Method and apparatus for wireless communication

Abstract

A method and apparatus for wireless communication are provided. The method includes: a terminal device determining a first transmission mode, the first transmission mode being used to indicate an association relationship between PRACH repetition and a plurality of transmission beams supported by the terminal device; the terminal device performing PRACH repetition transmission according to the first transmission mode; wherein the first transmission mode is associated with first information, and the first information includes at least one of the following: a preamble corresponding to the PRACH repetition transmission, an RO corresponding to the PRACH repetition transmission, a first PRACH resource configuration corresponding to the PRACH repetition transmission, a feature combination field corresponding to the PRACH repetition transmission, and first uplink information.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a method and apparatus for wireless communication. Background Technology

[0002] In communication systems, the enhanced coverage of the Physical Random Access Channel (PRACH) is achieved by allowing terminal devices to perform multiple PRACH transmissions with the same transmit beam in the time domain, and then monitoring the random access response. In some scenarios, terminal devices can also use multiple different transmit beams for PRACH transmissions. However, how terminal devices use multiple different transmit beams for PRACH transmissions is a question that needs to be considered. Summary of the Invention

[0003] This application provides a method and apparatus for wireless communication. The various aspects of this application will be described below.

[0004] In a first aspect, a method for wireless communication is provided, comprising: a terminal device determining a first transmission mode, the first transmission mode indicating the association between PRACH repetition and multiple transmit beams supported by the terminal device; the terminal device performing PRACH repetition transmission according to the first transmission mode; wherein the first transmission mode is associated with first information, the first information including at least one of the following: a preamble corresponding to the PRACH repetition transmission, a random access channel occasion (RO) corresponding to the PRACH repetition transmission, a first PRACH resource configuration corresponding to the PRACH repetition transmission, a feature combination field corresponding to the PRACH repetition transmission, and first uplink information.

[0005] In a second aspect, a method for wireless communication is provided, comprising: a network device determining a first transmission mode, the first transmission mode indicating the association between PRACH repetition and multiple transmit beams supported by a terminal device; the network device receiving PRACH repetition transmissions; wherein the first transmission mode is associated with first information, the first information including at least one of the following: a preamble corresponding to the PRACH repetition transmission, an RO corresponding to the PRACH repetition transmission, a first PRACH resource configuration corresponding to the PRACH repetition transmission, a feature combination field corresponding to the PRACH repetition transmission, and first uplink information.

[0006] Thirdly, an apparatus for wireless communication is provided, the apparatus being a terminal device, the apparatus comprising: a processing unit configured to determine a first transmission mode, the first transmission mode being configured to indicate the association relationship between PRACH repetition and multiple transmit beams supported by the terminal device; and a transmitting unit configured to perform PRACH repetition transmission according to the first transmission mode; wherein the first transmission mode is associated with first information, the first information including at least one of the following: a preamble corresponding to the PRACH repetition transmission, an RO corresponding to the PRACH repetition transmission, a first PRACH resource configuration corresponding to the PRACH repetition transmission, a feature combination field corresponding to the PRACH repetition transmission, and first uplink information.

[0007] Fourthly, an apparatus for wireless communication is provided, the apparatus being a network device, the apparatus comprising: a processing unit configured to determine a first transmission mode, the first transmission mode being configured to indicate the association between PRACH repetition and multiple transmit beams supported by a terminal device; and a receiving unit configured to receive PRACH repetition transmissions; wherein the first transmission mode is associated with first information, the first information including at least one of the following: a preamble corresponding to the PRACH repetition transmission, an RO corresponding to the PRACH repetition transmission, a first PRACH resource configuration corresponding to the PRACH repetition transmission, a feature combination field corresponding to the PRACH repetition transmission, and first uplink information.

[0008] Fifthly, a communication device is provided, including a memory and a processor, the memory for storing a program, and the processor for calling the program in the memory to perform the method as described in the first or second aspect.

[0009] A sixth aspect provides an apparatus including a processor for calling a program from memory to perform the method as described in the first or second aspect.

[0010] A seventh aspect provides a chip including a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method as described in the first or second aspect.

[0011] Eighthly, a computer-readable storage medium is provided having a program stored thereon that causes a computer to perform the method as described in the first or second aspect.

[0012] Ninth aspect, a computer program product is provided, including a program that causes a computer to perform the method as described in the first or second aspect.

[0013] In a tenth aspect, a computer program is provided that causes a computer to perform the method as described in the first or second aspect.

[0014] In this embodiment, the terminal device performs repeated PRACH transmissions based on a first transmission mode. The first transmission mode, which indicates the association between repeated PRACH transmissions and the terminal device's transmit beam, can be implicitly or explicitly indicated through first information, facilitating network device reception of the repeated PRACH transmissions. Implicit indication is achieved when the first information includes at least one of the preamble, RO, and first PRACH resource configuration corresponding to the PRACH transmission; explicit indication is achieved when the first information includes a feature combination field corresponding to the PRACH transmission and / or first uplink information. Therefore, by using the first information, network devices can identify the transmit beam reuse relationship of multiple PRACH transmissions within the RO group without increasing or only slightly increasing explicit signaling overhead, thereby improving transmission efficiency. Attached Figure Description

[0015] Figure 1 This is a system architecture example diagram of a wireless communication system to which embodiments of this application can be applied.

[0016] Figure 2 This is a schematic diagram of a network architecture applicable to embodiments of this application.

[0017] Figure 3A and Figure 3B This is a schematic diagram of a wireless protocol stack structure applicable to embodiments of this application.

[0018] Figure 4 This is a flowchart illustrating a method for wireless communication proposed in an embodiment of this application.

[0019] Figure 5 This is a schematic diagram of multiple preamble subsets corresponding to different transmission modes.

[0020] Figure 6 This is a schematic diagram of one possible implementation of transmitting four PRACHs using two different transmit beams.

[0021] Figure 7 This is a schematic diagram of another possible implementation of transmitting four PRACHs using two different transmit beams.

[0022] Figure 8 This is a schematic diagram of a device for wireless communication provided in an embodiment of this application.

[0023] Figure 9 This is a schematic diagram of another device for wireless communication provided in an embodiment of this application.

[0024] Figure 10 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0026] Figure 1 This is a system architecture example diagram of a wireless communication system 100 applicable to embodiments of this application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographical area and may communicate with the terminal device 120 located within that coverage area.

[0027] Figure 1 An exemplary network device and multiple terminal devices are illustrated, such as terminal devices 120a to 120j in the figure. Optionally, the wireless communication system 100 may include multiple network devices, and each network device may include other numbers of terminal devices within its coverage area; this application embodiment does not limit this.

[0028] Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, which is not limited in this embodiment.

[0029] It should be understood that the technical solutions of the embodiments of this application can be applied to various communication systems, such as: 5th-generation (5G) systems or new radio (NR) systems, long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, advanced long-term evolution (LTE-A) systems, enhanced 5G (5G advanced) systems, etc. The technical solutions provided in this application can also be applied to future communication systems, such as 6th-generation (6G) mobile communication systems, satellite communication systems, etc.

[0030] The communication system in this application embodiment can be applied to carrier aggregation (CA) scenarios, dual connectivity (DC) scenarios, and standalone (SA) network deployment scenarios.

[0031] The embodiments of this application can be applied to non-terrestrial network (NTN) systems. As an example, the NTN system can be an NR-based NTN system, a 6G-based NTN system, an Internet of Things (IoT)-based NTN system, or a narrowband Internet of Things (NB-IoT)-based NTN system.

[0032] The terminal device in this application embodiment can also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device in this application embodiment can be a device that provides voice and / or data connectivity to a user, and can be used to connect people, objects, and machines, such as a handheld device with wireless connectivity, vehicle-mounted device, etc. The terminal device in the embodiments of this application may be a mobile phone, tablet computer, laptop computer, handheld computer, camera equipment, mobile internet device (MID), wearable device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc. Optionally, the terminal device may be used to act as a base station. For example, the terminal device may act as a scheduling entity, providing sidelink signals between UEs in vehicle-to-everything (V2X) or device-to-device (D2D) connections. For example, cellular phones and cars communicate with each other using sidelink signals. Cellular phones and smart home devices can communicate without relaying communication signals through base stations.

[0033] The network device in this application embodiment can be a device for communicating with a terminal device. This network device can also be called an access network device or a radio access network device, such as a base station (BS). In this application embodiment, the network device can refer to a radio access network (RAN) node or a next-generation RAN (NG-RAN) node (or device) that connects the terminal device to the wireless network. A base station can broadly encompass, or be replaced by, various names including: NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, transmitting and receiving point (TRP), transmitting point (TP), master station (MeNB), secondary station (SeNB), multi-mode radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or a combination thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. Base stations can also be mobile switching centers, devices that perform base station functions in D2D, V2X, and machine-to-machine (M2M) communications, network-side devices in 6G networks, and devices that perform base station functions in future communication systems. Base stations can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the network equipment.

[0034] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station. In other examples, a helicopter or drone can be configured as a device to communicate with another base station.

[0035] In some deployments, the network device in this application embodiment may refer to a CU or a DU, or the network device may include both a CU and a DU. The gNB may also include an AAU.

[0036] Network devices and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located.

[0037] In this embodiment, the network device can provide services to a cell. The terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) used by the cell. The cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or to a base station corresponding to a small cell. The small cell can include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0038] It should be understood that all or part of the functions of the communication device in this application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (e.g., a cloud platform).

[0039] Figure 2 A schematic diagram of a network architecture 200 according to an embodiment of this application is illustrated. This network architecture 200 describes the network architecture of a 5G NR / LTE / LTE-A system, which can also be referred to as a 5G system (5GS) / evolved packet system (EPS) network architecture. The network architecture 200 includes at least one of the following: network device 110, terminal device 120, 5G core network (5GC) / evolved packet core (EPC) 210, home subscriber server (HSS) / unified data management (UDM) 220, and Internet service 230. Figure 2 The network devices and terminal devices in the diagram are illustrated using RAN and UE as examples, respectively.

[0040] like Figure 2As shown, network device 110 provides user plane and control plane protocol termination to terminal device 120. Network device 110 is connected to 5GC / EPC 210 via an S1 / NG interface. 5GC / EPC 210 includes a mobility management entity (MME) / authentication management field (AMF) / session management function (SMF) 211, other MMEs / AMFs / SMFs 214, a service gateway (S-GW) / user plane function (UPF) 212, and a packet data network gateway (P-GW) / UPF 213. MME / AMF / SMF 211 is the control node that handles signaling between terminal device 120 and 5GC / EPC 210. Generally, MME / AMF / SMF 211 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the S-GW / UPF212, which is itself connected to the P-GW / UPF213. The P-GW provides UE IP address allocation and other functions. The P-GW / UPF213 is connected to Internet service 230. Internet service 230 includes operator-compliant Internet Protocol services, specifically including the Internet, intranet, IP multimedia subsystem (IMS), and packet-switched streaming services. It is evident that network architecture 200 provides packet-switched services; however, those skilled in the art will readily understand that the various concepts presented herein can be extended to networks providing circuit-switched services or other cellular networks.

[0041] Figure 3A and Figure 3B The following are schematic diagrams of the wireless protocol stack structure of one embodiment of this application. Figure 3A and Figure 3B This introduction uses the 5G wireless protocol stack as an example. The 5G wireless protocol stack is divided into two planes: the user plane (UP) protocol stack and the control plane (CP) protocol stack. The user plane protocol stack contains the protocol suite used for user data transmission, while the control plane protocol stack contains the protocol suite used for control signaling transmission in the 5G system. The specific names of each protocol stack layer are as follows:

[0042] like Figure 3AAs shown, the user plane protocol stack, from top to bottom, includes: the Service Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, the Medium Access Control (MAC) layer, and the Physical (PHY) layer.

