Random access method and device, terminal equipment and network equipment

Abstract

Provided in an embodiment of the present application are a random access method and apparatus, a terminal device, and a network device, the method comprising: a terminal device determining a random access parameter corresponding to at least one target TRP, the target TRP being a TRP in a plurality of TRPs that is in an out-of-step state with an uplink of the terminal device; wherein at least part of the random access parameters corresponding to different TRPs are different; and the terminal equipment sends a physical random access channel (PRACH) to the at least one target TRP based on the random access parameter corresponding to the at least one target TRP, the PRACH being used for acquiring timing advance (TA) information corresponding to the at least one target TRP.

Description

Random access method and device, terminal equipment, and network equipment Technical Field

[0001] The embodiments of the present application relate to the field of mobile communication technology, and specifically to a random access method and apparatus, terminal equipment, and network equipment. Background Art

[0002] In order to reduce the impact of the delay in signaling between the terminal device and the network device (such as the base station) during spatial transmission, the terminal device can send a physical random access channel (PRACH) to the network device, so that the network device can perform uplink delay measurement based on the PRACH and determine the timing advance (TA) information of the terminal device. In this way, the terminal device can send an uplink channel or signal based on the TA information. In addition, the multiple transmission reception point (Multi-TRP) transmission technology means that multiple TRPs can communicate with one terminal device at the same time on the same carrier.

[0003] Currently, the New Radio (NR) protocol only supports terminal devices sending PRACH to one TRP. However, because the distances from terminal devices to different TRPs may vary, and there may be large synchronization errors between different TRPs, there is currently no clear solution for uplink synchronization between different TRPs.

[0004] Summary of the Invention

[0005] Embodiments of the present application provide a random access method and apparatus, a terminal device, and a network device.

[0006] This embodiment of the present application provides a random access method, including:

[0007] The terminal device determines random access parameters corresponding to at least one target TRP, where the target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device; wherein at least some of the random access parameters corresponding to different TRPs are different;

[0008] The terminal device sends a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to the at least one target TRP.

[0009] The embodiment of the present application further provides a random access method, including:

[0010] The network device receives the physical random access channel PRACH sent by the terminal device for each target TRP in at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to each target TRP. The target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device.

[0011] An embodiment of the present application provides a random access apparatus, applied to a terminal device, including:

[0012] a determining unit configured to determine random access parameters corresponding to at least one target TRP, the target TRP being a TRP among multiple TRPs that is in an out-of-sync state with an uplink of the terminal device; wherein at least some of the random access parameters corresponding to different TRPs are different;

[0013] The first sending unit is configured to send a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to the at least one target TRP.

[0014] An embodiment of the present application provides a random access device, applied to a network device, including:

[0015] The second receiving unit is configured to receive a physical random access channel PRACH sent by the terminal device for each target TRP in at least one target TRP, wherein the PRACH is used to obtain timing advance TA information corresponding to each target TRP. The target TRP is a TRP in multiple TRPs that is in an out-of-sync state with the uplink of the terminal device.

[0016] The communication device provided in an embodiment of the present application may be a terminal device or a network device in the above-mentioned solution, and includes a processor, a memory, and a transceiver. The transceiver is used to implement communication with other devices, the memory is used to store computer programs, and the processor is used to call and execute the computer programs stored in the memory to perform the above-mentioned random access method.

[0017] The chip provided in the embodiment of the present application is used to implement the above-mentioned random access method.

[0018] Specifically, the chip includes: a processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes the above-mentioned random access method.

[0019] The computer-readable storage medium provided in an embodiment of the present application is used to store a computer program, which enables a computer to execute the above-mentioned random access method.

[0020] The computer program product provided in the embodiments of the present application includes computer program instructions, which enable a computer to execute the above-mentioned random access method.

[0021] The computer program provided in the embodiment of the present application, when executed on a computer, enables the computer to execute the above-mentioned random access method.

[0022] An embodiment of the present application provides a random access method, wherein a terminal device determines a random access parameter corresponding to at least one target TRP, wherein the target TRP is a TRP among multiple TRPs that is out of sync with the uplink of the terminal device; the terminal device sends a PRACH to the at least one target TRP based on the random access parameter corresponding to the at least one target TRP, and the PRACH is used to obtain the time advance TA information corresponding to the at least one target TRP. In other words, the terminal device can send a random access to the target TRP based on the random access parameter corresponding to the out-of-sync target TRP to obtain the TA information dedicated to the target TRP. In this way, the terminal device accesses the target TRP that is out of sync with the uplink to ensure the correct transmission of uplink data. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] FIG1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0025] FIG2 is a schematic diagram of a signaling structure of a MAC RAR provided in an embodiment of the present application;

[0026] FIG3 is a schematic diagram of a frame structure relationship provided in an embodiment of the present application;

[0027] FIG4 is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0028] FIG5 is a flowchart of a random access method according to an embodiment of the present application;

[0029] FIG6 is a second flow diagram of a random access method provided in an embodiment of the present application;

[0030] FIG7A is a first schematic diagram of a grouping method provided in an embodiment of the present application;

[0031] FIG7B is a second schematic diagram of grouping provided in an embodiment of the present application;

[0032] FIG8 is a third flow chart of a random access method provided in an embodiment of the present application;

[0033] FIG9A is a schematic diagram of FDM repeated transmission provided in an embodiment of the present application;

[0034] FIG9B is a schematic diagram of TDM repeated transmission provided in an embodiment of the present application;

[0035] FIG9C is a schematic diagram of SFN transmission provided in an embodiment of the present application;

[0036] FIG10 is a schematic diagram of a random access process provided in an embodiment of the present application;

[0037] FIG11 is a schematic structural diagram of a random access device 1100 provided in an embodiment of the present application;

[0038] FIG12 is a schematic structural diagram of a random access device 1200 provided in an embodiment of the present application;

[0039] FIG13 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0040] FIG14 is a schematic structural diagram of a chip according to an embodiment of the present application;

[0041] FIG15 is a schematic block diagram of a communication system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] FIG1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application.

[0044] As shown in Figure 1, a communication system 100 may include a terminal device 110 and a network device 120. The network device 120 may communicate with the terminal device 110 via an air interface. The terminal device 110 and the network device 120 support multi-service transmission.

[0045] It should be understood that the embodiments of the present application are only illustrative of the communication system 100, but the embodiments of the present application are not limited thereto. That is, the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Internet of Things (IoT) system, Narrow Band Internet of Things (NB-IoT) system, enhanced Machine-Type Communications (eMTC) system, 5G communication system (also known as New Radio (NR) communication system), or future communication systems.

[0046] In the communication system 100 shown in Figure 1, the network device 120 may be an access network device that communicates with the terminal device 110. The access network device may provide communication coverage for a specific geographical area and may communicate with the terminal device 110 (eg, UE) located within the coverage area.

[0047] The network device 120 may be an evolved Node B (eNB or eNodeB) in a Long Term Evolution (LTE) system, or a Next Generation Radio Access Network (NG RAN) device, or a base station (gNB) in an NR system, or a wireless controller in a Cloud Radio Access Network (CRAN), or the network device 120 may be a relay station, an access point, an in-vehicle device, a wearable device, a hub, a switch, a bridge, a router, or a network device in a future evolved Public Land Mobile Network (PLMN), etc.

[0048] The terminal device 110 may be any terminal device, including but not limited to a terminal device connected to the network device 120 or other terminal devices by wire or wireless connection.

[0049] For example, the terminal device 110 may refer to an access terminal, user equipment (UE), a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user apparatus. An access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, an IoT device, a satellite handheld terminal, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolution network, etc.

[0050] The terminal device 110 can be used for device-to-device (D2D) communication.

[0051] The wireless communication system 100 may further include a core network device 130 for communicating with the base station. The core network device 130 may be a 5G core network (5G Core, 5GC) device, such as an Access and Mobility Management Function (AMF), an Authentication Server Function (AUSF), a User Plane Function (UPF), or a Session Management Function (SMF). Optionally, the core network device 130 may also be an Evolved Packet Core (EPC) device of an LTE network, such as a Session Management Function + Core Packet Gateway (SMF+PGW-C) device. It should be understood that SMF+PGW-C can simultaneously implement the functions that can be implemented by SMF and PGW-C. During the network evolution process, the above-mentioned core network device may also be called other names, or a new network entity may be formed by dividing the functions of the core network, which is not limited in the embodiments of the present application.

[0052] The functional units in the communication system 100 may also establish connections and implement communication via next generation (NG) network interfaces.

[0053] For example, the terminal device establishes an air interface connection with the access network device through the NR interface for transmitting user plane data and control plane signaling; the terminal device can establish a control plane signaling connection with the AMF through the NG interface 1 (referred to as N1); the access network device, such as the next generation wireless access base station (gNB), can establish a user plane data connection with the UPF through the NG interface 3 (referred to as N3); the access network device can establish a control plane signaling connection with the AMF through the NG interface 2 (referred to as N2); the UPF can establish a control plane signaling connection with the SMF through the NG interface 4 (referred to as N4); the UPF can exchange user plane data with the data network through the NG interface 6 (referred to as N6); the AMF can establish a control plane signaling connection with the SMF through the NG interface 11 (referred to as N11); the SMF can establish a control plane signaling connection with the PCF through the NG interface 7 (referred to as N7).

[0054] Figure 1 exemplarily shows a base station, a core network device and two terminal devices. Optionally, the wireless communication system 100 may include multiple base station devices and each base station may include other numbers of terminal devices within its coverage area, which is not limited in this embodiment of the present application.

[0055] It should be noted that Figure 1 is merely an example of a system applicable to this application. Of course, the methods described in the embodiments of this application can also be applied to other systems. Furthermore, the terms "system" and "network" are often used interchangeably herein. The term "and / or" herein simply describes an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " generally indicates that the associated objects are in an "or" relationship. It should also be understood that the "indication" mentioned in the embodiments of this application can be a direct indication, an indirect indication, or an indication of an association relationship. For example, "A indicates B" can mean that A directly indicates B, for example, B can obtain information through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can obtain information through C; or it can mean that A and B have an association relationship. It should also be understood that the "correspondence" mentioned in the embodiments of this application can mean that there is a direct or indirect correspondence between two objects, or that there is an association relationship between the two objects, or a relationship between an indicator and the indicated, a configuration and the configured, and so on. It should also be understood that the “predefined” or “predefined rules” mentioned in the embodiments of the present application can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in devices (for example, including terminal devices and network devices), and the present application does not limit its specific implementation method. For example, predefined can refer to what is defined in the protocol. It should also be understood that in the embodiments of the present application, the “protocol” may refer to a standard protocol in the field of communications, such as LTE protocols, NR protocols, and related protocols used in future communication systems, and the present application does not limit this.

[0056] To facilitate understanding of the technical solutions of the embodiments of the present application, the relevant technologies of the embodiments of the present application are described below. The following relevant technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional solutions, and they all fall within the protection scope of the embodiments of the present application.

[0057] Currently in the NR system, a terminal device can be configured with up to four timing advance groups (TAGs) in a cell group (CG).

[0058] In actual applications, a CG may include multiple service cells, and each service cell will be assigned a TAG identifier (ID). Each TAG will have a TA timer (TimeAlignmentTimer), and the network device and the terminal device jointly maintain the TA timer. When the TA timer has not timed out, the network device and the terminal device believe that the uplink between them is in a synchronized state; when the TA timer times out, the terminal device and the network device will believe that the uplink between them is in a desynchronized state. In addition, the TA timer will only be reset if the network device adjusts the TA value through the Media Access Control (MAC) control element (CE) or other signaling within the time when the TA timer is running. For example, if the value of the TA timer is configured to 500 milliseconds (ms), that is, the network device needs to update / adjust the TA value of the terminal device once within 500ms, otherwise, the terminal device may believe that it is out of sync with the uplink of the network device and initiate a random access process to the network device.

