Random access method and device

Abstract

The invention provides a random access method and device, belongs to the technical field of communication, and is used for enabling terminal equipment to send a random access request message in a multi-TRP transmission scene. In the method, a terminal device receives a first message and a PDCCH, the first message is used for configuring a first TAG and a second TAG in the same cell for the terminal device, the PDCCH is used for indicating a path loss resource corresponding to a random access request message, and the TAG corresponding to the PDCCH is the first TAG or the second TAG; according to the TAG corresponding to the PDCCH and the path loss resource, downlink timing adopted by the random access request message is determined, the random access request message is sent according to the downlink timing, and the downlink timing is first downlink timing corresponding to the first TAG or second downlink timing corresponding to the second TAG. Therefore, in a multi-TRP transmission scene, the terminal equipment can adopt correct downlink timing to realize sending of the random access request message.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular, to a random access method and apparatus. Background Art

[0002] In the 5th generation (5G) mobile communication system, both the uplink and downlink transmissions use time slots as the basic time unit, that is, data can be transmitted once within each time slot. When a terminal device performs uplink transmission, it needs to know the start time of its uplink time slot, that is, uplink timing; when the terminal device performs downlink reception, it needs to know the start time of its downlink time slot, that is, downlink timing. In a single transmission and reception point (TRP) transmission scenario, the terminal needs to determine one uplink timing and one downlink timing. In a multi-TRP transmission scenario, the terminal device needs to determine multiple uplink timings and multiple downlink timings, and these multiple uplink timings and multiple downlink timings are respectively used to send or receive data for different TRPs corresponding to a serving cell. The downlink timing can be determined by measuring the downlink reference information sent by the network device, and the uplink timing can be determined according to the downlink timing, the timing advance offset indicated by the network device, and the timing advance (TA) obtained in the random access process.

[0003] In a multi-TRP transmission scenario, such as in a scenario where a cell corresponds to two TRPs, the network device (collectively referred to as multiple TRPs) will send a physical downlink control channel (PDCCH) to the terminal device to instruct the terminal device to send a random access request message to the network device. However, in this case, the terminal device does not know which TRP to send the random access request message to. Therefore, in a multi-TRP transmission scenario, how the terminal device sends a random access request message is an urgent problem to be solved. Summary of the Invention

[0004] Embodiments of this application provide a random access method and apparatus, which are used to enable a terminal device to send a random access request message in a multi-TRP (two TRPs or more than two TRPs) transmission scenario.

[0005] To achieve the above object, this application adopts the following technical solutions:

[0006] In a first aspect, a random access method is provided. This method can be executed by a terminal device, or by components of the terminal device, such as the processor, chip, or chip system of the terminal device, etc., or can also be implemented by a logic module or software that can implement all or part of the functions of the terminal device. Hereinafter, an example will be given with this method being executed by the terminal device. The method includes: receiving a first message, where the first message is used to configure a first timing advance group (TAG) and a second TAG in the same cell for the terminal device; receiving a physical downlink control channel (PDCCH), where the PDCCH is used to indicate the path loss resource corresponding to the random access request message, and the TAG corresponding to the PDCCH is the first TAG or the second TAG; determining the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource, and sending the random access request message according to this downlink timing, where the downlink timing is the first downlink timing corresponding to the first TAG or the second downlink timing corresponding to the second TAG.

[0007] In a multi-TRP transmission scenario, when the terminal device sends a random access request message to the network device according to the PDCCH, it does not know which TRP to send the random access request message to, that is, the terminal device does not know which downlink timing to use to send the random access request message. Based on the method in the first aspect, it can be known that the terminal device can determine the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource. For example, by the relationship between the TAG corresponding to the physical downlink data channel (PDDCH) indicated by the path loss resource and the TAG corresponding to the random access request message, the TAG corresponding to the random access request message is determined, and the downlink timing adopted by the random access request message is determined according to this TAG. In this way, in a multi-TRP transmission scenario, the terminal device can use the correct downlink timing to send the random access request message.

[0008] It can be understood that the first TAG and the second TAG respectively correspond to one of the two TRPs corresponding to the above cell. For example, if the cell corresponds to TRP#1 and TRP#2, the first TAG corresponds to TRP#1 and the second TAG corresponds to TRP#2; or, the first TAG corresponds to TRP#2 and the second TAG can correspond to TRP#1.

[0009] In a possible design solution, the path loss resource is a first path loss resource or a second path loss resource. The first path loss resource is the quasi-co-location (QCL) reference signal resource in the transmission configuration indication (TCI) state adopted by the PDCCH, and the second path loss resource is the synchronization signal and physical broadcast channel block (SSB) indicated in the PDCCH. It can be understood that the first path loss resource can indicate that the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message, and the second path loss resource can indicate that the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message.

[0010] Optionally, when the path loss resource is the first path loss resource, the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message; or, when the path loss resource is the second path loss resource, the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message. It can be understood that the TAG corresponding to the random access request message is the first TAG or the second TAG. In this way, the TAG corresponding to the random access request message can be accurately determined according to the path loss resource and the TAG corresponding to the PDCCH.

[0011] Further, when the path loss resource is the second path loss resource, if the PDCCH corresponds to the first TAG, the random access request message corresponds to the second TAG; or, if the PDCCH corresponds to the second TAG, the random access request message corresponds to the first TAG.

[0012] Optionally, determining the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource includes: if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, determining that the random access request message adopts the first downlink timing; or, if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, determining that the random access request message adopts the second downlink timing; or, if the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource, determining that the random access request message adopts the second downlink timing; or, if the PDCCH corresponds to the second TAG and the path loss resource is the second path loss resource, determining that the random access request message adopts the first downlink timing. It can be understood that according to the TAG corresponding to the PDCCH and the path loss resource, the TAG corresponding to the random access request message can be determined, and the downlink timing adopted by the random access request message can be determined according to this TAG. For example, if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, the random access request message corresponds to the first TAG, and the random access request message adopts the first downlink timing. In this way, the downlink timing adopted by the random access request message can be accurately determined according to the TAG corresponding to the PDCCH and the path loss resource.

[0013] In a possible design, the TAG corresponding to the PDCCH is the TAG associated with the TCI state adopted by the PDCCH. That is, the TAG associated with the TCI state adopted by the PDCCH is the first TAG or the second TAG.

[0014] In a possible design solution, the downlink timing adopted by the random access request message is determined according to the TAG corresponding to the PDCCH and the path loss resource, including: when the first condition is satisfied, determining the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource; the first condition includes one or more combinations of the following: the network device configures two control channel groups in the cell for the terminal device, the network device configures two TAGs in the cell for the terminal device, the network device does not configure a supplementary cell corresponding to the cell for the terminal device, or the TCI state activated by the network device for the terminal device is not associated with the supplementary cell corresponding to the cell. It can be understood that the first condition can indicate that the current is a multi-TRP scenario, such as a scenario where one cell corresponds to two TRPs. In this case, the terminal device can determine the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource. In this way, it can be avoided that the terminal device determines the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource in a single-TRP scenario, resulting in unnecessary overhead.

[0015] In a possible design solution, the first message is a radio resource control (RRC) message. That is, the existing technology messages can be reused to configure the first TAG and the second TAG for the terminal device, thereby reducing the implementation difficulty.