[0043] like Figure 3B As shown, the control plane protocol stack, from top to bottom, includes: non-access stratum (NAS); radio resource control (RRC) layer, PDCP layer, RLC layer, MAC layer, and PHY layer.

[0044] It should be understood that the different layers in the above protocol stack have different functions, and they work together through inter-layer interaction to achieve communication between terminal devices and network devices. With the development of artificial intelligence technology, AI-assisted computing has permeated the processing implementation methods of the above protocol stack. For example, the scheduling algorithm of the MAC layer and the encoding / decoding algorithm of the PHY layer can apply artificial intelligence algorithms to improve the performance of communication algorithms.

[0045] As an example, Figure 3A and Figure 3B The wireless protocol architecture described herein is applicable to the terminal device described in this application.

[0046] As an example, Figure 3A and Figure 3B The wireless protocol architecture described herein is applicable to the network devices described in this application.

[0047] It should be understood that the interpretation of the terminology in the embodiments of this application may refer to the TS36, TS37 and TS38 series of specifications of the 3rd generation partnership project (3GPP), but may also refer to the specifications of the Institute of Electrical and Electronics Engineers (IEEE).

[0048] To facilitate understanding, some related technical knowledge involved in the embodiments of this application is first introduced. The following related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0049] In communication systems (e.g., NR systems), enhanced PRACH coverage can be achieved by repeatedly transmitting the same PRACH preamble associated with the same synchronization signal block (SSB). It should be noted that, in the embodiments of this application, SSB can also represent a synchronization signal (SS) / physical broadcast channel (PBCH) block, i.e., an SS / PBCH block.

[0050] As one example, a terminal device can transmit the same PRACH preamble associated with the same SSB multiple times in the time domain, and then perform random access response (RAR) monitoring to enhance PRACH coverage. In this mechanism, the terminal device can select RO resources located at the same frequency location and group them according to the number of transmissions indicated by the network device. Within an RO group, the PRACH preamble index selected by the terminal device for the first RO is reused across all ROs in the group. RAR monitoring can begin from the control resource set (CORESET) following the last valid RO in the RO group. The terminal device can use the random access radio network temporary identifier (RA-RNTI) calculated based on the last RO for monitoring. A key feature of this mechanism is that the terminal device transmits all PRACH preambles using the same transmit (Tx) beam. This allows the network device to improve PRACH detection performance by performing multiple detections or accumulating energy during transmission.

[0051] For example, the terminal device can maintain the same Tx beam across multiple PRACH transmissions. If the PRACH transmission is successful, the terminal device continues to instruct subsequent random access procedures to use the same beam via the physical uplink control channel (PUCCH). That is, the physical uplink shared channel (PUSCH) carrying message 3 (Msg3) and the feedback information for message 4 (Msg4) use the same Tx beam. The feedback information for message 4, for example, is a hybrid automatic repeat request (HARQ) acknowledgment (ACK).

[0052] As another embodiment, relevant 3GPP standards introduce a method for determining the number of PRACH repetitions for the same Tx beam based on the reference signal received power (RSRP). Specifically, for terminal devices that meet beam correspondence requirements and do not require Tx beam sweeping (or scanning), the optimal uplink (UL) Tx beam can be directly identified from the downlink (DL) received (Rx) beams. In this case, the coverage performance of PRACH transmission can be guaranteed by the corresponding number of repetitions.

[0053] As discussed above, the current system specifies multiple PRACH transmissions with the same Tx beam to improve PRACH coverage. In some scenarios, terminal devices can also use multiple different Tx beams for PRACH transmission. For example, 5G enhancement, 6G, and subsequent communication systems allow multiple Tx beams for PRACH transmission. Furthermore, for terminal devices relying on Tx beam scanning, even if the required number of repetitions is completed based on the RSRP threshold, coverage requirements may still not be met if the selected beam is not optimal. In such scenarios, it is necessary to determine the optimal Tx beam using multiple beams.

[0054] However, how terminal devices can use multiple different Tx beams for PRACH transmission is a technical problem that needs to be solved. For example, if terminal devices are allowed to use multiple different Tx beams for PRACH transmission, several problems will need to be addressed.

[0055] For example, if a terminal device is capable of transmitting using multiple Tx beams, the network device needs to identify the optimal beam pair, such as a beam pair consisting of the gNB Rx beam and the UE Tx beam. As mentioned earlier, while beam reciprocity allows the terminal device to select its Tx beam based on its Rx beam, this assumption may not always hold true. In this case, the network device can receive signals from multiple Tx beams of the terminal device, determine the most suitable beam, and then provide the corresponding beam index to the terminal device for subsequent transmission. To support this, it is necessary to consider whether the terminal device is capable of transmitting using multiple Tx beams and how many beams it can support. Since the network device is unaware of the terminal device's beam capabilities during PRACH transmission, a reasonable resource allocation must be designed to accommodate this uncertainty.

[0056] For example, if the terminal device can use multiple Tx beams for transmission, it is also necessary to consider the relationship between several factors, such as the beam capability of the terminal device, the number of ROs, the number of PRACH Tx beams required by the network device, and the RSRP threshold.

[0057] For example, if a terminal device can use multiple Tx beams for PRACH transmission, and the terminal device determines the transmission method itself, the network device needs to identify the transmission method. However, PRACH itself (i.e., message 1 (Msg1)) carries almost no freely expandable bits. Therefore, it is necessary to consider how to enable the network device to identify it without increasing or only slightly increasing the overhead.

[0058] For example, if the terminal device can use multiple Tx beams for PRACH transmission, how the network device configures SSB and resources is also an issue that needs to be considered.

[0059] For example, similar to the case of determining multiple PRACH transmissions with the same Tx beam based on RSRP, if network devices can indicate some PRACH transmissions with different Tx beams, how to define an RSRP threshold for multiple PRACH transmissions with different Tx beams is also a technical challenge worth studying.

[0060] To address the aforementioned issues, this application proposes a method for wireless communication. This method allows a terminal device to repeatedly transmit PRACH based on a first transmission mode. The first transmission mode, which indicates the association between PRACH repetition and the terminal device's transmit beam, can be implicitly or explicitly indicated through first information, facilitating network device reception of the repeated PRACH transmission. Implicit indication is achieved when the first information includes at least one of the following: the preamble, RO, and first PRACH resource configuration corresponding to the PRACH transmission. Explicit indication is achieved when the first information includes a feature combination field corresponding to the PRACH transmission and / or first uplink information. Therefore, by using the first information, network devices can identify the transmit beam reuse relationship of multiple PRACH transmissions within the RO group without increasing or only slightly increasing explicit signaling overhead, thereby improving transmission efficiency.

[0061] It should be noted that the beam mentioned in the embodiments of this application may include or be replaced by at least one of the following: physical beam, logical beam, spatial filter, spatial parameter, spatial domain filter, spatial domain transmission filter, spatial domain reception filter, and antenna port.

[0062] The embodiments of this application can be applied to the initial access process or the beam failure recovery process. Taking the initial access process as an example, the embodiments of this application can be applied to a four-step random access procedure (i.e., random access procedure type-1), or they can be applied to a two-step random access procedure (i.e., random access procedure type-2). The embodiments of this application are not limited in this respect.

[0063] To facilitate understanding, the following will be combined with... Figure 4 The present application provides an exemplary description of the method for wireless communication proposed in its embodiments. Figure 4 The method described is explained from the perspective of the interaction between the terminal device and the network device. The terminal device can be any of the communication terminals mentioned above, such as a UE. The network device can be any network-side device that communicates with the terminal device, such as a base station.

[0064] As one example, the terminal device may be Figure 1 Any of the terminal devices 120a to 120j shown.

[0065] As an example, the terminal device can be a relay, such as a relay terminal or a network control relay.

[0066] As an example, the terminal device can be any one of the multiple TRPs, and the network device can be any one of the multiple TRPs that communicates with the terminal device.

[0067] In some embodiments, the terminal device may have the capability to perform PRACH transmission using multiple different Tx beams. That is, the terminal device can select multiple different Tx beams for random access based on the received SSB.

[0068] In some embodiments, the terminal device and the network device can transmit and receive signals. For example, the terminal device receives signals, and the network device transmits signals. Alternatively, the terminal device transmits signals, and the network device receives signals.

[0069] As an example, data / signaling can be transmitted between the terminal device and the network device.

[0070] Network equipment can provide services to the serving cell where the terminal device is located. The cell where the terminal device is located can be an NTN cell or a terrestrial network cell, without limitation. As one embodiment, the terminal device is a UE in an NTN cell, and the network equipment is a satellite covering the NTN cell. As another embodiment, the terminal device and network equipment are a terminal and base station that interact in a 6G communication system or other future communication systems.

[0071] Figure 4 The method shown includes steps S410 and S420, which are described below. It should be noted that the wireless communication method proposed in this application includes, but is not limited to, these steps.

[0072] See Figure 4 In step S410, the terminal device determines the first transmission mode.

[0073] The first transmission mode is used to indicate the association between PRACH repetition and multiple transmit (Tx) beams supported by the terminal device. In other words, the first transmission mode is used by the terminal device to determine the transmit beam scheme used for repetitive PRACH transmission; therefore, the first transmission mode can also be called the first transmit beam usage mode.

[0074] As an example, the first transmission mode may include optional parameters such as the number of times PRACH is repeated and the transmission stage.

[0075] The multiple transmit beams supported by a terminal device can refer to all transmit beams that the terminal device can implement (are available), or it can refer to the transmit beams that the terminal device is currently able to implement. For example, the multiple transmit beams supported by a terminal device can refer to multiple transmit beams determined based on the capabilities of the terminal device. Alternatively, the multiple transmit beams supported by a terminal device can refer to multiple transmit beams determined based on the current communication environment or scenario of the terminal device.

[0076] In some embodiments, PRACH repetition is a single random access channel (RACH) attempt or multiple repetitions within a single random access attempt. That is, the PRACH repetition is multiple PRACH retransmissions during a random access process. For example, the PRACH repetition is multiple PRACH retransmissions during an initial access process. For example, the PRACH repetition is multiple PRACH retransmissions during a beam failure recovery process.

[0077] As an example, the random access procedure can be a 4-step RACH procedure or a 2-step RACH procedure.

[0078] As an example, the terminal device performs RAR monitoring only after sending all PRACHs that repeat the same PRACH.

[0079] The terminal device can determine the first transmission mode itself, or it can determine the first transmission mode based on the network device's configuration. For example, when enabling multiple PRACH transmissions with different transmit beams through a 4-step RACH process, the terminal device can determine which transmit beams to use in order to determine the transmit beam utilization of the multiple PRACH transmissions with different transmit beams. Alternatively, the network device can be configured to use the same transmit beam for a portion of the PRACH transmission. Furthermore, for multiple PRACH transmissions with different transmit beams, the network device can configure a maximum candidate value for the number of PRACH retransmission attempts in each RACH attempt.

[0080] In some embodiments, the terminal device determines the first transmission mode, which can be understood as the terminal device determining the number of PRACH retransmissions N in this random access attempt and the first transmission mode.

