WO2022247721A1

WO2022247721A1 - Random access method and apparatus

Info

Publication number: WO2022247721A1
Application number: PCT/CN2022/093824
Authority: WO
Inventors: 刘小成; 于天航; 罗禾佳; 王俊
Original assignee: 华为技术有限公司
Priority date: 2021-05-26
Filing date: 2022-05-19
Publication date: 2022-12-01
Also published as: CN115412950A

Abstract

The present application provides a random access method, comprising: determining a first time difference T1, the first time difference T1 being used for indicating a time difference between the time domain position of a first signal received from a network device and a first fixed time, the first fixed time being determined according to a global navigation satellite system 1 pulse per second (GNSS 1pps) signal; determining communication delay Td according to the first time difference T1; and sending an uplink physical random access channel (PRACH) preamble sequence to a network device according to the communication time delay Td. According to the technical solution of the present application, by determining the communication delay with the network device and sending the PRACH preamble sequence according to the communication delay, the terminal device can quickly and stably complete random access.

Description

Method and device for random access

This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office of China on May 26, 2021, with the application number 202110574961.3 and the application title "Method and device for random access", the entire contents of which are incorporated herein by reference Applying.

technical field

The present application relates to the communication field, and more specifically, to a random access method and device.

Background technique

In a wireless communication system, a terminal device needs to establish a connection with a network device, and this process is generally called a random access (RA) process. From the perspective of network equipment, it is necessary to receive the uplink Physical Random Access Channel (PRACH) sequence sent by the terminal equipment in a fixed time window, and analyze it. However, the absence of the PRACH sequence received by the network device will cause excessive delay and jitter between the terminal device and the network device, which is not conducive to the realization of the RA process.

At present, in order to reduce the access delay between the terminal device and the network device, a cyclic prefix (cyclic prefix, CP) is usually added to the PRACH sequence. However, in some large cell scenarios, such as satellite communication, existing technologies cannot meet the needs of practical applications.

Therefore, there is an urgent need for a random access method, which can ensure that terminal devices can quickly and stably complete random access in a cell with a large radius and in a satellite communication scenario.

Contents of the invention

The present application provides a method and device for random access, which help terminal equipment quickly and stably complete random access in a cell with a large radius and in a satellite communication scenario.

In a first aspect, a method for random access is provided, including: determining a first time difference T1, where the first time difference T1 is used to indicate the time difference between a time domain position for receiving a first signal from a network device and a first fixed time, the first A fixed time is determined according to the 1-second pulse GNSS 1pps signal of the global navigation satellite system; the communication delay Td is determined according to the first time difference T1; the uplink physical random access channel PRACH preamble is sent to the network device according to the communication delay Td.

According to the technical solution of the present application, by determining the communication delay with the network equipment and sending the PRACH preamble sequence according to the communication delay, it is helpful for the terminal equipment to quickly and stably complete random access.

Wherein, the first signal includes: a primary synchronization signal PSS or a physical broadcast channel PBCH.

With reference to the first aspect, in some implementations of the first aspect, determining the communication delay Td according to the first time difference T1 includes: acquiring a pre-configured second time difference Tf and a third time difference Tp, and the second time difference Tf is used to indicate The network device sends the time difference between the starting position of the 0th subframe of the air interface frame and the first fixed time, and the third time difference Tp is used to indicate the time difference between the time domain position where the network device sends the first signal and the first fixed time; according to the first time difference T1, the second time difference Tf and the third time difference Tp determine the communication delay Td.

With reference to the first aspect, in some implementations of the first aspect, the above method further includes: receiving GNSS 1pps signals.

In the second aspect, a random access method is provided, including: sending a first signal to a terminal device according to a first fixed time, the first fixed time is determined according to a 1-second pulse GNSS 1pps signal of a global navigation satellite system; The preamble sequence of the uplink physical random access channel PRACH of the terminal device.

With reference to the second aspect, in some implementations of the second aspect, the above method further includes: receiving a GNSS 1pps signal.

In a third aspect, a device for random access is provided, including: a processing unit configured to determine a first time difference T1, and the first time difference T1 is used to indicate the time domain position and the first fixed time point for receiving a first signal from a network device The time difference of time, the first fixed time is determined according to the global navigation satellite system 1 second pulse GNSS 1pps signal; The processing unit is also used to determine the communication time delay Td according to the first time difference T1; The network device sends the preamble sequence of the uplink physical random access channel PRACH.

With reference to the third aspect, in some implementations of the third aspect, the transceiver unit is specifically configured to: acquire a pre-configured second time difference Tf and a third time difference Tp, and the second time difference Tf is used to instruct the network device to send the air interface frame 0 The time difference between the starting position of the subframe and the first fixed time, and the third time difference Tp is used to indicate the time difference between the time domain position where the network device sends the first signal and the first fixed time; the processing unit is specifically configured to: according to the first time difference T1 , the second time difference Tf and the third time difference Tp determine the communication delay Td.

With reference to the third aspect, in some implementation manners of the third aspect, the transceiver unit is further configured to: receive GNSS 1pps signals.

In a fourth aspect, a device for random access is provided, including: a transceiver unit, configured to send a first signal to a terminal device according to a first fixed time, and the first fixed time is based on a 1-second pulse GNSS 1pps signal of a global navigation satellite system determined; the transceiving unit is further configured to receive an uplink physical random access channel PRACH preamble from the terminal device.

With reference to the fourth aspect, in some implementation manners of the fourth aspect, the transceiver unit is further configured to: receive GNSS 1pps signals.

In a fifth aspect, a communication device is provided, including: a processor, the processor is coupled with a memory, and the memory is used to store programs or instructions, and when the programs or instructions are executed by the processor, the device implements the first or second aspect. Any one of the two aspects and methods in various implementation manners thereof.