[0016] In a second aspect, a communication device is provided. The communication device includes: a module for performing the method described in the first aspect, such as a transceiver module and a processing module. For example, the transceiver module is used to indicate the transceiver function of the communication device, and the processing module is used to perform the functions of the communication device other than the transceiver function.

[0017] The transceiver module is used to receive a first message, where the first message is used to configure the first timing advance group (TAG) and the second TAG in the same cell for the terminal device; the transceiver module is further used to receive a PDCCH, where the PDCCH is used to indicate the path loss resource corresponding to the random access request message, and the TAG corresponding to the PDCCH is the first TAG or the second TAG; the processing module is used to determine the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource, where the downlink timing is the first downlink timing corresponding to the first TAG or the second downlink timing corresponding to the second TAG; the transceiver module is further used to send the random access request message according to the downlink timing.

[0018] In a possible design solution, the path loss resource is the first path loss resource or the second path loss resource. The first path loss resource is the quasi-co-location (QCL) reference signal resource in the transmission configuration indication (TCI) state adopted by the PDCCH, and the second path loss resource is the synchronization signal and physical broadcast channel block (SSB) indicated in the PDCCH.

[0019] Optionally, the processing module is specifically configured to determine that the random access request message uses the first downlink timing if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource; or, determine that the random access request message uses the second downlink timing if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource; or, determine that the random access request message uses the second downlink timing if the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource; or, determine that the random access request message uses the first downlink timing if the PDCCH corresponds to the second TAG and the path loss resource is the second path loss resource.

[0020] In a possible design, the processing module is specifically configured to, when the first condition is satisfied, determine the downlink timing used by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource; the first condition includes one or more combinations of the following: the network device configures two control channel groups in the cell for the terminal device, the network device configures two TAGs in the cell for the terminal device, the network device does not configure a supplementary cell corresponding to the cell for the terminal device, or the TCI state activated by the network device for the terminal device is not associated with the supplementary cell corresponding to the cell.

[0021] Optionally, the transceiver module may include a transmitting module and a receiving module. Among them, the transmitting module is used to implement the transmitting function of the communication device described in the second aspect, and the receiving module is used to implement the receiving function of the communication device described in the second aspect.

[0022] Optionally, the communication device described in the second aspect may further include a storage module, and the storage module stores programs or instructions. When the processing module executes the programs or instructions, the communication device can execute the method described in the first aspect.

[0023] It can be understood that the communication device described in the second aspect may be a terminal device, or a chip (system) or other components or assemblies that can be set in the terminal device, or a device including the terminal device. The present application does not limit this.

[0024] In addition, the technical effects of the communication device described in the second aspect can refer to the technical effects of the method described in the first aspect, and will not be elaborated here.

[0025] In a third aspect, a communication device is provided. The communication device includes: a processor, and the processor is used to execute the method described in any possible implementation manner in the first aspect.

[0026] In a possible design, the communication device described in the third 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 third aspect to communicate with other communication devices.

[0027] In a possible design, the communication device described in the third aspect may further include a memory. The memory may be integrated with the processor or may be provided separately. The memory may be used to store the computer programs and / or data involved in the method described in any aspect of the first aspect.

[0028] In the embodiments of the present application, the communication device described in the third aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly that can be disposed in the terminal device, or a device including the terminal device.

[0029] In addition, the technical effects of the communication device described in the third aspect may refer to the technical effects of the method described in any implementation manner of the first aspect, which will not be elaborated here.

[0030] In a fourth aspect, a communication device is provided. The communication device includes: a processor, the processor is coupled to a memory, and the processor is configured to execute a computer program stored in the memory so that the communication device executes the method described in any possible implementation manner of the first aspect.

[0031] In a possible design, the communication device described in the fourth 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 fourth aspect to communicate with other communication devices.

[0032] In the embodiments of the present application, the communication device described in the fourth aspect may be the terminal device described in the first aspect, or a chip (system) or other component or assembly that can be disposed in the terminal device, or a device including the terminal device.

[0033] In addition, the technical effects of the communication device described in the fourth aspect may refer to the technical effects of the method described in any implementation manner of the first aspect, which will not be elaborated here.

[0034] In a fifth aspect, a communication device is provided, including: a processor and a memory; the memory is used to store a computer program, and when the processor executes the computer program, the communication device is enabled to execute the method described in any implementation manner of the first aspect.

[0035] In a possible design, 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.

[0036] In the embodiments of the present application, the communication device described in the fifth aspect may be the terminal device described in the first aspect, or a chip (system), other component or assembly that can be disposed in the terminal device, or a device including the terminal device.

[0037] In addition, for the technical effects of the communication device described in the fifth aspect, reference may be made to the technical effects of the method described in any implementation manner in the first aspect, which will not be elaborated herein.

[0038] Sixth aspect, a communication device is provided, including: a processor and an interface circuit. The processor is used to communicate with other devices through the interface circuit and execute the method described in the first aspect above. The processor includes one or more.

[0039] Seventh aspect, a communication chip stores instructions, and when the chip runs on a communication device, the method described in any implementation manner in the first aspect is implemented.

[0040] Eighth 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 implementation manner in the first aspect is implemented.

[0041] Ninth aspect, a communication chip includes a processor, which is used to call a computer program or computer instructions in a memory, so that the processor executes any implementation manner in the first aspect above.

[0042] Optionally, the processor is coupled to the memory through an interface.

[0043] Tenth aspect, a communication system is provided. The communication system includes: a terminal device for executing the method described in the first aspect and a network device. The network device is used to send a first message and a PDCCH.

[0044] Eleventh aspect, a computer-readable storage medium is provided, including: a computer program or instructions; when the computer program or instructions run on a computer, the computer executes the method described in any possible implementation manner in the first aspect.

[0045] Twelfth aspect, a computer program product is provided, including a computer program or instructions. When the computer program or instructions run on a computer, the computer executes the method described in any possible implementation manner in the first aspect. Description of the Drawings

[0046] Figure 1Schematic diagram of uplink and downlink time slots of the network device and uplink and downlink time slots of the terminal device provided in the embodiments of the present application;

[0047] Figure 2 Schematic flow chart of the random access process provided in the embodiments of the present application;

[0048] Figure 3 Schematic diagram of the architecture of the communication system provided in the embodiments of the present application;

[0049] Figure 4 Schematic flow chart of the random access method provided in the embodiments of the present application;

[0050] Figure 5 Structural schematic of the communication device provided in the embodiments of the present application Figure 1 ;

[0051] Figure 6 Structural schematic of the communication device provided in the embodiments of the present application Figure 2 。 Detailed implementation manners

[0052] For ease of understanding, the technical terms involved in the embodiments of the present application are introduced first below.

[0053] 1. Downlink timing, uplink timing

[0054] In a 5G communication system, both uplink and downlink transmissions use time slots as the basic time unit, that is, data is transmitted once within each time slot. Time slots are divided into downlink time slots and uplink time slots.

[0055] The network device starts to send signals at the start time of its corresponding downlink time slot, and the terminal device starts to receive signals at the start time of its corresponding downlink time slot. The signals sent by the network device to the terminal device require a certain propagation delay. Therefore, the start times of the downlink time slots of the network device and the terminal device are not synchronized, that is, the start time of the downlink time slot of the terminal device is later than the start time of the downlink time slot of the network device. As Figure 1 shown, if the signal propagation time is T, the start time of the downlink time slot of the terminal device is later than the start time of the downlink time slot of the network device by T, that is, the start time of the downlink time slot of the network device is earlier than the start time of the downlink time slot of the terminal device by T.

