs within the time interval between the terminal receiving the SSB from the network device and receiving the RAR message from the network device. This ensures that the terminal receives the RAR message only after sending the Nth preamble, thereby reducing terminal overhead and avoiding invalid detection by the terminal.

[0188] Optionally, sending the preamble sequence N times according to the configuration information may specifically include: sending the preamble sequence N times through different or the same antenna ports according to the configuration information. It is understood that different antenna ports may correspond to different physical antennas or the same physical antenna. For example, as shown in FIG24 , two different antenna ports may be used to send the preamble sequence twice, and in case 1, different antenna ports correspond to different physical antennas, and in case 2, different antenna ports correspond to the same physical antenna.

[0189] It is understood that the N ROs used to transmit the preamble sequence N times may be ROs within different RO association periods or within the same RO association period. Furthermore, when the N ROs are ROs within the same RO association period, these N ROs are associated with the same SSB or with different SSBs. For details, please refer to the relevant descriptions in "Case 1" and "Case 2" above, which will not be repeated here.

[0190] It can also be understood that when M is greater than 1, the reference signals for the transmit power of the N preamble sequences may be the same, that is, each reference signal is associated with a certain SSB among the M SSBs included in the first SSB group. In other words, the transmit power of the N preamble sequences can be calculated based on the received power of a certain SSB among the M SSBs included in the first SSB group. When M is greater than 1, the reference signals for the transmit power of the N preamble sequences may be different, that is, each reference signal is associated with a different SSB among the M SSBs included in the first SSB group. In other words, the transmit power of the N preamble sequences can be calculated based on the received power of each SSB included in the first SSB group.

[0191] For S603:

[0192] The RAR message is a response message to the N preamble sequences sent by the terminal. For details, please refer to the relevant introduction of "4. Random Access S203" above and will not be repeated here. The transmission beam of the RAR message can refer to a certain SSB during random access. That is, the RAR message can be sent using the same beam as a certain SSB during random access, and this beam is related to the preamble sequence sent by the terminal.

[0193] Specifically, when a terminal sends a preamble sequence N times, if the N preamble sequences correspond to one SSB, the RAR message may be sent using the same beam as the SSB. If the N preamble sequences correspond to multiple SSBs, the RAR message may be sent using the same beam as the SSB that meets a preset condition among the multiple SSBs. The preset condition may be the maximum or minimum index value of the SSB, or other conditions that can determine an SSB from multiple SSBs, without limitation. When a terminal sends a preamble sequence once, if one SSB corresponds to at least one RO, the network device may send the RAR message using the same beam as the SSB associated with the RO that detected the preamble sequence. If multiple SSBs correspond to one RO, and different SSBs correspond to the same preamble sequence, the network device may send the RAR message using the same beam as the SSB with the strongest received signal among the multiple SSBs associated with the RO that detected the preamble sequence. If multiple SSBs correspond to one RO, and different SSBs correspond to different preamble sequences, the network device may send the RAR message using the same beam as the SSB that detected the preamble sequence and the SSB associated with the RO that detected the preamble sequence.

[0194] It is understood that the network device can jointly detect N preamble sequences based on the mapping relationship set, identify the terminal's random access request, and send a RAR message based on the random access request. For example, if SSB #1A corresponds to four ROs, RO#A1 to RO#A4, and the mapping relationship set is configured by preamble grouping, the network device can use SSB #1A to detect preambles on RO#A1 to RO#A4. For preamble sequences #A1 to #A25 in preamble sequence set #A1 used to transmit a preamble sequence once, the network device can perform detection on each RO in RO#A1 to RO#A4 based on preamble sequences #A1 to #A25. For preamble sequences #A26 to #A50 in preamble sequence set #A2 used to transmit a preamble sequence three times, the network device can perform joint detection on two consecutive ROs in RO#A1 to RO#A4 based on preamble sequences #A26 to #A50. For details of the joint detection, reference may be made to the existing technology and will not be elaborated here.

[0195] In summary, in the embodiment of the present application, when performing random access, the terminal can send the preamble sequence N times according to the resources configured by the network device for sending the preamble sequence N times. In this way, the terminal can use more resources to send Msg1, improve the uplink channel coverage capability of the terminal's initial access, and thus improve the success rate of the terminal's random access.

[0196] Optionally, in combination with the above embodiment, the RAR message may include scheduling information for indicating Msg3, and the scheduling information may include at least one of the following: a sending mode, a sending port, or a repeated sending parameter.