Optionally, there are one or more processors, and one or more memories.

Optionally, the memory may be integrated with the processor, or the memory may be separated from the processor.

In a sixth aspect, a communication system is provided, including a terminal device and a network device.

Wherein, the terminal device is configured to implement the method in each implementation manner in the above first aspect, and the network device is configured to implement the method in each implementation manner in the above second aspect.

In a possible design, the communication system further includes other devices that interact with the communication device in the solutions provided by the embodiments of the present application.

According to a seventh aspect, a computer program product is provided, and the computer program product includes: computer program code, when the computer program code is run on a computer, it causes the computer to execute the methods in the above aspects.

It should be noted that all or part of the above computer program code may be stored on the first storage medium, where the first storage medium may be packaged together with the processor, or may be packaged separately with the processor, and this embodiment of the present application does not make any Specific limits.

In an eighth aspect, a computer-readable medium is provided, the computer-readable medium stores program codes, and when the computer program codes are run on a computer, the computer is made to execute the methods in the above aspects.

A ninth aspect provides a chip system, including a memory and a processor, the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the communication device installed with the chip system executes the above-mentioned Any aspect from the first aspect to the fifth aspect and a method in a possible implementation thereof.

Wherein, the chip system may include an input chip or interface for sending information or data, and an output chip or interface for receiving information or data.

Description of drawings

FIG. 1 is a schematic diagram of a communication system 100 suitable for use in the present application.

FIG. 2 is a schematic diagram of an example of a network architecture applicable to this application.

Fig. 3 is a schematic diagram of an example of a network device communicating with a terminal device through a beamforming technology.

Fig. 4 is an example flow chart of contention random access in LTE system and 5G system.

Fig. 5 is a schematic diagram showing an example of leader sequence classification.

Fig. 6 is a schematic diagram of an example of the time domain position of the uplink physical random access channel PRACH.

Fig. 7 is a schematic diagram of an example of the frequency domain position of the uplink physical random access channel PRACH.

Fig. 8 is a schematic flow chart of an example of PRACH cell planning in the prior art.

FIG. 9 is a schematic diagram of an example of PRACH signal transmission and reception in the prior art.

Fig. 10 is a schematic flowchart of an example of the random access method of the present application.

Figure 11 is a schematic diagram of a GNSS 1pps signal applicable to this application.

Fig. 12 is a schematic flowchart of another example of the random access method of the present application.

FIG. 13 is a schematic diagram of an example of an air interface sequence applicable to the present application.

FIG. 14 is a schematic diagram of an example of PRACH signal transmission and reception in the present application.

Fig. 15 is a schematic structural diagram of an example of a random access device of the present application.

Fig. 16 is a schematic structural diagram of another example of a random access device of the present application.

Detailed ways

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

FIG. 1 is a schematic diagram of a communication system 100 applicable to an embodiment of the present application.

As shown in FIG. 1 , the communication system 100 may include a network device 101 and a terminal device 102 , and optionally, may also include a core network device 103 . Wherein, the network device 101 can communicate with the core network device 103 ; the terminal device 102 can communicate with the network device 101 .

The terminal equipment in the embodiment of the present application may refer to user equipment, access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication device, user agent or user device . The terminal in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (pad), a computer with a wireless transceiver function, a virtual reality (virtual reality, VR) terminal, an augmented reality (augmented reality, AR) terminal, an industrial Wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical, wireless terminals in smart grid, transportation safety Wireless terminals in smart cities, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop ( wireless local loop (WLL) station, personal digital assistant (personal digital assistant, PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, 5G network A terminal or a terminal in a future evolved network, etc.

Among them, wearable devices can also be called wearable smart devices, which is a general term for the application of wearable technology to intelligently design daily wear and develop wearable devices, such as glasses, gloves, watches, clothing and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not only a hardware device, but also achieve powerful functions through software support, data interaction, and cloud interaction. Generalized wearable smart devices include full-featured, large-sized, complete or partial functions without relying on smart phones, such as smart watches or smart glasses, etc., and only focus on a certain type of application functions, and need to cooperate with other devices such as smart phones Use, such as various smart bracelets and smart jewelry for physical sign monitoring.

In addition, the terminal device may also be a terminal device in an Internet of Things (internet of things, IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, so as to realize the intelligent network of human-machine interconnection and object interconnection. The present application does not limit the specific form of the terminal device.

It should be understood that, in this embodiment of the present application, the terminal device may be a device for realizing the function of the terminal device, or may be a device capable of supporting the terminal device to realize the function, such as a chip system, and the device may be installed in the terminal. In the embodiment of the present application, the system-on-a-chip may be composed of chips, or may include chips and other discrete devices.

The network device in this embodiment of the present application may be any device with a wireless transceiver function. The equipment includes but is not limited to: evolved Node B (evolved Node B, eNB), radio network controller (radio network controller, RNC), Node B (Node B, NB), base station controller (base station controller, BSC) , base transceiver station (base transceiver station, BTS), home base station (for example, home evolved nodeB, or home node B, HNB), base band unit (base band unit, BBU), wireless fidelity (wireless fidelity, WIFI) system Access point (access point, AP), wireless relay node, wireless backhaul node, transmission point (transmission point, TP) or transmission and reception point (transmission and reception point, TRP), etc., can also be 5G, such as, NR, a gNB in the system, or, a transmission point (TRP or TP), one or a group (including multiple antenna panels) antenna panels of a base station in a 5G system, or, it can also be a network node that constitutes a gNB or a transmission point , such as a baseband unit (BBU), or a distributed unit (distributed unit, DU), etc.

In some deployments, a gNB may include a centralized unit (CU) and a DU.

