Random access method and apparatus

Abstract

The present application belongs to the technical field of communications. Provided are a random access method and apparatus, which are used for realizing sending of a random-access request message by a terminal device in multi-TRP transmission scenarios. The method comprises: a terminal device receiving a first message and a PDCCH, wherein 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; and on the basis of the path loss resource and the TAG corresponding to the PDCCH, determining a downlink timing used by the random access request message, and sending the random access request message on the basis of the downlink timing, wherein the downlink timing is a first downlink timing corresponding to the first TAG or a second downlink timing corresponding to the second TAG. In this way, a terminal device can send a random access request message by using a correct downlink timing in multi-TRP transmission scenarios.

Description

Random access method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on December 28, 2023, with application number 202311850126.3 and application name “Random Access Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] In the fifth generation (5G) mobile communication system, both uplink and downlink transmissions use time slots as the basic time unit, that is, data can be transmitted once in each time slot. When the terminal device is performing uplink transmission, it needs to know the start time of its uplink time slot, that is, the uplink timing; when the terminal device is performing downlink reception, it needs to know the start time of its downlink time slot, that is, the downlink timing. In a single transmission and reception point (or Transmit / Receive Point, TRP) transmission scenario, the terminal needs to determine an uplink timing and a downlink timing. In a multi-TRP transmission scenario, the terminal device needs to determine multiple uplink timings and multiple downlink timings. These multiple uplink timings and multiple downlink timings are 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 based on the downlink timing, the timing advance offset indicated by the network device, and the timing advance (TA) obtained during the random access process.

[0004] In a multi-TRP transmission scenario, such as a scenario where one cell corresponds to two TRPs, the network device (a general term for 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 the random access request message is an urgent problem to be solved. Summary of the Invention

[0005] An embodiment of the present application provides a random access method and apparatus for enabling a terminal device to send a random access request message in a multi-TRP (two TRPs or more than two TRPs) transmission scenario.

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

[0007] In a first aspect, a random access method is provided, which can be executed by a terminal device, or by a component of the terminal device, such as a processor, chip, or chip system of the terminal device, or by a logic module or software that can realize all or part of the functions of the terminal device. The following is an illustration of the method being executed by a terminal device. The method includes: receiving a first message, the first message being used to configure a first timing advance group TAG and a second TAG in the same cell for the terminal device; receiving a PDCCH, the PDCCH being used to indicate a path loss resource corresponding to a random access request message, the TAG corresponding to the PDCCH being the first TAG or the second TAG; determining the downlink timing used by the random access request message based on the TAG and the path loss resource corresponding to the PDCCH, and sending the random access request message based on the downlink timing, the downlink timing being the first downlink timing corresponding to the first TAG or the second downlink timing corresponding to the second TAG.

[0008] 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 to which TRP the random access request message should be sent, that is, the terminal device does not know which downlink timing should be used to send the random access request message. Based on the method of the first aspect, it can be known that the terminal device can determine the downlink timing used by the random access request message according to the TAG corresponding to the PDCCH and the path loss resources, such as the relationship between the TAG corresponding to the PDCCH indicated by the path loss resources and the TAG corresponding to the random access request message, and determine the downlink timing used by the random access request message according to the TAG. In this way, in a multi-TRP transmission scenario, the terminal device can use the correct downlink timing to realize the sending of the random access request message.

[0009] It can be understood that the first TAG and the second TAG respectively correspond to one of the two TRPs corresponding to the above-mentioned 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.

[0010] In one possible design, the path loss resource is a first path loss resource or a second path loss resource. The first path loss resource is a quasi-colocated QCL reference signal resource in a transmission configuration indication (TCI) state used by the PDCCH, and the second path loss resource is a synchronization signal and physical broadcast channel block (SSB) indicated in the PDCCH. It will be appreciated that the first path loss resource may 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 may indicate that the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message.

[0011] Optionally, when the path loss resource is a 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 a second path loss resource, the TAG corresponding to the PDCCH is different from the TAG corresponding to the random access request message. It is 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 based on the path loss resource and the TAG corresponding to the PDCCH.

[0012] Furthermore, 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.

[0013] Optionally, determining the downlink timing used by the random access request message based on the TAG and path loss resources corresponding to the PDCCH includes: if the PDCCH corresponds to a first TAG and the path loss resources are first path loss resources, determining that the random access request message uses the first downlink timing; or, if the PDCCH corresponds to the first TAG and the path loss resources are second path loss resources, determining that the random access request message uses the second downlink timing; or, if the PDCCH corresponds to a second TAG and the path loss resources are first path loss resources, determining that the random access request message uses the second downlink timing; or, if the PDCCH corresponds to a second TAG and the path loss resources are second path loss resources, determining that the random access request message uses the first downlink timing. It can be understood that based on the TAG and path loss resources corresponding to the PDCCH, the TAG corresponding to the random access request message can be determined, and the downlink timing used by the random access request message can be determined based on the TAG. For example, if the PDCCH corresponds to the first TAG and the path loss resources are first path loss resources, the random access request message uses the first downlink timing for the first TAG corresponding to the random access request message. 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 resources.

[0014] In one possible design, the TAG corresponding to the PDCCH is the TAG associated with the TCI state used by the PDCCH. That is, the TAG associated with the TCI state used by the PDCCH is the first TAG or the second TAG.

[0015] In a possible design scheme, the downlink timing adopted by the random access request message is determined according to the TAG and path loss resources corresponding to the PDCCH, including: when the first condition is met, the downlink timing adopted by the random access request message is determined according to the TAG and path loss resources corresponding to the PDCCH; 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 the 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 scenario is multiple TRP, 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 and path loss resources corresponding to the PDCCH. In this way, it can avoid the terminal device determining the downlink timing adopted by the random access request message according to the TAG and path loss resources corresponding to the PDCCH in a single TRP scenario, thereby avoiding unnecessary overhead.