[0056] The terminal device starts to send signals at the start time of its corresponding uplink time slot, and the network device starts to receive information at the start time of its corresponding uplink time slot. The information sent by the terminal device to the network device requires a certain propagation delay. Therefore, the start times of the uplink time slots of the terminal device and the network device are not synchronized, that is, the start time of the uplink time slot of the network device is later than the start time of the uplink time slot of the terminal device. Please continue to refer to Figure 1, the start time of the uplink time slot of the network device is T later than the start time of the uplink time slot of the terminal device. That is, the start time of the uplink time slot of the terminal device is T earlier than the start time of the uplink time slot of the network device.

[0057] The uplink time slot and the downlink time slot of the network device are generally aligned. Assuming that the start time of the uplink time slot and the downlink time slot of the network device is t0, then the start time of the downlink time slot of the terminal device is t0 - T, and the start time of the uplink time slot of the terminal device is t0 + T.

[0058] For the terminal device to perform downlink reception, it needs to know the start time of its downlink time slot, and this start time is the downlink timing of the terminal device. The downlink timing of the terminal device can be obtained by measuring the downlink reference signal. That is, the network device can send a downlink reference signal to the terminal device, and the terminal device measures this reference signal and takes the time when it first receives this reference signal as its downlink timing.

[0059] For the terminal device to perform uplink transmission, it needs to know the start time of its uplink time slot. The protocol stipulates that the terminal device needs to send an uplink signal at a specific start time so that the time when the uplink signal reaches the network device is exactly the start time of the uplink time slot of the network device, and this specific start time is the uplink timing of the terminal device.

[0060] The uplink timing of the terminal device can be determined through the random access process. The specific process is as follows: The terminal device sends a random access request message, that is, a physical random access channel (PRACH) message, to the network device using the downlink timing (t0 + T). The network device receives this random access request message at t0 + 2T, and subtracts the start time t0 of its uplink time slot from the time when it receives this random request message to obtain a time difference of 2T. This time difference is the time experienced by the random access request message during two transmissions between the network device and the terminal device, and this time difference is also called the timing advance (TA). The network device notifies this time difference to the terminal device, and the terminal device advances this time difference based on its downlink timing for uplink transmission, that is, performs uplink transmission at t0 + T - 2T. In this way, it can be ensured that the time when the uplink signal reaches the network device is the start time t0 of the uplink time slot of the network device.

[0061] It can be understood that the premise of the above content is that the start time of the uplink time slot and the start time of the downlink time slot of the network device are the same. However, in some cases, the start time of the uplink time slot and the start time of the downlink time slot of the network device can be different. For example, in a time division duplex (TDD) system, it takes time for the network device to perform uplink-downlink switching, resulting in a timing offset (denoted as TA_offset) between the uplink time slot and the downlink time slot itself. In this case, when the terminal device performs uplink transmission, in addition to using the above-mentioned timing advance, it also needs to use TA_offset. That is to say, the terminal device needs to perform uplink transmission TA_offset and TA time in advance based on its downlink timing. That is, the total advance of the uplink time slot relative to the downlink time slot is: TA_offset + TA determined by the random access process. In addition, in this case, the time when the terminal device sends the random access request message is not its downlink timing, but TA_offset in advance based on its downlink timing.

[0062] It can also be understood that in the single-TRP transmission scenario, the terminal device needs to determine a downlink timing and an uplink timing. That is to say, at this time, the terminal device needs to determine a TA_offset and a TA. In the two-TRP transmission scenario, the terminal device needs to determine two downlink timings and two uplink timings. That is to say, the terminal device needs to determine a TA_offset and two TAs.

[0063] 2. Random access (random access channel, RA)

[0064] The terminal device can access the network through the random access process to achieve uplink-downlink synchronization with the network device. The random access process refers to the process from the terminal device sending a random access preamble to start attempting to access the network until a basic signaling connection is established with the network; or rather, the terminal device can access the network through the random access process. The random access process can be triggered by some events. For example, the terminal device can perform initial access from the idle state, or execute a radio resource control layer (RRC) connection restoration process from the inactive state, or be triggered by the network device sending a PDCCH to the terminal device.

[0065] As Figure 2 shown, the random access process of 5G NR mainly includes the following 5 steps, namely S201 to S205. They are introduced separately below.

[0066] S201, the network device sends a PDCCH to the terminal device. Correspondingly, the terminal device receives the PDCCH from the network device.

[0067] The PDCCH can be used to trigger a random access procedure, that is, the PDCCH can indicate to the terminal device to send a random access request message to the network device.

[0068] S202, the terminal device sends message (message, Msg) 1 to the network device according to the PDCCH. Correspondingly, the network device receives Msg1 from the terminal device.

[0069] Msg1 can also be referred to as a random access request message, which includes a preamble sequence, that is, a preamble. The role of the preamble sequence is to notify the network device that there is a random access request message and enable the network device to calculate the transmission delay between it and the terminal device, so that the network device can calibrate the uplink timing and inform the terminal device of the calibration information through TA time adjustment information.

[0070] It can be understood that the time when the terminal device sends Msg1 is the time of the terminal device's downlink timing plus the time of TA_offset.

[0071] S203, the network device sends Msg2 to the terminal device according to Msg1. Correspondingly, the terminal device receives Msg2 from the network device.

[0072] The network device estimates the TA of the terminal device according to the received Msg1 and sends the TA value to the terminal device through Msg2. Msg2 is a response message to Msg1, and it can also be referred to as a random access response (RAR). Msg2 may include a hopping flag, physical uplink shared channel (PUSCH) frequency resource allocation, uplink authorization, and a temporary cell radio network device temporary identifier, etc. The uplink authorization is used to indicate the transmission resources of Msg3.

[0073] S204, the terminal device sends Msg3 to the network device according to Msg2. Correspondingly, the network device receives Msg3 from the terminal device.

[0074] After receiving Msg2, the terminal device can send Msg3 on the transmission resources indicated by the uplink authorization.

[0075] S205, the network device sends Msg4 to the terminal device according to Msg3. Correspondingly, the terminal device receives Msg4 from the network device.

[0076] After receiving Msg3, the network device sends Msg4 to the terminal device to indicate that the terminal device has successfully accessed.

[0077] It can be understood that in a single-TRP transmission scenario, the terminal device needs to determine a downlink timing and an uplink timing. In a multi-TRP transmission scenario, the terminal device needs to determine multiple uplink timings and multiple downlink timings, which are respectively used to send or receive data for different TRPs of a serving cell. Moreover, in a multi-TRP transmission scenario, the network device will send a PDCCH to the terminal device to instruct the terminal device to send a random access request message to the network device. However, in this case, the terminal device does not know which TRP to send the random access request message to, that is, it does not know which downlink timing to adopt. Therefore, how the terminal device sends a random access request message in a multi-TRP transmission scenario is an urgent problem to be solved.

[0078] In view of the above technical problems, the embodiments of the present application propose the following technical solutions to enable the terminal device to send a random access request message in a multi-TRP transmission scenario.

[0079] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0080] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as the 4th generation (4G) mobile communication system, such as the long term evolution (LTE) system, the 5th generation (5G) mobile communication system, such as the new radio (NR) system, and the communication system evolved after 5G, such as the 6th generation (6G) mobile communication system. It can also be applied to wireless fidelity (WiFi) systems, vehicle to everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle networking communication systems, etc.