The gNB may also include an active antenna unit (active antenna unit, AAU for short). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, and realizing the functions of radio resource control (radio resource control, RRC) and packet data convergence protocol (packet data convergence protocol, PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services, realizing the functions of the radio link control (radio link control, RLC) layer, media access control (media access control, MAC) layer and physical (physical, PHY) layer. The AAU implements some physical layer processing functions, radio frequency processing and related functions of active antennas. Since the information of the RRC layer will eventually become the information of the PHY layer, or be transformed from the information of the PHY layer, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU , or, sent by DU+AAU. It can be understood that the network device may be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU can be divided into network devices in an access network (radio access network, RAN), and the CU can also be divided into network devices in a core network (core network, CN), which is not limited in this application.

It should be understood that, in the embodiment of the present application, the network device may be a device for realizing the function of the network device, or may be a device capable of supporting the network device to realize the function, such as a chip system, and the device may be installed in the network device.

In the embodiment of the present application, the core network device may be a session management function (session management function, SMF) network element, an access and mobility management function (access and mobility management function, AMF) network element or a user plane function (user plane function) , UPF) network element, which is not limited in this application.

The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: global system for mobile communications (GSM) system, code division multiple access (code division multiple access, CDMA) system, wideband code division multiple access ( wideband code division multiple access (WCDMA) system, general packet radio service (general packet radio service, GPRS), long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division Duplex (time division duplex, TDD), universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5th generation, 5G) system Or future evolution of the communication system, vehicle to other devices (vehicle-to-X V2X), where V2X can include vehicle to Internet (vehicle to network, V2N), vehicle to vehicle (vehicle to vehicle, V2V), vehicle to infrastructure (vehicle to infrastructure, V2I), vehicle to pedestrian (vehicle to pedestrian, V2P), etc., long term evolution-vehicle (LTE-V), vehicle networking, machine type communication (MTC) , Internet of things (IoT), long term evolution-machine (LTE-M), machine-to-machine (M2M), device-to-device (D2D) Wait.

It should be understood that this application can be applied to independently deployed 5G or LTE systems, and can also be applied to non-independently deployed 5G or LTE systems, such as the application scenario of integrated satellite communication and 5G network shown in FIG. 2 .

In this scenario, the ground mobile terminal UE accesses the network through the 5G new air interface, and the 5G base station is deployed on the satellite and connected to the core network on the ground through a wireless link. At the same time, there is a wireless link between the satellites to complete signaling interaction and user data transmission between base stations.

Wherein, the terminal device may be a mobile device supporting 5G new air interface, such as a mobile phone, a tablet computer and other mobile devices, and the specific form may refer to the example in the above-mentioned FIG. 1 . For the specific form and function of 5G base stations and 5G core network, please refer to the description in Figure 1 above. The ground station is responsible for forwarding signaling and service data between the satellite base station and the 5G core network. The wireless link between the terminal equipment and the base station is the 5G new air interface, the interface between the 5G base station and the base station is the Xn interface, which is mainly used for signaling interaction such as handover, and the interface between the 5G base station and the 5G core network is the NG interface, mainly Interact signaling such as NAS of the core network and user service data.

In this embodiment of the present application, a terminal device or a network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system may be any one or more computer operating systems that implement business processing through processes, for example, Linux operating system, Unix operating system, Android operating system, iOS operating system, or windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software. Moreover, the embodiment of the present application does not specifically limit the specific structure of the execution subject of the method provided by the embodiment of the present application, as long as the program that records the code of the method provided by the embodiment of the present application can be run to provide the method according to the embodiment of the present application. For example, the execution subject of the method provided by the embodiment of the present application may be a terminal device or a network device, or a functional module in a terminal device or a network device that can call a program and execute the program.

Additionally, various aspects or features of the present application may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term "article of manufacture" as used in this application covers a computer program accessible from any computer readable device, carrier or media. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or tapes, etc.), optical disks (e.g., compact discs (compact discs, CDs), digital versatile discs (digital versatile discs, DVDs), etc.), smart cards and flash memory devices (for example, erasable programmable read-only memory (EPROM), card, stick or key drive, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and/or carrying instructions and/or data.

In order to facilitate understanding of the embodiment of the present application, concepts involved in the embodiment are first described below.

1. Cellular mobile communication (CMC)

Cellular mobile communication adopts cellular wireless networking mode, and connects terminal devices and network devices through wireless channels, so that users can communicate with each other during activities. Its main feature is the mobility of terminal equipment, and it has the functions of handover and automatic roaming across local networks. Cellular mobile communication services refer to voice, data, video and image services provided through a cellular mobile communication network composed of base station subsystems and mobile switching subsystems.

NR (New Radio, new air interface) is a global 5G standard based on a new OFDM air interface design, and is a very important next-generation cellular mobile technology. 5G technology will achieve ultra-low latency and high reliability. With the adoption of this standard by 3GPP (3rd Generation Partnership Project, the third generation cooperation project), the term NR has been used and has become another synonym for 5G, just as LTE (Long Term Evolution) is used to describe 4G wireless standards. The protocol-related content mentioned in this application refers to the NR protocol.

2. Satellite communication

The satellite communication system consists of three parts: the satellite terminal, the ground terminal, and the user terminal. In the previous satellite communication system, the satellite terminal played the role of a relay station in the air, that is, it amplified the electromagnetic wave sent by the ground station and then sent it back to another ground station. The satellite body includes two major subsystems: on-board equipment and satellite parent body. The ground station is the interface between the satellite system and the ground public network. Ground users can also enter and exit the satellite system through the ground station to form a link. The ground station also includes the ground satellite control center, and its tracking, telemetry and command stations. The client end refers to various user terminal devices.

The application fields of satellite communication continue to expand. In addition to finance, securities, post and telecommunications, meteorology, earthquakes and other departments, distance education, telemedicine, emergency disaster relief, emergency communications, emergency TV broadcasting, sea, land and air navigation, Internet telephone, TV, etc. will be widely used.