[0016] In one possible design solution, the first message is a radio resource control (RRC) message. That is, the messages in the prior art can be reused to configure the first TAG and the second TAG for the terminal device, thereby reducing the difficulty of implementation.

[0017] In a second aspect, a communication device is provided. The communication device includes: a module for executing 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 functions of the communication device other than the transceiver function.

[0018] The transceiver module is used to receive 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; the transceiver module is also used to receive a PDCCH, where the PDCCH is used to indicate the path loss resources 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 used by the random access request message based on the TAG and path loss resources corresponding to the PDCCH, 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 also used to send a random access request message based on the downlink timing.

[0019] In one possible design scheme, the path loss resource is a first path loss resource or a second path loss resource. The first path loss resource is a quasi-coordinated QCL reference signal resource in the TCI state indicated by the transmission configuration 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.

[0020] Optionally, the processing module is specifically used 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, if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, determine 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, determine 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, determine that the random access request message adopts the first downlink timing.

[0021] In one possible design scheme, the processing module is specifically used to determine the downlink timing adopted by the random access request message based on the TAG and path loss resources corresponding to the PDCCH when a first condition is met; 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.

[0022] Optionally, the transceiver module may include a sending module and a receiving module, wherein the sending module is used to implement the sending function of the communication device described in the second aspect, and the receiving module is used to implement the receiving function of the communication device described in the second aspect.

[0023] Optionally, the communication device described in the second aspect may further include a storage module, wherein the storage module stores a program or instruction. When the processing module executes the program or instruction, the communication device may execute the method described in the first aspect.

[0024] It can be understood that the communication device described in the second aspect can be a terminal device, or a chip (system) or other parts or components that can be set in the terminal device, or a device that includes a terminal device. This application does not impose any restrictions on this.

[0025] 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 repeated here.

[0026] In a third aspect, a communication device is provided, comprising: a processor configured to execute the method described in any possible implementation of the first aspect.

[0027] In one possible design solution, 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.

[0028] In one possible design, the communication device described in the third aspect may further include a memory. The memory may be integrated with the processor or provided separately. The memory may be used to store the computer program and / or data involved in the method described in any aspect of the first aspect.

[0029] In an embodiment 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 parts or components that may be set in the terminal device, or a device that includes the terminal device.

[0030] In addition, the technical effects of the communication device described in the third aspect can refer to the technical effects of the method described in any implementation method of the first aspect, and will not be repeated here.

[0031] In a fourth aspect, a communication device is provided, comprising: a processor coupled to a memory, the processor configured to execute a computer program stored in the memory, so that the communication device performs the method described in any possible implementation of the first aspect.

[0032] In one possible design solution, 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.

[0033] In an embodiment 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 parts or components that may be set in the terminal device, or a device that includes the terminal device.

[0034] In addition, the technical effects of the communication device described in the fourth aspect can refer to the technical effects of the method described in any implementation method of the first aspect, and will not be repeated here.

[0035] In a fifth aspect, a communication device is provided, comprising: 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 executes the method described in any one of the implementation methods in the first aspect.

[0036] In one possible design solution, the communication device described in the fifth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fifth aspect to communicate with other communication devices.

[0037] In an embodiment 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) or other parts or components that may be set in the terminal device, or a device that includes the terminal device.

[0038] In addition, the technical effects of the communication device described in the fifth aspect can refer to the technical effects of the method described in any implementation method of the first aspect, and will not be repeated here.

[0039] In a sixth aspect, a communication device is provided, comprising: a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and execute the method described in the first aspect. The processor may comprise one or more processors.

[0040] In a seventh aspect, a communication chip stores instructions, which, when the chip is run on a communication device, enables the method described in any one of the implementation methods of the first aspect to be implemented.

[0041] In an eighth aspect, a communication chip comprises: a logic circuit and a communication interface, wherein 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, and when the logic circuit executes the computer instructions, the method described in any one of the implementation methods in the first aspect is implemented.

[0042] In a ninth aspect, a communication chip includes a processor for calling a computer program or computer instruction in a memory so that the processor executes any one of the implementation methods in the first aspect above.

[0043] Optionally, the processor is coupled to the memory via an interface.

[0044] In a tenth aspect, a communication system is provided, comprising: a terminal device and a network device configured to execute the method described in the first aspect, wherein the network device is configured to send a first message and a PDCCH.

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

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

[0047] FIG1 is a schematic diagram of uplink and downlink time slots of a network device and a terminal device according to an embodiment of the present application;

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

[0049] FIG3 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0050] FIG4 is a schematic diagram of a flow chart of a random access method provided in an embodiment of the present application;

[0051] FIG5 is a first structural diagram of a communication device provided in an embodiment of the present application;

[0052] FIG6 is a second structural diagram of the communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] For ease of understanding, the technical terms involved in the embodiments of this application are first introduced below.

[0054] 1. Downlink timing and uplink timing.

[0055] In 5G communication systems, both uplink and downlink transmissions are based on time slots, meaning data is transmitted once in each time slot. Time slots are divided into downlink time slots and uplink time slots.

[0056] Network devices begin transmitting signals at the start of their corresponding downlink time slots, and terminal devices begin receiving signals at the start of their corresponding downlink time slots. Signals sent from network devices to terminal devices require a certain propagation delay. Therefore, the downlink time slot start times of the network and terminal devices are asynchronous. That is, the downlink time slot start time of the terminal device is later than that of the network device. As shown in Figure 1, if the signal propagation time is T, the downlink time slot start time of the terminal device is T later than the downlink time slot start time of the network device. In other words, the downlink time slot start time of the network device is T earlier than that of the terminal device.

[0057] The terminal device begins transmitting signals at the start time of its corresponding upper limit time slot, and the network device begins receiving information at the start time of its corresponding upper limit time slot. Information sent from 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 asynchronous. That is, the start time of the uplink time slot of the network device is later than that of the terminal device. Continuing with Figure 1, the start time of the uplink time slot of the network device is T later than that of the terminal device. That is, the start time of the uplink time slot of the terminal device is T earlier than that of the uplink time slot of the network device.