[0059] It should be understood that during the initial access (cell) of the terminal device, after the terminal device sends PRACH to the network device, the terminal device expects the network device to give the terminal device a TA indication through a MAC random access response (Random Access Response, RAR) within a certain time window.

[0060] Referring to a schematic diagram of a MAC RAR signaling structure shown in FIG2 , the MAC RAR may include a timing advance command (Timing Advance Command), an uplink grant (UL Grant), a temporary cell radio network identifier (C-RNTI), and reservation information R.

[0061] It should be understood that the terminal device can obtain the initial TA based on the received MAC RAR.

[0062] Referring to the frame structure relationship diagram shown in Figure 3, if the terminal device operates in the single transmission reception point (Single-TRP) mode, the reference point of the terminal device's timing advance is calculated from the reception time of the downlink data frame and is advanced forward (N TA +N TA,offset )*T C time to send the uplink channel or signal.

[0063] Among them, N TA,offset The timing advance offset (TA offset) configured for the current serving cell. It should be understood that in a CG, each serving cell can be pre-configured with a TA offset. C is the minimum time unit in the NR system, T C =1 / (4096*480kHz). In addition, the TA adjustment amount (N TA ) is performed based on the pre-configured TA offset.

[0064] In some embodiments, N TA The MAC CE sent by the network device can provide differential adjustment, that is, the current TA adjustment (new) is based on the previous TA (old), adjusted forward or backward in time, where the calculation formula is

[0065] In other embodiments, N TA It can be an absolute value adjustment, that is, there is no need to consider the previous TA value, and the MAC CE of the network device directly gives an absolute value N TA , the value range is 0 to 3846. Specifically, its adjustment range for TA is N TA =T A *16*64*2 μ .

[0066] To enhance uplink coverage and transmission reliability, the NR system currently supports repetition of the Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH) based on multiple TRPs. Specifically, the terminal device can send PUCCH / PUSCH carrying the same content to different TRPs.

[0067] For repeated transmission of PUSCH, the NR system currently supports multiple PUSCH repeated transmission based on single downlink control information (sDCI) and multiple PUSCH repeated transmission based on multiple DCI (mDCI).

[0068] In repeated PUSCH transmissions, the terminal device uses a timing advance (TA) to sequentially send PUSCH to different TRPs. Since multiple TRPs may not have an ideal backhaul link as a connection, multiple TRPs independently schedule the terminal device. This operation may cause the PUSCH / PUCCH of different TRPs to overlap in time, so different TA updates or instructions are required for different TRPs.

[0069] For example, refer to the application scenario diagram shown in Figure 4. In the scenario where multiple DCIs are used to schedule multiple TRPs (mDCI-mTRP) within a cell, TRP#1 and TRP#2 use the same PCI. Each TRP can schedule its PDSCH / PUSCH transmission through its own DCI. It is worth noting that in the mDCI-mTRP scenario, control resource sets (CORESETs) can be grouped to correspond to different TRPs. The network device can configure the grouping of CORESETs through the parameter CORESETPoolIndex in the Radio Resource Control (RRC) message. Among them, CORESETs with a CORESETPoolIndex of "0" are grouped into one group, corresponding to one TRP; CORESETs with a CORESETPoolIndex of "1" are grouped into another group, corresponding to another TRP. It should be noted that when the network device does not configure CORESETPoolIndex for a CORESET, its default value is "0".

[0070] In the inter-cell mDCI-mTRP scenario, TRP#1 can be the TRP that the terminal device initially accesses. The terminal device and TRP#1 are already synchronized uplink and downlink, and TRP#1 has a dedicated PCI#1. For other TRPs, since the network device can select one from up to seven TRPs to provide additional uplink transmission services for the terminal device, these TRPs have different PCIs than TRP#1 and often have not established uplink and downlink synchronization with the terminal device in advance.

[0071] The current TA indication technology can only adjust the timing advance with TAG as the granularity, where the smallest unit of TAG is a serving cell. In addition, the current NR system only supports random access of terminal devices to one TRP, and multiple TRPs in a TAG use the same TA to receive uplink data. Since the distance from the terminal device to different TRPs may be different, there may be large synchronization errors between different TRPs. However, there is currently no clear solution for how to perform uplink synchronization on different TRPs and obtain a TRP-specific TA.

[0072] Furthermore, 3GPP is currently discussing mechanisms for simultaneous PUCCH / PUSCH transmission to multiple TRPs using multiple antenna panels in a terminal device. Even with multiple uplink transmit antenna panels and multiple TRPs, a terminal device can only use one TA for early transmission within a serving cell. This limitation should clearly be overcome by supporting TRP-specific TA acquisition and indication.

[0073] Based on this, an embodiment of the present application provides a random access method, wherein a terminal device determines a random access parameter corresponding to at least one target TRP, wherein the target TRP is a TRP among multiple TRPs that is out of sync with the uplink of the terminal device; the terminal device sends a PRACH to the at least one target TRP based on the random access parameter corresponding to the at least one target TRP, and the PRACH is used to obtain the time advance TA information corresponding to the at least one target TRP. In other words, the terminal device can send a random access to the target TRP based on the random access parameter corresponding to the out-of-sync target TRP to obtain the TA information dedicated to the target TRP. In this way, the terminal device accesses the target TRP that is out of sync on the uplink to ensure the correct transmission of uplink data.

[0074] To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined arbitrarily with the technical solutions of the embodiments of the present application as optional solutions, and all of them fall within the scope of protection of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0075] FIG5 is a flowchart diagram 1 of a random access method provided in an embodiment of the present application. As shown in FIG5 , the method includes the following contents.

[0076] Step 510: The terminal device determines random access parameters corresponding to at least one target TRP, where the target TRP is a TRP among multiple TRPs that is out of synchronization with the uplink of the terminal device.

[0077] Step 520: The terminal device sends PRACH to at least one target TRP based on the random access parameters corresponding to at least one target TRP. The PRACH is used to obtain TA information corresponding to at least one target TRP.

[0078] It should be understood that the terminal device can communicate with multiple TRPs (2 or more TRPs) simultaneously on the same carrier. Multi-TRP transmission can include intra-cell multi-TRP transmission and inter-cell multi-TRP transmission. Among them, in the intra-cell multi-TRP transmission scenario, multiple TRPs belong to the same cell, and multiple TRPs have the same physical cell identifier (Physical Cell ID, PCI). In the inter-cell multi-TRP transmission scenario, up to 7 TRPs with different PCIs communicate with the terminal device.

[0079] In an embodiment of the present application, after determining that the uplink is out of sync with at least one target TRP, the terminal device can send PRACH to the corresponding target TRP according to the random access parameters corresponding to each target TRP in the at least one target TRP, in the hope of obtaining exclusive TA information for each target TRP.

[0080] Optionally, the terminal device may determine the at least one target TRP based on a synchronization timer (TimeAlignmentTimer), or the terminal device may determine the at least one target TRP based on an instruction from a network device, and this embodiment of the present application does not impose any restrictions on this. In other words, the random access process for at least one target TRP may be triggered by a synchronization timer or by an indication from a network device.

[0081] In some embodiments, the terminal device may set one or more synchronization timers (TimeAlignmentTimer). Each synchronization timer may be associated with at least one TRP among the above-mentioned multiple TRPs. If one of the synchronization timers times out, the terminal device may determine that the uplinks between all TRPs associated with the timed-out synchronization timer are out of sync. In this way, the terminal device may determine the TRP with the out-of-sync uplink as the target TRP.

[0082] Exemplarily, the terminal device may set a synchronization timer, and the multiple TRPs may be associated with the synchronization timer. If the synchronization timer times out, the terminal device may determine that the uplinks of the terminal device and all TRPs are out of sync. In addition, the terminal device may set a synchronization timer for each TRP. When any synchronization timer times out, the terminal device may determine that the uplinks of the terminal device and the TRPs associated with the synchronization timer are out of sync.

[0083] In some other embodiments, the terminal device may receive second indication information sent by the network device, where the second indication information may indicate a target TRP with which the uplink of the terminal device is out of synchronization. Exemplarily, the network device may indicate at least one target TRP with which the uplink is out of synchronization to the terminal device via a Physical Downlink Control Channel (PDCCH) order.

[0084] Optionally, the random access parameter includes at least one of the following:

[0085] Preamble sequence, transmit beam, random access opportunity.

[0086] It should be understood that the terminal device can send a preamble sequence to the TRP via PRACH to obtain uplink synchronization. In addition, the transmit beam refers to the beam through which the terminal device sends the PRACH. The transmit beam can be determined based on the SSB corresponding to the TRP received by the terminal device. Normally, the terminal device can select a suitable SSB and use the beam that receives the SSB to send the PRACH. The random access opportunity (RACH Occasion, RO) refers to the time-frequency resources used by the terminal device to send the corresponding PRACH after selecting the SSB.

[0087] Among them, at least some parameters of the random access parameters corresponding to different TRPs are different. For example, for different TRPs, the terminal device can send the same preamble sequence of PRACH to different TRPs, the random access timing can be the same, and the transmission beam can be different.

[0088] Correspondingly, the network device receives the PRACH sent by the terminal device for each target TRP through each target TRP in at least one target TRP.

[0089] It should be understood that the network device can measure the uplink delay of the terminal device through the PRACH sent by the terminal device. In an embodiment of the present application, the network device can receive the PRACH sent by the terminal device through each target TRP in at least one target TRP, and each target TRP can measure the uplink delay information of the terminal device based on the received PRACH to obtain TA information exclusive to each target TRP. The network device can send the TA information corresponding to each target TRP to the terminal device through each target TRP.

[0090] In summary, the terminal device can send random access to the target TRP based on the random access parameters corresponding to the out-of-sync target TRP to obtain the TA information dedicated to the target TRP. In this way, the terminal device can access the target TRP with uplink out-of-sync and ensure the correct transmission of uplink data with the target TRP.

[0091] In the embodiment of the present application, the terminal device may determine at least one target TRP in a variety of ways, two of which are described below.

[0092] Method 1, as shown in FIG6 , in step 510, the terminal device determines the random access parameters corresponding to at least one target TRP, which can be implemented by the following steps:

[0093] Step 5101: The terminal device determines a target group associated with each target TRP in at least one target TRP from multiple groups.

[0094] Step 5102: The terminal device selects target parameters from the target group associated with each target TRP to obtain target parameters corresponding to each target TRP;

[0095] Step 5103: The terminal device determines the random access parameters corresponding to each target TRP based on the target parameters corresponding to each target TRP.

[0096] The multiple groups include multiple signal groups and / or multiple resource groups. The multiple signal groups include signals for downlink synchronization, and the resource groups include resources for random access.

[0097] It should be understood that in the scenario of multiple TRP transmission, the network device will configure a certain number of signals for each TRP to facilitate downlink synchronization or downlink data transmission of the terminal device. In the embodiment of the present application, the signal can be an SSB, a tracking reference signal (TRS), a channel state information reference signal (CSI-RS), etc., and the embodiment of the present application does not limit this.

[0098] For example, in the FR2 frequency band, the network device can configure up to 64 SSBs, and each SSB is set with an index value. After the terminal device measures and selects a suitable SSB, it will send PRACH for the SSB, so that the network device can measure the TA value of the terminal device under the selected SSB. It should be noted that a suitable SSB means that the received power (Reference Signal Receive Power, RSRP) of the SSB is greater than or equal to the specified threshold value.