In order to achieve more flexible networking, satellite communications tend to adopt cellular technology, for example, moving base stations (BS) to satellites.

3. Beamforming

In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), and full-dimensional MIMO (full-dimension MIMO, FD-MIMO) are discussed in 5G systems. ), array antenna, digital beamforming (digital beamforming), analog beamforming (analog beamforming) and other antenna technologies.

Network devices (eg, gNB or TRP) in the 5G system can interact with user equipment through beamforming technology. A network device can usually form multiple downlink (down link, DL) transmission beams (transmit beam, Tx beam), and send downlink signals to terminal devices within the coverage of the beam on one or more DL Tx beams. The terminal device can receive through a receive beam (receive beam, Rx beam) or an omnidirectional antenna to obtain a larger array gain. Through beamforming technology, a higher data transmission rate is achieved between network equipment and user equipment.

Fig. 3 shows a schematic diagram of a network device communicating with a terminal device through a beamforming technology. As shown in FIG. 3 , the network device 101 can use beamforming technology, such as digital beamforming or analog beamforming, to form multiple transmission beams or receiving beams. The angles covered by each beam can be the same or different. Beams with different coverage angles There may be overlapping parts, for example, the network device 101 may use a beam with a wider coverage angle to send control information, and use a beam with a narrower coverage angle to send data information. The user equipment 102 may receive information sent by the network device within the coverage of one or more beams or beam sets or beam groups.

In cellular communication, the terminal device needs to first realize the time synchronization with the network device. In the case of synchronization, according to the agreement agreed in advance, the network device and the terminal device can analyze the specific content contained in the signal. The first thing the terminal equipment needs to detect is the master synchronization signal. Taking NR as an example, in the synchronization process, the network device first sends a synchronization signal block (Synchronization Signal Block, SSB) beam to the terminal device, and the terminal device scans with a wide beam. After both UE and BS scan once, confirm the narrow beam range of the network device. and wide beams for end devices.

Among them, in the NR system, the repetition period of SSB is 5ms, and each period contains one SSB. Therefore, the terminal device can acquire the 5ms timing of the cell by capturing the primary synchronization signal (primary synchronization signal, PSS).

The random access of LTE system and 5G system is divided into contention random access and non-contention random access. FIG. 4 shows a flow chart of contention random access in an LTE system and a 5G system.

The competitive random access of the LTE system and the 5G system is used for: (1) initial terminal access; (2) radio resource control (radio resource control, RRC) connection re-establishment and handover; (3) RRC connection state in an asynchronous state (4) Arrival of uplink data in RRC connection state; (5) Positioning in RRC connection state. In addition, the 5G system also introduces system message requests, inactive terminals to restore connections, etc. The competitive random access process is shown in Figure 2, which is mainly divided into four steps:

Message 1 (Msg1): The UE selects a random access preamble Preamble and a physical random access channel (physical random access channel, PRACH) resource, and sends the selected random access preamble Preamble to the base station on the selected PRACH resource (ie Msg1).

Message 2 (Msg2): The base station receives the random access request Msg1, and sends a random access response (random access response, RAR, Msg2) to the UE. The random access response includes the uplink timing advance and the uplink resources allocated for Msg3 UL grant, temporary cell radio network temporary identifier (temporary C-RNTI) assigned by the network side, etc. The physical downlink control channel (PDCCH) carrying the Msg2 scheduling message is scrambled with a random access-radio network temporary identifier (RA-RNTI), Msg2 also carries the Preamble ID, and the UE passes RA-RNTI and Preamble ID determine that the Msg2 corresponds to the Msg1 sent by it.

Message 3 (Msg3): The UE sends a scheduled transmission (Msg3) on the UL grant specified by Msg2. The Msg3 message contains layer 2/layer 3 (L2/L3) random access information. The content of the uplink transmission of the access reason Msg3 is different, for example, for initial access, Msg3 transmits an RRC connection establishment request.

Message 4 (Msg4): The base station sends a contention resolution message (contention resolution, Msg4) to the UE, and the UE can judge whether the random access is successful according to the Msg4. For the initial access UE, after the contention is successfully resolved, the temporary C-RNTI is automatically converted into the unique UE identifier C-RNTI of the UE in the cell.

Wherein, after receiving the message 1 sent by the terminal device, the network device must first demodulate the PRACH sequence before synchronizing with the terminal device. Therefore, the PRACH preamble sequence needs to have strong demodulation performance.

Under normal circumstances, a PRACH sequence consists of a cyclic prefix (cyclic prefix, CP), a preamble sequence (Preamble) and a guard interval. More specifically, in the time domain, a PRACH sequence includes a time length TCP of a cyclic prefix, a time length TSEQ of a preamble sequence, and a guard time TGT. Multiple subcarriers are used in the frequency domain, for the long format preamble, 839 subcarriers are used; for the short format preamble, 139 subcarriers are used.

For ease of understanding, the PRACH preamble sequence will be described in detail below by taking the preamble sequence ZC (Zadoff-Chu) as an example.

The leader of the leader sequence ZC, the leader is generated by cyclic shifting the ZC root sequence. Among them, the logical index of the ZC root sequence is determined by system parameters. For the long-form preamble, the value ranges from 0 to 837; for the short-form preamble, the value ranges from 0 to 137. The logical index of the ZC root sequence is cyclically continuous, namely:

The next index of logical index 837 of the long form leader is 0;

The next index of logical index 137 of the short form leader is 0;

The number of bits for cyclic shift (cyclic shift value used for random access preamble generation, Ncs) is determined by gNodeB according to the cell type and cell radius.

Since each cell can be configured with 64 preambles, if the number of sequences generated by the cyclic shift of the ZC root sequence is less than 64, the cyclic shift of the next ZC root sequence in the logical order continues to generate preambles until the number of preambles reaches 64 .