[0081] As an example, the terminal device determines a first transmission mode, including the terminal device determining the first transmission mode according to the number of transmission beams supported by the terminal device and the number of repetitions of PRACH transmission. For example, the terminal device may determine the usage mode of transmission beams (i.e., the first transmission mode) based on the number of transmission beams supported (denoted as K) and the number of repetitions of PRACH transmission (denoted as N), where both K and N are positive integers. The number of repetitions of PRACH transmission is the number of PRACH transmissions for each RACH attempt. When the first transmission mode indicates the use of multiple different transmission beams, K is greater than 1.

[0082] It should be understood that one of the key considerations for PRACH transmission with different transmission beams is the relationship between the number of transmission beams K available to the terminal device and the number of repetitions N of PRACH transmission. As an example, the following two cases can be considered.

[0083] Case 1 (K≥N): The terminal device can use K different transmission beams to send PRACH during the initial transmission and retransmission processes.

[0084] Case 2 (K<N): The terminal device can skip some PRACH transmissions during the RACH attempt, or use the same transmission beam for multiple PRACH transmissions.

[0085] As an example, the first transmission mode indicates at least one of the following: when K is greater than N, N of the K transmission beams are used for the initial transmission of PRACH repetition transmission, and the transmission beams other than the N transmission beams among the K transmission beams are used for the retransmission of PRACH repetition transmission; when K is equal to N, the K transmission beams are used for the initial transmission and / or retransmission of PRACH repetition transmission; when K is less than N, some of the K transmission beams are used for multiple PRACH transmissions; when K is less than N, some of the N PRACH repetition transmissions are skipped.

[0086] For example, when K>N, the terminal device can use N different transmission beams to send PRACH during the initial transmission and may receive the RAR. If retransmission is required, the terminal device can utilize the remaining K-N transmission beams that were not used previously, or may reuse some of the initial N beams. This method can effectively allow the terminal device to utilize all K available transmission beams during the RACH attempt, thus maximizing the beam diversity gain.

[0087] 又如,K=N时,终端设备可以在初始传输中使用N个不同的发射波束发送PRACH,并可能接收RAR。如果需要重传,终端设备可以再次使用N个不同的发射波束发送PRACH,也可以进行调整。

[0088] For another example, when K < N, the terminal device can use all K available transmit beams in the initial PRACH transmission. For the remaining N - K transmissions in the initial PRACH transmission, some of the K transmit beams can be reused or some transmissions can be skipped. However, even if the terminal device repeats the PRACH transmission using the same transmit beam, the benefit of improving the detection performance through multiple transmissions may not be achieved. This is because the network device cannot determine whether the same transmit beam is used in different RACH occasions, so effective combination cannot be performed, resulting in some PRACH transmissions being wasted. Therefore, the network device needs to know the first transmission mode.

[0089] It can be seen that when the number of available transmit beams (K) at the terminal device is different from the number of PRACH transmissions (N) per RACH attempt, both the cases of K ≥ N and K < N are operationally feasible. When K > N, full beam diversity can be achieved without the risk of inefficiency caused by undetected beam reuse.

[0090] In some embodiments, the number of PRACH retransmissions is carried in the configuration information of the network device. The configuration information can directly indicate the number of PRACH retransmissions or indicate multiple candidate numbers. When the configuration information includes multiple candidate numbers of PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: determined according to the number of transmit beams supported by the terminal device; the first transmission of the PRACH retransmission uses the minimum value among the multiple candidate numbers, and the retransmission of the PRACH retransmission uses any value greater than the minimum value.

[0091] It should be understood that in an actual scenario, the number of transmit beams supported by the terminal device does not always match the number of PRACH retransmissions indicated by the network device. In some scenarios, the terminal device can select the transmission number closest to the number of beams based on the number of beams. In other scenarios, the terminal device can select an appropriate transmission number according to the communication requirements. Based on this, it can be reasonably assumed that the terminal device may not use different transmit beams for each PRACH transmission. Some PRACH transmissions can be repeated using the same transmit beam.

[0092] As an embodiment, in multiple PRACH transmissions with different transmit beams, when multiple candidate values indicating the number of PRACH transmissions are given, the following two design methods can be considered.

[0093] Method 1, the terminal device selects the number of PRACH transmissions according to the number of transmit beams it supports.

[0094] Method 2 involves the terminal device initially selecting a smaller number of PRACH transmissions. If a PRACH fails, it increases the number of transmissions to enhance coverage. For multiple PRACH transmissions with different transmit beams, compared to a design using the same beam, it not only supports transmit beam indication but also achieves coverage enhancement by increasing PRACH repetition.

[0095] As an example, when the configuration information indicates multiple candidate transmission counts, the number of PRACH retransmissions in the initial transmission and retransmission can be the same or different. When the number of PRACH retransmissions changes, the number of transmit beams used in the initial transmission and retransmission can be the same or different. When the network device indicates multiple candidate values ​​for the number of PRACH retransmissions, there can be two scenarios.

[0096] Case 1 (Method 1 only): When the indicated number of PRACH transmissions is N1 and N2, such as N1 and N2 being 4 and 8 respectively, the terminal device uses a different transmit beam for each PRACH transmission. The terminal device should select a number of PRACH transmissions that matches the number of transmit beams it supports. If the number of transmissions and the number of transmit beams are inconsistent (i.e., cannot be matched), then the transmission number closest to the number of beams is selected. The number of bits required for transmit beam indication depends on the number of PRACH transmissions.

[0097] Scenario 2 (Method 1 + Method 2): When the indicated number of PRACH transmissions is N1 and N2, such as N1 and N2 being 4 and 8 respectively. When the number is 4, the terminal device uses a different transmit beam for each transmission. When the number is 8, the terminal device repeats some transmit beams (e.g., each beam is used twice) to enhance coverage. This allows network devices to maintain a consistent number of transmit beam indications across different values ​​of the PRACH transmission number. For example, if the terminal device supports 8 transmit beams, it can use 4 beams (repeated twice) for the initial transmission, and the remaining 4 for retransmissions, thus effectively utilizing all beams.

[0098] As one embodiment, the network device configures one or more RO groups. Each RO group contains N PRACH transmission opportunities (e.g., N can be 4, 8, or other indicable values). The terminal device selects the number of PRACH transmissions N based on the number K of transmit beams it supports. After determining N and the first transmission mode, the terminal device selects a preamble index p from the preamble subset corresponding to (N, first transmission mode, stage) and reuses the same preamble index p in multiple PRACH transmissions within that RO group. The terminal device can determine the number of PRACH transmissions N for this RO group according to at least one of the following methods.

[0099] Optionally, N=4 and N=8 can both use different beams. The terminal device uses a different transmit beam for each PRACH transmission within the RO group, regardless of whether N is 4 or 8. In this case, the terminal device can select a PRACH transmission count N that matches its supported transmit beam count K. The network device can identify this pattern based on the previously selected preamble subset, thus performing detection and beam search with different beams each time. If the terminal device initially selects fewer PRACH transmissions and fails, increasing the number of transmissions may result in the reuse of the same beam. The terminal device can switch to a different beam set / preamble subset corresponding to a different transmission mode after the initial transmission failure.

[0100] Optionally, N=4 represents different beams, and N=8 represents repeated beams. When N=4, the terminal device uses four different transmit beams for each of the four PRACH transmissions within the RO group; when N=8, the terminal device maintains the same number of unique transmit beams (e.g., four), and repeats some transmit beams (e.g., each beam is used twice) to enhance coverage. Thus, the network device can maintain a consistent number of transmit beam indications under different N values ​​(e.g., 4 and 8) (e.g., always interpreting transmit beam indication information as four unique transmit beams), and can merge multiple PRACH reception results corresponding to the same transmit beam to achieve coverage enhancement, while still utilizing multiple unique transmit beams for beam refinement. Furthermore, when the terminal device supports 8 transmit beams, the terminal device can use the first group of 4 beams in the initial transmission (e.g., N=4), use the second group of 4 beams in the retransmission enhancement (e.g., N=8), or repeat the first group of 4 beams in N=8 and switch to another group of beams in the retransmission stage, thereby making more efficient use of all beam resources.

[0101] The association between PRACH repetition and multiple transmit beams supported by the terminal device can indicate whether the PRACH repetition uses the same transmit beam or multiple different transmit beams, which transmit beam or beams among multiple transmit beams are used, and the number of repetitions for any transmit beam used in the PRACH repetition. For example, the first transmission mode can include which PRACH transmissions use the same transmit beam and which PRACH transmissions use different transmit beams.

[0102] It should be understood that in PRACH repetition transmissions, multiple PRACH transmissions with the same transmit beam will provide combined gain, while multiple PRACH transmissions with different transmit beams will provide transmit beam refinement. Depending on the deployment and end-device conditions, both settings may also be required simultaneously. Therefore, end-devices can combine multiple PRACH transmissions with the same and / or different transmit beams. For example, an end-device can send PRACH four times with two beams, making each beam used twice. By allowing this functionality, combined gain and transmit beam refinement can be achieved, enabling the network to adapt to various end-device conditions.

[0103] As one embodiment, the first transmission mode is one of multiple transmission modes. The multiple transmission modes may include: PRACH repeated transmission using one beam (beam repeat mode), PRACH repeated transmission using multiple different beams (beam scan mode), and a portion of the PRACH repeated transmission using different beams while another portion uses the same beam (repeated + scan mode).

[0104] As an example, repeated PRACH transmissions performed by a terminal device include multiple PRACH transmissions using a single transmit beam.

[0105] As an example, the PRACH repetitions performed by the terminal device include multiple PRACH transmissions using different transmit beams.

[0106] As an example, repeated PRACH transmissions performed by a terminal device include at least two PRACH transmissions using the same transmit beam and at least two PRACH transmissions using different transmit beams.

[0107] As an example, the association between PRACH repetition and multiple transmit beams supported by the terminal device includes at least one of the following: whether the PRACH repetition is transmitted through at least two of the multiple transmit beams; the index of one or more transmit beams used to transmit the PRACH repetition; and the number of times the PRACH repetition is transmitted on any of the multiple transmit beams. In multiple PRACH transmissions with different transmit beams, it is reasonable to assume that the terminal device can reuse all or part of the same transmit beams for some transmissions, and that the network device can recognize this reuse to facilitate PRACH merging and improve coverage performance. The terminal device does not need to use different transmit beams for each PRACH transmission and can notify the network device which PRACH transmissions use the same transmit beams. By merging at the network device, the accuracy of PRACH detection and the enhancement of coverage can be improved.

[0108] The first transmission mode is associated with first information, which is used by the network device to determine the first transmission mode. That is, the network device can determine the transmission mode selected by the terminal device based on the first information to perform PRACH combination or beam refinement respectively, thereby improving the transmission efficiency of PRACH repetition transmission. For multiple PRACH transmissions, simultaneous transmission of the same and different transmit beams in the same PRACH attempt is supported. In any RO group used to support Release 20+ PRACH transmissions and beam scanning, a transmission mode combining beam scanning and repetition is allowed, i.e., repetition using each beam is permitted. When a group of ROs is used for different purposes, such as different combinations of repetition and transmit beam scanning, the network device must fully understand the behavior of the terminal device to correctly combine and detect the received signals. Therefore, the separation of these operating modes is necessary and can be achieved through the first information.

[0109] It should be understood that PRACH itself (Msg1) carries almost no freely expandable bits; the initial information can be indicated through implicit notification. In this implicit manner, the terminal device does not need to send explicit bits for the i-th and j-th times of the same beam sequentially. Instead, it selects a beam reuse mode, and the network device can determine the beam grouping relationship corresponding to each PRACH in the RO group based on the terminal device's selection.