[0081] The present application will present various aspects, embodiments or features around a system that may include multiple devices, components, modules, etc. It should be understood and clear that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. In addition, combinations of these solutions can also be used.

[0082] In addition, in the embodiments of the present application, words such as "exemplary" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" in the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of the word "exemplary" is intended to present concepts in a specific manner.

[0083] In the embodiments of the present application, "information", "signal", "message", "channel", and "signaling" may sometimes be used interchangeably. It should be noted that when the differences are not emphasized, their intended meanings are consistent. "Of", "corresponding", and "corresponding" may sometimes be used interchangeably. It should be noted that when the differences are not emphasized, their intended meanings are consistent. In addition, " / " mentioned in the present application can be used to represent the relationship of "or".

[0084] The network architecture and service scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art can understand that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0085] To facilitate the understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first introduced.

[0086] The communication system includes: a terminal device and a network device. It can be understood that in the embodiments of the present application, one cell corresponds to multiple TRPs. For example, one cell corresponds to two TRPs. The network device can be understood as a general term for all devices on the network side, that is, the multiple TRPs can be collectively referred to as the network device. The terminal device and the network device can respectively refer to the relevant introductions of "terminal device 120" and "network device 110" below, which will not be elaborated here. In addition, the communication system may further include other network devices and / or other terminal devices.

[0087] To facilitate the understanding of the embodiments of the present application, Figure 3 The application scenario used in the present application is described by taking the communication system architecture shown as an example. Figure 3 It is a possible and non-limiting system schematic diagram. As Figure 3 shown, the communication system 3000 includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN 100 includes at least one network device (such as Figure 3 110a and 110b in Figure 3 , collectively referred to as 110) and at least one terminal device (such as Figure 3etc. (not shown in the figure). The terminal device 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 devices in the core network 200 and the network device 110 in the RAN 100 may be different physical devices respectively, or may be the same physical device integrating the core network logical function and the radio access network logical function.

[0088] The RAN 100 may be a cellular system related to the 3rd generation partnership project (3GPP), for example, the 4th generation (4G) mobile communication system, such as the long-term evolution (LTE) system, the 5G mobile communication system, such as the NR system, and the communication system evolved after 5G, such as the 6th generation (6G) mobile communication system. It can also be applied to wireless fidelity (WiFi) systems, vehicle to everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle networking communication systems, etc. 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 integrating two or more of the above systems.

[0089] The terminal and network device provided in the embodiments of the present application can be applied to the network device 110 or the terminal device 120. It can be understood that Figure 3 only one possible communication system architecture to which the embodiments of the present application can be applied is shown. In other possible scenarios, other devices may also be included in the communication system architecture.

[0090] The network device 110 is a node in the RAN, and can also be called an access network device or a RAN node (or device). The network device 110 is used to help the terminal achieve wireless access. The multiple network devices 110 in the communication system 3000 may be of the same type of node or different types of nodes. In some scenarios, the roles of the network device 110 and the terminal device 120 are relative. For example, Figure 3The intermediate network element 120i can be a helicopter or a drone, which can be configured as a mobile base station. For the terminals 120j accessing 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 device 120 are sometimes both called communication devices, such as Figure 3 The intermediate network elements 110a and 110b in the figure 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.

[0091] In a possible scenario, the 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, a router, a server, a switch, a bridge, etc., an integrated access and backhaul (IAB) node, a network device in a non-terrestrial network (NTN) communication system, that is, it can be deployed on a high-altitude platform or a satellite, etc. The network device can be a macro base station (such as Figure 3 110a in the figure), a micro base station or an indoor station (such as Figure 3 110b in the figure), a relay node or a donor node, or a radio controller in a CRAN scenario. The network device can also be a device that serves as a base station function in device-to-device (D2D) communication, vehicle-to-everything communication, drone communication, and machine communication. Optionally, the network device can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in vehicle-to-everything (V2X) technology can be a road side unit (RSU).

[0092] In another possible scenario, multiple network devices cooperate to assist a terminal in achieving wireless access, and different network devices respectively implement some functions of a base station. For example, the network device can be a central unit (CU), a distributed unit (DU), a CU - control plane (CP), a CU - user plane (UP), or a radio unit (RU), etc. The CU and the 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 included in 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, or a DU node, or a device including a CU node and a DU node. In addition, the CU can be classified as a network device in the radio access network (RAN), or the CU can be classified as a network device in the core network (CN), which is not limited herein.

[0093] In different systems, the 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, the CU can also be called an O (open) - CU, the DU can also be called an O - DU, the CU - CP can also be called an O - CU - CP, the CU - UP can also be called an O - CU - UP, and the RU can also be called an O - RU. For the convenience of description, in this application, the CU, CU - CP, CU - UP, DU, and RU are used as examples for description. Any one of the 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.

[0094] In the embodiments of this application, the form of the network device is not limited. The device for implementing the functions of the network device can be the network device; it can also be a device capable of supporting the network device to implement this function, such as a chip system. This device can be installed in the network device or used in matching with the network device.

[0095] The terminal device 120 can also be referred to as a user equipment (UE), a mobile station (MS), a mobile terminal (MT), a user device, a terminal device, an access terminal, a user unit, a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user device, etc., or a device for providing voice or data connectivity to a user, and can also be an Internet of Things device. For example, the terminal device includes a handheld device with a wireless connection function, a vehicle-mounted device, etc. Currently, the terminal device can be: a mobile phone, a tablet computer (Pad), a computer with a wireless transceiver function, a laptop computer, a handheld computer, a mobile Internet device (MID), a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), a vehicle-mounted device (such as a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed train, etc.), a satellite terminal, a virtual reality (VR) device, an augmented reality (AR) device, a smart point of sale (POS) machine, a customer-premises equipment (CPE), a wireless terminal in industrial control, a smart home device (such as a refrigerator, a TV, an air conditioner, an electric meter, etc.), a smart robot, a robotic arm, a workshop device, a wireless terminal in unmanned driving, a wireless terminal in remote medical treatment, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, or a wireless terminal in a smart home, a flight device (such as a smart robot, a hot air balloon, a drone, an airplane), etc. The terminal device can also be other devices with terminal functions. For example, the terminal device can also be a device that serves as a terminal function in D2D communication.

[0096] The embodiments of this application do not limit the device form of the terminal. The device for implementing the functions of the terminal device can be the terminal device; it can also be a device that can support the terminal device to implement this function, such as a chip system. This device can be installed in the terminal device or used in matching with the terminal device. In the embodiments of this application, the chip system can be composed of chips or can also include chips and other discrete devices.

[0097] 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 with the names of the corresponding functions in other communication systems. Moreover, the network architecture and service scenarios described in the embodiments of the present application are for more clearly explaining the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0098] In a communication system, a terminal device can determine the downlink timing adopted by a random access request message according to the TAG corresponding to the PDCCH and the path loss resource, such as determining the downlink timing adopted by the random access request message through the relationship between the TAG corresponding to the PDDCH indicated by the path loss resource and the TAG corresponding to the random access request message. In this way, the terminal device can adopt the correct downlink timing in a multi-TRP transmission scenario to realize the transmission of the random access request message.