[0099] In the current multi-TRP transmission scenario, multiple TRPs share the above 64 SSBs. The terminal device cannot determine which SSBs correspond to the TRP in the uplink synchronization state and which SSBs correspond to the TRP in the uplink desynchronization state. Based on this, when the terminal device initiates random access for the TRP with uplink desynchronization, it is possible that the selected SSB is from the SSB corresponding to the TRP in the uplink synchronization state. If the terminal device continues to send PRACH to the SSB, it will not be able to achieve the purpose of uplink synchronization with another TRP.

[0100] In addition, in the case of multiple TRP transmissions, the network device will also configure a certain amount of resources for random access for each TRP so that the terminal device can use the resources to send PRACH. Among them, the resources mentioned in the embodiment of the present application can be RO resources.

[0101] Similarly, in a multi-TRP transmission scenario, when a terminal device initiates random access to a TRP that is out of uplink synchronization, it may use RO resources corresponding to a TRP that is in uplink synchronization. If the terminal device continues to use this RO resource to send PRACH to the TRP, it will not be able to achieve uplink synchronization with another TRP.

[0102] Based on this, in an embodiment of the present application, multiple signals for downlink synchronization and / or resources for random access can be grouped to facilitate distinguishing different TRPs.

[0103] Optionally, the above-mentioned signal grouping may include SSB grouping and / or TRS grouping; wherein, different SSB groups include SSBs with different index values, and different TRS groups include TRSs with different index values; resource grouping includes RO grouping; different RO groups include ROs with different index values.

[0104] Optionally, the signals / resources (which can be any one of SSB, TRS, or RO resources) can be grouped according to their index values. For example, all signals / resources (which can be any one of SSB, TRS, or RO resources) can be divided into two groups according to whether the index value is an odd number or an even number. Taking the signal as SSB as an example, the 64 SSBs configured in the NR system can be divided into two SSB groups. Among them, the first SSB group SSB Group#0 = {SSB#0, SSB#2,…, SSB#62}; the second SSB group SSB Group#1 = {SSB#1, SSB#3,…, SSB#63}. In addition, the signal / resource can also be divided equally according to the index value. Still taking the example of dividing the SSB into two SSB groups, the first SSB group SSB Group#0 = {SSB#0, SSB#1, ..., SSB#31}; the second SSB group SSB Group#1 = {SSB#32, SSB#33, ..., SSB#63}.

[0105] Taking the signal / resource as an example, as shown in Figure 7A, the RO resources can be divided into two groups according to whether the index value of the RO resource is odd or even. The first RO resource group RO Group #0 = {RO #0, RO #2, ..., RO #6}, and the second RO resource group RO Group #1 = {RO #1, RO #3, ..., RO #7}. Referring to Figure 7B, the RO resources can be divided into two groups according to the order of the RO resource index values. The first RO resource group RO Group #0 = {RO #0, RO #1, RO #4, RO #5, ..., RO #124, RO #125}, and the second RO resource group RO Group #1 = {RO #2, RO #3, RO #6, RO #7, ..., RO #126, RO #127}.

[0106] Optionally, the above-mentioned multiple groups can be determined according to protocol pre-definition, pre-configuration information or network configuration information, and the embodiments of the present application do not limit this. For example, the network device can configure multiple groups for the terminal device through RRC signaling, and the terminal device can also divide multiple signals / resources into multiple groups according to predefined rules (such as according to the odd or odd index value).

[0107] It should be noted that multiple groups can be associated / bound with multiple TRPs to establish a corresponding relationship between multiple groups and multiple TRPs. Multiple groups can also not be bound with multiple TRPs. The embodiments of the present application do not impose any restrictions on this.

[0108] In one example, for the mDCI-mTRP scenario, the network device groups CORESETs through the parameter CORESETPoolIndex in the RRC message, and different CORESETs groups correspond to different TRPs. That is, CORESETPoolIndex can implicitly indicate the "TRP ID". Based on this, in order to achieve the purpose of distinguishing different TRPs, the network device can configure SSB grouping through RRC messages, for example, configuring the first SSB group SSB Group#0 = {SSB Index#A, SSB Index#B,…, SSB Index#C} and the second SSB group SSB Group#1 = {SSB Index#X, SSB Index#Y,…, SSB Index#Z} through RRC messages. In addition, the network device can configure SSB Group#0 to be bound to CORESETPoolIndex#0, and SSB Group#1 to be bound / associated with CORESETPoolIndex#1. In this way, a TRP can be bound / associated with an SSB group from the protocol level.

[0109] Similarly, the network device can also configure the TRS group / RO resource group through the RRC message, and bind / associate different TRS groups / RO resource groups with CORESETPoolIndex to bind / associate one TRP with one TRS group / RO resource group.

[0110] In some embodiments, for the sDCI-mTRP scenario, the network device may not configure the parameter CORESETPoolIndex in the RRC message to implicitly inform the TRP corresponding to each SSB group. The network device can divide all SSBs into multiple SSB groups according to predefined rules and indicate multiple SSB groups to the terminal device. In this way, when the terminal device selects an SSB, it can select from other SSB groups other than the group to which the SSB corresponding to the uplink synchronized TRP belongs. In this way, even if the correspondence between the SSB group and the TRP is not established, the purpose of distinguishing SSB groups of different TRPs can still be achieved.

[0111] Similarly, the network device can divide all TRSs into multiple TRS groups according to predefined rules and indicate multiple TRS groups to the terminal device. The network device can divide all RO resources into multiple RO resource groups according to predefined rules and indicate multiple RO resource groups to the terminal device.

[0112] In some embodiments, in addition to the RRC message configuration method in the above example, the terminal device and the network device can also be grouped according to predefined rules. Furthermore, the terminal device and the network device can bind multiple groups grouped according to the preset rules to multiple TRPs respectively to establish a corresponding relationship. Alternatively, the terminal device and the network device can bind multiple groups grouped according to the preset rules to multiple TRPs.

[0113] In one embodiment of the present application, multiple groups correspond to multiple TRPs one-to-one. Accordingly, in step 5101, the terminal device determines the target group associated with each target TRP in at least one target TRP from the multiple groups, which can be achieved by:

[0114] The terminal device selects a group associated with each target TRP from the multiple groups based on the first corresponding relationship to obtain a target group associated with each target TRP;

[0115] Among them, the first corresponding relationship is used to indicate the corresponding relationship between multiple groups and multiple TRPs.

[0116] Optionally, the first correspondence between multiple groups and multiple TRPs can be determined based on protocol pre-definition, pre-configuration information or network configuration information, and the embodiments of the present application do not limit this.

[0117] It should be understood that the correspondence between multiple groups and multiple TRPs can be configured by the network device through RRC signaling, or determined by the network device and the terminal device according to predefined rules. For specific configuration and determination methods, please refer to the description in the above embodiments. For the sake of brevity, they will not be repeated here.

[0118] It should be noted that the first correspondence between multiple groups and multiple TRPs can be determined by the binding relationship between multiple groups and multiple CORESETPoolIndex.

[0119] In an embodiment of the present application, when a terminal device needs to perform uplink synchronization with a target TRP, that is, when sending a PRACH to the target TRP, the terminal device can determine the target group corresponding to the target TRP based on the first corresponding relationship. Then, the terminal device determines the random access parameters exclusive to the target TRP by selecting an appropriate parameter from the target group.

[0120] Taking the SSB group as an example, when the terminal device needs to synchronize uplink with the target TRP, the terminal device can determine the SSB group corresponding to the target TRP based on the first correspondence, and select a suitable SSB from the SSB group as the downlink time reference for sending PRACH. Furthermore, the terminal device can also determine the RO resource associated with the SSB and an associated preamble sequence. In this way, the terminal device can send PRACH to the target TRP based on the RO resource and preamble sequence determined by the SSB.

[0121] Taking the RO resource grouping as an example, when the terminal device needs to synchronize uplink with the target TRP, the terminal device can select an RO resource from the RO resources associated with the target TRP and use the SSB corresponding to the RO resource as the downlink time reference for sending PRACH. Furthermore, the terminal device sends PRACH to the target TRP based on the RO resource, the SSB corresponding to the RO resource, and the preamble sequence associated with the SSB.

[0122] It should be noted that RO resources can correspond to SSBs. When a terminal device selects an SSB, it naturally selects the corresponding RO. It should be understood that after selecting the appropriate SSB, the terminal device can use the RO resources associated with the SSB to send PRACH. Based on this, when deploying SSBs and TRPs for RO resources, network devices can also deploy corresponding RO resources for each SSB.

[0123] Optionally, there are two correspondence modes between SSB and RO: one is that multiple SSBs correspond to one RO resource, and the other is that one SSB corresponds to multiple RO resources.

[0124] For example, with respect to multiple SSBs corresponding to one RO resource, as shown in FIG7A , in the first RO resource group RO Group #0 = {RO #0, RO #2, ..., RO #6}, RO #0 can correspond to SSBs #0 to #7, RO #2 can correspond to SSBs #16 to #23, RO #4 can correspond to SSBs #32 to #39, and RO #6 can correspond to SSBs #48 to #55. Furthermore, in the second RO resource group RO Group #1 = {RO #1, RO #3, ..., RO #7}, RO #1 can correspond to SSBs #8 to #15, RO #3 can correspond to SSBs #24 to #31, RO #5 can correspond to SSBs #40 to #47, and RO #7 can correspond to SSBs #56 to #63.

[0125] For one SSB corresponding to multiple RO resources, as shown in Figure 7B, in the first RO resource group RO Group#0 = {RO#0, RO#1, RO#4, RO#5,…, RO#124, RO#125}, RO#0 and RO#1 can correspond to SSB#0, RO#2 and RO#3 can correspond to SSB#1, and so on. RO#126 and RO#127 can correspond to SSB#63.

[0126] For example, in the scenario shown in FIG7A , when the terminal device needs to perform uplink synchronization with TRP#0, the terminal device can select RO#7 from RO Group#0 (RO Group#0 = {RO#0, RO#2, …, RO#6}) associated with TRP#0, and select SSB#63 from the SSB corresponding to RO#0 as the downlink time reference for sending PRACH. And send PRACH to TRP#0 based on SSB#63, RO#0, and the preamble sequence corresponding to SSB#63. In the scenario shown in FIG7B , when the terminal device needs to perform uplink synchronization with TRP#0, the terminal device can select RO#125 from RO Group#0 (RO Group#0 = {RO#0, RO#1, RO#4, RO#5, …, RO#124, RO#125}) associated with TRP#0, and use SSB#62 corresponding to RO#125 as the downlink time reference for sending PRACH.

[0127] It should be noted that if multiple ROs are associated with one SSB, as shown in FIG7B , the terminal device can select an RO by itself or randomly select an RO for transmission.

[0128] It can be seen that the embodiment of the present application groups the signals used for downlink synchronization and / or the resources used for random access, and associates different groups with different TRPs. In this way, the terminal device can distinguish different TRPs by looking for the target group associated with the target TRP that is out of sync uplink. Furthermore, by determining the random access parameters through the parameters in the target group, the terminal device can determine the exclusive random access parameters of the target TRP. In this way, the terminal device can avoid sending PRACH again to the synchronized TRP.

[0129] In another embodiment of the present application, no corresponding relationship is established between the multiple groups and the multiple TRPs. Based on this, in step 5101, the terminal device determines the target group associated with each target TRP in the at least one target TRP from the multiple groups, which can be achieved by:

[0130] The terminal device determines the group to which the parameters associated with the first TRP belong, and obtains a reference group; the first TRP is a TRP in a synchronized state with an uplink of the terminal device among the multiple TRPs;

[0131] The terminal device uses other groups except the reference group as target groups associated with at least one target TRP, wherein each target TRP in the at least one target TRP corresponds to a group in the other groups.