[0110] The first information includes at least one of the following: the preamble corresponding to the PRACH retransmission, the RO corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

[0111] In some embodiments, the preamble corresponding to the repeated PRACH transmission belongs to a first preamble subset. The first preamble subset is a subset of preambles from multiple preamble subsets that correspond to the first transmission mode, and these multiple preamble subsets correspond one-to-one with multiple transmission modes. That is, multiple transmission modes can be bound to multiple preamble subsets respectively. These multiple preamble subsets can also be referred to as multiple preamble sets.

[0112] As an example, the terminal device selects a preamble index from the preamble set / preamble subset bound to the first transmission mode, reuses the same preamble index in multiple PRACH transmissions within the RO group, and sends multiple PRACHs according to the first transmission mode.

[0113] As one example, any one of the preambles in the multiple preamble subsets is a preamble used for contention-based random access (CBRA). Alternatively, any one of the preambles in the multiple preamble subsets is a preamble used for contention-free random access (CFRA).

[0114] As an example, the terminal device can implicitly indicate the first transmission mode through a subset of preambles. That is, different combinations of beam scanning and beam repetition within a RO group can be separated by preamble partitioning. By partitioning the possible operating modes for different combinations using preambles, each mode will be limited to a set of usable preambles. Based on a specific combination of repetition and beam scanning, a terminal device transmitting PRACH repetition transmissions within a group of ROs can transmit using a single preamble from the set of preambles allowed for that combination in all transmissions within the group. Compared to transmitting different preambles across ROs, this method is simpler to implement in both the terminal device and the network device.

[0115] In the above embodiments, the PRACH retransmission corresponds to the same preamble. During PRACH retransmission, the terminal device uses the same preamble on all ROs in the RO group, regardless of the transmission pattern defined by the number of beams and the number of repetitions per beam. Based on this method, network devices can be required to allocate fewer preambles to support this function, and resource consumption can also be reduced.

[0116] As an example, a network device can divide the available PRACH preamble indices into several groups. For instance, the network device can group the preambles used by CBRA. When divided into n groups (n subsets of preambles), it can include group 1, group 2, group 3... group n. Each group corresponds to a beam scan × repetition combination pattern (transmission mode). The following is just one example where N is 4.

[0117] Group 1 in the preamble set corresponds to mode A. Mode A can be a pure scanning mode, such as using beams b1, b2, b3, b4.

[0118] Group 2 in the preamble set corresponds to mode B. Mode B can be a pure repetition mode, such as using beam b1,b1,b1,b1.

[0119] Group 3 in the preamble set corresponds to mode C. Mode C can be a 2-beam × 2-mode, for example, using beams b1, b1, b2, b2.

[0120] If a terminal device wants to use a certain combination pattern (e.g., two beams, each beam repeated twice), it can select a preamble from the preamble group corresponding to that pattern (e.g., group 3). The terminal device uses the same preamble in all PRACH transmissions within that RO group (only the order of beam usage / repetition count varies according to the pattern). For the network device, once it confirms which group the detected preamble belongs to, it knows which scanning / repetition combination the terminal device has used, thus enabling it to correctly perform merging and detection.

[0121] As one embodiment, the network device divides the available set of PRACH preamble indexes into multiple preamble subsets. Each preamble subset is bound to one or more parameters. These parameters include: the number of PRACH transmissions N within the RO group, and the transmit beam usage pattern (transmission pattern) identifier (patternID). The transmit beam usage pattern identifier is used to characterize which PRACH transmissions within that RO group use the same transmit beam and which use different transmit beams. The network device can also define the RO and beam mapping template corresponding to each PatternID.

[0122] For example:

[0123] Subset S0: PatternID = 0 (Full sweep: different beam each time);

[0124] Subset S1: PatternID = 1 (paired repetition: used twice per beam);

[0125] Subset S2: PatternID = 2 (three repetitions: three times per beam).

[0126] After determining N and the transmission mode identifier, the terminal device selects a preamble index p from the preamble subset corresponding to N and the transmission mode identifier, and reuses preamble index p in multiple PRACH transmissions within the RO group. Simultaneously, it transmits multiple PRACHs according to the transmit beam reuse relationship indicated by the transmission mode identifier. Upon detecting preamble index p, the network device determines the transmission mode identifier based on the preamble subset to which p belongs, thereby determining which PRACH transmissions within the RO group use the same transmit beam. It then performs merging processing on the received results of PRACHs using the same transmit beam to improve detection performance or coverage.

[0127] For example, N=8, PatternID=1 (4 unique beams, each repeated twice); the 8 ROs are RO#1, RO#2, RO#3, RO#4, RO#5, RO#6, RO#7, and RO#8. Network devices can perform merging by group:

[0128] RO#1 and RO#2 use the same transmitted beam b1, and the combined (RO1+RO2) is used to obtain the combined metric of b1;

[0129] RO#3 and RO#4 use the same transmitted beam b2, and the combined (RO3+RO4) is used to obtain the combined metric of b2;

[0130] RO#5 and RO#6 use the same transmitted beam b3, and the combined (RO5+RO6) yields the combined metric of b3;

[0131] RO#7 and RO#8 use the same transmission beam b4, and the combined (RO7+RO8) yields the combined metric of b4.

[0132] Network devices can perform PRACH detection based on the merging metric and can select the beam pair corresponding to the transmit beam with the largest merging metric for subsequent access procedures.

[0133] For example, a corresponding detection statistic can be generated based on the detected preamble. This detection statistic can be the amplitude, amplitude square, energy, peak power, or a decision value compared to a threshold, etc. The network device merges the detection statistics of multiple PRACH transmissions using the same transmit beam to generate a merge metric. The merge metric combines the detection statistics of the ROs (Realization Occurrences) of repeated transmissions from the same transmit beam to form a more reliable statistic, which is used to compare multiple candidate beams / groups and select the most likely beam or the strongest group. If the merge metric can be an incoherent merge metric, the network device accumulates the energy-related detection statistics of multiple PRACH transmissions belonging to the same transmit beam. For example, for the detection statistic m corresponding to the i-th PRACH transmission... i m i This can represent the maximum squared magnitude of the correlated output over the candidate delay, a value associated with the i-th PRACH transmission and the predetermined preamble sequence. Network devices can sum the detection statistics of multiple PRACH transmissions corresponding to the same transmit beam to obtain a merging metric.

[0134] As an example, the terminal device can select a subset of preambles based on its own capability information. If the terminal device previously sent message 1 / message 2 (Msg2) / message 3 and the access failed, the preamble used when attempting to access again can belong to the same subset of preambles as the one used in the first transmission.

[0135] In some embodiments, the first information may include a feature combination field related to a first transmission mode, namely, a feature combination field corresponding to the current PRACH repeat transmission. This feature combination field may indicate the characteristics of the PRACH repeat transmission, i.e., the PRACH repeat characteristic.

[0136] As an example, the feature combination field can be any combination of relevant feature parameters based on the transmission mode. For example, the K field represents the number of transmit beams supported by the terminal device; the N field represents the number of PRACH retransmissions in a single RACH attempt; the U field represents the number of unique transmit beams used in this transmission; and the r field represents the number of repetitions of the same transmit beam. In other words, the set of basic possible values ​​for the feature combination field is all combinations of (K, N, U, r) that satisfy the constraints. It should be understood that some of the four parameters can also be arbitrarily combined, such as combinations of two or three parameters.

[0137] In a single random access attempt, the terminal device may send multiple PRACH messages. The number of different transmit beams actually used by the terminal device in these PRACH transmissions is the unique transmit beam count.

[0138] As one embodiment, different feature combinations correspond to different preamble subsets, or multiple candidate values ​​of any feature in a feature combination correspond to multiple preamble subsets. Network devices can introduce new preamble sets (or subsets) into feature combinations and assign available preambles to PRACH repetitions using different beams. For example, different repetition counts N can be distinguished by using separate preambles. New separate preamble sets (or subsets) are assigned to specific PRACH repetition features, such as PRACH transmission repetition using multiple transmit beams via a feature combination field, as... Figure 5 As shown.

[0139] Figure 5 This illustrates a preamble partitioning scheme supporting PRACH repetition transmissions with different transmit beams. The available preamble is divided into three preamble subsets based on different repetition counts N. These three preamble subsets correspond to N (N = 2, 4, and 8) PRACH repetitions with different beams. Based on the different preamble subsets, the transmit pattern includes six patterns corresponding to different numbers of maximum transmit beams (max Tx beams).

[0140] See Figure 5The network can introduce new, independent preamble subsets from the feature combinations of PRACH transmissions to distinguish different PRACH repetition features. Available preambles are assigned to PRACH repetition transmissions using different transmit beams, with the number of PRACH repetitions distinguished by selecting different preamble subsets. Specifically, for scenarios using multiple transmit beams for PRACH repetition transmissions, the network assigns separate preamble subsets to the corresponding PRACH repetition features. The terminal device determines the PRACH repetition method and beam usage based on the feature combination field and selects a preamble from the corresponding preamble subset for PRACH transmission. By detecting the received preamble, the network can identify the PRACH repetition features used by the terminal device and their corresponding transmission modes, thereby correctly associating, merging, and detecting multiple PRACH transmissions.

[0141] The RO corresponding to the repeated transmission of PRACH can be one or more ROs, and this application does not limit this.

[0142] In some embodiments, the RO corresponding to a PRACH repetition is an RO in a first subset of ROs. The first subset of ROs is one of multiple subsets of ROs. Multiple subsets of ROs are associated with different transmit beams, or multiple subsets of ROs are associated with RO transmission modes. The RO transmission mode is used by the terminal device to determine whether the ROs corresponding to the same transmit beam performing the PRACH repetition are consecutive.

[0143] As one example, the network device configures one or more RO groups, each RO group containing N PRACH transmission opportunities. The network device can also configure candidate values ​​for N, PRACH resource sets, or multiple RO subsets. RO subsets are also called RO subgroups.

[0144] As one example, a network device can divide multiple ROs within an RO group into multiple RO subsets. Each RO subset is associated with a specific transmit beam, or each RO subset may be associated with a specific RO transmission mode.

[0145] For example, each RO subset is associated with a specific transmit beam. The terminal device uses the same transmit beam for transmission within each RO subset and can reuse or switch beams between RO subsets. Depending on the terminal device's capabilities, it may use more or fewer transmit beams than the number of RO subsets configured for the network device. If the terminal device supports fewer transmit beams than the number of RO subsets, the same transmit beam can be reused across multiple RO subsets. If the terminal device supports more than or equal to the number of RO subsets, different transmit beams can be used across multiple RO subsets.

[0146] In the above embodiments, the configuration parameters (ReconfigurationWithSync) and system information (SI) requests related to CBRA and CFRA can support multiple PRACH transmissions with different transmit beams.

[0147] For example, by transmitting in separate resources, each RO transmission mode with a different number of repetitions can be distinguished. RO transmission modes can include continuous mode (the terminal device transmits in continuous ROs) and comb mode (the terminal device transmits in non-continuous ROs). Figure 6 and Figure 7 The diagram illustrates continuous emission and comb emission on a RO group when N is 4, K or U is 2, respectively.

[0148] See Figure 6 In continuous transmission type, the terminal device transmits PRACH with transmit beam 0 on the first two consecutive ROs, and then transmits PRACH with transmit beam 1 on the next two consecutive ROs. Figure 6 It can be seen that the RO transmission mode is a continuous mode, and SSB0 and SSB1 correspond to RO group 1 and RO group 2, respectively. RO group 1 includes two RO subsets: one consisting of RO 0 and RO 1, and the other consisting of RO 2 and RO 3. Different RO subsets correspond to different transmission beams.