[0058] The uplink and downlink timeslots of network devices are generally aligned. Assuming that the start time of the uplink and downlink timeslots of the network device is t0, the start time of the downlink timeslot of the terminal device is t0-T, and the start time of the uplink timeslot of the terminal device is t0+T.

[0059] To perform downlink reception, a terminal device needs to know the start time of its downlink timeslot, which is the downlink timing of the terminal device. The downlink timing of a terminal device can be determined by measuring a downlink reference signal. Specifically, the network device can send a downlink reference signal to the terminal device, which then measures the signal and uses the earliest received time as its downlink timing.

[0060] For a terminal device to perform an uplink transmission, it needs to know the start time of its uplink timeslot. The protocol stipulates that the terminal device must send an uplink signal at a specific start time so that the uplink signal arrives at the network device at the start time of the network device's uplink timeslot. This specific start time is the uplink timing of the terminal device.

[0061] The uplink timing of the terminal device can be determined through the random access process. The specific process is as follows: the terminal device uses the downlink timing (t0+T) to send a random access request message, that is, a physical random access channel (PRACH) message, to the network device. The network device receives the random access request message at t0+2T, and subtracts its uplink time slot start time t0 from the time of receiving the random request message to obtain a time difference 2T. This time difference is the time it takes for the random access request message to be transmitted twice between the network device and the terminal device, and this time difference is also called the uplink timing advance (TA). The network device notifies the terminal device of the time difference, and the terminal device, based on its downlink timing, advances the time difference for uplink transmission, that is, uplink transmission at t0+T-2T. This ensures that the time when the uplink signal arrives at the network device is the uplink time slot start time t0 of the network device.

[0062] It can be understood that the premise of the above content is that the start time of the uplink time slot of the network device and the start time of the downlink time slot are the same. However, in some cases, the start time of the uplink time slot of the network device may be different. For example, in a time division duplex (TDD) system, it takes time for the network device to switch between uplink and downlink, resulting in a timing offset (denoted as TA_offset) between the uplink time slot and the downlink time slot. In this case, when the terminal device performs uplink transmission, in addition to adopting the above-mentioned timing advance, it is also necessary to adopt TA_offset. That is, the terminal device must advance the time of TA_offset and TA for uplink transmission 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 is advanced by TA_offset based on its downlink timing.

[0063] It can also be understood that in a single TRP transmission scenario, the terminal device needs to determine one downlink timing and one uplink timing, that is, the terminal device needs to determine one TA_offset and one TA. In a two-TRP transmission scenario, the terminal device needs to determine two downlink timings and two uplink timings, that is, the terminal device needs to determine one TA_offset and two TAs.

[0064] 2. Random access channel (RA).

[0065] The terminal device can access the network through the random access process and achieve uplink and downlink synchronization with the network equipment. The random access process refers to the process from the terminal device sending a random access preamble to attempt to access the network to the establishment of a basic signaling connection with the network; in other words, the terminal device can access the network through the random access process. The random access process can be triggered by some events, such as the terminal device performing initial access from the idle state, or performing the radio resource control layer (RRC) connection recovery process from the inactive state, or by the network device sending a PDCCH trigger to the terminal device.

[0066] As shown in Figure 2, the 5G NR random access process mainly includes the following five steps, namely S201 to S205. They are introduced below.

[0067] S201: The network device sends a PDCCH to the terminal device. Correspondingly, the terminal device receives the PDCCH from the network device.

[0068] The PDCCH may be used to trigger a random access process, that is, the PDCCH may instruct the terminal device to send a random access request message to the network device.

[0069] S202: The terminal device sends a message (Msg) 1 to the network device according to the PDCCH. Correspondingly, the network device receives the Msg 1 from the terminal device.

[0070] Msg1, also known as a random access request message, includes a preamble sequence, also known as a preamble code. The preamble sequence notifies the network device of the presence of a random access request message and enables the network device to calculate the transmission delay between it and the terminal device, allowing the network device to calibrate the uplink timing and notify the terminal device of the calibration information through the TA time adjustment information.

[0071] It can be understood that the time when the terminal device sends Msg1 is the time of the terminal device's downlink timing plus TA_offset.

[0072] S203: The network device sends Msg2 to the terminal device according to Msg1. Correspondingly, the terminal device receives Msg2 from the network device.

[0073] Based on the received Msg1, the network device estimates the terminal device's TA and sends the TA value to the terminal device via Msg2. Msg2 is the response message to Msg1, which can also be called a random access response (RAR). Msg2 may include a frequency hopping flag, physical uplink shared channel (PUSCH) frequency resource allocation, uplink grant, and temporary cell wireless network equipment temporary identification. The uplink grant is used to indicate the transmission resources for Msg3.

[0074] S204: The terminal device sends Msg3 to the network device according to Msg2. Correspondingly, the network device receives Msg3 from the terminal device.

[0075] After receiving Msg2, the terminal device can send Msg3 on the transmission resources indicated by the uplink authorization.

[0076] S205: The network device sends Msg4 to the terminal device according to Msg3. Correspondingly, the terminal device receives Msg4 from the network device.

[0077] After receiving Msg3, the network device sends Msg4 to the terminal device to indicate that the terminal device has successfully accessed.

[0078] 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 used to send or receive data for different TRPs of a service cell. In addition, 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 the random access request message should be sent to, that is, it does not know which downlink timing should be used. Therefore, in a multi-TRP transmission scenario, how the terminal device sends a random access request message is an urgent problem to be solved.

[0079] In response to 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.

[0080] The technical solution in this application will be described below with reference to the accompanying drawings.