[0132] In an embodiment of the present application, when multiple groups are not bound / associated with multiple TRPs, the terminal device can remove the groups associated with the uplink synchronized TRP from the multiple groups, and use the remaining other groups as target groups associated with at least one target TRP. It should be understood that the uplink of the terminal device and the first TRP are in a synchronized state, so the terminal device can easily know to which group the parameters used when accessing the first TRP (such as any one of SSB, TRS, and RO resources) belong.

[0133] Exemplarily, referring to FIG7A , assuming that the index value of the RO resource used by the terminal device to access the first TRP is RO#0, and RO#0 belongs to the first RO resource group, the terminal device can use the second RO resource group as the target group associated with the target TRP.

[0134] Optionally, the number of the first TRP may include one or more, which is not limited in the embodiment of the present application.

[0135] Optionally, when the number of other groups remaining after removing the group associated with the first TRP parameter is greater than the number of at least one target TRP, the terminal device can randomly select the same number of groups as at least one target TRP from the other groups as the target groups associated with each target TRP.

[0136] Optionally, the number of multiple TRPs may be the same as the number of multiple groups. The number of other groups remaining after removing the group associated with the first TRP parameter may be the same as the number of at least one target TRP. The terminal device may use the multiple groups included in the other groups as target groups associated with each target TRP. The terminal device may use the multiple groups in the other groups as target groups associated with at least one target TRP in the order of the index values ​​of the groups. For example, the group with the lowest index value in the other groups may be used as the target group associated with the target TRP with the lowest index value, the group with the second lowest index value in the other groups may be used as the target group associated with the target TRP with the second lowest index value, and so on; or, the group with the lowest index value in the other groups may be used as the target group associated with the target TRP with the highest index value, the group with the second lowest index value in the other groups may be used as the target group associated with the target TRP with the second highest index value, and so on.

[0137] In summary, even if multiple groups are not associated with TRPs, the terminal device can still select exclusive random access parameters for different target TRPs based on different groups to achieve the purpose of distinguishing different TRPs. In this way, the terminal device can access the target TRP with uplink synchronization loss and ensure the correct transmission of uplink data with the target TRP.

[0138] It should be noted that, for the random access process of the target TRP triggered by the synchronization timer, the above-mentioned method 1 can be used to determine the random access parameters corresponding to the target TRP. In addition, for the random access process of the target TRP triggered by the network device through an indication (such as PDCCH Order), the above-mentioned method 1 can also be used to determine the random access parameters corresponding to the target TRP. The embodiment of the present application does not limit the usage scenario of method 1.

[0139] In the second method, as shown in FIG8 , the terminal device determines the random access parameters corresponding to at least one target TRP in step 510, which can be implemented by the following steps:

[0140] Step 5104: The terminal device receives first indication information, where the first indication information is used to indicate the random access parameters corresponding to each target TRP in at least one target TRP.

[0141] In an embodiment of the present application, the network device may send a first indication message to the terminal device, and indicate the random access parameters exclusive to each target TRP in at least one target TRP through the first indication message.

[0142] Optionally, the first indication information may include at least one of the following:

[0143] The leading sequence index value corresponding to each target TRP;

[0144] RO resource index value corresponding to each target TRP;

[0145] The SSB index value corresponding to each target TRP; The SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0146] Physical cell identification information associated with each target TRP.

[0147] It should be understood that the transmit beam used by the terminal device to send PRACH can have the same beam parameters as the received SSB. Therefore, the network device can indicate the index value of the SSB corresponding to each target TRP to facilitate the terminal device to determine the transmit beam used to send PRACH.

[0148] Optionally, after the synchronization timer expires, the terminal device can send parameter configuration information to the TRP that is still in the uplink synchronization state with the terminal device, so that the network device can indicate the dedicated random access parameters of the target TRP with uplink out-of-sync to the terminal device through the first indication information based on the parameter configuration information.

[0149] Optionally, the network device may trigger a random access process of the terminal device for at least one target TRP through the second indication information. In addition, the network device may indicate a random access parameter dedicated to each TRP in at least one target TRP through the first indication information.

[0150] It should be noted that the second indication information and the first indication information may be the same information or different information, which is not limited in this embodiment of the present application.

[0151] Optionally, the first indication information may be carried by a first DCI, which is used to trigger a random access process of the terminal device.

[0152] It should be understood that the network device can trigger the random access process of the terminal device through specified downlink control information, namely the first DCI. Optionally, the first DCI can be a PDCCH Order. The PDCCH Order in the protocol is implemented through a specified DCI format, such as DCI format 1_0, or other evolved formats, and this embodiment of the present application does not limit this.

[0153] Optionally, when DCI format 1_0 is scrambled by C-RNTI and the FDRA field is all 1, the terminal device should understand this DCI as a PDCCH Order. The PDCCH Order may include a random access preamble sequence index value (Random Access Preamble index), an uplink / supplementary uplink indicator (UL / SUL indicator), a synchronization signal block index value (SS / PBCH index), a random access timing index value (PRACH Mask index), etc. Among them, the Random Access Preamble index is used to indicate the preamble sequence of the PRACH, the SS / PBCH index is used to indicate the SSB, and the PRACH Mask index is used to indicate the RO associated with the SSB.

[0154] It should be noted that the parameters carried in the current PDCCH Order can only correspond to one TRP, that is, the current PDCCH Order can only trigger random access of a single TRP. The embodiment of the present application can expand the PDCCH Order to carry random access parameters corresponding to multiple TRPs, so as to trigger random access of multiple TRPs.

[0155] In some embodiments, when the first indication information is PDCCH Order, the PDCCH Order may include the following information: Random Access Preamble index, Random Access Preamble index 2, SS / PBCH index, SS / PBCH index 2, PCI, PRACH Mask index, PRACH Mask index 2.

[0156] It can be understood that, in addition to the original content, the PDCCH Order may also include a second random access preamble sequence index value (Random Access Preamble index 2), which is used to indicate another preamble sequence, a second synchronization signal block index value (SS / PBCH index2), a second random access timing index value (PRACH Mask index 2), and physical cell identification information, which is used to indicate the TRP associated with another SSB.

[0157] In some embodiments, when the number of at least one target TRP includes multiple, the first DCI includes a unified transmission configuration indicator (TCI) field, and the unified TCI field can be used to indicate the SSB index value corresponding to any target TRP among the multiple target TRPs.

[0158] In practical applications, network equipment can indicate the beam direction of the terminal device's uplink transmission through the unified TCI field in the PDCCH Order. Because it is for uplink transmission, the unified TCI type is UL TCI state or Joint TCI state. It should be noted that the reference signal contained in the unified TCI state can be from within the cell or from between cells. Therefore, the PRACH transmission triggered by the PDCCH order can be directed to the TRP within the cell or to the TRP between cells.

[0159] It should be understood that the role of the UL / joint TCI state is to include an SSB index or CSI-RS resource index. Based on this, the embodiment of the present application can reuse the unified TCI field to indicate the SSB index value corresponding to any target TRP in multiple target TRPs through the unified TCI field.

[0160] It should be noted that the SS / PBCH index 2 and the unified TCI field are in an "or" relationship, and only one of them exists in the PDCCH order.

[0161] Optionally, when the terminal device adopts PRACH repeated transmission, if the PRACH repeated transmission is based on time division multiplexing (TDM) or frequency division multiplexing (FDM), the network device can set the PRACH Mask index and PRACH Mask index 2 in the first indication information to indicate whether the RO resource is TDM or FDM.

[0162] Optionally, when the terminal device adopts a single frequency network (SFN) to transmit the PRACH, the first indication information may include at least one of the following:

[0163] A first preamble sequence index value, where the first preamble sequence index value is used to indicate the preamble sequence corresponding to each target TRP;

[0164] A first RO resource index value, where the first RO resource index value is used to indicate a leading sequence corresponding to each target TRP;

[0165] The SSB index value corresponding to each target TRP; The SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0166] Physical cell identification information associated with each target TRP.

[0167] It should be understood that SFN transmission is that the terminal device uses the same time-frequency resources to send the same channel, but uses different beams to transmit toward multiple TRPs. The advantage of this is that multiple TRPs can be merged for reception, increasing the reliability of uplink transmission.

[0168] That is to say, when the terminal device adopts SFN to transmit PRACH, the terminal device only needs to include an additional SSB index value, namely SS / PBCH index 2, and the PCI of the target TRP in the current PDCCH Order.

[0169] Optionally, when the terminal device adopts SFN to transmit PRACH, the first indication information may include at least one of the following:

[0170] The leading sequence index value corresponding to each target TRP;

[0171] RO resource index value corresponding to each target TRP;

[0172] The SSB index value corresponding to each target TRP; The SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0173] Physical cell identification information associated with each target TRP.

[0174] Among them, the leading sequence index value corresponding to each target TRP is the same, and the RO resource index value corresponding to each target TRP is also the same.

[0175] It should be noted that, for the random access process of the target TRP triggered by the synchronization timer, if the uplink between at least one TRP among the multiple TRPs and the terminal device is in a synchronized state, then the terminal device can use the above-mentioned method 2 to determine the random access parameters corresponding to the target TRP (for example, the network device can send a first indication information to the terminal device through the TRP in the uplink synchronization state); if multiple TRPs are out of sync with the uplink of the terminal device, then the terminal device can determine the random access parameters corresponding to the target TRP through method 1. In addition, for the random access process of the target TRP triggered by the network device through an indication (for example, PDCCH Order), the above-mentioned method 2 can also be used to determine the random access parameters corresponding to the target TRP. The embodiment of the present application does not limit the usage scenario of method 1.

[0176] Optionally, in one embodiment of the present application, when it is determined that one or more synchronization timers in at least one synchronization timer have timed out, if the multiple TRPs include a first TRP, and the first TRP is a TRP that is in a synchronized state with the uplink of the terminal device, the terminal device determines to clean up / release the uplink resources associated with at least one target TRP; or, the terminal device determines to retain the uplink resources associated with the target TRP.

[0177] In some embodiments, multiple TRPs can be associated with a synchronization timer at the same time. When the synchronization timer times out, the terminal device can determine that all TRP uplinks are out of sync. When multiple TRPs are out of sync with the uplink of the terminal device, the MAC layer of the terminal device can perform the following related operations on the primary timing advance group (PTAG) or secondary timing advance group (STAG) associated with the synchronization timer.

[0178] If the synchronization timer (TimeAlignmentTimer) is associated with PTAG, the following operations are performed:

[0179] Refresh all Hybrid Automatic Repeat reQuest (HARQ) buffers of all serving cells;

[0180] Notify RRC to release PUCCH for all serving cells (if configured);

[0181] Notify RRC to release SRS for all serving cells (if configured);

[0182] Clears any configured downlink allocations and configured uplink grants;

[0183] Clear any PUSCH resources for semi-persistent CSI reporting;

[0184] Treat all running synchronization timers as expired;

[0185] Maintain N of all TAGs TA .

[0186] Otherwise, if the synchronization timer is associated with a STAG, then for all serving cells belonging to the TAG:

[0187] Flush all HARQ buffers;

[0188] Notify RRC to release PUCCH (if configured);

[0189] Notify RRC to release SRS (if configured);

[0190] Clears any configured downlink allocations and configured uplink grants;

[0191] Clear any PUSCH resources for semi-persistent CSI reporting;

[0192] Maintain the N of the TAGs TA .