[0197] The sending mode can be used to indicate whether to repeatedly send Msg3. For example, bit 0 can be used to indicate sending Msg3 once, that is, not sending Msg3 repeatedly; bit 1 can be used to indicate sending Msg3 repeatedly, that is, sending Msg3 multiple times. It can be understood that the network device can determine whether the terminal should repeatedly send Msg3 based on actual conditions. For example, when the receiving power of a certain preamble sequence received by the network device is greater than or equal to the receiving power threshold, it can indicate that the network quality is good. At this time, it can indicate sending Msg3 once, thereby ensuring the reception of Msg3 and reducing the communication overhead of the terminal; when the receiving power of a certain preamble sequence received by the network device is less than the receiving power threshold, it can indicate that the network quality is poor, and it can indicate sending Msg3 repeatedly to ensure that Msg3 can be received.

[0198] The sending port can be used to indicate the antenna port for sending Msg3. Exemplarily, the network device can indicate the antenna port for Msg3 by indicating the preamble sequence received at a certain time. Exemplarily, the sending port can be 3, that is, indicating that the antenna port of the preamble sequence sent for the third time is used to send Msg3. It can be understood that the network device can determine the antenna port for Msg3 based on the received power of each received preamble sequence. Specifically, the network device can determine the preamble sequence with the largest received power among the received preamble sequences, and send the sending order of the preamble sequence to the terminal, so that the terminal uses the antenna port that sends the preamble sequence to send Msg3, thereby increasing the probability that the network device receives Msg3.

[0199] The repetition parameter can be used to indicate the number of times Msg3 is repeated and the time-frequency resource location when Msg3 is repeatedly sent. This time-frequency resource location can be used to send Msg3, which can be RO. By carrying scheduling information in the RAR message, the transmission method of Msg3 can be indicated. The network device can determine the number of times Msg3 is repeated based on actual conditions. For example, when the network quality is good, the number of Msg3 repetitions can be small; otherwise, the number of Msg3 repetitions can be large.

[0200] It is understood that by including scheduling information in the RAR message, the network device can indicate the transmission method of Msg3. This facilitates the network device's reception of Msg3 and allows it to adjust the transmission method of Msg3 based on actual conditions. Furthermore, scheduling information may include other information, such as TA time adjustment information and uplink grants. For details, please refer to the aforementioned "4. Random Access S203" and will not be repeated here.

[0201] Optionally, in combination with the above embodiment, after sending the preamble sequence N times according to the configuration information (S603), the above random access method may further include: the terminal receives a random access response RAR message, where the transmit beam of the RAR message is related to at least one SSB in the first SSB group. In other words, the network device may select one SSB from the M SSBs included in the first SSB group, such as the SSB with the largest index value, the SSB with the smallest index value, or the SSB with the largest received signal strength among the M SSBs, and use the transmit beam corresponding to the SSB to send the RAR message.

[0202] Furthermore, after the terminal receives the RAR message, the random access method may further include: sending Msg3 Y times according to the RAR message (S604 in FIG6 ), where Y is an integer greater than 0. There are multiple ways for the terminal to send Msg3 Y times, which are described below.

[0203] Method 1: Y is 1, which means Msg3 is sent once.

[0204] After receiving the RAR message, the terminal can send a Msg3 once at a specified time-frequency domain position according to the RAR message. Specifically, if the N preamble sequences sent by the terminal are associated with one antenna port, that is, the preamble sequence is sent N times through one antenna port in step S602, then the antenna port can be used to send the Msg3 once. If the N preamble sequences sent by the terminal are associated with multiple antenna ports, that is, the preamble sequence is sent N times through multiple antenna ports in step S602, then the antenna port used to send the Msg3 once can be determined according to a preset rule. The preset rule can be to use the antenna port that sent the preamble sequence for the Jth time, where J is an integer greater than 0 and less than N; or, to use the antenna port with the strongest downlink SSB signal energy received among the multiple antenna ports, without restriction.

[0205] Method 2: Y is greater than 1, that is, Msg3 is sent multiple times.

[0206] After receiving the RAR message, the terminal can send multiple Msg3s at the specified time-frequency domain position according to the RAR message. The same antenna port or different antenna ports can be used to send multiple Msg3s; or, the same beam or different beams can be used to send multiple Msg3s. Specifically, when one antenna port is used to send multiple Msg3s, the method for determining an antenna port can refer to the relevant introduction of "Method 2" above, which will not be repeated here. When different antenna ports are used to send multiple Msg3s, if the N preamble sequences sent by the terminal are associated with one antenna port (denoted as antenna port #B1), the antenna port #B1 and other antenna ports can be used to send multiple Msg3s, that is, the multiple antenna ports used to send multiple Msg3s include antenna port #B1. If the N preamble sequences sent by the terminal are associated with multiple antenna ports, then when Y is equal to N, these multiple antenna ports can be used to send multiple Msg3s, that is, multiple antenna ports that send N preamble sequences can be used to send multiple Msg3s; when Y is less than N, the antenna port that sent the first Y preamble sequences among the N preamble sequences can be used to send multiple Msg3s; when Y is greater than N, multiple antenna ports associated with the N preamble sequences can be repeatedly used to send multiple Msg3s.