[0081] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as 4th generation (4G) mobile communication systems, such as long term evolution (LTE) systems, fifth generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems after 5G, such as sixth generation (6G) mobile communication systems. They can also be applied to wireless fidelity (WiFi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, and Internet of Vehicles communication systems.

[0082] This application will present various aspects, embodiments, or features in the context of systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in conjunction with the figures. Furthermore, combinations of these aspects may also be used.

[0083] Additionally, in the embodiments of this application, words such as "exemplary" and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner.

[0084] In the embodiments of the present application, "information", "signal", "message", "channel" and "signaling" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are matched. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are matched. In addition, the " / " mentioned in this application can be used to express an "or" relationship.

[0085] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field will know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0086] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first introduced.

[0087] The communication system includes: terminal devices and network devices. It can be understood that in the embodiment of the present application, one cell corresponds to multiple TRPs, such as 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 network devices. The terminal device and the network device can refer to the relevant introduction of "terminal device 120" and "network device 110" below, respectively, and will not be repeated here. In addition, the communication system may also include other network devices and / or other terminal devices.

[0088] To facilitate understanding of the embodiments of the present application, the application scenarios used in the present application are described using the communication system architecture shown in FIG3 as an example. FIG3 is a possible, non-limiting system schematic diagram. As shown in FIG3, 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 110a and 110b in FIG3, collectively referred to as 110) and at least one terminal device (such as 120a to 120j in FIG3, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG3). The terminal device 120 is connected to the network device 110 via a wireless connection. The network device 110 is connected to the core network 200 via a wireless or wired connection. The core network device in the core network 200 and the network device 110 in the RAN 100 can be different physical devices, or they can be the same physical device that integrates the core network logical functions and the radio access network logical functions.

[0089] The RAN 100 may be a cellular system related to the Third Generation Partnership Project (3GPP), for example, a 4G mobile communication system such as an LTE system, a 5G mobile communication system such as an NR system, and a communication system evolved after 5G, such as a 6G mobile communication system. It may also be applied to a WiFi system, a V2X communication system, a D2D communication system, an Internet of Vehicles communication system, 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 that integrates two or more of the above systems.

[0090] The terminal device and network device provided in the embodiment of the present application can be applied to the network device 110 or the terminal device 120. It is understood that FIG3 only shows a possible communication system architecture that can be applied in the embodiment of the present application. In other possible scenarios, the communication system architecture can also include other devices.

[0091] The network device 110 is a node in the RAN, which can also be called an access network device or a RAN node (or device). The network device 110 is used to help terminal devices achieve wireless access. The multiple network devices 110 in the communication system 3000 can be nodes of the same type or different types. In some scenarios, the roles of the network device 110 and the terminal device 120 are relative. For example, the network element 120i in Figure 3 can be a helicopter or a drone, which can be configured as a mobile base station. For terminal devices 120j that access the RAN 100 through the network element 120i, the network element 120i is a base station; but for the network element 110a, the network element 120i is a terminal device. The network device 110 and the terminal device 120 are sometimes referred to as communication devices. For example, the network elements 110a and 110b in Figure 3 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 device functions.

[0092] In one possible scenario, a network device can be a base station, an evolved NodeB (eNodeB), a Transmitting Point (TP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, a satellite, or an access point (AP) in a WiFi system, such as a home gateway, router, server, switch, bridge, etc. It can also be an integrated access and backhaul (IAB) node, a mobile switching center, or a network device in a non-terrestrial network (NTN) communication system, i.e., it can be deployed on a high-altitude platform or satellite. The network device can be a macro base station (such as 110a in Figure 3), a micro base station or an indoor station (such as 110b in Figure 3), a relay node or a donor node, or a wireless controller in a CRAN scenario. The network device can also be a device that functions as a base station in D2D communication, Internet of Vehicles communication, drone communication, or machine communication. Optionally, the network device can also be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in the V2X technology may be a road side unit (RSU).

[0093] In another possible scenario, multiple network devices collaborate to assist the terminal in achieving wireless access, and different network devices respectively implement part of the functions of the base station. For example, the network device can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). It can be understood that the network device can be a CU node, a DU node, or a device including a CU node and a DU node. In addition, the CU can be divided into a network device in the access network RAN, or the CU can be divided into a network device in the core network CN, which is not limited here.

[0094] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O (open)-CU, DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0095] In the embodiments of the present application, the form of the network device is not limited. The device used to implement the function of the network device can be a network device; it can also be a device that can support the network device to implement the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device.

[0096] The terminal device 120 may also be referred to as user equipment (UE), mobile station (MS), mobile terminal (MT), user device, terminal device, access terminal, subscriber unit, subscriber station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent, or user device, or may be a device for providing voice or data connectivity to a user, or an IoT device. For example, the terminal device includes a handheld device with wireless connectivity, an in-vehicle device, and the like. Currently, terminal devices can be: mobile phones, tablet computers, computers with wireless transceiver functions, laptops, PDAs, mobile internet devices (MIDs), wearable devices (such as smart watches, smart bracelets, pedometers, etc.), vehicle-mounted equipment (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), satellite terminals, virtual reality (VR) devices, augmented reality (AR) devices, smart point of sale (POS) machines, customer-premises equipment (CPE), wireless terminals in industrial control, smart home devices (such as refrigerators, televisions, air conditioners, electricity meters, etc.), intelligent robots, robotic arms, workshop equipment, wireless terminals in unmanned driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, flying equipment (such as intelligent robots, hot air balloons, drones, airplanes), etc. The terminal device may also be other devices with terminal functions. For example, the terminal device may also be a device that serves as a terminal in D2D communication.

[0097] The embodiments of this application do not limit the device form factor of the terminal. The device used to implement the functions of the terminal device can be the terminal device; it can also be a device that supports the terminal device to implement the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of this application, the chip system can be composed of chips or include chips and other discrete devices.