[0193] In other embodiments, multiple TRPs may also be associated with different synchronization timers. If each TRP is associated with a TAG, when any synchronization timer times out, the terminal device may determine that the uplink between it and the TRP associated with the synchronization timer is out of sync. If some synchronization timers time out, and there are still synchronization timers that have not timed out (i.e., there are still TRPs that are synchronized with the uplink of the terminal device), the MAC layer of the terminal device may have two options. The first is to clean up / release the uplink resources associated with all target TRPs that are out of sync. The specific operations may include:

[0194] If the synchronization timer (TimeAlignmentTimer) is associated with PTAG, the following operations are performed:

[0195] Flush all HARQ buffers of all serving cells;

[0196] Notify RRC to release PUCCH for all serving cells (if configured);

[0197] Notify RRC to release SRS for all serving cells (if configured);

[0198] Clears any configured downlink allocations and configured uplink grants;

[0199] Clear any PUSCH resources for semi-persistent CSI reporting;

[0200] Treat all running synchronization timers as expired;

[0201] Maintain N of all TAGs TA .

[0202] Otherwise, if the synchronization timer is associated with a STAG, then for all serving cells belonging to the TAG:

[0203] Flush all HARQ buffers;

[0204] Notify RRC to release PUCCH (if configured);

[0205] Notify RRC to release SRS (if configured);

[0206] Clears any configured downlink allocations and configured uplink grants;

[0207] Clear any PUSCH resources for semi-persistent CSI reporting;

[0208] Maintain the N of the TAGs TA .

[0209] The other option is to retain all uplink resources associated with the target TRP. Because there is still a TRP in uplink synchronization at this time, the network device can send signaling through this TRP to enable the terminal device to re-establish uplink synchronization with the target TRP that has lost uplink synchronization, thereby avoiding the signaling overhead of reallocating uplink resources.

[0210] The following details the process of a terminal device sending PRACH to multiple TRPs.

[0211] In an embodiment of the present application, when the number of at least one target TRP is multiple, in step 520, the terminal device sends a PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, which can be implemented in any of the following ways:

[0212] The terminal device sends a PRACH corresponding to each target TRP to multiple target RTPs based on a first transmission mode; the first transmission mode indicates that the terminal device sends a PRACH corresponding to each target TRP to each target TRP based on a random access parameter corresponding to each TRP;

[0213] The terminal device repeatedly sends the PRACH corresponding to each target TRP to multiple target TRPs based on the second transmission mode, where the second transmission mode is the FDM transmission mode;

[0214] The terminal device repeatedly sends the PRACH corresponding to each target TRP to multiple target TRPs based on the third transmission mode, where the third transmission mode is a TDM transmission mode;

[0215] Based on the fourth transmission mode, the terminal device sends the PRACH corresponding to each target TRP to multiple target TRPs at the same time. The fourth transmission mode is the SFN transmission mode.

[0216] In some embodiments, the terminal device may obtain TA from multiple target TRPs by independently sending PRACH. In an embodiment of the present application, the first transmission mode is a mode in which the terminal device independently sends PRACH to each target TRP. It should be understood that the terminal device may use the random access parameters of each target TRP determined in step 510 to send PRACH to the corresponding target TRP. Among them, when PRACH is sent independently to each TRP, the transmit beam corresponding to the PRACH of each target TRP is different (facing different target TRPs), the RO resources may be different, and the preamble sequence may also be different.

[0217] Optionally, when each target TRP is associated with an independent synchronization timer, if multiple synchronization timers expire, the terminal device can independently send PRACH using the first transmission mode.

[0218] In addition, the terminal device may obtain TA from multiple target TRPs by repeated transmission of PRACH. The preamble sequence used for two or more repeated transmissions of PRACH may be the same, while the transmit beam and RO resources may be different.

[0219] Optionally, the multiplexing mode of the PRACH for two or more repeated transmissions may be the second transmission mode (ie, FDM) or the third transmission mode (ie, TDM).

[0220] Referring to Figure 9A, the second transmission mode can be that the terminal device uses different frequency domain resources to simultaneously send PRACH to multiple TRPs (only two TRPs are shown in Figure 9A) on the same time domain resources (such as time slots, sub-time slots, time domain symbols, etc.). The above-mentioned time domain resources and frequency domain resources are pre-configured by different RO resources, and the transmit beam of each target TRP can be used to receive the receive beam corresponding to the SSB selected by the TRP.

[0221] Referring to Figure 9B , a third transmission mode may be that the terminal device uses the same frequency domain resources to send PRACH to multiple TRPs (only two TRPs are shown in Figure 9B ) on different time domain resources. The above-mentioned time domain resources and frequency domain resources are pre-configured by different RO resources, and the transmit beam of each target TRP can be used to receive the receive beam corresponding to the SSB selected by the TRP.

[0222] In an embodiment of the present application, the terminal device may obtain TA from multiple target TRPs by SNF transmission of PRACH, which is the fourth transmission method mentioned above.

[0223] Referring to Figure 9C, in the fourth transmission mode, the terminal device can use the same time-frequency resources to send the same PRACH to multiple target TRPs at the same time, but use different transmission beams to transmit toward multiple TRPs. The advantage of this is that multiple target TRPs can be merged for reception, increasing the reliability of uplink transmission.

[0224] It should be noted that for the fourth transmission mode, the terminal device selects the corresponding SSB according to the target TRP for each uplink desynchronization. It should be noted here that the two selected SSBs correspond to one RO resource and use the same preamble sequence to generate PRACH, but use two different transmit beams (the RO resource is associated with two SSBs from different TRPs).

[0225] It should be noted that the above four transmission modes can be applicable to random access triggered by a synchronization timer, and can also be applicable to random access triggered by a network device through indication information, and the embodiments of the present application do not limit this.

[0226] It should be understood that which of the above four transmission modes the terminal device uses can be configured by the network device or selected by the terminal device based on its own capabilities. The embodiments of the present application do not impose any restrictions on this.

[0227] Optionally, in the random access method provided in the embodiment of the present application, the following contents may be further performed before step 520:

[0228] The terminal device receives third indication information, which is used to instruct the terminal device to transmit PRACH using a target transmission mode, where the target transmission mode is any one of the first transmission mode, the second transmission mode, the third transmission mode, and the fourth transmission mode.

[0229] That is to say, when the number of target TRPs includes multiple ones, the network device can configure a method for sending PRACH to multiple target TRPs for the terminal device.

[0230] It should be understood that the second, third, and fourth transmission modes require the terminal device to transmit PRACH using the same time domain resources and / or frequency domain resources, which places higher requirements on the terminal device's radio frequency implementation. Not all terminal devices may support the second through fourth transmission modes.

[0231] Based on this, the terminal device in the embodiment of the present application can report the capabilities of the terminal device before sending PRACH to multiple target TRPs, and inform the network device whether the terminal device indicates the above-mentioned transmission method.

[0232] Optionally, in the random access method provided in the embodiment of the present application, before the terminal device receives the third indication information, the following steps may be further performed:

[0233] The terminal device sends terminal capability information, where the terminal capability information is used to indicate at least one of the following:

[0234] The ability to transmit information through frequency division multiplexing, the ability to transmit information through time division multiplexing, and the ability to transmit information through single frequency network.

[0235] It should be understood that the network device configures the transmission mode supported by the terminal capability for the terminal device through the third indication information only when it determines that the terminal device supports the above capabilities.

[0236] It should be noted that, when the network device indicates the random access parameters corresponding to each target TRP through the first indication information, the third indication information can indicate which of the above transmission modes to use for the multiple target TRPs through the RO resource index values ​​used by the multiple target TRPs in the first indication information. It is understandable that, in this case, the third indication information can be carried by the first indication information.

[0237] Optionally, the third indication information may also be carried by the second indication information, and the third indication information may also be independent information, which is not limited in the embodiment of the present application.

[0238] It can be seen from this that the terminal device can use an appropriate transmission method to send PRACH to multiple target TRPs based on the configuration of the network device, thereby improving the flexibility of PRACH transmission.

[0239] In some embodiments, the terminal device can select an appropriate transmission method according to its own capabilities to send PRACH to multiple TRPs to obtain TA information of multiple TRPs, thereby improving the flexibility of PRACH transmission while avoiding the signaling overhead caused by configuring the transmission method through the third indication information through the network device.

[0240] In an embodiment of the present application, the random access method provided in the embodiment of the present application may further include the following steps:

[0241] The terminal device receives the fourth indication information sent by each target TRP in at least one target TRP, where the fourth indication information is used to indicate the TA information corresponding to each target TRP.

[0242] It should be understood that the network device can receive the PRACH sent for each target TRP through each target TRP in at least one target TRP, so that each target TRP can perform delay measurement based on the received PRACH to determine the TA information between each TRP and the uplink of the terminal device. Furthermore, each TRP of the network device can send its corresponding TA information to the terminal device through the fourth indication information.

[0243] Optionally, the fourth indication information may be carried by MAC RAR or MAC CE, which is not limited in this embodiment of the present application.

[0244] Optionally, as shown in reference to FIG10 , the terminal device may monitor the fourth indication information sent by each target TRP in the time window corresponding to each target TRP.

[0245] It should be noted that the time windows corresponding to each target TRP may be the same or different, and this embodiment of the present application does not impose any limitation on this.

[0246] In an embodiment of the present application, the time window corresponding to each target TRP can be predefined by a protocol, or can be determined by pre-configuration information or network configuration information, and the embodiment of the present application does not impose any restrictions on this.

[0247] Optionally, the network device can configure the time window corresponding to each target TRP through an RRC message, such as 10ms, 100ms, etc. Exemplarily, the network device can carry the time window information in the TimeWindowForTA field in the RRC message. The time window can be timed from the first symbol or time slot after the PRACH is sent.

[0248] Optionally, the random access method provided in the embodiment of the present application may further include the following contents:

[0249] If the terminal device does not receive the fourth indication information sent by the first target TRP in the time window corresponding to the first target TRP, the terminal device re-sends PRACH to the first target TRP based on the random access parameters corresponding to the first target TRP; the first target TRP is any one of the at least one target TRP.

[0250] That is, if the terminal device receives the fourth indication information sent by the corresponding TRP within the time window, the terminal device can be considered to have completed uplink synchronization with the TRP; otherwise, the terminal device retransmits the PRACH corresponding to the TRP after the end of the current time window. For PRACH retransmission, the terminal device can add 1 to the PRACH retransmission counter.

[0251] Optionally, the terminal device may also increase the transmit power of the PRACH, i.e., power ramping, such as increasing the transmit power of the PRACH by 3dB for each retransmission so that the TRP can receive the PRACH.

[0252] The current random access process can be a four-step random access process, including four random access message interactions: Msg.1 (PRACH), Msg.2 (RAR), Msg.3 (PUSCH) and Msg.4 (contention resolution); the current random access process can also be a two-step random access process, including two random access message interactions: Msg.A and Msg.B. In addition to using Msg.1 or Msg.A to complete uplink synchronization, the RACH process will also carry other information in the system (such as SIB1, etc.) for interaction. After the terminal device has completed the initial access of the first TRP (uplink synchronized TRP) among multiple TRPs, it only needs to perform uplink synchronization with the target TRP (uplink desynchronized TRP), so it can be considered to avoid repeated system information exchange during the random access process.

[0253] That is to say, when the terminal device sends PRACH for the purpose of obtaining TA information of a certain TRP, a simplified random access process can be used.

[0254] In an embodiment of the present application, before sending PRACH to the target TRP, the terminal device can inform the TRP in a specific manner whether the terminal device's sending of PRACH this time triggers a simplified random access process or a normal random access process.