[0099] For ease of understanding, the following will specifically elaborate on Figure 4 the random access method provided by the embodiments of the present application. This random access method is introduced in the case where one cell corresponds to two TRPs (i.e., in a two-TRP transmission scenario).

[0100] Figure 4 The flowchart of the random access method provided by the embodiments of the present application. This method can be applied to the interaction between a terminal device and a network device in the above communication system.

[0101] As Figure 4 shown, the process of this random access method is as follows:

[0102] S401, the network device sends a first message. Correspondingly, the terminal device receives the first message.

[0103] The first message can be used to configure a first timing advance group (TAG) and a second TAG in the same cell (denoted as cell #1) for the terminal device. Exemplarily, the first message may include information about the first TAG and the second TAG, such as the index of the first TAG and the index of the second TAG.

[0104] Cell #1 is the serving cell configured by the network device for the terminal device for data transmission. That is to say, the network device needs to configure the parameters of cell #1 for the terminal device so that the terminal device can independently perform data transmission through this cell #1. It can be understood that cell #1 can correspond to two TRPs, such as two TRPs are deployed in cell #1, or cell #1 has associated supplementary cells (introduced below).

[0105] A TAG is a parameter used for TA management, which can maintain the TA value of a TRP. Each TAG corresponds to a TA. That is to say, the first TAG corresponds to a TA (denoted as the first TA); the second TAG corresponds to a TA (denoted as the second TA), and the first TA is different from the second TA. It can be understood that the first TAG corresponds to one of the two TRPs corresponding to the above-mentioned cell #1, such as the first TRP. At this time, the first TA is the TA corresponding to the first TRP. That is, when the terminal device performs uplink transmission to the first TRP, the first TA needs to be used. The second TAG corresponds to the other TRP of the two TRPs corresponding to the above-mentioned cell #1, such as the second TRP. At this time, the second TA is the TA corresponding to the second TRP. That is, when the terminal device performs uplink transmission to the second TRP, the second TA needs to be used.

[0106] The network device configures two TAGs for the terminal device through the first message, which can be used to maintain the TA values of the two TRPs corresponding to cell #1, and can indicate that the terminal device is in a scenario of multi-station joint transmission, that is, a multi-TRP scenario. In this case, the terminal device needs to maintain two downlink timings, that is, the first downlink timing and the second downlink timing. The first downlink timing is associated with the first TAG and the first TRP, and can be determined by measuring the downlink reference signal sent by the first TRP. The second downlink timing is associated with the second TAG and the second TRP, and can be determined by measuring the downlink reference signal sent by the second TRP. The downlink reference signal can be signals such as a synchronization signal and a physical broadcast channel block (SSB), or a tracking reference signal (TRS), etc., which can be specifically determined according to the actual situation, and the embodiments of the present application do not limit this. It can be understood that when the terminal device maintains the first downlink timing and the second downlink timing, the first downlink timing can be associated with the first TAG, and the second downlink timing can be associated with the second TAG.

[0107] The first message can also be used to configure other configuration parameters of cell #1. The configuration parameters can include parameters related to uplink timing, such as control channel grouping. The control channel grouping can be used to group the control channels of cell #1, and each group of control channel grouping corresponds to one of the two TRPs corresponding to cell #1. For example, the first control channel grouping corresponds to the first TRP mentioned above, and the second control channel grouping corresponds to the second TRP mentioned above. Each group of control channel grouping corresponds to a control channel grouping identifier (CORESETPoolIndex), and the value of the control channel grouping identifier can be 0 or 1, which can be specifically set according to the actual situation. Exemplarily, the first control channel grouping corresponds to the control channel grouping identifier 0, and the second control channel grouping corresponds to the control channel grouping identifier 1; or, the first control channel grouping corresponds to the control channel grouping identifier 1, and the second control channel grouping corresponds to the control channel grouping identifier 0.

[0108] The first message can also be used to configure the configuration parameters of other cells, which can be flexibly set according to the actual situation without limitation.

[0109] In addition, the first message can be an RRC message, and the RRC message can include RRC configuration information. In this case, the RRC configuration information can include the configuration parameters of cell #1, such as the first TAG and the second TAG, etc.; or, the RRC configuration information can include the configuration parameters of cell #1 and other cells, and specific reference can be made to the relevant introduction above, which will not be elaborated here.

[0110] S402, the network device sends the PDCCH. Correspondingly, the terminal device receives the PDCCH.

[0111] The PDCCH can be used to indicate the path loss resource corresponding to the random access request message. And the TAG corresponding to the PDCCH can be the TAG associated with the TCI state adopted by the PDCCH, which can be the first TAG or the second TAG.

[0112] The above random access request message is the random access request message sent by the terminal device to the network device after receiving the PDCCH. The TAG corresponding to the random access request message can be the first TAG or the second TAG. It can be understood that the TAG corresponding to the random access request message refers to the TAG corresponding to the TA value determined based on the random access request message, or the TAG corresponding to the TA value included in the random access response message corresponding to the random access request message.

[0113] The path loss resource is a resource used to determine the path loss of a random access request message. That is, the terminal device can determine the path loss of the transmitted random access request message through this path loss resource. The path loss resource can be a first path loss resource or a second path loss resource. The first path loss resource is the quasi-collocation (QCL) reference signal resource in the transmission configuration indicator (TCI) state adopted by the PDCCH, and the first path loss resource can indicate that the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message. The second path loss resource is the SSB indicated in the PDCCH, and the second path loss resource can indicate that the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message. The beam corresponding to the SSB can be used to transmit the preamble. When the path loss resource is the first path loss resource, the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message, that is, the TRP corresponding to the PDCCH is the same as the TRP corresponding to the random access request message. Or, when the path loss resource is the second path loss resource, the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message, that is, the TRP corresponding to the PDCCH is different from the TRP corresponding to the random access request message. It can be seen that by whether the path loss resource corresponding to the random access request message is the first path loss resource or the second path loss resource, it can be indirectly determined whether the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message.

[0114] Exemplarily, when the path loss resource is the first path loss resource, if the PDCCH corresponds to the first TAG, then the random access request message corresponds to the first TAG; or, if the PDCCH corresponds to the second TAG, then the random access request message corresponds to the second TAG. When the path loss resource is the second path loss resource, if the PDCCH corresponds to the first TAG, then the random access request message corresponds to the second TAG; or, if the PDCCH corresponds to the second TAG, then the random access request message corresponds to the first TAG.

[0115] It can be understood that the path loss resource can be indicated by the first field in the PDCCH signaling. This first field can reuse the fields in the prior art or be a newly defined field. For example, this first field is a PRACH association indication field, and the value of this PRACH association indication field can indicate that the path loss resource is the first path loss resource or the second path loss resource. Exemplarily, when the value of this PRACH association indication field is 0, it can indicate that the random access request message uses the first path loss resource; when the value of this PRACH association indication field is 1, it can indicate that the random access request message uses the second path loss resource; or, when the value of this PRACH association indication field is 0, it can indicate that the random access request message uses the second path loss resource; when the value of this PRACH association indication field is 1, it can indicate that the random access request message uses the first path loss resource.

[0116] The PDCCH can also be used to indicate other information, such as the preamble used in the random access message, etc. And the PDCCH can also include other fields, such as the identification field of the random access preamble, the SSB identification field, etc. The identification field of the random access preamble can be used to indicate which preamble the terminal device sends to the network device. The SSB identification field can be used to indicate which beam corresponding to the SSB is used to send the preamble, and the beam corresponding to the SSB can be understood as the receiving beam of the terminal device corresponding to the SSB.