The logical index and cyclic shift of the ZC sequence are transmitted in cells. For the SA networking scenario, the PRACH configuration information element is carried by the SIB1 message; for the NSA networking scenario, the PRACH configuration information element is carried by the configuration message.

According to the RA competition mechanism, the 64 preambles of the cell are divided into random preambles and dedicated preambles, as shown in FIG. 5 . Among them, the proportion of the random preamble sequence to the random preamble sequence and the dedicated preamble sequence can be configured through parameters, and the number of random sign-ins is related to the random access scenario, and can also be configured and issued through parameters.

It should be understood that the foregoing introductions to cellular mobile communication, satellite communication, beamforming, random access, etc. are only for the convenience of understanding the technical solutions of the present application, and do not constitute any limitation to the present application.

Fig. 6 shows an example of the time domain position of the PRACH.

Wherein, the position of the PRACH in the time domain refers to the frame number and the slot number of the preamble that the terminal device sends, and is determined through the PRACH configuration index. The PRACH configuration index used by the terminal device is determined by the parameters:

When the value is not 65535, the PRACH configuration index used by the terminal device is the configured value of this parameter.

When the value is 65535, the PRACH configuration index used by the terminal device is automatically generated by the terminal device, and is related to the system frequency point, duplex mode, uplink and downlink subframe ratio, PUSCH SCS and cell radius.

The terminal device can search the corresponding table in the protocol according to the PRACH configuration index, and obtain its preamble format, frame number, subframe number, and symbol of the system where it is located.

Fig. 7 shows an example of the frequency domain position of the PRACH.

The starting position of the PRACH frequency domain is also determined by system parameters. As shown in FIG. 7 , assuming that the value of the parameter is X, the starting position of the PRACH in the frequency domain is the Xth RB in the initial BWP. When the value is 65535, the PRACH is in the low frequency band of the initial BWP. When Long PUCCH is configured in the initial BWP bandwidth, PRACH is next to Long PUCCH; when Long PUCCH is not configured in the initial BWP bandwidth, PRACH is next to Common PUCCH.

Wherein, the PRACH occupies multiple PRBs in the frequency domain, and the number of PRBs is related to the Preamble length, PRACH subcarrier spacing, and PUSCH subcarrier spacing.

Next, the specific flow of PRACH cell planning in the prior art will be introduced with reference to FIG. 8 . Among them, the two cell radii of network device 1 and network device 2 are both 0.9KM, the preamble format is 0, the default cell radius is 10KM, and the root sequences of the two cells are 0 and 2 respectively.

Step 1: Calculate Ncs according to Formula 1, and send it to the terminal device through the Ncs configuration format index.

N _CS T _S >T _RTD +T _MD +T _Adsch (1)

Among them, the values of relevant parameters in formula (1) are shown in Table 1 below:

前导格式leading format	RA-SCS(kHz)RA-SCS(kHz)	T _S T _S	T _RTD T _RTD	T _MD T _MD	T _ADSCL T _ADSCL
C2C2	1515	1000/(RA-SCS)/1391000/(RA-SCS)/139	20/3小区半径20/3Cell radius	4.69/SCS154.69/SCS15	00
Fotmat 0 Fotmat 0	1.251.25	1000/(RA-SCS)/8391000/(RA-SCS)/839	20/3小区半径20/3Cell radius	6.26.2	22

Table 1 Ncs parameter list

For the cell of network device 1, the Ncs value of the PRACH of the cell can be calculated:

Ncs>1.04875*(6.67*10+5+2)＝77.29

Step 2: According to the protocol table of 3GPP, look up the Ncs value in the table. Preferably, the Ncs value is greater than the Ncs value calculated in step 1. For example, if the Ncs value calculated in step 1 is greater than 77.29, query the Ncs configuration format table, the value is between 76 and 93, take the value 93, and send the corresponding Ncs configuration format index to the UE through the SIB message.

Step 3: Calculate the number of leading sequences that a root sequence can produce using the Ncs according to formula (2):

Num_Preamle＝floor((139 or 839)/Ncs) (2)

After receiving the message, the terminal device can look up the table according to the Ncs configuration format index to obtain the Ncs value of 93. Therefore, for the cell of network device 1, the number of PRACH preamble sequences in the cell can be calculated as:

Num_Preamle=floor(839/93)=9 (rounded down)

Step 4: Calculate the number of roots needed by a community according to formula (3):

Num_root＝ceiling(64/Num_Preamle) (3)

For the cell of network device 1, further, the number of roots required for the cell can be calculated as:

Num_root=ceiling(64/9)=8 (round up)

Therefore, the terminal device can use the following root sequence to access the cell of the network device 1: 1, 2, 3, 4, 5, 6, 7, 8. If, within the overlapping range of two cells, the terminal device selects the root sequence 2 to generate a preamble sequence and initiates random access to the cell of network device 1, after receiving the preamble sequence, network device 1 checks that it belongs to a legal root sequence, and sends The terminal device sends a response RAR. At this time, since the UE is in the coverage area of the cell of the network device 2, the network device 2 can also receive the preamble sequence sent by the UE, check that the root sequence 2 is also legal in the cell of the network device 2, and respond RAR to the UE as well. At this time, false alarms or collisions will occur when the cell receives and detects the access request.

The UE uses the physical cell identifier (PCI) of the network device 1 to receive the RAR, and can only receive the RAR sent by the network device 1, but cannot receive the RAR responded by the network device 2, so the RAR sent by the network device 2 will cause damage to the RAR. The UE's downlink reception generates interference, which reduces the signal to interference plus noise ratio (SINR) of the cell of network device 1, resulting in incomplete received signals, resulting in a large delay between the terminal device and the network device .

At the same time, the bandwidth of the physical downlink shared channel (PDSCH) of the cell of the network device 2 is wasted.