[0149] See Figure 7 In the comb-type transmission, the terminal device transmits a PRACH on the first two consecutive ROs with transmit beams of 0 and 1, and then transmits a PRACH with transmit beams of 0 and 1 on the next two consecutive ROs. Figure 7 It can be seen that SSB0 and SSB1 also correspond to two RO groups. Since the RO transmission mode is a comb mode, the ROs corresponding to the same transmitted beam in the RO group are not continuous.

[0150] By using the aforementioned RO transmission mode, network devices can first combine repetitions of PRACH transmissions with similar channel conditions—that is, transmissions using the same transmit beam and similar wireless channel conditions—and then detect the preamble index using a general algorithm. In fact, when configuring the transmission mode, whether it's continuous transmission or comb transmission, both achieve coherence gain on the receiver side. Furthermore, network devices can introduce RO transmission modes distinguished by individual resources and determined by the number of repetitions, and limit the number of transmit beams used for PRACH transmissions through network configuration.

[0151] In some embodiments, the RO corresponding to the PRACH retransmission is an RO in a second RO group. The second RO group is one of at least one RO group configured by the network device for the first transmission mode. That is, multiple transmission modes are associated with different RO groups.

[0152] In some embodiments, the first PRACH resource configuration is the PRACH resource configuration bound to the first transport mode among a plurality of PRACH resource configurations configured by the network device. The PRACH resource configuration may include the configuration of the aforementioned RO group and the configuration of the RO subset.

[0153] As one example, a network device can configure multiple PRACH resource configurations or multiple RO group resource sets (e.g., multiple PRACH configuration indices, multiple RO group configurations, or multiple PRACH resource subsets) for the same cell. Different PRACH resource configurations or RO group resource sets are bound to different transmission modes. This transmission mode is used to identify the transmit beam reuse relationship of multiple PRACH transmissions within an RO group. In other words, multiple PRACH resource configurations correspond one-to-one with multiple transmission modes.

[0154] After determining the first transmission mode, the terminal device selects the PRACH resource configuration or RO group resource set corresponding to the first transmission mode, and performs PRACH transmission on the selected resource configuration or resource set. The network device identifies the transmit beam usage mode based on the PRACH resource configuration or RO group resource set adopted by the terminal device, thereby determining which PRACH transmissions within the RO group use the same transmit beam, and performs merging processing on the PRACH reception results using the same transmit beam to improve detection performance or coverage.

[0155] In some embodiments, the first information may include first uplink information following a PRACH retransmission. After performing a PRACH transmission, the terminal device explicitly indicates the transmit beam reuse relationship (i.e., the first transmission mode) to the network device through subsequent uplink messages.

[0156] As an example, the first uplink information is carried in the adjacent uplink transmission following the PRACH retransmission. Since the PRACH retransmission may use multiple transmit beams, explicitly indicating the first transmission mode in the adjacent uplink transmission can facilitate network devices to promptly determine the optimal beam pair after the connection is established and to conduct subsequent communication based on the optimal beam pair.

[0157] As one embodiment, a feature combination field associated with the first transmission mode can be carried in the first uplink information. That is, the first uplink signal can carry the aforementioned feature combination field to indicate the first transmission mode.

[0158] As an example, the first uplink information can be carried in a message during the random access process (e.g., message 3 in four-step random access, or the payload portion of message A (MsgA) in two-step random access). The first uplink information can carry a mode identifier, beamgroup information, or bitmap information of the first transmission mode. That is, the first uplink information can be explicitly represented within the corresponding RO group to indicate which PRACH transmissions use the same transmit beam.

[0159] In some embodiments, the Returning Arrays (ROs) corresponding to repeated PRACH transmissions include shared ROs and / or independent ROs. Shared ROs are used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams, while independent ROs are used for PRACH transmissions corresponding to different transmit beams. Therefore, shared ROs and independent ROs can be used to distinguish the modes employed by one or more PRACH transmissions.

[0160] As an example, multiple PRACH transmissions with different transmit beams can be distinguished from PRACH transmissions with the same transmit beam by using shared ROs or separate ROs. This distinction relates to resource configuration, power ramp behavior, and RO allocation. In the case of shared ROs, many aspects of the configuration for multiple PRACH transmissions with the same transmit beam can be used for transmissions with different transmit beams. On the other hand, when a separate configuration is applied and a separate RO is explicitly indicated (independent RO), independent configurations, including dedicated parameters and values, can be provided for different transmit beams. In the scenario of the same transmit beam, depending on the number of PRACH transmissions, only a subset of the ROs indicated in the RACH configuration can be used, while other ROs may remain unused due to offset or other configuration parameters.

[0161] As an example, if an RO used for the same transmit beam is also used for different transmit beams, it can be considered as a shared RO.

[0162] As an example, if an unused transmit route (RO) (from the perspective of the same transmit beam) is used for a different transmit beam, it can be considered a separate RO. Separate ROs can be divided into two categories: ROs that provide different transmit beams through separate RACH configurations; and ROs that are not used for the same transmit beam (but are indicated in the same RACH configuration) and are reused for different transmit beams.

[0163] As an example, the shared RO corresponding to a PRACH repetition transmission is one or more ROs in a shared RO pool. A network device can configure a shared RO pool via RRC (or system information). This shared RO pool can be divided into one or more RO subsets. For example, the shared RO pool may include a second RO subset and a third RO subset. The ROs in the second RO subset are used for one or more PRACH transmissions using the same transmit beam during PRACH repetition transmission, while the ROs in the third RO subset are used for one or more PRACH transmissions using different transmit beams during PRACH repetition transmission. That is, the second RO subset is used for multiple PRACH transmissions using the same transmit beam (for repetition / combination gain purposes); the third RO subset is used for multiple PRACH transmissions using different transmit beams (for scanning / refinement purposes).

[0164] In the above embodiments, each RO subset can be bound to its own set of parameters, such as the available set of PRACH transmission counts, mapping / association rules with SSB, power control / power ramp strategies, etc. When the terminal device chooses to perform the same transmit beam repetition, the terminal device only performs N PRACH transmissions on the ROs in the second RO subset and reuses the same preamble within the RO group corresponding to that subset. That is, the PRACH within the group uses the same transmit beam, thereby supporting energy accumulation and improving detection performance. When the terminal device chooses to perform different transmit beam scanning, the terminal device only performs N PRACH transmissions on the ROs in the third RO subset and switches the transmit beam (or partially reuses) within the RO group according to predetermined rules. As long as the network device sees which RO subset the PRACH falls into, it knows whether the terminal device is performing a repetition or scanning type this time, and thus performs multiple detections / energy accumulation (combined gain) on the second RO subset based on the assumption of same transmit beam repetition, and performs candidate beam selection / refinement on the third RO subset based on the assumption of multi-transmit beam refinement.

[0165] In the above embodiments, each RO subset can be bound to different power control / slope strategies: Repetitive subsets (same transmit beam): can be configured to no slope (or small step) within the group and slope across attempts, making the group more suitable for energy accumulation; that is, multiple transmissions of the same transmit beam are beneficial for network devices to accumulate energy and improve detection. Scanning subsets (different transmit beams): can be configured to maintain the same power reference (or uniform compensation rule) within the group, avoiding interference from power differences in determining which beam is better; the actual slope is still reserved for the next RACH attempt after a failure. Regarding RO allocation, the network can arrange repetitive ROs as continuous time-domain ROs (facilitating merging within a window) and scanning ROs as ROs covering more time slots / more SSBs (facilitating beam search). For example, the ROs in the second RO subset are continuous in the time domain, while the ROs in the third RO subset correspond to multiple SSBs or occupy multiple time slots.

[0166] In some embodiments, PRACH transport resources can be configured from at least two of the following dimensions:

[0167] (1) The time domain distribution dimension of RO can be considered to determine whether the RO time domain is continuous, for example, whether the RO is continuous or discontinuous;

[0168] (2) The beam association dimension can take into account the usage mode of SSB, such as: fixed SSB / variable SSB / segmented SSB.

[0169] In some embodiments, the RO corresponding to a PRACH retransmission is an RO in the first RO group. The mapping relationship between the ROs in the first RO group, the SSB, and the transmit beam is related to the SSB usage mode. The first RO group can be an RO group in a shared RO pool.

[0170] As an example, all ROs in the first RO group are associated with the same SSB index. This usage pattern can be called SSB fixed. When SSB is fixed, all ROs within the first RO group can use the same transmit beam and / or the same preamble.

[0171] For example, under a shared RO, if the SSB is fixed, network devices maintain the existing SSB-to-RO association rules within the shared RO pool. When the same transmit beam needs to be repeated, network devices can constrain all ROs within the same RO group to be associated with the same SSB index (e.g., all SSB#3). Correspondingly, the terminal device reuses the same preamble and transmits multiple PRACHs within that RO group using the same transmit beam. For example, the terminal device selects a preamble p from a subset of preambles bound to fixed SSBs (or selects the RO subset corresponding to that pattern). The terminal device uses the ROs corresponding to the same SSB index (i.e., the batch of ROs associated with SSB#3) for ROs #1 through #N, and reuses the same preamble p. The network device knows that N PRACHs are repeated if p belongs to the SSB fixed subset (or the PRACH falls into the RO subset of the fixed mode). Based on the preamble subset or RO subset used by the received PRACH, the network device determines that the terminal device adopts the SSB fixed mode. The network device performs merging detection (e.g., energy accumulation or multiple detection fusion) on these PRACH transmissions, generates a merging metric and compares it with the detection threshold to improve the PRACH detection probability and coverage performance.

[0172] As an example, different ROs in the first RO group are associated with different SSB indices. This usage pattern can be called SSB variation. When the SSB varies, different ROs within the first RO group use different transmit beams and / or the same preamble.

[0173] For example, shared ROs can also support scanning / refinement (SSB can vary). When a terminal device needs multiple PRACH transmissions from different transmit beams to achieve transmit beam refinement, different ROs within the same RO group are allowed to be associated with different SSB indices (e.g., RO#1 uses SSB#1, RO#2 uses SSB#3, RO#3 uses SSB#6, etc.). This is equivalent to the terminal device switching between multiple transmit beams in different directions within the RO group to transmit PRACH (partial scanning / refinement). The terminal device transmits on RO#1 to RO#N and can still reuse the same preamble p. The terminal device selects different transmit beams for PRACH transmission based on different SSB indices. The network device can detect the PRACH on the receiving side using the SSBs associated with each RO (and their corresponding receive beam assumptions) and determine a more suitable beam pair from the receive results of multiple terminal device transmit beams. The network device knows that these transmissions come from different transmit beam directions and should not simply accumulate energy into one transmission. Instead, it should treat this as multi-beam candidate information for beam selection / refinement (finding the optimal beam pair). This method can achieve

[0174] As an example, the first RO group includes multiple RO subsets, each corresponding one-to-one with a multiple SSB index. This usage pattern can be called SSB bucketing. When SSB bucketing is performed, all ROs within the same RO subset use the same transmit beam, while different RO subsets use different transmit beams.

[0175] For example, shared ROs can also support a mixed mode (SSB bucketing + intra-bucket duplication). That is, it allows ROs with different SSBs (different transmit beams) and duplicate ROs with the same SSB (same transmit beam) to exist within the same RO group. Specifically, the network device predefines or configures an SSB bucketing rule: dividing the ROs within the RO group into multiple subsets, each subset associated with an SSB index; terminal devices use the same transmit beam to repeatedly transmit within the same subset, and use different transmit beams to transmit between different subsets.