[0255] In some embodiments, the terminal device may send fifth indication information to the first target TRP, instructing the terminal device to adopt a simplified random access process for the first target TRP through the fifth indication information.

[0256] It should be noted that the simplified random access process is used to characterize that the terminal device only obtains the TA information of the first target TRP.

[0257] It should be understood that if the terminal device only wants to obtain the dedicated TA information of the first target TRP, the terminal device can inform its intention through the fifth indication information when sending PRACH to the first target TRP.

[0258] Optionally, the fifth indication information can be carried in the PRACH. Exemplarily, when the fifth indication information is configured in the PRACH, it can indicate that the terminal device adopts a simplified random access process for the first target TRP; when the fifth indication information is not configured in the PRACH, it can indicate that the terminal device adopts a normal random access process for the first target TRP. Alternatively, when the codeword value of the field where the fifth indication information in the PRACH is located is a first value, it can indicate that the terminal device adopts a simplified random access process for the first target TRP; when the codeword value of the field where the fifth indication information is located is a second value, it can indicate that the terminal device adopts a normal random access process for the first target TRP. The embodiment of the present application does not limit the indication method of the fifth indication information.

[0259] In other embodiments, the terminal device may instruct the terminal device to adopt a simplified random access process for the first target TRP by setting the leading sequence corresponding to the first target TRP to a sequence in a preset leading sequence set, and / or the RO resource corresponding to the first target TRP to a resource in a preset resource set.

[0260] In some embodiments, the network may pre-divide a certain number of preamble sequences to form a preset preamble sequence set, and the preamble sequences in the preset preamble sequence set are dedicated to the simplified random access procedure. That is, when the terminal device uses the preamble sequence in the preset preamble sequence set to send a PRACH to the first target TRP, it can be considered that the terminal device expects a simplified random access procedure.

[0261] In some embodiments, the network device may also pre-divide a certain number of RO resources (which may be achieved through a PRACH mask index) to form a preset resource set, and the RO resources in the preset resource set may be dedicated to a simplified random access procedure. That is, when the terminal device uses the RO resources in the preset resource set to send a PRACH to the first target TRP, it can be considered that the terminal device expects a simplified random access procedure.

[0262] In some embodiments, the network device may also combine a preset preamble sequence set and a preset resource set. When the terminal device uses the preamble sequence in the preset preamble sequence set and the RO resource in the preset resource set to send PRACH to the first target TRP, it can be considered that the terminal device expects a simplified random access process.

[0263] It should be noted that the simplified random access process allows the terminal device and network equipment to avoid the repeated system information exchange required in the standard random access process, reducing signaling overhead and improving random access efficiency. In addition, for the four-step random access process, after transmitting the TA information via the MAC RAR message, the terminal device and network equipment can avoid the interaction of Msg.3 (PUSCH) and Msg.4 (contention resolution), further reducing signaling overhead.

[0264] It should be noted that the number of the above-mentioned first target TRPs may include one or more, that is, the terminal device can implement a simplified random access process for one or more target TRPs.

[0265] The preferred embodiments of the present application are described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, the technical solution of the present application can be subjected to a variety of simple modifications, and these simple modifications all fall within the scope of protection of the present application. For example, the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present application will no longer describe the various possible combinations separately. For another example, the various different embodiments of the present application can also be arbitrarily combined, as long as they do not violate the idea of ​​the present application, they should also be regarded as the contents disclosed in the present application. For another example, under the premise of no conflict, the various embodiments and / or the technical features in each embodiment described in the present application can be arbitrarily combined with the prior art, and the technical solution obtained after the combination should also fall within the scope of protection of the present application.

[0266] It should also be understood that in the various method embodiments of the present application, the sequence numbers of the above-mentioned processes do not imply a precedence in 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. In addition, in the embodiments of the present application, the terms "downlink," "uplink," and "sidelink" are used to indicate the transmission direction of signals or data, where "downlink" is used to indicate the first direction of transmission of signals or data from a site to a user equipment in a cell, "uplink" is used to indicate the second direction of transmission of signals or data from a user equipment in a cell to a site, and "sidelink" is used to indicate the third direction of transmission of signals or data from user equipment 1 to user equipment 2. For example, "downlink signal" indicates that the transmission direction of the signal is the first direction. In addition, in the embodiments of the present application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. Specifically, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0267] FIG11 is a schematic diagram of the structure of a random access device 1100 provided in an embodiment of the present application, which is applied to a terminal device. As shown in FIG11 , the random access device includes:

[0268] The determining unit 1101 is configured to determine random access parameters corresponding to at least one target TRP, where the target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device; wherein at least some of the random access parameters corresponding to different TRPs are different;

[0269] The first sending unit 1102 is configured to send a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to the at least one target TRP.

[0270] Optionally, the random access parameter includes at least one of the following:

[0271] Preamble sequence, transmit beam, random access opportunity.

[0272] Optionally, the determination unit 1101 is further configured to determine the target group associated with each target TRP in the at least one target TRP from multiple groups; the multiple groups include multiple signal groups and / or multiple resource groups, the multiple signal groups include signals for downlink synchronization, and the resource groups include resources for random access; select target parameters from the target groups associated with each target TRP to obtain the target parameters corresponding to each target TRP; and determine the random access parameters corresponding to each target TRP based on the target parameters corresponding to each target TRP.

[0273] Optionally, the signal group includes a synchronization signal block SSB group and / or a tracking reference signal TRS group; wherein different SSB groups include SSBs with different index values, and different TRS groups include TRSs with different index values;

[0274] The resource grouping includes random access opportunity RO groups; different RO groups include ROs with different index values.

[0275] Optionally, the plurality of groups correspond to the plurality of TRPs one-to-one; the determining unit 1101 is further configured to select, based on the first correspondence, a group associated with each target TRP from the plurality of groups to obtain a target group associated with each target TRP;

[0276] Among them, the first corresponding relationship is used to indicate the corresponding relationship between the multiple groups and the multiple TRPs.

[0277] Optionally, the first corresponding relationship is determined according to protocol pre-definition, pre-configuration information or network configuration information.

[0278] Optionally, no correspondence is established between the multiple groups and the multiple TRPs, and the determination unit 1101 is further configured to determine the group to which the parameters associated with the first TRP belong to obtain a reference group; the first TRP is the TRP among the multiple TRPs that is in a synchronized state with the uplink of the terminal device; and other groups except the reference group are used as target groups associated with the at least one target TRP, wherein each target TRP in the at least one target TRP corresponds to a group among the other groups.

[0279] Optionally, the multiple groups are determined according to protocol pre-definition, pre-configuration information or network configuration information.

[0280] Optionally, the determination unit 1101 is further configured to receive first indication information; the first indication information is used to indicate the random access parameters corresponding to each target TRP in the at least one target TRP.

[0281] Optionally, the first indication information includes at least one of the following:

[0282] The leading sequence index value corresponding to each target TRP;

[0283] The RO resource index value corresponding to each target TRP;

[0284] The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0285] The physical cell identification information associated with each target TRP.

[0286] Optionally, when the terminal device transmits the PRACH through a single frequency network, the first indication information includes at least one of the following:

[0287] A first preamble sequence index value, where the first preamble sequence index value is used to indicate the preamble sequence corresponding to each target TRP;

[0288] A first RO resource index value, where the first RO resource index value is used to indicate a preamble sequence corresponding to each target TRP;

[0289] The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0290] The physical cell identification information associated with each target TRP.

[0291] Optionally, the first indication information is carried by a first DCI, and the first DCI is used to trigger a random access process of the terminal device.

[0292] Optionally, the number of the at least one target TRP includes multiple, and the first DCI includes a unified transmission configuration indication field, and the unified transmission configuration indication field is used to indicate the SSB index value corresponding to any target TRP among the multiple target TRPs.

[0293] Optionally, the terminal device is provided with at least one synchronization timer, and each synchronization timer of the at least one synchronization timer is associated with at least one TRP of the multiple TRPs;

[0294] The at least one target TRP is a TRP associated with one or more synchronization timers that have timed out among the at least one synchronization timer;

[0295] or,

[0296] The at least one target TRP is indicated by the second indication information.

[0297] Optionally, the determining unit 1101 is further configured to, when it is determined that one or more synchronization timers in at least one synchronization timer have timed out, determine to clear / release the uplink resources associated with the at least one target TRP if the multiple TRPs include a first TRP, and the first TRP is a TRP in a synchronized state with the uplink of the terminal device; or, the terminal device determines to retain the uplink resources associated with the target TRP;

[0298] The at least one target TRP is a TRP associated with one or more expired synchronization timers among the at least one synchronization timer.

[0299] Optionally, the number of the at least one target TRP includes multiple ones, and the first sending unit 1102 is further configured to do any one of the following:

[0300] The terminal device sends the PRACH corresponding to each target TRP to the multiple target RTPs based on the first transmission mode; the first transmission mode indicates that the terminal device sends the PRACH corresponding to each target TRP to each target TRP based on the random access parameters corresponding to each TRP;

[0301] The terminal device repeatedly sends the PRACH corresponding to each target TRP to the multiple target TRPs based on a second transmission mode, where the second transmission mode is a frequency division multiplexing transmission mode;

[0302] The terminal device repeatedly sends the PRACH corresponding to each target TRP to the multiple target TRPs based on a third transmission mode, where the third transmission mode is a time division multiplexing transmission mode;

[0303] The terminal device simultaneously sends the PRACH corresponding to each target TRP to the multiple target TRPs based on the fourth transmission mode, and the fourth transmission mode is a single frequency network transmission mode.

[0304] Optionally, the random access device 1100 also includes a first receiving unit configured to receive third indication information, wherein the third indication information is used to instruct the terminal device to transmit PRACH using a target transmission mode, and the target transmission mode is any one of the first transmission mode, the second transmission mode, the third transmission mode, and the fourth transmission mode.

[0305] Optionally, the first sending unit 1102 is further configured to send terminal capability information, where the terminal capability information is used to indicate at least one of the following:

[0306] The ability to transmit information through frequency division multiplexing, the ability to transmit information through time division multiplexing, and the ability to transmit information through single frequency network.

[0307] Optionally, the first receiving unit is further configured to receive fourth indication information sent by each target TRP in the at least one target TRP, where the fourth indication information is used to indicate the timing advance TA information corresponding to each target TRP.

[0308] Optionally, the random access device 1100 further includes a monitoring unit configured to monitor the fourth indication information sent by each target TRP in the time window corresponding to each target TRP.

[0309] Optionally, the first sending unit 1102 is further configured to resend the PRACH to the first target TRP based on the random access parameters corresponding to the first target TRP if the fourth indication information sent by the first target TRP is not received in the time window corresponding to the first target TRP; the first target TRP is any one of the at least one target TRP.

[0310] Optionally, the first sending unit 1102 is further configured to send fifth indication information to the first target TRP by the terminal device, and the fifth indication information is used to instruct the terminal device to adopt a simplified random access process for the first target TRP, and the first target TRP is any one of the at least one target TRP.

[0311] Optionally, the terminal device instructs the terminal device to adopt a simplified random access process for the first target TRP by setting the leading sequence corresponding to the first target TRP to a sequence in a preset leading sequence set, and / or the random access timing corresponding to the first target TRP to a resource in a preset resource set.

[0312] Optionally, the simplified random access process is used to characterize that the terminal device only obtains the TA information of the first target TRP.

[0313] FIG12 is a schematic diagram of the structure of a random access device 1200 provided in an embodiment of the present application, which is applied to a network device. As shown in FIG12 , the random access device 1200 includes:

[0314] The second receiving unit 1201 is configured to receive a physical random access channel PRACH sent by the terminal device for each target TRP in at least one target TRP, wherein the PRACH is used to obtain timing advance TA information corresponding to each target TRP. The target TRP is a TRP in multiple TRPs that is in an out-of-sync state with the uplink of the terminal device.