[0117] The PDCCH can indicate the above-mentioned path loss resource when the first condition is met. The first condition can include one or more combinations of the following: the network device configures two control channel groups in cell #1 for the terminal device (denoted as condition #1), the network device configures two TAGs in cell #1 for the terminal device (denoted as condition #2), the network device does not configure a supplementary cell corresponding to cell #1 for the terminal device (denoted as condition #3), or the TCI state activated by the network device for the terminal device is not associated with the supplementary cell corresponding to cell #1 (denoted as condition #4). Among them, condition #1 and condition #2 can indicate that there are two TRPs corresponding to cell #1; condition #3 can indicate that cell #1 is not configured with a supplementary cell; condition #4 can indicate that the TCI state activated by the network device for the terminal device has no association with the supplementary cell corresponding to cell #1, that is, the supplementary cell configured for cell #1 is not used. It can be understood that when there are multiple TRPs corresponding to cell #1, condition #3 or condition #4 can indicate a multi-TRP transmission scenario in the same cell. It can be seen that the first condition can indicate the current two-TRP transmission scenario. For example: if the first condition includes condition #1, condition #2, and condition #3, it can indicate that two TRPs are deployed in cell #1, that is, the current is a two-TRP transmission scenario. The PDCCH can indicate the above-mentioned path loss resource in the two-TRP transmission scenario.

[0118] It can be understood that in addition to configuring a serving cell (such as cell #1) for a terminal device, a network device can also configure one or more supplementary cells associated with the serving cell for the terminal device. These supplementary cells can be used for data transmission to a certain extent. However, only one supplementary cell is active at the same time. The network device can use a serving cell and the active supplementary cell corresponding to the serving cell for joint transmission, that is, cross-cell multi-TRP transmission. In addition, the network device does not need to configure all parameters of the supplementary cell for the terminal device, but can configure the information of the supplementary cell as a parameter of the serving cell for the terminal device, that is, the supplementary cell works depending on the serving cell associated with the supplementary cell. The supplementary cell can be represented by a physical cell index.

[0119] S403. The terminal device determines the downlink timing used for the random access request message according to the TAG corresponding to the PDCCH and the path loss resource.

[0120] The downlink timing of the random access request message can be the first downlink timing corresponding to the first TAG or the second downlink timing corresponding to the second TAG, which is related to the TAG corresponding to the PDCCH and the path loss resource.

[0121] Determining the downlink timing used for the random access request message according to the TAG corresponding to the PDCCH and the path loss resource can specifically include: if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, then determine that the random access request message uses the first downlink timing; or, if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, then determine that the random access request message uses the second downlink timing; or, if the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource, then determine that the random access request message uses the second downlink timing; or, if the PDCCH corresponds to the second TAG and the path loss resource is the second path loss resource, then determine that the random access request message uses the first downlink timing.

[0122] It can be understood that the principle for the terminal device to determine whether to adopt the first downlink timing or the second downlink timing is as follows: The downlink timing corresponding to the TRP to which the random access request message is sent is adopted. That is, if the random access request message is sent to the first TRP, the first downlink timing corresponding to the first TRP is adopted; if the random access request message is sent to the second TRP, the second downlink timing corresponding to the second TRP is adopted. The terminal device can determine the TAG corresponding to the random access request message based on the TAG corresponding to the PDCCH and the path loss resource, and then determine which TRP the random access request message is sent to according to this TAG. That is to say, the terminal device can determine the relationship between the TAG corresponding to the PDCCH and the TAG corresponding to the random access request message by the path loss resource being the first path loss resource or the second path loss resource, that is, whether the two are the same; and then through the TAG corresponding to the PDCCH and this relationship, the TAG corresponding to the random access request message can be determined, that is, the random access request message is sent to the TRP corresponding to this TAG; and the downlink timing of the random access request message can be determined according to the TAG corresponding to the random access request message.

[0123] Exemplarily, if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, it means that the TAG corresponding to the random access request message is the same as the TAG corresponding to the PDCCH, that is, the random access request message corresponds to the first TAG. At this time, the terminal device should send the random access request message to the first TRP corresponding to the first TAG, so the random access request message adopts the first downlink timing corresponding to the first TAG. If the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, it means that the TAG corresponding to the random access request message is different from the TAG corresponding to the PDCCH, that is, the random access request message corresponds to the second TAG. At this time, the terminal device should send the random access request message to the second TRP corresponding to the second TAG, so the random access request message adopts the second downlink timing corresponding to the second TAG. It can be understood that the cases where the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource or the second path loss resource are similar to the above cases and can be understood by referring to the above cases, which will not be elaborated here.

[0124] The path loss resource corresponding to the random access request message can be indicated by the first field in the PDCCH. For example, if the value of the first field is 0, it means that the first path loss resource is used for the random access request message; if the value of the first field is 1, it means that the second path loss resource is used for the random access request message. In this case, the terminal device can determine the downlink timing used for the random access request message based on the TAG corresponding to the PDCCH and the value of this first field. Exemplarily, if the PDCCH corresponds to the first TAG and the value of the first field is 0, then the first downlink timing is used for the random access request message; or, if the PDCCH corresponds to the first TAG and the value of the first field is 1, then the second downlink timing is used for the random access request message; or, if the PDCCH corresponds to the second TAG and the value of the first field is 0, then the second downlink timing is used for the random access request message; or, if the PDCCH corresponds to the second TAG and the value of the first field is 1, then the first downlink timing is used for the random access request message. It can be understood that when the value of the first field is 1, indicating that the first path loss resource is used for the random access request message, and the value of the first field is 0, indicating that the second path loss resource is used for the random access request message, the method for determining the downlink timing used for the random access request message according to the TAG corresponding to the PDCCH and the value of the first field is similar to the above method and can be understood by referring to the above content, which will not be elaborated here.

[0125] In addition, it can be specified that under the condition of meeting the first condition, the terminal device determines the downlink timing used for the random access request message according to the TAG corresponding to the PDCCH and the path loss resource. The first condition can refer to the relevant introduction of the foregoing "S402" and will not be elaborated here. In this way, it can be avoided that the terminal device determines the downlink timing used for the random access request message according to the TAG corresponding to the PDCCH and the path loss resource in the single-TRP scenario, thereby generating unnecessary overhead.

[0126] S404, the terminal device sends a random access request message according to the downlink timing used for the random access request message.

[0127] After the terminal device determines the downlink timing used for the random access request message, it can determine the time to send the random access request message (denoted as the transmission time) according to this downlink timing, and then send the random access request message according to this transmission time. This transmission time is the downlink timing used for the random access request message plus TA_offset, that is, the terminal device can send the random access request message TA_offset earlier based on this downlink timing. For example, if the first downlink timing is used for the random access request message, then the transmission time of this random access request message is the first downlink timing + TA_offset. The value of this TA_offset can be configured by the network device or predefined by the protocol, and the embodiments of the present application do not limit this.

[0128] In summary, in the embodiments of the present application, the terminal device can determine the TAG corresponding to the random access request message according to the TAG corresponding to the PDCCH and the path loss resource, and determine which TRP to send the random access request message according to the TAG, so as to determine the downlink timing adopted by the random access request message. In this way, the terminal device can use the correct downlink timing in the two-TRP transmission scenario to send the random access request message.