[0176] As an example, the network device binds a subset of preambles (or subsets of ROs) to one of the following via RRC parameters and broadcasts / configures it: SSB fixed (same SSB) mode; SSB changing (across multiple SSBs) mode; SSB bucketing (same SSB within a bucket, different SSBs between buckets) mode; or the terminal device implicitly indicates the SSB usage method by selecting the appropriate subset.

[0177] Therefore, in a shared RO pool, network devices can maintain the association rules between SSBs and ROs and configure different SSB usage modes via RRC. For the repeat mode, ROs within an RO group are associated with the same SSB. For the scan mode, ROs within an RO group are allowed to be associated with different SSBs. For the mixed mode, the RO group is divided into multiple subsets associated with different SSBs; repeat is performed within a subset, and scan is performed between subsets. The terminal device indicates the adopted SSB usage mode by selecting a preamble subset (or RO subset) bound to the mode, enabling the network device to correctly combine detection and perform beam selection.

[0178] As explained in the first information above, the transmit beam reuse relationship / PRACH repetition feature adopted by the terminal device can be implicitly or explicitly indicated in at least one of the following ways, including but not limited to: preamble subset selection; RO subset selection; PRACH resource configuration selection; and feature combination fields. For example, the network device determines the first transmission mode based on the detected preamble set / subset and / or the PRACH resource configuration and RO subset selected by the terminal device, thereby performing merging processing on the PRACH reception results belonging to the same transmit beam, or performing beam refinement and selection on the reception results of different transmit beams.

[0179] In the embodiments of this application, K represents the number of transmit beams supported by the terminal device, N represents the total number of PRACH transmissions in a single RACH attempt, U represents the number of unique transmit beams used in the RACH attempt, and r represents the number of repeated transmissions to the same transmit beam, where N = U × r or N ≥ U.

[0180] In step S420, the terminal device performs PRACH retransmission according to the first transmission mode. The network device receives the PRACH retransmission. If the network device determines the first transmission mode before or during receiving the PRACH retransmission, it can receive the PRACH retransmission according to the first transmission mode. If the network device determines the first transmission mode after receiving the PRACH retransmission, it can determine the optimal beam pair according to the first transmission mode. Therefore, the PRACH retransmission sent by the terminal device is transmitted according to the first transmission mode. The PRACH retransmission received by the network device is associated with the first transmission mode.

[0181] As an example, when receiving a PRACH repeat transmission, the network device may determine a first transmission mode based on at least one implicit indication in the first information (e.g., the preamble, RO, or PRACH resource configuration corresponding to the PRACH repeat transmission), and receive the PRACH repeat transmission according to the first transmission mode.

[0182] As another example, after receiving repeated PRACH transmissions, the network device may determine a first transmission mode based on at least one explicit indication in the first information (e.g., a feature combination field or first uplink information).

[0183] In some embodiments, repeated PRACH transmissions may include at least two PRACH transmissions using the same transmit beam. As described above, these at least two PRACH transmissions are used by the network device to perform a combining process. Through this combining process, a combining metric for the transmit beams corresponding to the at least two PRACH transmissions can be obtained. The metrics and / or combining metrics of all transmit beams used in the first transmission mode can be used by the network device to select the optimal beam pair.

[0184] As an example, the terminal device performs RAR monitoring after performing repeated PRACH transmissions.

[0185] Terminal devices can perform RAR monitoring within the RAR window. The RAR window is defined in the same way as multiple PRACH transmissions with the same transmit beam. Specifically, the RAR window begins after the last valid RO in the RO group, regardless of whether the terminal device discards the transmission within that RO.

[0186] As an example, in multiple PRACH transmissions with different transmit beams, the RA-RNTI detected in the RAR can correspond to the last valid RO in the RO group. For example, monitoring multiple RA-RNTIs by the terminal device increases the probability of false alarms. The terminal device can preferably monitor a single RA-RNTI corresponding to the last RO in the RO group. This monitoring method is similar to multiple PRACH transmissions with the same transmit beam.

[0187] For multiple PRACH transmissions with different transmit beams, the same definition as in the case of the same beam can be reused, where the RAR window begins after the last PRACH transmission, and RA-RNTI is calculated based on the last RO. Transmit beam indication is performed using RA-RNTI, i.e., the RAR window begins after the last PRACH transmission.

[0188] As an example, the network device may also support indicating UL beam information through a combination of one or more of the following options. The network device may indicate one or more beam information.

[0189] Option 1 is implicitly represented by RA-RNTI.

[0190] Option 2, explicitly indicated by downlink control information (DCI) format 1_0, uses RA-RNTI encryption (e.g., reserved bits).

[0191] Option 3, explicitly state this by rearranging the fields in the UL Grant within the RAR.

[0192] Option 4, explicitly indicate this by introducing a new field in MAC RAR.

[0193] Option 5 supports beam indication in the MAC control element (MAC-CE) of message 2.

[0194] As an example, the terminal device sends first uplink information indicating a first transmission mode. After receiving the first uplink information, the network device determines the transmit beam reuse relationship (first transmission mode) according to the explicit indication, and adopts the corresponding merging strategy or beam selection strategy in subsequent access processing, retransmission strategy, beam management or link establishment process accordingly.

[0195] As an example, the network device can indicate the RO index corresponding to the strongest detected PRACH repetition in a RO group or subset. The information of the indicated RO (index) can be carried by message 2, such as RAR. Using the indicated RO (index), the terminal device can determine the network-preferred UL transmit beam based on prior knowledge of the UL transmit beams transmitted on the indicated RO (index) within the RO set. That is, the terminal device already knows the one-to-one mapping between each RO in the RO group or subset and the UL beam used for that RO in the current attempt; therefore, the indicated RO index can implicitly identify the network device's preferred UL beam without explicitly sending a beam identity (ID). The ROs can be indexed according to the set of ROs used by the terminal device for multiple PRACH transmissions. For example, the RO index order can be an ascending time index with defined reference ROs, such as the first valid RO in the RO set. This design deliberately maintains the specificity of beam selection implementation by the terminal device, allowing the network device to indicate only RO-related information it has reliably observed, and minimizing signaling overhead.

[0196] The above text combined Figures 4 to 7This paper introduces a first transmission mode in which the terminal device indicates repeated PRACH transmissions based on first information, and various implementation methods for indicating whether multiple transmit beams are used. Based on the first information, network devices can identify the reuse relationship of transmit beams in multiple PRACH transmissions within a RO group without increasing or only slightly increasing explicit signaling overhead. Furthermore, by binding and multiplexing preamble sets / resource sets, the number of preambles that need to be reserved on the network side is reduced, and the implementation complexity is lowered.

[0197] Furthermore, network devices can improve PRACH detection probability and enhance coverage by supporting the merging of multiple PRACH reception results corresponding to the same transmit beam. Network devices can also improve beam matching performance for uplink transmissions such as message 3 by supporting beam refinement and optimal beam pair selection for multiple transmit beams.

[0198] The above text combined Figures 1 to 7 The method embodiments of this application are described in detail below. Figures 8 to 10 The present application provides a detailed description of the apparatus embodiments. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any parts not described in detail can be found in the foregoing method embodiments.

[0199] Figure 8 This is a schematic block diagram of a device for wireless communication according to an embodiment of this application. The device 800 can be any of the terminal devices described above. Figure 8 The apparatus 800 shown includes a processing unit 810 and a transmitting unit 820.

[0200] The processing unit 810 can be used to determine a first transmission mode, which is used to indicate the association between PRACH repeat and multiple transmit beams supported by the terminal device.

[0201] The transmitting unit 820 can be used to perform PRACH retransmission according to the first transmission mode; wherein the first transmission mode is associated with first information, and the first information includes at least one of the following: the preamble corresponding to the PRACH retransmission, the RO corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

[0202] Optionally, the first information is used by the network device to determine the first transmission mode.

[0203] Optionally, the association includes at least one of the following: whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; the index of one or more transmit beams among the plurality of transmit beams used to transmit the PRACH repeat; and the number of times the PRACH repeat is transmitted on any of the plurality of transmit beams.

[0204] Optionally, determining the first transmission mode includes: determining the first transmission mode based on the number of transmit beams supported by the terminal device and the number of times the PRACH is repeatedly transmitted.

[0205] Optionally, the number of PRACH retransmissions is carried in the configuration information of the network device. When the configuration information includes multiple candidate numbers for PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: determined according to the number of transmit beams supported by the terminal device; the initial transmission of the PRACH retransmission uses the minimum value among the multiple candidate numbers, and the retransmission of the PRACH retransmission uses any value greater than the minimum value.

[0206] Optionally, the first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission. The terminal device supports K transmit beams, where N is a positive integer, and the number of PRACH repeated transmissions is N, where N is a positive integer. The first transmission mode indicates at least one of the following: when K is greater than N, N transmit beams of the K transmit beams are used for the initial transmission of the PRACH repeated transmission, and the transmit beams of the K transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeated transmission; when K is equal to N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; when K is less than N, some transmit beams of the K transmit beams are used for multiple PRACH transmissions; when K is less than N, some PRACH repeated transmissions of the N PRACH repeated transmissions are skipped.

[0207] Optionally, the first transmission mode is one of a plurality of transmission modes, the preamble corresponding to the repeated PRACH transmission belongs to a first preamble subset, the first preamble subset is a preamble subset of a plurality of preamble subsets that corresponds to the first transmission mode, and the plurality of preamble subsets correspond one-to-one with the plurality of transmission modes.

[0208] Optionally, any one of the preambles in the plurality of preamble subsets is a preamble used by CBRA.

[0209] Optionally, the first transmission mode is one of a plurality of transmission modes, the RO corresponding to the PRACH repeated transmission is an RO in a first subset of ROs, and the first subset of ROs is one of a plurality of RO subsets; the plurality of RO subsets are associated with different transmit beams, or the plurality of RO subsets are associated with RO transmission modes.

[0210] Optionally, the RO corresponding to the repeated PRACH transmission includes a shared RO and / or an independent RO. The shared RO is used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams, and the independent RO is used for PRACH transmissions corresponding to different transmit beams.

[0211] Optionally, the shared RO is one or more ROs in a shared RO pool, the shared RO pool including a second subset of ROs and a third subset of ROs, the ROs in the second subset of ROs being used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission, and the ROs in the third subset of ROs being used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

[0212] Optionally, the RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: all ROs in the first RO group are associated with the same Synchronization Signal Block (SSB) index; different ROs in the first RO group are associated with different SSB indices; the first RO group includes multiple RO subsets, and the multiple RO subsets correspond one-to-one with multiple SSB indices.

[0213] Optionally, the first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among a plurality of PRACH resource configurations configured by the network device.

[0214] Optionally, the feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

[0215] Optionally, the PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

[0216] Optionally, the processing unit 810 in the device 800 can be a processor 1010, the transmitting unit 820 can be a transceiver 1030, and the device 800 may also include a memory 1020, specifically as follows: Figure 10 As shown.

[0217] Figure 9 This is a schematic block diagram of another device for wireless communication according to an embodiment of this application. The device 900 can be any of the network devices described above. Figure 9 The apparatus 900 shown includes a processing unit 910 and a receiving unit 920.

[0218] The processing unit 910 can be used to determine a first transmission mode, which is used to indicate the association between the PRACH repeat and multiple transmit beams supported by the terminal device.

[0219] The receiving unit 920 can be used to receive PRACH repeated transmissions; wherein the first transmission mode is associated with first information, the first information including at least one of the following: the preamble corresponding to the PRACH repeated transmission, the RO corresponding to the PRACH repeated transmission, the first PRACH resource configuration corresponding to the PRACH repeated transmission, the feature combination field corresponding to the PRACH repeated transmission, and the first uplink information.