In addition, in the current technology, the network equipment receives the PRACH signal in a fixed time window. If the UE is too far away from the base station and the Preamble series falls outside the window, it will fail to resolve. Therefore, relying on the leading CP to handle UE delay, the cell radius that can be reached can reach tens of kilometers, which is already the limit. As shown in Figure 9, the signal b received by the network device cannot receive the desired signal at all. In some large cell scenarios, such as satellite communication using cellular technology, the existing technology must be improved.

Based on this, the present application proposes a method and device for random access, which help terminal equipment to quickly and stably complete random access in a cell with a large radius and in a satellite communication scenario.

Fig. 10 shows a schematic flowchart of an example of the random access method of the present application.

As shown in FIG. 10, at S910, the terminal device 102 determines a first time difference T1.

Wherein, the first time difference T1 is used to indicate the time difference between the time domain position of receiving the first signal from the network device and the first fixed time, and the first fixed time is determined according to the 1-second pulse GNSS 1pps signal of the global navigation satellite system.

Wherein, the first signal may be a signal with a fixed position in the sending time domain, including but not limited to a primary synchronization signal (primary synchronization signal, PSS) or a physical broadcast channel (physical broadcast channel, PBCH).

Specifically, the terminal device 102 can receive the GNSS 1pps signal, align the rising edge of the 1-second signal of the terminal device with the rising edge of the GNSS 1pps signal, and the network device 101 can receive the GNSS 1pps signal, and align the rising edge of the 1-second signal of the network device with the rising edge of the GNSS 1pps signal The rising edges of the GNSS 1pps signal are aligned, so that the terminal device 102 and the network device 101 can define the same first fixed time, for example, 10ms, 1ms, 0.125ms and so on.

Among them, the GNSS 1pps signal, as shown in Figure 11, is a square wave signal with a frequency of 1Hz. Its characteristic is that no matter where the GNSS module is located, the output 1pps pulse edges are strictly aligned, that is, the GNSS module output in each geographic location The 1pps pulse signals are all synchronous.

Taking the first fixed time as 10 ms as an example, the first time difference T1 is a time difference of 10 ms between the time domain position at which the terminal device 102 receives the first signal from the network device.

At S920, the terminal device 102 determines the communication delay Td according to the first time difference T1.

Wherein, the communication delay Td may be used to indicate the communication delay between the terminal device 102 and the network device 101 .

At S930, the terminal device 102 sends an uplink physical random access channel PRACH preamble to the network device 101 according to the communication delay Td.

Specifically, the terminal device 102 may send the uplink physical random access channel PRACH preamble sequence to the network device 101 in advance of the communication delay Td. In this way, it can be ensured that the network device receives the PRACH preamble at the fixed detection serial port, thereby completing random access for the terminal device 102 .

Fig. 12 shows a schematic flowchart of another example of the random access method of the present application.

As shown in Fig. 12, at S1010 and S1011, the network device 101 and the terminal device 102 respectively receive the 1-second GNSS 1pps signal of the global navigation satellite system.

As described above for FIG. 11 , since the 1pps pulse signals output by the GNSS modules in each geographic location are synchronous, the terminal device 102 and the network device 101 can perform step S1020 to determine the first fixed time according to the GNSS 1pps signal.

After defining the same first fixed time (for example, 10 ms), the network device 101 may execute step S1030 to send the first signal according to the first fixed time. Wherein, the first signal may be a signal with a fixed position in the transmission time domain, including but not limited to a primary synchronization signal PSS or a physical broadcast channel PBCH. The time difference between the starting position of the 0th subframe of the air interface frame sent by the network device 101 and 10 ms is preconfigured as the second time difference Tf, and the time difference between the time domain position of the network device sending the first signal and 10 ms is the third time difference Tp.

At S1040, the terminal device 102 determines a first time difference T1.

Specifically, the terminal device may receive the above-mentioned first signal, and determine the first time difference T1 according to the time difference between the time domain position where the first signal is received and the time difference of 10 ms.

At S1050, the terminal device 102 acquires the preconfigured second time difference Tf and third time difference Tp.

At S1060, the terminal device 102 determines the communication delay Td.

Specifically, the terminal device may determine the communication delay Td according to the first time difference T1, the second time difference Tf, and the third time difference Tp. As shown in FIG. 13 , it can be obtained according to timing analysis: Td=T1-Tf-Tp.

At S1070, the terminal device 102 may send the uplink physical random access channel PRACH preamble sequence to the network device 101 according to the communication delay Td. In this way, as shown in FIG. 14 , it can be ensured that the network device receives the PRACH preamble at the fixed detection serial port, preventing the network device 101 from failing to detect the PRACH preamble in a fixed time window, thereby completing random access for the terminal device 102 .

According to the foregoing method, FIG. 15 is a schematic diagram of an apparatus 1100 for random access provided in an embodiment of the present application.

Wherein, the apparatus 1100 may be a terminal device (for example, the terminal device 102 ), or may be a chip or a circuit, such as a chip or a circuit that may be provided in the terminal device.

The apparatus 1100 may include a processing unit 1110 (ie, an example of a processing unit), and optionally, may also include a storage unit 1120 . The storage unit 1120 is used for storing instructions.

In a possible manner, the processing unit 1110 is configured to execute the instructions stored in the storage unit 1120, so that the apparatus 1100 implements the steps performed by the terminal device (for example, the terminal device 102) in the above method.

Further, the device 1100 may further include an input port 1130 (ie, an example of a communication unit) and an output port 1140 (ie, another example of a communication unit). Further, the processing unit 1110 , the storage unit 1120 , the input port 1130 and the output port 1140 can communicate with each other and transmit control and/or data signals through internal connection paths. The storage unit 1120 is used to store a computer program, and the processing unit 1110 can be used to call and run the computer program from the storage unit 1120 to complete the steps of the terminal device in the above method. The storage unit 1120 may be integrated in the processing unit 1110 , or may be set separately from the processing unit 1110 .