[0098] It should be noted that the solutions in the embodiments of the present application can also be applied to other communication systems, and the corresponding names can also be replaced by the names of corresponding functions in other communication systems. The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0099] In a communication system, a terminal device can determine the downlink timing used by a random access request message based on the TAG corresponding to the PDCCH and the path loss resources. For example, the downlink timing used by the random access request message can be determined based on the relationship between the TAG corresponding to the PDCCH indicated by the path loss resources and the TAG corresponding to the random access request message. In this way, the terminal device can use the correct downlink timing to send the random access request message in a multi-TRP transmission scenario.

[0100] For ease of understanding, the random access method provided in the embodiment of the present application will be specifically described below in conjunction with Figure 4. The random access method is introduced with one cell corresponding to two TRPs (i.e., in a two TRP transmission scenario).

[0101] Figure 4 is a flow chart of a random access method provided by an embodiment 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.

[0102] As shown in FIG4 , the process of the random access method is as follows:

[0103] S401: A network device sends a first message, and a terminal device receives the first message accordingly.

[0104] The first message may 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.

[0105] Cell #1 is the serving cell configured by the network device for data transmission by the terminal device. In other words, the network device needs to configure the parameters of cell #1 for the terminal device so that the terminal device can independently transmit data through cell #1. It is understood that cell #1 can correspond to two TRPs, such as if two TRPs are deployed in cell #1, or if cell #1 has an associated supplementary cell (described below).

[0106] TAG is a parameter used for TA management, which can maintain the TA value of TRP. Each TAG corresponds to a TA, that is, the first TAG corresponds to a TA (recorded as the first TA); the second TAG corresponds to a TA (recorded 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.

[0107] 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, namely 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 a synchronization signal and a physical broadcast channel block (SS / PBCH block, abbreviated as SSB), or a tracking reference signal (TRS) and other signals, which can be specifically determined according to actual conditions, 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, it can associate the first downlink timing with the first TAG and the second downlink timing with the second TAG.

[0108] The first message can also be used to configure other configuration parameters of cell #1, which may include parameters related to uplink timing, such as control channel groups. The control channel grouping can be used to group the control channels of cell #1, and each group of control channel groups corresponds to one of the two TRPs corresponding to cell #1, such as the first control channel group corresponding to the above-mentioned first TRP, and the second control channel group corresponding to the above-mentioned second TRP. Each group of control channel groups corresponds to a control channel group identifier (CORESETPoolIndex), and the value of the control channel group identifier can be 0 or 1, which can be set according to actual conditions. For example, the first control channel group corresponds to control channel group identifier 0, and the second control channel group corresponds to control channel group identifier 1; or, the first control channel group corresponds to control channel group identifier 1, and the second control channel group corresponds to control channel group identifier 0.

[0109] The first message may also be used to configure configuration parameters of other cells, which may be flexibly set according to actual conditions without limitation.

[0110] In addition, the first message may be an RRC message, which may include RRC configuration information. In this case, the RRC configuration information may include configuration parameters of cell #1, such as the first TAG and the second TAG; or, the RRC configuration information may include configuration parameters of cell #1 and other cells. For details, please refer to the aforementioned related introduction and will not be repeated here.

[0111] S402: The network device sends a PDCCH, and the terminal device receives the PDCCH accordingly.

[0112] The PDCCH may be used to indicate the path loss resources corresponding to the random access request message, and the TAG corresponding to the PDCCH may be a TAG associated with the TCI state used by the PDCCH, which may be the first TAG or the second TAG.

[0113] The random access request message is a 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 will 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.

[0114] The path loss resource is a resource used to determine the path loss of the random access request message, that is, the terminal device can determine the path loss for sending the random access request message through the 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 a quasi-colocation (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 send a preamble code. In the case where 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. Alternatively, 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 whether the path loss resource corresponding to the random access request message is the first path loss resource or the second path loss resource can indirectly determine whether the TAG corresponding to the PDCCH is the same as the TAG corresponding to the random access request message.

[0115] Exemplarily, when the path loss resource is a first path loss resource, if the PDCCH corresponds to the first TAG, the random access request message corresponds to the first TAG; or, if the PDCCH corresponds to the second TAG, the random access request message corresponds to the second TAG. When the path loss resource is a 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.

[0116] It can be understood that the path loss resource can be indicated by the first field in the PDCCH signaling, and the first field can reuse the field in the existing technology, or be a newly defined field. For example, the first field is the PRACH association indication field, and the value of the 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 the PRACH association indication field is 0, it can indicate that the random access request message adopts the first path loss resource; when the value of the PRACH association indication field is 1, it can indicate that the random access request message adopts the second path loss resource; or, when the value of the PRACH association indication field is 0, it can indicate that the random access request message adopts the second path loss resource; when the value of the PRACH association indication field is 1, it can indicate that the random access request message adopts the first path loss resource.

[0117] The PDCCH can also be used to indicate other information, such as the preamble used by the random access message. The PDCCH can also include other fields, such as a random access preamble identification field and an SSB identification field. The random access preamble identification field 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 SSB-corresponding beam is used to transmit the preamble. The SSB-corresponding beam can be understood as the receiving beam of the terminal device corresponding to the SSB.

[0118] PDCCH can indicate the above-mentioned path loss resources when the first condition is met. The first condition may include a combination of one or more of the following: the network device configures two control channel groups in cell #1 for the terminal device (recorded as condition #1), the network device configures two TAGs in cell #1 for the terminal device (recorded as condition #2), the network device does not configure the supplementary cell corresponding to cell #1 for the terminal device (recorded 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 (recorded as condition #4). Among them, condition #1 and condition #2 can indicate that cell #1 corresponds to two TRPs; 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 is not associated 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 cell #1 corresponds to multiple TRPs, 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 that the current transmission scenario is two TRPs. For example, if the first condition includes condition #1, condition #2, and condition #3, it can indicate that cell #1 is deployed with two TRPs, that is, the current transmission scenario is two TRPs. The PDCCH can indicate the above path loss resources in the two TRP transmission scenario.