[0220] Optionally, the first information is used by the network device to determine the first transmission mode.

[0221] Optionally, the association includes at least one of the following: whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; the index of one or more transmit beams among the plurality of transmit beams used to transmit the PRACH repeat; and the number of times the PRACH repeat is transmitted on any of the plurality of transmit beams.

[0222] Optionally, the first transmission mode is determined based on the number of transmit beams supported by the terminal device and the number of times PRACH is repeatedly transmitted.

[0223] Optionally, the number of PRACH retransmissions is carried in the configuration information of the network device. When the configuration information includes multiple candidate numbers for PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: determined according to the number of transmit beams supported by the terminal device; the initial transmission of the PRACH retransmission uses the minimum value among the multiple candidate numbers, and the retransmission of the PRACH retransmission uses any value greater than the minimum value.

[0224] Optionally, the first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission. The terminal device supports K transmit beams, where N is a positive integer, and the number of PRACH repeated transmissions is N, where N is a positive integer. The first transmission mode indicates at least one of the following: when K is greater than N, N transmit beams of the K transmit beams are used for the initial transmission of the PRACH repeated transmission, and the transmit beams of the K transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeated transmission; when K is equal to N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; when K is less than N, some transmit beams of the K transmit beams are used for multiple PRACH transmissions; when K is less than N, some PRACH repeated transmissions of the N PRACH repeated transmissions are skipped.

[0225] Optionally, the first transmission mode is one of a plurality of transmission modes, the preamble corresponding to the repeated PRACH transmission belongs to a first preamble subset, the first preamble subset is a preamble subset of a plurality of preamble subsets that corresponds to the first transmission mode, and the plurality of preamble subsets correspond one-to-one with the plurality of transmission modes.

[0226] Optionally, any one of the preambles in the plurality of preamble subsets is a preamble used by CBRA.

[0227] Optionally, the first transmission mode is one of a plurality of transmission modes, the RO corresponding to the PRACH repeated transmission is an RO in a first subset of ROs, and the first subset of ROs is one of a plurality of RO subsets; the plurality of RO subsets are associated with different transmit beams, or the plurality of RO subsets are associated with RO transmission modes.

[0228] Optionally, the RO corresponding to the repeated PRACH transmission includes a shared RO and / or an independent RO. The shared RO is used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams, and the independent RO is used for PRACH transmissions corresponding to different transmit beams.

[0229] Optionally, the shared RO is one or more ROs in a shared RO pool, the shared RO pool including a second subset of ROs and a third subset of ROs, the ROs in the second subset of ROs being used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission, and the ROs in the third subset of ROs being used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

[0230] Optionally, the RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: all ROs in the first RO group are associated with the same Synchronization Signal Block (SSB) index; different ROs in the first RO group are associated with different SSB indices; the first RO group includes multiple RO subsets, and the multiple RO subsets correspond one-to-one with multiple SSB indices.

[0231] Optionally, the first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among a plurality of PRACH resource configurations configured by the network device.

[0232] Optionally, the feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

[0233] Optionally, the PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

[0234] Optionally, the processing unit 910 in the device 900 can be a processor 1010, the receiving unit 920 can be a transceiver 1030, and the device 900 may also include a memory 1020, specifically as follows: Figure 10 As shown.

[0235] Figure 10 The diagram shown is a structural schematic of a communication device according to an embodiment of this application. Figure 10 The dashed lines indicate that the unit or module is optional. The device 1000 can be used to implement the methods described in the above method embodiments. The device 1000 can be a chip, a terminal device, or a network device.

[0236] Apparatus 1000 may include one or more processors 1010. The processor 1010 may support apparatus 1000 in implementing the methods described in the preceding method embodiments. The processor 1010 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0237] The apparatus 1000 may further include one or more memories 1020. The memories 1020 store a program that can be executed by the processor 1010, causing the processor 1010 to perform the methods described in the preceding method embodiments. The memories 1020 may be independent of the processor 1010 or integrated within the processor 1010.

[0238] The device 1000 may also include a transceiver 1030. The processor 1010 can communicate with other devices or chips via the transceiver 1030. For example, the processor 1010 can send and receive data with other devices or chips via the transceiver 1030.

[0239] This application also provides a computer-readable storage medium for storing a program. This computer-readable storage medium can be applied to a terminal device or network device provided in this application embodiment, and the program causes a computer to execute the methods performed by the terminal device or network device in the various embodiments of this application.

[0240] The computer-readable storage medium can be any available medium that a computer can read, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs, DVDs), or semiconductor media (e.g., solid-state disks, SSDs), etc.

[0241] This application also provides a computer program product. The computer program product includes a program. This computer program product can be applied to a terminal device or network device provided in the embodiments of this application, and the program causes a computer to execute the methods performed by the terminal device or network device in the various embodiments of this application.

[0242] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0243] This application also provides a computer program. This computer program can be applied to the terminal device or network device provided in this application, and the computer program causes the computer to execute the methods performed by the terminal device or network device in various embodiments of this application.

[0244] In this application, the terms "system" and "network" are used interchangeably. Furthermore, the terminology used in this application is only for explaining specific embodiments of the application and is not intended to limit the application. The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0245] In the embodiments of this application, the term "instruction" can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0246] In the embodiments of this application, the term "correspondence" may indicate a direct or indirect correspondence between two things, or an association between two things, or a relationship such as instruction and being instructed, configuration and being configured.

[0247] In the embodiments of this application, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0248] In the embodiments of this application, the term "protocol" may refer to standard protocols in the field of communications, such as LTE protocols, NR protocols, and related protocols applied in future communication systems. This application does not limit the scope of these protocols.

[0249] In the embodiments of this application, determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0250] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0251] In the embodiments of this application, the order of the above-mentioned process numbers does not imply 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 this application.

[0252] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0253] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0254] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0255] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for wireless communication, characterized in that, include: The terminal device determines a first transmission mode, which is used to indicate the association between the Physical Random Access Channel (PRACH) repeat and multiple transmit beams supported by the terminal device. The terminal device performs repeated PRACH transmissions according to the first transmission mode; Wherein, the first transmission mode is associated with the first information, the first information including at least one of the following: the preamble corresponding to the PRACH retransmission, the random access channel timing (RO) corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

2. The method according to claim 1, characterized in that, The first information is used by the network device to determine the first transmission mode.

3. The method according to claim 1 or 2, characterized in that, The association includes at least one of the following: Whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; The index of one or more transmit beams used to transmit the PRACH repeats among the plurality of transmit beams; The PRACH repeats the transmission a number of times on any of the plurality of transmit beams.

4. The method according to any one of claims 1-3, characterized in that, The terminal device determines the first transmission mode, including: The terminal device determines the first transmission mode based on the number of transmit beams supported by the terminal device and the number of times the PRACH is repeatedly transmitted.

5. The method according to claim 4, characterized in that, The number of PRACH retransmissions is carried in the network device's configuration information. When the configuration information includes multiple candidate numbers for the PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: Determined based on the number of transmit beams supported by the terminal device; The initial transmission of the PRACH repeating uses the minimum value among the multiple candidate transmissions, and the retransmission of the PRACH repeating uses any value greater than the minimum value.

6. The method according to claim 4 or 5, characterized in that, The first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission, the terminal device supports K transmit beams, where N is a positive integer, the number of PRACH repeated transmissions is N, where N is a positive integer, and the first transmission mode indicates at least one of the following: When K is greater than N, N of the K transmit beams are used for the initial transmission of the PRACH repeating transmission, and the transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeating transmission. When K equals N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; When K is less than N, some of the K transmit beams are used for multiple PRACH transmissions; When K is less than N, some of the PRACH repeat transmissions in the N PRACH repeat transmissions are skipped.

7. The method according to any one of claims 1-6, characterized in that, The first transmission mode is one of multiple transmission modes, and the preamble corresponding to the repeated PRACH transmission belongs to the first preamble subset. The first preamble subset is a preamble subset corresponding to the first transmission mode in multiple preamble subsets, and the multiple preamble subsets correspond one-to-one with the multiple transmission modes.

8. The method according to claim 7, characterized in that, Any one of the preambles in the plurality of preamble subsets is a preamble used by contention-based random access CBRA.

9. The method according to any one of claims 1-8, characterized in that, The first transmission mode is one of multiple transmission modes, and the RO corresponding to the PRACH repeated transmission is an RO in the first RO subset, which is one of multiple RO subsets; the multiple RO subsets are associated with different transmit beams, or the multiple RO subsets are associated with RO transmission modes.

10. The method according to any one of claims 1-8, characterized in that, The ROs corresponding to the repeated PRACH transmissions include shared ROs and / or independent ROs. The shared ROs are used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams. The independent ROs are used for PRACH transmissions corresponding to different transmit beams.

11. The method according to claim 10, characterized in that, The shared RO is one or more ROs in a shared RO pool. The shared RO pool includes a second subset of ROs and a third subset of ROs. The ROs in the second subset of ROs are used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission. The ROs in the third subset of ROs are used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

12. The method according to any one of claims 1-8, characterized in that, The RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: All ROs in the first RO group are associated with the same synchronization signal block SSB index; Different ROs in the first RO group are associated with different SSB indexes; The first RO group includes multiple RO subsets, and each of the multiple RO subsets corresponds one-to-one with a multiple SSB index.

13. The method according to any one of claims 1-12, characterized in that, The first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among the multiple PRACH resource configurations configured by the network device.

14. The method according to any one of claims 1-13, characterized in that, The feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

15. The method according to any one of claims 1-14, characterized in that, The PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

16. A method for wireless communication, characterized in that, include: The network device determines a first transmission mode, which is used to indicate the association between the physical random access channel (PRACH) repeat and multiple transmit beams supported by the terminal device. The network device receives repeated PRACH transmissions; Wherein, the first transmission mode is associated with the first information, the first information including at least one of the following: the preamble corresponding to the PRACH retransmission, the random access channel timing (RO) corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

17. The method according to claim 16, characterized in that, The first information is used by the network device to determine the first transmission mode.

18. The method according to claim 16 or 17, characterized in that, The association includes at least one of the following: Whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; The index of one or more transmit beams used to transmit the PRACH repeats among the plurality of transmit beams; The PRACH repeats the transmission a number of times on any of the plurality of transmit beams.

19. The method according to any one of claims 16-18, characterized in that, The first transmission mode is determined based on the number of transmit beams supported by the terminal device and the number of times the PRACH is repeatedly transmitted.

20. The method according to claim 19, characterized in that, The number of PRACH retransmissions is carried in the network device's configuration information. When the configuration information includes multiple candidate numbers for the PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: Determined based on the number of transmit beams supported by the terminal device; The initial transmission of the PRACH repeating uses the minimum value among the multiple candidate transmissions, and the retransmission of the PRACH repeating uses any value greater than the minimum value.

21. The method according to claim 19 or 20, characterized in that, The first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission, the terminal device supports K transmit beams, where N is a positive integer, the number of PRACH repeated transmissions is N, where N is a positive integer, and the first transmission mode indicates at least one of the following: When K is greater than N, N of the K transmit beams are used for the initial transmission of the PRACH repeating transmission, and the transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeating transmission. When K equals N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; When K is less than N, some of the K transmit beams are used for multiple PRACH transmissions; When K is less than N, some of the PRACH repeat transmissions in the N PRACH repeat transmissions are skipped.