[0129] Optionally, in combination with the above embodiments, after the terminal device sends the random access request message according to the downlink timing adopted by the random access request message, the above random access method may further include: the network device sends a random access response message to the terminal device. Correspondingly, the terminal device receives the random access response message from the network device.

[0130] The random access response message may include a TA value and an index of the TAG corresponding to the TA value. The TA value is calculated by the network device according to the received random access request message. It can be understood that there is a corresponding relationship between the downlink timing adopted by the random access request message and the TA value, that is, if the random access request message adopts the first downlink timing, the TA value is the TA value corresponding to the first TAG; if the random access request message adopts the second downlink timing, the TA value is the TA value corresponding to the second TAG. In addition, the terminal device can obtain the TA values corresponding to two TAGs (the first TAG and the second TAG) through two random access processes.

[0131] It can be understood that the above content introduces the random access method with one cell corresponding to two TRPs. When one cell corresponds to more than two TRPs, the random access method is similar to the above method. The difference is that when the TAG corresponding to the PDCCH is different from the TAG of the random access request message, that is, when the path loss resource is the second path loss resource, the PDCCH may carry information for indicating the TAG corresponding to the random access request message, such as information indicating the third TAG corresponding to the random access request message. Other content can refer to the relevant introduction of the foregoing "S401" to "404", which will not be elaborated here. The following uses an example to specifically illustrate the random access method when one cell corresponds to more than two TRPs.

[0132] Step 1, the network device sends a first message. Correspondingly, the terminal device receives the first message.

[0133] The first message is used to configure the first TAG, the second TAG, and the third TAG in the same cell (denoted as cell #1) for the terminal device. The first TAG, the second TAG, and the third TAG respectively correspond to one of the three TRPs corresponding to cell #1. For example, the first TAG corresponds to the first TRP, the second TAG corresponds to the second TRP, and the third TAG corresponds to the third TRP.

[0134] Step 2: The network device sends a PDCCH. Correspondingly, the terminal device receives the PDCCH.

[0135] The PDCCH is used to indicate the path loss resource corresponding to the random access request message and the third TAG corresponding to the random access request. This path loss resource is the second path loss resource. And the first TAG corresponding to the PDCCH.

[0136] Step 3: The terminal device determines the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource.

[0137] That is, the random access request message can be determined not to correspond to the first TAG according to the first TAG corresponding to the PDCCH and the second path loss resource. And the third TAG corresponding to the random access request message can be determined according to the information in the PDCCH used to indicate the third TAG corresponding to the random access request message. That is, the terminal device should send a random access request message to the third TRP corresponding to the third TAG. Therefore, the random access request message adopts the third downlink timing corresponding to the third TAG.

[0138] Step 4: The terminal device sends a random access request message according to the downlink timing of the random access request message.

[0139] The terminal device can add TA_offset to the third downlink timing to determine the time to send the random access request message, and send the random access request message according to this time. That is to say, the terminal device can send the random access request message TA_offset in advance based on the third downlink timing.

[0140] It can be understood that Steps 1 - 4 are similar to the embodiments shown above Figure 4 and can specifically refer to the relevant introductions of the foregoing "S401" to "404", which will not be elaborated here.

[0141] The above has described in detail the random access method provided by the embodiments of the present application. The following will be described in detail Figure 4 the communication device for executing the random access method provided by the embodiments of the present application. Figures 5 - 6 is a schematic structural diagram of the communication device provided by the embodiments of the present application.

[0142] Figure 5 is the schematic structure Figure 1Exemplarily, as Figure 5 shown, the communication device 500 includes a transceiver module 501 and a processing module 502. For ease of explanation, Figure 5 only the main components of the communication device are shown.

[0143] In some embodiments, the communication device 500 can be applied to the above communication system and perform the functions of the terminal device in the above random access method.

[0144] Among them, the transceiver module 501 is used to receive a first message, and the first message is used to configure a first TAG and a second TAG in the same cell for the terminal device; the transceiver module 501 is also used to receive a PDCCH, and the PDCCH is used to indicate the path loss resource corresponding to the random access request message, and the TAG corresponding to the PDCCH is the first TAG or the second TAG; the processing module 502 is used to determine the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource, and the downlink timing is the first downlink timing corresponding to the first TAG or the second downlink timing corresponding to the second TAG; the transceiver module 501 is also used to send the random access request message according to the downlink timing.

[0145] In a possible design, the path loss resource is a first path loss resource or a second path loss resource. The first path loss resource is the QCL reference signal resource in the TCI state adopted by the PDCCH, and the second path loss resource is the SSB indicated in the PDCCH.

[0146] Optionally, when the path loss resource is the first path loss resource, the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message; or, when the path loss resource is the second path loss resource, the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message.

[0147] Further, when the path loss resource is the second path loss resource, if the PDCCH corresponds to the first TAG, then the random access request message corresponds to the second TAG; or, if the PDCCH corresponds to the second TAG, then the random access request message corresponds to the first TAG.

[0148] Optionally, the processing module 502 is specifically configured to determine that the random access request message adopts the first downlink timing if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource; or, determine that the random access request message adopts the second downlink timing if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource; or, determine that the random access request message adopts the second downlink timing if the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource; or, determine that the random access request message adopts the first downlink timing if the PDCCH corresponds to the second TAG and the path loss resource is the second path loss resource.

[0149] In a possible design solution, the TAG corresponding to the PDCCH is the TAG associated with the TCI state adopted by the PDCCH.

[0150] In a possible design solution, the processing module 502 is specifically configured to determine the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource when the first condition is met; the first condition includes one or a combination of the following: the network device configures two control channel groups in the cell for the terminal device, the network device configures two TAGs in the cell for the terminal device, the network device does not configure a supplementary cell corresponding to the cell for the terminal device, or the TCI state activated by the network device for the terminal device is not associated with the supplementary cell corresponding to the cell.

[0151] Optionally, the transceiver module 501 may include a sending module ( Figure 5 not shown in the figure) and a receiving module ( Figure 5 not shown in the figure). Among them, the sending module is used to implement the sending function of the communication device 500, and the receiving module is used to implement the receiving function of the communication device 500.

[0152] Optionally, the communication device 500 may further include a storage module ( Figure 5 not shown in the figure), and the storage module stores programs or instructions. When the processing module 502 executes the programs or instructions, the communication device 500 can execute the functions of the terminal device in the method shown above Figure 4 in the method shown.

[0153] It can be understood that the communication device 500 may be a terminal device, or a chip (system) or other components or assemblies that can be set in the terminal device, or a device including the terminal device. The present application does not make any limitations in this regard.

[0154] In addition, the technical effects of the communication device 500 can refer to the technical effects of the random access method shown in Figure 4 the figure, which will not be elaborated here.

[0155] Figure 6 The following is the structural schematic diagram of the communication device provided by the embodiments of the present application Figure 2 . Exemplarily, the communication device may be a terminal device, or a chip (system) or other components or assemblies that can be set in the terminal device. As Figure 6 shown in the figure, the communication device 600 may include a processor 601. Optionally, the communication device 600 may further include a memory 602 and / or a transceiver 603. Among them, the processor 601 is coupled to the memory 602 and the transceiver 603, and may be connected through a communication bus, for example.