[0119] It can be understood that in addition to configuring a service cell (such as cell #1) for the terminal device, the network device can also configure one or more supplementary cells associated with the service cell for the terminal device, and the supplementary cell can be used for data transmission to a certain extent. However, only one supplementary cell is activated at the same time, and the network device can use a service cell and the activated supplementary cell corresponding to the service cell for joint transmission, that is, cross-cell multi-TRP transmission. In addition, the network device does not need to configure all the parameters of the supplementary cell to the terminal device, but can configure the information of the supplementary cell as the parameters of the service cell to the terminal device, that is, the supplementary cell depends on the service cell associated with the supplementary cell to work. The supplementary cell can be represented by a physical cell index / identifier (PCI).

[0120] S403: The terminal device determines the downlink timing used by the random access request message according to the TAG and path loss resources corresponding to the PDCCH.

[0121] The downlink timing of the random access request message may 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 resources.

[0122] Determining the downlink timing adopted by the random access request message according to the TAG and path loss resources corresponding to the PDCCH may specifically include: if the PDCCH corresponds to the first TAG and the path loss resources are the first path loss resources, 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 resources are the second path loss resources, 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 resources are the first path loss resources, 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 resources are the second path loss resources, determining that the random access request message adopts the first downlink timing.

[0123] It can be understood that the principle by which the terminal device determines whether to use the first downlink timing or the second downlink timing is: the downlink timing corresponding to the TRP to which the random access request message is sent is used, that is, if the random access request message is sent to the first TRP, the first downlink timing corresponding to the first TRP is used; if the random access request message is sent to the second TRP, the second downlink timing corresponding to the first TRP is used. 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 resources, and then determine which TRP it is sent to based on the TAG. In other words, the terminal device can determine the relationship between the TAG corresponding to the PDCCH and the TAG corresponding to the random access request message, that is, whether the two are the same, by using the TAG corresponding to the PDCCH and the relationship, that is, the TAG corresponding to the random access request message, that is, the random access request message is sent to the TRP corresponding to the TAG; and the downlink timing of the random access request message can be determined based on the TAG corresponding to the random access request message.

[0124] For example, if the PDCCH corresponds to the first TAG and the path loss resource is the first path loss resource, it means that the TAG of 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 a 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 of 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 a 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 situation 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 is similar to the above situation, and can be understood with reference to the above situation, and will not be repeated here.

[0125] The path loss resources 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 random access request message adopts the first path loss resources. If the value of the first field is 1, it means that the random access request message adopts the second path loss resources. In this case, the terminal device can determine the downlink timing adopted by the random access request message through the TAG corresponding to the PDCCH and the value of the first field. For example, if the PDCCH corresponds to the first TAG and the value of the first field is 0, the random access request message adopts the first downlink timing; or, if the PDCCH corresponds to the first TAG and the value of the first field is 1, the random access request message adopts the second downlink timing; or, if the PDCCH corresponds to the second TAG and the value of the first field is 0, the random access request message adopts the second downlink timing; or, if the PDCCH corresponds to the second TAG and the value of the first field is 1, the random access request message adopts the first downlink timing. It can be understood that when the value of the first field is 1, it indicates that the random access request message uses the first path loss resource, and the value of the first field is 0, indicating that the random access request message uses the second path loss resource, the method for determining the downlink timing used by 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. You can refer to the above content for understanding, and will not repeat it here.

[0126] Furthermore, it can be provided that, when the first condition is met, the terminal device determines the downlink timing used for the random access request message based on the TAG and path loss resources corresponding to the PDCCH. This first condition can be described in detail in "S402" above and will not be further elaborated here. This avoids unnecessary overhead caused by the terminal device determining the downlink timing used for the random access request message based on the TAG and path loss resources corresponding to the PDCCH in a single TRP scenario.

[0127] S404: The terminal device sends a random access request message according to the downlink timing adopted by the random access request message.

[0128] After determining the downlink timing used by the random access request message, the terminal device can determine the time to send the random access request message (recorded as the sending time) based on the downlink timing, and then send the random access request message based on the sending time. The sending time is the downlink timing used by the random access request message plus TA_offset, that is, the terminal device can send the random access request message in advance by TA_offset based on the downlink timing. For example, if the random access request message uses the first downlink timing, the sending time of the random access request message is the first downlink timing + TA_offset. The value of the TA_offset can be configured by the network device or predefined by the protocol, and the embodiment of the present application does not impose any restrictions on this.

[0129] In summary, in the embodiment of the present application, 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 resources, and determine to which TRP to send the random access request message based on the TAG, thereby determining the downlink timing used by the random access request message. In this way, the terminal device can use the correct downlink timing in two TRP transmission scenarios to implement the transmission of the random access request message.

[0130] Optionally, in combination with the above embodiment, after the terminal device sends the random access request message according to the downlink timing used by the random access request message, the random access method may further include: the network device sending a random access response message to the terminal device according to the random access request message. Correspondingly, the terminal device receives the random access response message from the network device.

[0131] The random access response message may include a TA value and the index of the TAG corresponding to the TA value. The TA value is calculated by the network device based on the received random access request message. It can be understood that the downlink timing used by the random access request message has a corresponding relationship with the TA value, that is, if the random access request message uses the first downlink timing, the TA value is the TA value corresponding to the first TAG; if the random access request message uses 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.

[0132] It can be understood that the above content introduces the random access method based on the case where one cell corresponds to two TRPs. When one cell corresponds to more than two TRPs, the random access method is similar to the above method, except 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 can carry information for indicating the TAG corresponding to the random access request message, such as information indicating that the random access request message corresponds to the third TAG. For other content, please refer to the relevant introduction of "S401" to "404" above, which will not be repeated here. The following example specifically illustrates the random access method when one cell corresponds to more than two TRPs.

[0133] Step 1: The network device sends a first message, and the terminal device receives the first message accordingly.