[0315] Optionally, the random access parameter includes at least one of the following:

[0316] Preamble sequence, transmit beam, random access opportunity.

[0317] Optionally, the random access parameter corresponding to each target TRP is determined based on a target parameter in a target group associated with each target TRP; the target parameter is any one of multiple parameters in the target group;

[0318] The target group is any one of a plurality of groups; the plurality of groups include a plurality of signal groups and / or a plurality of resource groups, the plurality of signal groups include signals for downlink synchronization, and the resource groups include resources for random access.

[0319] Optionally, the signal grouping includes a synchronization signal block SSB grouping and / or a tracking reference signal TRS grouping; wherein different SSB groups include SSBs with different index values, and different TRS groups include TRSs with different index values;

[0320] The resource grouping includes random access opportunity RO groups; different RO groups include ROs with different index values.

[0321] Optionally, the multiple groups correspond one-to-one to the multiple TRPs;

[0322] The target group associated with each target TRP is determined based on a first correspondence relationship, and the first correspondence relationship is used to indicate the correspondence between the multiple groups and the multiple TRPs.

[0323] Optionally, the first corresponding relationship is determined according to protocol pre-definition, pre-configuration information or network configuration information.

[0324] Optionally, no correspondence is established between the multiple groups and the multiple TRPs, and the target group associated with each target TRP is determined based on other groups except the reference group, the reference group is the group to which the parameters associated with the first TRP belong, and the first TRP is the TRP among the multiple TRPs that is in a synchronized state with the uplink of the terminal device.

[0325] Optionally, the multiple groups are determined according to protocol pre-definition, pre-configuration information or network configuration information.

[0326] Optionally, the random access device 1200 also includes a second sending unit configured to send first indication information to the terminal device, where the first indication information is used to indicate the random access parameters corresponding to each target TRP in the at least one target TRP.

[0327] Optionally, the first indication information includes at least one of the following:

[0328] The leading sequence index value corresponding to each target TRP;

[0329] The RO resource index value corresponding to each target TRP;

[0330] The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0331] The physical cell identification information associated with each target TRP.

[0332] Optionally, when the terminal device transmits the PRACH through a single frequency network, the first indication information includes at least one of the following:

[0333] A first preamble sequence index value, where the first preamble sequence index value is used to indicate the preamble sequence corresponding to each target TRP;

[0334] A first RO resource index value, where the first RO resource index value is used to indicate a preamble sequence corresponding to each target TRP;

[0335] The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP;

[0336] The physical cell identification information associated with each target TRP.

[0337] Optionally, the first indication information is carried through a first DCI, and the first DCI is used to trigger a random access process of the terminal device.

[0338] Optionally, the number of the at least one target TRP includes multiple, and the first DCI includes a unified transmission configuration indication field, and the unified transmission configuration indication field is used to indicate the SSB index value corresponding to any target TRP among the multiple target TRPs.

[0339] Optionally, the second sending unit is further configured to send second indication information to the terminal device, where the second indication information is used to indicate the at least one target TRP.

[0340] Optionally, the second sending unit is further configured to send a third indication information to the terminal device, wherein the third indication information is used to instruct the terminal device to transmit PRACH using a target transmission mode, and the target transmission mode is any one of a first transmission mode, a second transmission mode, a third transmission mode, and a fourth transmission mode, wherein the first transmission mode characterizes that the terminal device sends the PRACH corresponding to each target TRP to each target TRP based on the random access parameters corresponding to each TRP, the second transmission mode is a frequency division multiplexing transmission mode, the third transmission mode is a time division multiplexing transmission mode, and the fourth transmission mode is a single frequency network transmission mode.

[0341] Optionally, the second receiving unit 1201 is further configured to receive terminal capability information sent by the terminal device, where the terminal capability information is used to indicate at least one of the following:

[0342] The ability to transmit information through frequency division multiplexing, the ability to transmit information through time division multiplexing, and the ability to transmit information through single frequency network.

[0343] Optionally, the second sending unit is further configured to send the fourth indication information corresponding to each TRP through each target TRP, where the fourth indication information is used to indicate the time advance TA information corresponding to the target TRP.

[0344] Optionally, the second receiving unit 1201 is further configured to receive, through the first target TRP, fifth indication information sent by the terminal device for the first target TRP, wherein the fifth indication information is used to instruct the terminal device to adopt a simplified random access process for the first target TRP.

[0345] Optionally, when the leading sequence in the PRACH corresponding to the first target TRP is a sequence in a preset leading sequence set, and / or the random access opportunity is a resource in a preset resource set, the network device determines that the terminal device adopts a simplified random access process for the first target TRP.

[0346] Optionally, the simplified random access process is used to characterize that the terminal device only obtains the TA information of the first target TRP.

[0347] Those skilled in the art should understand that the relevant description of the above-mentioned random access device in the embodiment of the present application can be understood with reference to the relevant description of the random access method in the embodiment of the present application.

[0348] Figure 13 is a schematic diagram of a communication device 1300 provided in an embodiment of the present application. The communication device can be a terminal device or a network device. The communication device 1300 shown in Figure 13 includes a processor 1310, which can call and execute a computer program from a memory to implement the method in the embodiment of the present application.

[0349] Optionally, as shown in FIG13 , the communication device 1300 may further include a memory 1320. The processor 1310 may call and execute a computer program from the memory 1320 to implement the method in the embodiment of the present application.

[0350] The memory 1320 may be a separate device independent of the processor 1310 , or may be integrated into the processor 1310 .

[0351] Optionally, as shown in FIG13 , the communication device 1300 may further include a transceiver 1330 , and the processor 1310 may control the transceiver 1330 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0352] The transceiver 1330 may include a transmitter and a receiver. The transceiver 1330 may further include an antenna, and the number of antennas may be one or more.

[0353] Optionally, the communication device 1300 may specifically be a network device in an embodiment of the present application, and the communication device 1300 may implement the corresponding processes implemented by the network device in each method in the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0354] Optionally, the communication device 1300 may specifically be a terminal device of an embodiment of the present application, and the communication device 1300 may implement the corresponding processes implemented by the terminal device in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0355] Figure 14 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 1400 shown in Figure 14 includes a processor 1410, which can call and run a computer program from a memory to implement the method according to the embodiment of the present application.

[0356] Optionally, as shown in FIG14 , the chip 1400 may further include a memory 1420 , wherein the processor 1910 may call and execute a computer program from the memory 1420 to implement the method in the embodiment of the present application.

[0357] The memory 1420 may be a separate device independent of the processor 1410 , or may be integrated into the processor 1410 .

[0358] Optionally, the chip 1400 may further include an input interface 1430. The processor 1410 may control the input interface 1430 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

[0359] Optionally, the chip 1400 may further include an output interface 1440. The processor 1410 may control the output interface 1440 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

[0360] Optionally, the chip can be applied to the network device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the network device in each method of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0361] Optionally, the chip can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0362] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0363] FIG15 is a schematic block diagram of a communication system 1500 provided in an embodiment of the present application. As shown in FIG15 , the communication system 1500 includes a terminal device 1510 and a network device 1520 .

[0364] Among them, the terminal device 1510 can be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 1520 can be used to implement the corresponding functions implemented by the network device in the above method. For the sake of brevity, they are not repeated here.

[0365] It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0366] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and 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 RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0367] It should be understood that the above-mentioned memories are exemplary but not restrictive. For example, the memories in the embodiments of the present application may also be 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 RAM RAM (DR RAM), etc. In other words, the memories in the embodiments of the present application are intended to include, but are not limited to, these and any other suitable types of memories.

[0368] An embodiment of the present application also provides a computer-readable storage medium for storing a computer program.

[0369] Optionally, the computer-readable storage medium can be applied to the network device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

[0370] Optionally, the computer-readable storage medium can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0371] An embodiment of the present application also provides a computer program product, including computer program instructions.

[0372] Optionally, the computer program product can be applied to the network device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, they are not repeated here.

[0373] Optionally, the computer program product can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0374] The embodiments of the present application also provide a computer program. Optionally, the computer program can be applied to the network device in the embodiments of the present application. When the computer program is run on a computer, the computer executes the corresponding processes implemented by the network device in the various methods of the embodiments of the present application. For the sake of brevity, this is not described in detail here. Optionally, the computer program can be applied to the mobile terminal / terminal device in the embodiments of the present application. When the computer program is run on a computer, the computer executes the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, this is not described in detail here.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] 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.

[0380] 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, a server, or a 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 read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0381] 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 the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A random access method, comprising: The terminal device determines random access parameters corresponding to at least one target TRP, where the target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device; wherein at least some of the random access parameters corresponding to different TRPs are different; The terminal device sends a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to the at least one target TRP.

2. The method according to claim 1, wherein The random access parameter includes at least one of the following: Preamble sequence, transmit beam, random access opportunity.

3. The method according to claim 1 or 2, wherein: The terminal device determines a random access parameter corresponding to at least one target TRP, including: The terminal device determines, from a plurality of groups, a target group associated with each target TRP in the at least one target TRP; the plurality of groups include a plurality of signal groups and / or a plurality of resource groups, the plurality of signal groups include signals for downlink synchronization, and the resource groups include resources for random access; The terminal device selects a target parameter from the target group associated with each target TRP to obtain the target parameter corresponding to each target TRP; The terminal device determines the random access parameters corresponding to each target TRP based on the target parameters corresponding to each target TRP.

4. The method according to claim 3, wherein: The signal grouping includes a synchronization signal block SSB grouping and / or a tracking reference signal TRS grouping; wherein different SSB groups include SSBs with different index values, and different TRS groups include TRSs with different index values; The resource grouping includes random access opportunity RO groups; different RO groups include ROs with different index values.

5. The method according to claim 3 or 4, wherein: The multiple groups correspond one-to-one to the multiple TRPs; The terminal device determines, from a plurality of groups, a target group associated with each target TRP in the at least one target TRP, including: The terminal device selects, based on the first correspondence, a group associated with each target TRP from the multiple groups to obtain a target group associated with each target TRP; Among them, the first corresponding relationship is used to indicate the corresponding relationship between the multiple groups and the multiple TRPs.

6. The method according to claim 5, wherein: The first corresponding relationship is determined according to protocol pre-definition, pre-configuration information or network configuration information.

7. The method according to claim 3 or 4, wherein: There is no corresponding relationship between the multiple groups and the multiple TRPs. The terminal device determines, from a plurality of groups, a target group associated with each target TRP in the at least one target TRP, including: The terminal device determines a group to which a parameter associated with a first TRP belongs, and obtains a reference group; the first TRP is a TRP in the plurality of TRPs that is in synchronization with an uplink of the terminal device; The terminal device uses other groups except the reference group as target groups associated with the at least one target TRP, wherein each target TRP in the at least one target TRP corresponds to a group in the other groups.

8. The method according to any one of claims 2 to 5, wherein: The multiple groups are determined according to protocol pre-definition, pre-configuration information or network configuration information.

9. The method according to claim 1 or 2, wherein: The terminal device determines a random access parameter corresponding to at least one target TRP among the multiple TRPs, including: The terminal device receives first indication information; the first indication information is used to indicate the random access parameters corresponding to each target TRP in the at least one target TRP.

10. The method according to claim 9, wherein: The first indication information includes at least one of the following: The leading sequence index value corresponding to each target TRP; The RO resource index value corresponding to each target TRP; The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP; The physical cell identification information associated with each target TRP.