[0156] Next, in combination with Figure 6Specific introduction to each component of the communication device 600:

[0157] Among them, the processor 601 is the control center of the communication device 600, which can be a single processor or a collective term for multiple processing elements. For example, the processor 601 is one or more central processing units (CPUs), or can be an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as: one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs).

[0158] Optionally, the processor 601 can execute various functions of the communication device 600 by running or executing software programs stored in the memory 602 and calling data stored in the memory 602, such as executing the above-mentioned random access method.

[0159] In a specific implementation, as an embodiment, the processor 601 can include one or more CPUs, such as Figure 6 CPU0 and CPU1 shown in

[0160] In a specific implementation, as an embodiment, the communication device 600 can also include multiple processors, such as Figure 6 processor 601 and processor 604 shown in

[0161] Among them, the memory 602 is used to store the software program for executing the solution of the present application and is controlled by the processor 601 for execution. The specific implementation manner can refer to the above method embodiments and will not be elaborated here.

[0162] Optionally, the memory 602 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 602 can be integrated with the processor 601 or exist independently, and is coupled to the processor 601 through the interface circuit of the communication device 600 ( Figure 6 not shown in the figure), and the embodiments of the present application do not make specific limitations on this.

[0163] The transceiver 603 is used for communication with other communication devices. For example, when the communication device 600 is a terminal, the transceiver 603 can be used for communication with a network device or with another terminal.

[0164] Optionally, the transceiver 603 can include a receiver and a transmitter ( Figure 6 not shown separately in the figure). Among them, the receiver is used to implement the receiving function, and the transmitter is used to implement the sending function.

[0165] Optionally, the transceiver 603 can include a transmitter, a receiver, a radio frequency circuit, an antenna, and an input / output device ( Figure 6 not shown separately in the figure). The transmitter is used to implement the sending function; the receiver is used to implement the receiving function; the radio frequency circuit is mainly used for the conversion between the baseband signal and the radio frequency signal and the processing of the radio frequency signal; the antenna is mainly used for receiving and sending radio frequency signals in the form of electromagnetic waves; the input / output device can include a touch screen, a display screen, or a keyboard, etc.; the input / output device is mainly used for receiving data input by the user and outputting data to the user. It should be noted that some types of terminal devices may not have an input / output device.

[0166] When data needs to be sent, after the processor performs baseband processing on the data to be sent, it outputs a baseband signal to the radio frequency circuit. Then, the radio frequency circuit performs radio frequency processing on the baseband signal and sends the radio frequency signal out in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna. The radio frequency circuit converts the radio frequency signal into a baseband signal and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data. In an actual terminal device product, there may be one or more processors and one or more memories. The memory can also be referred to as a storage medium or a storage device, etc. The memory can be set independently of the processor or integrated with the processor. The embodiments of the present application do not limit this.

[0167] In the embodiments of the present application, the antenna and the radio frequency circuit with transceiver functions can be regarded as the transceiver module of the terminal device, and the processor with processing functions can be regarded as the processing module of the terminal device.

[0168] Optionally, the transceiver 603 can be integrated with the processor 601 or exist independently, and is coupled to the processor 601 through the interface circuit of the communication device 600 ( Figure 6 not shown in the figure), and the embodiments of the present application do not make specific limitations on this.

[0169] When the communication device 600 is a communication chip, the transceiver 603 can be the input interface and output interface of the chip. Among them, the input interface is used to implement the receiving function, and the output interface is used to implement the sending function. The processor can be a processing module integrated on the chip, a microprocessor, or an integrated circuit. The sending operation of the network device or terminal device in the above method embodiments can be understood as the output of the chip, and the receiving operation of the network device or terminal device in the above method embodiments can be understood as the input of the chip.

[0170] It can be understood that Figure 6 the structure of the communication device 600 shown in the figure does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than shown in the figure, or combine some components, or have different component arrangements.

[0171] In addition, the technical effects of the communication device 600 can refer to the technical effects of the method described in the above method embodiments, and will not be elaborated here.

[0172] It should be understood that the processor in the embodiments of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0173] It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0174] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wired (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that contains one or more collections of available media. The available media can be magnetic media (such as floppy disks, hard disks, magnetic tapes), optical media (such as DVDs), or semiconductor media. The semiconductor media can be a solid-state drive.

[0175] It should be understood that the term "and / or" in this document is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. In addition, the character " / " in this document generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be specifically understood by referring to the context.

[0176] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0177] It should be understood that in various embodiments of the present application, the magnitudes of the sequence numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0178] Those of ordinary skill in the art will realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0179] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0180] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0181] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0182] In addition, the functional units in each embodiment of this application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0183] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0184] As described above, the above are only specific implementation manners of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A random access method, characterized in that, The method includes: Receiving a first message for configuring a first timing advance group (TAG) and a second TAG in the same cell for a terminal device; Receiving a physical downlink control channel (PDCCH) for indicating a path loss resource corresponding to a random access request message, where the TAG corresponding to the PDCCH is the first TAG or the second TAG; Determining a downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource, where the downlink timing is a first downlink timing corresponding to the first TAG or a second downlink timing corresponding to the second TAG; Sending the random access request message according to the downlink timing.

2. The method according to claim 1, wherein The path loss resource is a first path loss resource or a second path loss resource. The first path loss resource is a quasi - co - located (QCL) reference signal resource in a transmission configuration indication (TCI) state adopted by the PDCCH, and the second path loss resource is a synchronization signal and a physical broadcast channel block (SSB) indicated in the PDCCH.

3. The method according to claim 2, characterized in that When the path loss resource is the first path loss resource, the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message; or, When the path loss resource is the second path loss resource, the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message.

4. The method according to claim 3, characterized in that, When the path loss resource is the second path loss resource, if the PDCCH corresponds to the first TAG, then the random access request message corresponds to the second TAG; Or, If the PDCCH corresponds to the second TAG, then the random access request message corresponds to the first TAG.

5. The method according to claim 2, wherein The determining of the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource includes: If the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, determining that the random access request message adopts the first downlink timing; or, If the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, determining that the random access request message adopts the second downlink timing; or, If the PDCCH corresponds to the second TAG and the path loss resource is the first path loss resource, determining that the random access request message adopts the second downlink timing; or, If the PDCCH corresponds to the second TAG and the path loss resource is the second path loss resource, determining that the random access request message adopts the first downlink timing.

6. The method according to any one of claims 1-5, characterized in that, The TAG corresponding to the PDCCH is the TAG associated with the TCI state adopted by the PDCCH.

7. The method according to any one of claims 1-6, characterized in that, The determining of the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource includes: Under the condition of satisfying a first condition, determining the downlink timing adopted by the random access request message according to the TAG corresponding to the PDCCH and the path loss resource; The first condition includes a combination of one or more of the following: the network device configures two control channel groups in the cell for the terminal device, the network device configures two TAGs in the cell for the terminal device, the network device does not configure a supplementary cell corresponding to the cell for the terminal device, or the TCI state activated by the network device for the terminal device is not associated with the supplementary cell corresponding to the cell.

8. A communication device, characterized in that, The apparatus includes: a module for performing the method according to any one of claims 1-7.

9. 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 according to any one of claims 1-7 is implemented.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program or instruction. When the computer program or instruction runs on a communication device, the communication device is caused to execute the method according to any one of claims 1-7.

11. A computer program product, characterized in that, The computer program product includes a computer program or instruction. When the computer program or instruction is run by a communication device, the method according to any one of claims 1-7 is caused to be executed.

Images