[0134] The first message is used to configure the first TAG, second TAG, and third TAG in the same cell (denoted as cell #1) for the terminal device. The first TAG, second TAG, and third TAG respectively correspond to one of the three TRPs corresponding to cell #1, such as 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.

[0135] Step 2: The network device sends the PDCCH, and the terminal device receives the PDCCH accordingly.

[0136] 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, where the path loss resource is the second path loss resource and the first TAG corresponding to the PDCCH.

[0137] Step 3: The terminal device determines the downlink timing used by the random access request message based on the TAG and path loss resources corresponding to the PDCCH.

[0138] That is, it can be determined that the random access request message does not correspond to the first TAG based on the first TAG and the second path loss resource corresponding to the PDCCH. And the third TAG corresponding to the random access request message can be determined based on 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 the random access request message to the third TRP corresponding to the third TAG, so the random access request message adopts the third downlink timing corresponding to the third TAG.

[0139] Step 4: The terminal device sends a random access request message according to the downlink timing of the random access request message.

[0140] 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 the time. In other words, the terminal device can send the random access request message in advance by TA_offset based on the third downlink timing.

[0141] It can be understood that steps 1 to 4 are similar to the embodiment shown in FIG. 4 . For details, please refer to the related introduction of “S401” to “404”, which will not be repeated here.

[0142] The random access method provided in the embodiment of the present application is described in detail above in conjunction with Figure 4. The following describes in detail a communication device for executing the random access method provided in the embodiment of the present application in conjunction with Figures 5-6.

[0143] Figure 5 is a structural diagram of a communication device according to an embodiment of the present application. As shown in Figure 5 , the communication device 500 includes a transceiver module 501 and a processing module 502. For ease of illustration, Figure 5 only shows the main components of the communication device.

[0144] In some embodiments, the communication device 500 may be applicable to the above-mentioned communication system to perform the functions of the terminal device in the above-mentioned random access method.

[0145] Among them, the transceiver module 501 is used to receive a first message, which is used to configure the first TAG and the second TAG in the same cell for the terminal device; the transceiver module 501 is also used to receive PDCCH, which is used to indicate the path loss resources 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 used by the random access request message according to the TAG and path loss resources corresponding to the PDCCH, 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 a random access request message according to the downlink timing.

[0146] In one possible design, the path loss resource is a first path loss resource or a second path loss resource, the first path loss resource is a QCL reference signal resource in a TCI state adopted by the PDCCH, and the second path loss resource is an SSB indicated in the PDCCH.

[0147] 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.

[0148] Furthermore, 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.

[0149] Optionally, the processing module 502 is specifically used 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, if the PDCCH corresponds to the first TAG and the path loss resource is the second path loss resource, determine 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, determine 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, determine that the random access request message adopts the first downlink timing.

[0150] In one possible design scheme, the TAG corresponding to the PDCCH is the TAG associated with the TCI state used by the PDCCH.

[0151] In one possible design scheme, the processing module 502 is specifically used to determine the downlink timing adopted by the random access request message based on the TAG and path loss resources corresponding to the PDCCH when a first condition is met; 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.

[0152] Optionally, the transceiver module 501 may include a sending module (not shown in FIG5 ) and a receiving module (not shown in FIG5 ). 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 .

[0153] Optionally, the communication device 500 may further include a storage module (not shown in FIG5 ) storing a program or instruction. When the processing module 502 executes the program or instruction, the communication device 500 may perform the functions of the terminal device in the method shown in FIG4 in the above method.

[0154] It can be understood that the communication device 500 can be a terminal device, or a chip (system) or other parts or components that can be set in the terminal device, or a device that includes a terminal device, which is not limited in this application.

[0155] 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, and will not be repeated here.

[0156] FIG6 is a second structural diagram of a communication device provided in an embodiment of the present application. For example, the communication device may be a terminal device, or a chip (system) or other component or assembly that can be provided in a terminal device. As shown in FIG6 , a communication device 600 may include a processor 601. Optionally, the communication device 600 may further include a memory 602 and / or a transceiver 603. The processor 601 is coupled to the memory 602 and the transceiver 603, such as by a communication bus.

[0157] The following is a detailed introduction to the various components of the communication device 600 with reference to FIG6 :

[0158] The processor 601 is the control center of the communication device 600 and can be a single processor or a collective term for multiple processing elements. For example, the processor 601 can be one or more central processing units (CPUs), 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).

[0159] Optionally, the processor 601 may execute various functions of the communication device 600 , such as executing the above-mentioned random access method, by running or executing a software program stored in the memory 602 and calling data stored in the memory 602 .

[0160] In a specific implementation, as an embodiment, the processor 601 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG. 6 .

[0161] In a specific implementation, as an embodiment, the communication device 600 may also include multiple processors, such as the processor 601 and the processor 604 shown in FIG6 . Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0162] The memory 602 is used to store the software program for executing the solution of the present application, and the execution is controlled by the processor 601. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0163] Alternatively, the memory 602 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store 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 may be integrated with the processor 601 or exist independently and be coupled to the processor 601 via an interface circuit (not shown in FIG6 ) of the communication device 600. This embodiment of the present application does not specifically limit this.

[0164] The transceiver 603 is used for communicating with other communication devices. For example, if the communication device 600 is a terminal device, the transceiver 603 can be used for communicating with a network device or another terminal device.

[0165] Optionally, the transceiver 603 may include a receiver and a transmitter (not shown separately in FIG6 ), wherein the receiver is used to implement a receiving function, and the transmitter is used to implement a sending function.

[0166] Optionally, the transceiver 603 may include a transmitter, a receiver, a radio frequency circuit, an antenna, and input / output devices (not shown separately in FIG6 ). The transmitter is used to implement the transmission function; the receiver is used to implement the reception function; the radio frequency circuit is mainly used for converting baseband signals into radio frequency signals and processing radio frequency signals; the antenna is mainly used to transmit and receive radio frequency signals in the form of electromagnetic waves; the input / output devices may include a touch screen, a display screen, or a keyboard, etc.; the input / output devices are mainly used to receive data input by the user and output data to the user. It should be noted that some types of terminal devices may not have input / output devices.