[0207] It is understood that Methods 1 and 2 describe antenna ports that can be used when sending multiple Msg3s. It is also understood that the antenna port can be indicated by a network device, such as by carrying the sending port in a RAR message, or can be determined independently by the terminal according to the above method, without limitation. It can be seen that in this embodiment of the present application, the antenna port for sending Msg3s Y times is at least partially the same as the antenna port for sending the preamble sequence N times.

[0208] In addition, the method of sending multiple Msg3s through different antenna ports is similar to the method of sending N preamble sequences through different antenna ports. For details, please refer to the above-mentioned related introduction and will not be repeated here.

[0209] The random access method provided in the embodiment of the present application is described in detail above in conjunction with Figure 6. The following describes in detail a communication device for executing the random access method provided in the embodiment of the present application in conjunction with Figures 25-26.

[0210] Figure 25 is a schematic diagram of the structure of a communication device according to an embodiment of the present application. As shown in Figure 25, the communication device 2500 includes a transceiver module 2501 and a processing module 2502. For ease of illustration, Figure 25 only shows the main components of the communication device.

[0211] In some embodiments, the communication device 2500 may be applicable to the above-mentioned communication system to perform the functions of the terminal device in the random access method shown in Figure 6. It is understood that the communication device 2500 may be a terminal, a chip (system) or other component or assembly that can be provided in a terminal, or a device including a terminal, and this application does not limit this.

[0212] In some embodiments, the communication device 2500 may be applicable to the above-mentioned communication system to perform the functions of the network device in the random access method shown in Figure 6. It is understood that the communication device 2500 may be a network device, a chip (system) or other component or assembly that can be provided in a network device, or a device that includes a network device, and this application does not limit this.

[0213] As shown in Figure 26, communication device 2600 includes a processor 2601 and an interface circuit 2602. Processor 2601 and interface circuit 2602 are coupled to each other. It is understood that interface circuit 2602 can be a transceiver or an input / output interface. Optionally, communication device 2600 may also include a memory 2603 for storing instructions executed by processor 2601, or storing input data required by processor 2601 to execute instructions, or storing data generated after processor 2601 executes instructions. Sometimes, interface circuit 2602 can also be understood as part of processor 2601, in which case communication device 2600 includes processor 2601.

[0214] When the communication device 2600 is used to implement the method shown in FIG6 , the processor 2601 is used to implement the functions of the processing module 2502 , and the interface circuit 2602 is used to implement the functions of the transceiver module 2501 .

[0215] When the above-mentioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above-mentioned method embodiment. When the terminal chip receives information from the base station, it can be understood that the information is first received by other modules in the terminal (such as a radio frequency module or antenna) and then sent to the terminal chip by these modules. When the terminal chip sends information to the base station, it can be understood that the information is first sent to other modules in the terminal (such as a radio frequency module or antenna) and then sent to the base station by these modules.

[0216] When the above-mentioned communication device is a chip applied to a base station, the base station chip implements the functions of the base station in the above-mentioned method embodiment. When the base station chip receives information from the terminal, it can be understood that the information is first received by other modules in the base station (such as a radio frequency module or antenna) and then sent to the base station chip by these modules. When the base station chip sends information to the terminal, it can be understood that the information is sent to other modules in the base station (such as a radio frequency module or antenna) and then sent to the terminal by these modules.

[0217] In this application, when entity A sends information to entity B, it can be done directly from A to B or indirectly through another entity. Similarly, when entity B receives information from entity A, it can be done directly from entity B or indirectly through another entity. Entities A and B herein can be RAN nodes or terminals, or modules within a RAN node or terminal. The sending and receiving of information can be information exchange between a RAN node and a terminal, for example, between a base station and a terminal; the sending and receiving of information can also be information exchange between two RAN nodes, for example, between a CU and a DU; the sending and receiving of information can also be information exchange between different modules within a device, for example, between a terminal chip and other modules in the terminal, or between a base station chip and other modules within the base station.

[0218] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0219] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and storage medium can also exist in a base station or a terminal as discrete components.

[0220] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0221] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0222] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of this application, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0223] The present application presents various aspects, embodiments, or features in the context of systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in conjunction with the figures. Furthermore, combinations of these aspects may also be used.

[0224] In the embodiments of the present application, "information", "signal", "message", "channel" and "signaling" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are matched. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are matched. In addition, the " / " mentioned in this application can be used to express an "or" relationship.

[0225] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A random access method, characterized in that: The method comprises: receiving configuration information, where the configuration information indicates resources used to send N preamble sequences, where N is an integer greater than 1; According to the configuration information, the preamble sequence is sent N times.