11. The method according to claim 9, wherein: In a case where the terminal device transmits the PRACH through a single frequency network, the first indication information includes at least one of the following: A first preamble sequence index value, where the first preamble sequence index value is used to indicate the preamble sequence corresponding to each target TRP; A first RO resource index value, where the first RO resource index value is used to indicate a preamble sequence corresponding to each target TRP; The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP; The physical cell identification information associated with each target TRP.

12. The method according to any one of claims 9 to 11, wherein: The first indication information is carried by first downlink control information DCI, and the first DCI is used to trigger the random access process of the terminal device.

13. The method according to claim 12, wherein: The number of the at least one target TRP includes multiple ones, and the first DCI includes a unified transmission configuration indication field, and the unified transmission configuration indication field is used to indicate the SSB index value corresponding to any target TRP among the multiple target TRPs.

14. The method according to any one of claims 1 to 13, wherein: The terminal device is provided with at least one synchronization timer, each synchronization timer of the at least one synchronization timer is associated with at least one TRP of the plurality of TRPs; The at least one target TRP is a TRP associated with one or more synchronization timers that have timed out among the at least one synchronization timer; or, The at least one target TRP is indicated by the second indication information.

15. The method according to any one of claims 1 to 14, wherein: Also includes: In a case where it is determined that one or more synchronization timers of at least one synchronization timer have timed out, if the multiple TRPs include a first TRP, and the first TRP is a TRP that is in a synchronized state with the uplink of the terminal device, the terminal device determines to clear / release the uplink resources associated with the at least one target TRP; or, the terminal device determines to retain the uplink resources associated with the target TRP; The at least one target TRP is a TRP associated with one or more expired synchronization timers among the at least one synchronization timer.

16. The method according to any one of claims 1 to 15, wherein: The number of the at least one target TRP includes a plurality; The terminal device sends a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, including any one of the following: The terminal device sends the PRACH corresponding to each target TRP to the multiple target RTPs based on the first transmission mode; the first transmission mode indicates that the terminal device sends the PRACH corresponding to each target TRP to each target TRP based on the random access parameters corresponding to each TRP; The terminal device repeatedly sends the PRACH corresponding to each target TRP to the multiple target TRPs based on a second transmission mode, where the second transmission mode is a frequency division multiplexing transmission mode; The terminal device repeatedly sends the PRACH corresponding to each target TRP to the multiple target TRPs based on a third transmission mode, where the third transmission mode is a time division multiplexing transmission mode; The terminal device simultaneously sends the PRACH corresponding to each target TRP to the multiple target TRPs based on the fourth transmission mode, and the fourth transmission mode is a single frequency network transmission mode.

17. The method according to claim 16, wherein The method further comprises: The terminal device receives third indication information, where the third indication information is used to instruct the terminal device to transmit PRACH using a target transmission mode, where the target transmission mode is any one of the first transmission mode, the second transmission mode, the third transmission mode, and the fourth transmission mode.

18. The method according to claim 17, wherein Before the terminal device receives the third indication information, the method further includes: The terminal device sends terminal capability information, where the terminal capability information is used to indicate at least one of the following: The ability to transmit information through frequency division multiplexing, the ability to transmit information through time division multiplexing, and the ability to transmit information through single frequency network.

19. The method according to any one of claims 1 to 18, wherein: The method further comprises: The terminal device receives fourth indication information sent by each target TRP in the at least one target TRP, where the fourth indication information is used to indicate the timing advance TA information corresponding to each target TRP.

20. The method according to claim 19, wherein Also included: The terminal device listens to the fourth indication information sent by each target TRP in the time window corresponding to each target TRP.

21. The method according to claim 20, wherein Also includes: If the terminal device does not receive the fourth indication information sent by the first target TRP in the time window corresponding to the first target TRP, the terminal device resends the PRACH to the first target TRP based on the random access parameters corresponding to the first target TRP; the first target TRP is any one of the at least one target TRP.

22. The method according to any one of claims 1 to 21, wherein: Also includes: The terminal device sends fifth indication information to the first target TRP, where the fifth indication information is used to instruct the terminal device to adopt a simplified random access process for the first target TRP, where the first target TRP is any one of the at least one target TRP.

23. The method according to any one of claims 1 to 21, wherein: The terminal device instructs the terminal device to adopt a simplified random access process for the first target TRP by setting the leading sequence corresponding to the first target TRP to a sequence in a preset leading sequence set, and / or the random access timing corresponding to the first target TRP to a resource in a preset resource set.

24. The method according to claim 22 or 23, wherein The simplified random access process is used to characterize that the terminal device only obtains the TA information of the first target TRP.

25. A random access method, the method comprising: The network device receives the physical random access channel PRACH sent by the terminal device for each target TRP in at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to each target TRP. The target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device.

26. The method according to claim 25, wherein The random access parameter includes at least one of the following: Preamble sequence, transmit beam, random access opportunity.

27. The method according to claim 25 or 26, wherein The random access parameter corresponding to each target TRP is determined based on the target parameter in the target group associated with each target TRP; the target parameter is any one of multiple parameters in the target group; The target group is any one of a plurality of groups; the plurality of groups include a plurality of signal groups and / or a plurality of resource groups, the plurality of signal groups include signals for downlink synchronization, and the resource groups include resources for random access.

28. The method according to claim 27, wherein The signal grouping includes a synchronization signal block SSB grouping and / or a tracking reference signal TRS grouping; wherein different SSB groups include SSBs with different index values, and different TRS groups include TRSs with different index values; The resource grouping includes random access opportunity RO groups; different RO groups include ROs with different index values.

29. The method according to claim 27 or 28, wherein The multiple groups correspond one-to-one to the multiple TRPs; The target group associated with each target TRP is determined based on a first correspondence relationship, and the first correspondence relationship is used to indicate the correspondence between the multiple groups and the multiple TRPs.

30. The method according to claim 29, wherein The first corresponding relationship is determined according to protocol pre-definition, pre-configuration information or network configuration information.

31. The method according to claim 27 or 28, wherein There is no corresponding relationship between the multiple groups and the multiple TRPs. The target group associated with each target TRP is determined based on other groups except the reference group, and the reference group is the group to which the parameters associated with the first TRP belong, and the first TRP is the TRP among the multiple TRPs that is in synchronization with the uplink of the terminal device.

32. The method according to any one of claims 27 to 31, wherein: The multiple groups are determined according to protocol pre-definition, pre-configuration information or network configuration information.

33. The method according to claim 25 or 26, wherein The method further comprises: The network device sends first indication information to the terminal device, where the first indication information is used to indicate the random access parameters corresponding to each target TRP in the at least one target TRP.

34. The method according to claim 33, wherein The first indication information includes at least one of the following: The leading sequence index value corresponding to each target TRP; The RO resource index value corresponding to each target TRP; The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP; The physical cell identification information associated with each target TRP.

35. The method of claim 33, wherein: In a case where the terminal device transmits the PRACH through a single frequency network, the first indication information includes at least one of the following: A first preamble sequence index value, where the first preamble sequence index value is used to indicate the preamble sequence corresponding to each target TRP; A first RO resource index value, where the first RO resource index value is used to indicate a preamble sequence corresponding to each target TRP; The SSB index value corresponding to each target TRP; the SSB index value corresponding to each target TRP is used to determine the transmit beam corresponding to each target TRP; The physical cell identification information associated with each target TRP.

36. The method according to any one of claims 33 to 35, wherein: The first indication information is carried by first downlink control information DCI, and the first DCI is used to trigger the random access process of the terminal device.

37. The method according to claim 36, wherein The number of the at least one target TRP includes multiple ones, and the first DCI includes a unified transmission configuration indication field, and the unified transmission configuration indication field is used to indicate the SSB index value corresponding to any target TRP among the multiple target TRPs.

38. The method according to any one of claims 25 to 37, wherein: The method further comprises: The network device sends second indication information to the terminal device, where the second indication information is used to indicate the at least one target TRP.

39. The method according to any one of claims 25 to 38, wherein: The method further comprises: The network device sends a third indication message to the terminal device, and the third indication message is used to instruct the terminal device to transmit PRACH using a target transmission mode, where the target transmission mode is any one of a first transmission mode, a second transmission mode, a third transmission mode, and a fourth transmission mode, wherein the first transmission mode characterizes that the terminal device sends the PRACH corresponding to each target TRP to each target TRP based on the random access parameters corresponding to each TRP, the second transmission mode is a frequency division multiplexing transmission mode, the third transmission mode is a time division multiplexing transmission mode, and the fourth transmission mode is a single frequency network transmission mode.

40. The method of claim 39, wherein Before the network device sends the third indication information to the terminal device, the method further includes: The network device receives terminal capability information sent by the terminal device, where the terminal capability information is used to indicate at least one of the following: The ability to transmit information through frequency division multiplexing, the ability to transmit information through time division multiplexing, and the ability to transmit information through single frequency network.

41. The method according to any one of claims 25 to 40, wherein: The method further comprises: The network device sends the fourth indication information corresponding to each target TRP through each target TRP, and the fourth indication information is used to indicate the time advance TA information corresponding to the target TRP.

42. The method according to any one of claims 25 to 41, wherein: Also includes: The network device receives the fifth indication information sent by the terminal device for the first target TRP through the first target TRP, and the fifth indication information is used to instruct the terminal device to adopt a simplified random access process for the first target TRP.

43. The method according to any one of claims 25 to 41, wherein: When the leading sequence in the PRACH corresponding to the first target TRP is a sequence in a preset leading sequence set, and / or the random access opportunity is a resource in a preset resource set, the network device determines that the terminal device adopts a simplified random access process for the first target TRP.

44. The method according to claim 42 or 43, wherein The simplified random access process is used to characterize that the terminal device only obtains the TA information of the first target TRP.

45. A random access device, applied to a terminal device, comprising: a determining unit configured to determine random access parameters corresponding to at least one target TRP, the target TRP being a TRP among multiple TRPs that is in an out-of-sync state with an uplink of the terminal device; wherein at least some of the random access parameters corresponding to different TRPs are different; The first sending unit is configured to send a physical random access channel PRACH to the at least one target TRP based on the random access parameters corresponding to the at least one target TRP, and the PRACH is used to obtain the timing advance TA information corresponding to the at least one target TRP.

46. ​​A random access device, applied to a network device, comprising: The second receiving unit is configured to receive a physical random access channel PRACH sent by the terminal device for each target TRP in at least one target TRP, wherein the PRACH is used to obtain timing advance TA information corresponding to each target TRP. The target TRP is a TRP among multiple TRPs that is in an out-of-sync state with the uplink of the terminal device.

47. A terminal device comprising: Memory, processors, and transceivers, The transceiver is used to achieve communication with a network device, the memory stores a computer program that can be run on a processor, and the processor implements the method according to any one of claims 1 to 24 when executing the program in conjunction with the transceiver.

48. A network device comprising: Memory, processors, and transceivers, The transceiver is used to achieve communication with a terminal device, the memory stores a computer program that can be run on a processor, and the processor implements the method described in any one of claims 25 to 44 when executing the program in conjunction with the transceiver.

49. A computer storage medium storing one or more programs, wherein the one or more programs can be executed by one or more processors to implement the method of any one of claims 1 to 24, or claims 25 to 44.

50. A chip, comprising: A processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes the method according to any one of claims 1 to 24, or claims 25 to 44.

51. A computer program product, comprising a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and wherein when the instructions are executed by the at least one processor, the method according to any one of claims 1 to 24 or claims 25 to 44 is implemented.

52. A computer program, the computer program causing a computer to execute the method according to any one of claims 1 to 24, or claims 25 to 44.

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