[0167] When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs the baseband signal to the RF circuit. Then, the RF circuit performs RF processing on the baseband signal and sends the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the RF circuit receives the RF signal through the antenna. The RF circuit converts the RF 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 may also be referred to as a storage medium or a storage device, etc. The memory may be set independently of the processor or integrated with the processor, and the embodiments of the present application do not limit this.

[0168] In the embodiment of the present application, the antenna and radio frequency circuit with transceiver functions can be regarded as the transceiver module of the terminal device, and the processor with processing function can be regarded as the processing module of the terminal device.

[0169] Optionally, the transceiver 603 may be integrated with the processor 601 or exist independently and be coupled to the processor 601 through an interface circuit (not shown in FIG. 6 ) of the communication device 600 . This embodiment of the present application does not specifically limit this.

[0170] When the communication device 600 is a communication chip, the transceiver 603 may be the chip's input and output interfaces. The input interface is used to implement a receiving function, and the output interface is used to implement a transmitting function. The processor may be a processing module, microprocessor, or integrated circuit integrated on the chip. In the above method embodiments, the transmitting operation of the network device or terminal device may be understood as an output of the chip, and the receiving operation of the network device or terminal device in the above method embodiments may be understood as an input of the chip.

[0171] It is understandable that the structure of the communication device 600 shown in FIG6 does not constitute a limitation on the communication device, and an actual communication device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0172] In addition, the technical effects of the communication device 600 can refer to the technical effects of the methods described in the above method embodiments, and will not be repeated here.

[0173] It should be understood that the processor in the embodiments of the present application may be a CPU, but may also be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0174] It should also be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an EEPROM, or a flash memory. The volatile memory can be a RAM, which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0175] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. 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 program are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (such as infrared, wireless, microwave, etc.) method. 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 data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0176] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. A and B can be singular or plural. Furthermore, the character " / " as used herein generally indicates an "or" relationship between the associated objects, but it may also indicate an "and / or" relationship. For specific understanding, please refer to the context.

[0177] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0178] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0179] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0180] Those skilled in the art will 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 aforementioned method embodiments and will not be repeated here.

[0181] 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 schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0182] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0183] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0184] If the 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 the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0185] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A random access method, characterized in that, The method includes: Receiving a first message for configuring a first control channel group and a second control channel group 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; Determining a downlink timing for the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource, where the downlink timing is a first downlink timing corresponding to the first control channel group or a second downlink timing corresponding to the second control channel group; 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-Location (QCL) reference signal resource in a Transmission Configuration Indicator (TCI) state adopted by the PDCCH, and the second path loss resource is a Synchronization Signal and Physical Broadcast Channel Block (SSB) indicated in the PDCCH.

3. The method according to claim 2, characterized in that, The determining of the downlink timing for the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource includes: If the PDCCH corresponds to the first control channel group 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 control channel group 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 control channel group 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 control channel group and the path loss resource is the second path loss resource, determining that the random access request message adopts the first downlink timing.

4. The method according to any one of claims 1-3, characterized in that, The determining of the downlink timing for the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource includes: Determining the downlink timing for the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource when a first condition is met; 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 Timing Advance Groups (TAGs) in the cell for the terminal device, and the network device does not configure a supplementary cell corresponding to the cell for the terminal device.

5. A communication device, characterized in that, The apparatus includes: a transceiver module and a processing module; The transceiver module is configured to receive a first message for configuring a first control channel group and a second control channel group in the same cell for a terminal device; The transceiver module is further configured to receive a Physical Downlink Control Channel (PDCCH) for indicating a path loss resource corresponding to a random access request message; The processing module is configured to determine the downlink timing adopted by the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource, where the downlink timing is the first downlink timing corresponding to the first control channel group or the second downlink timing corresponding to the second control channel group; The transceiver module is further configured to determine the downlink timing adopted by the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource, where the downlink timing is the first downlink timing corresponding to the first control channel group or the second downlink timing corresponding to the second control channel group.

6. The device according to claim 5, characterized in that, 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; If the PDCCH corresponds to the second control channel group, the random access request message corresponds to the first control channel group.

7. The device according to claim 6, characterized in that The processing module is further configured to determine the downlink timing adopted by the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource, including: The processing module is further configured to, when the PDCCH corresponds to the first control channel group and the path loss resource is the first path loss resource, determine that the random access request message adopts the first downlink timing; or, when the PDCCH corresponds to the first control channel group and the path loss resource is the second path loss resource, determine that the random access request message adopts the second downlink timing; or, when the PDCCH corresponds to the second control channel group and the path loss resource is the first path loss resource, determine that the random access request message adopts the second downlink timing; or, when the PDCCH corresponds to the second control channel group and the path loss resource is the second path loss resource, determine that the random access request message adopts the first downlink timing.

8. The device according to any one of claims 5-7, characterized in that, The processing module is further configured to determine the downlink timing adopted by the random access request message according to the control channel group corresponding to the PDCCH and the path loss resource, including: The processing module is configured to, when a first condition is satisfied, determine the downlink timing adopted by the random access request message according to the control channel group 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 transmission opportunity groups (TAGs) in the cell for the terminal device, and the network device does not configure a supplementary cell corresponding to the cell for the terminal device.

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 computer instructions, the method described in any one of claims 1-4 is implemented.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program or instructions. When the computer program or instructions run on a communication device, the communication device is caused to execute the method described in any one of claims 1-4.

11. A computer program product, characterized in that, The computer program product includes a computer program or instructions. When the computer program or instructions are run by a communication device, the method described in any one of claims 1-4 is caused to be executed.

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