2. The method according to claim 1, characterized in that The configuration information includes at least one of the following: a first random access channel opportunity RO group for sending N preamble sequences, a first synchronization signal and physical broadcast channel block SSB group corresponding to the RO for sending N preamble sequences, or a first preamble sequence set for sending N preamble sequences.

3. The method according to claim 2, characterized in that The first preamble sequence set includes at least one preamble sequence, and any preamble sequence of the at least one preamble sequence is sent N times during an access process.

4. The method according to claim 2 or 3, characterized in that: The first SSB group includes M SSBs. When M is greater than 1, the index values ​​of the M SSBs are continuous, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in the same time slot, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in adjacent time slots, and M is an integer greater than 0 and less than N.

5. The method according to claim 4, characterized in that The first RO group includes N ROs, and the M SSBs are associated with the N ROs.

6. The method according to claim 5, characterized in that When M is equal to 1, the numbers of the N ROs are adjacent, or the time domain positions occupied by the N ROs are adjacent, or the N ROs occupy different frequency domain positions in the same time slot.

7. The method according to any one of claims 1 to 6, characterized in that The sending of the preamble sequence N times according to the configuration information includes: According to the configuration information, the preamble sequence is sent N times through different antenna ports.

8. The method according to any one of claims 1 to 7, characterized in that After the Nth preamble sequence is sent, the random access response window timing starts.

9. The method according to any one of claims 1 to 8, characterized in that After sending the preamble sequence N times according to the configuration information, the method further includes: A random access response RAR message is received, wherein a transmission beam of the RAR message is related to at least one SSB in the first SSB group.

10. The method according to claim 9, characterized in that The RAR message includes scheduling information for indicating message three Msg3, and the scheduling information includes at least one of the following: a sending mode, a sending port, or a repeated sending parameter, and the sending mode is used to indicate whether to repeatedly send the Msg3.

11. The method according to claim 9 or 10, characterized in that: After receiving the RAR message, the method further includes: According to the RAR message, Msg3 is sent Y times, the antenna port for sending the Msg3 Y times is at least partially the same as the antenna port for sending the preamble sequence N times, and Y is an integer greater than 0.

12. A random access method, characterized in that: The method comprises: Sending configuration information, where the configuration information indicates resources used to send N preamble sequences, where N is an integer greater than 1; N preamble sequences are received, and a random access response RAR message is sent according to the N preamble sequences.

13. The method according to claim 12, characterized in that The configuration information includes at least one of the following: a first random access channel opportunity RO group for sending N preamble sequences, a first synchronization signal and physical broadcast channel block SSB group corresponding to the RO for sending N preamble sequences, or a first preamble sequence set for sending N preamble sequences.

14. The method according to claim 13, characterized in that The first preamble sequence set includes at least one preamble sequence, and any preamble sequence of the at least one preamble sequence is sent N times during an access process.

15. The method according to claim 13 or 14, characterized in that The first SSB group includes M SSBs. When M is greater than 1, the index values ​​of the M SSBs are continuous, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in the same time slot, or the time-frequency domain resources of at least two SSBs among the M SSBs are located in adjacent time slots, and M is an integer greater than 0 and less than N.

16. The method according to claim 15, characterized in that The first RO group includes N ROs, and the M SSBs are associated with the N ROs.

17. The method according to claim 16, characterized in that When M is equal to 1, the numbers of the N ROs are adjacent, or the time domain positions occupied by the N ROs are adjacent, or the N ROs occupy different frequency domain positions in the same time slot.

18. The method according to any one of claims 12 to 17, characterized in that: The transmission beam of the RAR message is related to at least one SSB in the first SSB group.

19. The method according to any one of claims 12 to 18, characterized in that: The RAR message includes scheduling information for indicating message three Msg3, and the scheduling information includes at least one of the following: a sending mode, a sending port, or a repeated sending parameter, and the sending mode is used to indicate whether to repeatedly send the Msg3.

20. A communication device, characterized in that: The apparatus comprises: a module for executing the method according to any one of claims 1 to 11, or a module for executing the method according to any one of claims 12 to 19.

21. A communication chip, characterized in that: The communication chip includes: a logic circuit and a communication interface, the logic circuit is used to execute computer instructions, and the communication interface is used for the communication chip to communicate with other devices or chips. When the logic circuit executes the computer instructions, the method described in any one of claims 1 to 11 is implemented, or the method described in any one of claims 12 to 19 is implemented.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a computer program or instructions. When the computer program or instructions are executed on a communication device, the communication device executes the method according to any one of claims 1 to 11, or executes the method according to any one of claims 12 to 19.

23. A computer program product, characterized in that The computer program product comprises a computer program or instructions, and when the computer program or instructions are executed by a communication device, the method according to any one of claims 1 to 11 is executed, or the method according to any one of claims 12 to 19 is executed.

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