22. The method according to any one of claims 16-21, characterized in that, The first transmission mode is one of multiple transmission modes, and the preamble corresponding to the repeated PRACH transmission belongs to the first preamble subset. The first preamble subset is a preamble subset corresponding to the first transmission mode in multiple preamble subsets, and the multiple preamble subsets correspond one-to-one with the multiple transmission modes.

23. The method according to claim 22, characterized in that, Any one of the preambles in the plurality of preamble subsets is a preamble used by contention-based random access CBRA.

24. The method according to any one of claims 16-23, characterized in that, The first transmission mode is one of multiple transmission modes, and the RO corresponding to the PRACH repeated transmission is an RO in the first RO subset, which is one of multiple RO subsets; the multiple RO subsets are associated with different transmit beams, or the multiple RO subsets are associated with RO transmission modes.

25. The method according to any one of claims 16-23, characterized in that, The ROs corresponding to the repeated PRACH transmissions include shared ROs and / or independent ROs. The shared ROs are used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams. The independent ROs are used for PRACH transmissions corresponding to different transmit beams.

26. The method according to claim 25, characterized in that, The shared RO is one or more ROs in a shared RO pool. The shared RO pool includes a second subset of ROs and a third subset of ROs. The ROs in the second subset of ROs are used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission. The ROs in the third subset of ROs are used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

27. The method according to any one of claims 16-23, characterized in that, The RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: All ROs in the first RO group are associated with the same synchronization signal block SSB index; Different ROs in the first RO group are associated with different SSB indexes; The first RO group includes multiple RO subsets, and each of the multiple RO subsets corresponds one-to-one with a multiple SSB index.

28. The method according to any one of claims 16-27, characterized in that, The first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among the multiple PRACH resource configurations configured by the network device.

29. The method according to any one of claims 16-28, characterized in that, The feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

30. The method according to any one of claims 16-29, characterized in that, The PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

31. A device for wireless communication, characterized in that, The device is a terminal device, and the device includes: A processing unit is configured to determine a first transmission mode, wherein the first transmission mode is configured to indicate the association between the Physical Random Access Channel (PRACH) repeat and multiple transmit beams supported by the terminal device. A transmitting unit is configured to perform repeated PRACH transmissions according to the first transmission mode; Wherein, the first transmission mode is associated with the first information, the first information including at least one of the following: the preamble corresponding to the PRACH retransmission, the random access channel timing (RO) corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

32. The apparatus according to claim 31, characterized in that, The first information is used by the network device to determine the first transmission mode.

33. The apparatus according to claim 31 or 32, characterized in that, The association includes at least one of the following: Whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; The index of one or more transmit beams used to transmit the PRACH repeats among the plurality of transmit beams; The PRACH repeats the transmission a number of times on any of the plurality of transmit beams.

34. The apparatus according to any one of claims 31-33, characterized in that, Determining the first transmission mode includes: The first transmission mode is determined based on the number of transmit beams supported by the terminal device and the number of times the PRACH is repeatedly transmitted.

35. The apparatus according to claim 34, characterized in that, The number of PRACH retransmissions is carried in the network device's configuration information. When the configuration information includes multiple candidate numbers for the PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: Determined based on the number of transmit beams supported by the terminal device; The initial transmission of the PRACH repeating uses the minimum value among the multiple candidate transmissions, and the retransmission of the PRACH repeating uses any value greater than the minimum value.

36. The apparatus according to claim 34 or 35, characterized in that, The first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission, the terminal device supports K transmit beams, where N is a positive integer, the number of PRACH repeated transmissions is N, where N is a positive integer, and the first transmission mode indicates at least one of the following: When K is greater than N, N of the K transmit beams are used for the initial transmission of the PRACH repeating transmission, and the transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeating transmission. When K equals N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; When K is less than N, some of the K transmit beams are used for multiple PRACH transmissions; When K is less than N, some of the PRACH repeat transmissions in the N PRACH repeat transmissions are skipped.

37. The apparatus according to any one of claims 31-36, characterized in that, The first transmission mode is one of multiple transmission modes, and the preamble corresponding to the repeated PRACH transmission belongs to the first preamble subset. The first preamble subset is a preamble subset corresponding to the first transmission mode in multiple preamble subsets, and the multiple preamble subsets correspond one-to-one with the multiple transmission modes.

38. The apparatus according to claim 37, characterized in that, Any one of the preambles in the plurality of preamble subsets is a preamble used by contention-based random access CBRA.

39. The apparatus according to any one of claims 31-38, characterized in that, The first transmission mode is one of multiple transmission modes, and the RO corresponding to the PRACH repeated transmission is an RO in the first RO subset, which is one of multiple RO subsets; the multiple RO subsets are associated with different transmit beams, or the multiple RO subsets are associated with RO transmission modes.

40. The apparatus according to any one of claims 31-38, characterized in that, The ROs corresponding to the repeated PRACH transmissions include shared ROs and / or independent ROs. The shared ROs are used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams. The independent ROs are used for PRACH transmissions corresponding to different transmit beams.

41. The apparatus according to claim 40, characterized in that, The shared RO is one or more ROs in a shared RO pool. The shared RO pool includes a second subset of ROs and a third subset of ROs. The ROs in the second subset of ROs are used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission. The ROs in the third subset of ROs are used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

42. The apparatus according to any one of claims 31-38, characterized in that, The RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: All ROs in the first RO group are associated with the same synchronization signal block SSB index; Different ROs in the first RO group are associated with different SSB indexes; The first RO group includes multiple RO subsets, and each of the multiple RO subsets corresponds one-to-one with a multiple SSB index.

43. The apparatus according to any one of claims 31-42, characterized in that, The first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among the multiple PRACH resource configurations configured by the network device.

44. The apparatus according to any one of claims 31-43, characterized in that, The feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

45. The apparatus according to any one of claims 31-44, characterized in that, The PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

46. ​​A device for wireless communication, characterized in that, The device is a network device, and the device includes: The processing unit is configured to determine a first transmission mode, wherein the first transmission mode is configured to indicate the association between the physical random access channel (PRACH) repeat and multiple transmit beams supported by the terminal device. The receiving unit is used to receive repeated PRACH transmissions; Wherein, the first transmission mode is associated with the first information, the first information including at least one of the following: the preamble corresponding to the PRACH retransmission, the random access channel timing (RO) corresponding to the PRACH retransmission, the first PRACH resource configuration corresponding to the PRACH retransmission, the feature combination field corresponding to the PRACH retransmission, and the first uplink information.

47. The apparatus according to claim 46, characterized in that, The first information is used by the network device to determine the first transmission mode.

48. The apparatus according to claim 46 or 47, characterized in that, The association includes at least one of the following: Whether the PRACH repeat is transmitted through at least two of the plurality of transmit beams; The index of one or more transmit beams used to transmit the PRACH repeats among the plurality of transmit beams; The PRACH repeats the transmission a number of times on any of the plurality of transmit beams.

49. The apparatus according to any one of claims 46-48, characterized in that, The first transmission mode is determined based on the number of transmit beams supported by the terminal device and the number of times the PRACH is repeatedly transmitted.

50. The apparatus according to claim 49, characterized in that, The number of PRACH retransmissions is carried in the network device's configuration information. When the configuration information includes multiple candidate numbers for the PRACH retransmissions, the number of PRACH retransmissions satisfies at least one of the following: Determined based on the number of transmit beams supported by the terminal device; The initial transmission of the PRACH repeating uses the minimum value among the multiple candidate transmissions, and the retransmission of the PRACH repeating uses any value greater than the minimum value.

51. The apparatus according to claim 49 or 50, characterized in that, The first transmission mode includes the initial transmission and / or retransmission of the PRACH repeated transmission, the terminal device supports K transmit beams, where N is a positive integer, the number of PRACH repeated transmissions is N, where N is a positive integer, and the first transmission mode indicates at least one of the following: When K is greater than N, N of the K transmit beams are used for the initial transmission of the PRACH repeating transmission, and the transmit beams other than the N transmit beams are used for the retransmission of the PRACH repeating transmission. When K equals N, the K transmit beams are used for the initial transmission and / or retransmission of the PRACH repeated transmission; When K is less than N, some of the K transmit beams are used for multiple PRACH transmissions; When K is less than N, some of the PRACH repeat transmissions in the N PRACH repeat transmissions are skipped.

52. The apparatus according to any one of claims 46-51, characterized in that, The first transmission mode is one of multiple transmission modes, and the preamble corresponding to the repeated PRACH transmission belongs to the first preamble subset. The first preamble subset is a preamble subset corresponding to the first transmission mode in multiple preamble subsets, and the multiple preamble subsets correspond one-to-one with the multiple transmission modes.

53. The apparatus according to claim 52, characterized in that, Any one of the preambles in the plurality of preamble subsets is a preamble used by contention-based random access CBRA.

54. The apparatus according to any one of claims 46-53, characterized in that, The first transmission mode is one of multiple transmission modes, and the RO corresponding to the PRACH repeated transmission is an RO in the first RO subset, which is one of multiple RO subsets; the multiple RO subsets are associated with different transmit beams, or the multiple RO subsets are associated with RO transmission modes.

55. The apparatus according to any one of claims 46-53, characterized in that, The ROs corresponding to the repeated PRACH transmissions include shared ROs and / or independent ROs. The shared ROs are used for PRACH transmissions corresponding to the same transmit beam and PRACH transmissions corresponding to different transmit beams. The independent ROs are used for PRACH transmissions corresponding to different transmit beams.

56. The apparatus according to claim 55, characterized in that, The shared RO is one or more ROs in a shared RO pool. The shared RO pool includes a second subset of ROs and a third subset of ROs. The ROs in the second subset of ROs are used for one or more PRACH transmissions using the same transmit beam in the PRACH repetition transmission. The ROs in the third subset of ROs are used for one or more PRACH transmissions using different transmit beams in the PRACH repetition transmission.

57. The apparatus according to any one of claims 46-53, characterized in that, The RO corresponding to the PRACH repeated transmission is an RO in the first RO group, and the RO in the first RO group satisfies one of the following: All ROs in the first RO group are associated with the same synchronization signal block SSB index; Different ROs in the first RO group are associated with different SSB indexes; The first RO group includes multiple RO subsets, and each of the multiple RO subsets corresponds one-to-one with a multiple SSB index.

58. The apparatus according to any one of claims 46-57, characterized in that, The first PRACH resource configuration is the PRACH resource configuration that is bound to the first transmission mode among the multiple PRACH resource configurations configured by the network device.

59. The apparatus according to any one of claims 46-58, characterized in that, The feature combination field is carried in the first uplink information, which is carried in the adjacent uplink transmission after the PRACH retransmission.

60. The apparatus according to any one of claims 46-59, characterized in that, The PRACH repeat transmission includes at least two PRACH transmissions using the same transmit beam, the at least two PRACH transmissions being used by the network device to perform a merging process, the merging process being used to determine a merging metric for the transmit beams corresponding to the at least two PRACH transmissions.

61. A communication device, characterized in that, It includes a memory and a processor, the memory being used to store a program, and the processor being used to invoke the program in the memory to perform the method as described in any one of claims 1-30.

62. An apparatus, characterized in that, Includes a processor for calling a program from memory to perform the method as described in any one of claims 1-30.

63. A chip, characterized in that, Includes a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 1-30.

64. A computer-readable storage medium, characterized in that, It contains a program that causes a computer to perform the method as described in any one of claims 1-30.

65. A computer program product, characterized in that, Includes a program that causes a computer to perform the method as described in any one of claims 1-30.

66. A computer program, characterized in that, The computer program causes the computer to perform the method as described in any one of claims 1-30.

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