Optionally, in a possible manner, the input port 1130 may be a receiver, and the output port 1140 may be a transmitter. Wherein, the receiver and the transmitter may be the same or different physical entities. When they are the same physical entity, they can be collectively referred to as transceivers.

Optionally, in a possible manner, the input port 1130 is an input interface, and the output port 1140 is an output interface.

As an implementation, the functions of the input port 1130 and the output port 1140 may be realized by a transceiver circuit or a dedicated transceiver chip. The processing unit 1110 may be realized by a dedicated processing chip, a processing circuit, a processing unit, or a general-purpose chip.

As another implementation manner, it may be considered to use a general-purpose computer to implement the measurement configuration device (for example, the terminal device 102 ) provided in the embodiment of the present application. The program codes that are about to realize the functions of the processing unit 1110, the input port 1130 and the output port 1140 are stored in the storage unit 1120, and the general processing unit realizes the functions of the processing unit 1110, the input port 1130 and the output port 1140 by executing the codes in the storage unit 1120 .

In one implementation, the processing unit 1110 is configured to determine a first time difference T1, where the first time difference T1 is used to indicate a time difference between a time domain position at which the first signal from the network device is received and a first fixed time, and the first fixed time It is determined according to the 1 second pulse GNSS 1pps signal of the global navigation satellite system. The processing unit 1110 is further configured to determine the communication delay Td according to the first time difference T1. The output port 1140 is configured to send the uplink physical random access channel PRACH preamble to the network device according to the communication delay Td.

Wherein, the apparatus 1100 is configured in or itself is a terminal device (such as the terminal device 102).

Optionally, the foregoing first signal includes a primary synchronization signal PSS or a physical broadcast channel PBCH.

Optionally, the input port 1130 is used to obtain the pre-configured second time difference Tf and the third time difference Tp, and the second time difference Tf is used to indicate the time difference between the starting position of the 0th subframe of the network device sending the air interface frame and the first fixed time , the third time difference Tp is used to indicate the time difference between the time domain position where the network device sends the first signal and the first fixed time. The processing unit 1110 is configured to determine the communication delay Td according to the first time difference T1, the second time difference Tf and the third time difference Tp.

Optionally, the input port 1130 is also used to receive GNSS 1pps signals.

Wherein, the functions and actions of each module or unit in the device 1100 listed above are only illustrative. The unit may be used to execute various actions or processing procedures performed by the terminal device in the above measurement configuration method. Here, in order to avoid redundant description, its detailed description is omitted.

For concepts, explanations, detailed descriptions and other steps involved in the device 1100 related to the technical solutions provided by the embodiments of the present application, please refer to the foregoing methods or descriptions of these contents in other embodiments, and details are not repeated here.

According to the foregoing method, FIG. 16 is a schematic diagram of an apparatus 1200 for random access provided in an embodiment of the present application.

Wherein, the apparatus 1200 may be a network device (for example, the network device 101 ), or may be a chip or a circuit, such as a chip or a circuit that may be provided in the network device.

The apparatus 1200 may include a processing unit 1210 (ie, an example of a processing unit), and optionally, may also include a storage unit 1220 . The storage unit 1220 is used for storing instructions.

In a possible manner, the processing unit 1210 is configured to execute instructions stored in the storage unit 1220, so that the apparatus 1200 implements the steps performed by the network device (for example, the network device 101 ) in the foregoing method.

Further, the device 1200 may further include an input port 1230 (ie, an example of a communication unit) and an output port 1240 (ie, another example of a communication unit). Further, the processing unit 1210 , the storage unit 1220 , the input port 1230 and the output port 1240 can communicate with each other and transmit control and/or data signals through internal connection paths. The storage unit 1220 is used to store a computer program, and the processing unit 1210 can be used to call and run the computer program from the storage unit 1220 to complete the steps of the network device in the above method. The storage unit 1220 may be integrated in the processing unit 1210 , or may be set separately from the processing unit 1210 .

Optionally, in a possible manner, the input port 1230 may be a receiver, and the output port 1240 may be a transmitter. Wherein, the receiver and the transmitter may be the same or different physical entities. When they are the same physical entity, they can be collectively referred to as transceivers.

Optionally, in a possible manner, the input port 1230 is an input interface, and the output port 1240 is an output interface.

As an implementation manner, the functions of the input port 1230 and the output port 1240 may be realized by a transceiver circuit or a dedicated chip for transceiver. The processing unit 1210 may be considered to be implemented by a dedicated processing chip, a processing circuit, a processing unit, or a general-purpose chip.

As another implementation manner, it may be considered to use a general-purpose computer to implement the measurement configuration device (for example, the network device 101 ) provided in the embodiment of the present application. The program codes that are about to realize the functions of the processing unit 1210, the input port 1230 and the output port 1240 are stored in the storage unit 1220, and the general processing unit realizes the functions of the processing unit 1210, the input port 1230 and the output port 1240 by executing the codes in the storage unit 1220 .

In one implementation, the processing unit 1210 is configured to determine the first fixed time according to the 1-second pulse GNSS 1pps signal of the global navigation satellite system. The output port 1240 is used for sending the first signal to the terminal device according to the first fixed time. The input port 1230 is used for receiving the preamble sequence of the uplink physical random access channel PRACH from the terminal equipment.

Optionally, the input port 1230 is also used to receive GNSS 1pps signals.

Wherein, the functions and actions of the modules or units in the device 1200 listed above are only for illustrative purposes. The unit may be used to perform various actions or processing procedures performed by the network device in the above measuring method. Here, in order to avoid redundant description, its detailed description is omitted.

For the concepts, explanations, detailed descriptions and other steps involved in the device 1200 related to the technical solutions provided by the embodiments of the present application, please refer to the foregoing methods or descriptions of these contents in other embodiments, and details are not repeated here.

According to the method provided in the embodiment of the present application, the embodiment of the present application further provides a random access system, which includes the aforementioned terminal device and network device.

It should be understood that, in the embodiment of the present application, the processor may be a central processing unit (central processing unit, CPU), and the processor may also be other general-purpose processors, digital signal processors (digital signal processor, DSP), dedicated integrated Circuit (application specific integrated circuit, ASIC), off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

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

The above-mentioned embodiments may be implemented in whole or in part by software, hardware, firmware or other arbitrary combinations. When implemented using software, the above-described embodiments may be implemented in whole or in part in the form of computer program products. The computer program product comprises one or more computer instructions or computer programs. When the computer instruction or computer program is loaded or executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or a data center that includes one or more sets of available media. The available media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media. The semiconductor medium may be a solid state drive.

It should be understood that the term "and/or" in this article is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B may mean: A exists alone, and A and B exist at the same time , there are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the order of execution, and the execution order of the processes should be determined by their functions and internal logic, and should not be used in the embodiments of the present application. The implementation process constitutes any limitation.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application. Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media capable of storing program codes such as U disk, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk. The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

A random access method, characterized by comprising:

Determine the first time difference T1, the first time difference T1 is used to indicate the time difference between the time domain position of receiving the first signal from the network device and the first fixed time, the first fixed time is based on the global navigation satellite system 1 second pulse GNSS 1pps signal determined;

determining the communication delay Td according to the first time difference T1;

Sending a PRACH preamble sequence to the network device according to the communication delay Td.
The method according to claim 1, wherein the first signal comprises: a primary synchronization signal (PSS) or a physical broadcast channel (PBCH).
The method according to claim 1, wherein the determining the communication delay Td according to the first time difference T1 comprises:

Obtaining a preconfigured second time difference Tf and a third time difference Tp, the second time difference Tf is used to indicate the time difference between the starting position of the 0th subframe of the air interface frame sent by the network device and the first fixed time, the The third time difference Tp is used to indicate the time difference between the time domain position where the network device sends the first signal and the first fixed time;

The communication delay Td is determined according to the first time difference T1, the second time difference Tf and the third time difference Tp.
The method according to any one of claims 1 to 3, wherein the method further comprises:

Receive the GNSS 1pps signal.
A random access method, characterized by comprising:

Send the first signal to the terminal device according to the first fixed time, the first fixed time is determined according to the 1-second pulse GNSS 1pps signal of the Global Navigation Satellite System;

receiving a preamble sequence of an uplink physical random access channel PRACH from the terminal device.
The method according to claim 5, wherein the first signal comprises: a primary synchronization signal (PSS) or a physical broadcast channel (PBCH).
The method according to claim 5 or 6, wherein the method further comprises:

Receive the GNSS 1pps signal.
A device for random access, characterized in that it includes:

A processing unit, configured to determine a first time difference T1, the first time difference T1 is used to indicate the time difference between the time domain position of receiving the first signal from the network device and a first fixed time, the first fixed time is based on global navigation Determined by the 1 second pulse GNSS 1pps signal of the satellite system;

The processing unit is further configured to determine a communication delay Td according to the first time difference T1;

A transceiver unit, configured to send an uplink physical random access channel PRACH preamble to the network device according to the communication delay Td.
The device according to claim 8, wherein the first signal comprises: a primary synchronization signal (PSS) or a physical broadcast channel (PBCH).
The device according to claim 8, characterized in that

The transceiver unit is specifically used for:

Obtaining a preconfigured second time difference Tf and a third time difference Tp, the second time difference Tf is used to indicate the time difference between the starting position of the 0th subframe of the air interface frame sent by the network device and the first fixed time, the The third time difference Tp is used to indicate the time difference between the time domain position where the network device sends the first signal and the first fixed time;

The processing unit is specifically used for:

The communication delay Td is determined according to the first time difference T1, the second time difference Tf and the third time difference Tp.
The device according to any one of claims 8 to 10, wherein the transceiver unit is also used for:

Receive the GNSS 1pps signal.
A device for random access, characterized in that it includes:

The transceiver unit is used to send the first signal to the terminal device according to the first fixed time, and the first fixed time is determined according to the 1 second pulse GNSS 1pps signal of the global navigation satellite system;

The transceiving unit is further configured to receive an uplink physical random access channel PRACH preamble from the terminal device.
The device according to claim 12, wherein the first signal comprises: a primary synchronization signal (PSS) or a physical broadcast channel (PBCH).
The device according to claim 12 or 13, wherein the transceiver unit is also used for:

Receive the GNSS 1pps signal.
A communication device, characterized in that it includes: a processor, the processor is coupled with a memory, and the memory is used to store a program or an instruction, and when the program or instruction is executed by the processor, the device A method as described in any one of claims 1 to 4 is realized.
A communication device, characterized in that it includes: a processor, the processor is coupled with a memory, and the memory is used to store a program or an instruction, and when the program or instruction is executed by the processor, the device A method as described in any one of claims 5 to 7 is realized.
A computer-readable storage medium, which is characterized in that a computer program/instruction is stored thereon, and is characterized in that, when the computer program/instruction is executed by a processor, the method according to any one of claims 1 to 7 is implemented.
A system on a chip, characterized in that it includes: a processor, configured to call and run a computer program from a memory, so that a communication device equipped with the system on a chip implements the method according to any one of claims 1 to 7 .
A computer program product, characterized in that it includes a computer program, and when the computer program is run on a computer, the method described in any one of claims 1 to 7 is executed.
A communication system, characterized by comprising the device according to any one of claims 8 to 11, and the device according to any one of claims 12 to 14.