Communication method, apparatus, and system

Abstract

The present application provides a communication method, an apparatus, and a system. In the method, a terminal uses a Z4 sequence as a preamble and processes the preamble to obtain a signal for requesting random access, and the terminal can request access to a network on the basis of the signal for requesting random access. Upon receiving the signal for requesting random access sent by the terminal, a network device can demodulate the signal, thereby obtaining the preamble for the terminal requesting random access. Using the Z4 sequence as the preamble for requesting random access, on the basis of a large capacity of the Z4 sequence, not only can the probability of transmission collision when a plurality of terminals perform random access be reduced, but also channel estimation performance can be improved on the basis of a constant modulus sequence characteristic and a good autocorrelation and cross-correlation characteristic of the Z4 sequence.

Description

A communication method, apparatus and system

[0001] This application claims priority to Chinese Patent Application No. 202411482025.X, filed on October 22, 2024, entitled "A Communication Method, Apparatus and System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more particularly to a communication method, apparatus, and system. Background Technology

[0003] With the continuous development of communication technology, the number of terminals accessing future communication systems will increase, and the connection density of terminals will also increase accordingly. For example, the connection density of terminals will reach ten million connections per square kilometer or even more.

[0004] Currently, preambles generated from multiple cyclic shifts and root indices of the Zadoff-Chu (ZC) sequence can enable multiple terminals to access the network on the same time-frequency resources, thereby improving the capacity of the random access channel (RACH). Network devices need to traverse all available preambles in the preamble set and perform correlation detection with the received signal. Furthermore, the network device can perform channel estimation based on the detected preamble signal, eliminate the channel's influence on the received signal based on the channel estimation result, and then perform correlation detection again with locally available preambles to improve detection performance.

[0005] However, as the number of connected terminals increases, the probability of collisions during terminal access also increases. Furthermore, to meet the needs of high-speed mobile applications, the number of cyclic shifts available for the preamble needs to be further limited. Therefore, the capacity of RACH is limited. How to reduce the collision probability of multi-terminal random access while ensuring channel estimation performance is a pressing technical problem that needs to be solved. Summary of the Invention

[0006] This application provides a communication method, apparatus, and system to improve RACH capacity, reduce the probability of transmission collisions when multiple terminals randomly access each other, and improve channel estimation performance.

[0007] Firstly, a communication method is provided, which can be applied to a communication device. This device may be, for example, a terminal, a component configured in the terminal (such as a chip, chip system, processor, etc.), or a logic module or software capable of implementing all or part of the terminal's functions, etc. This application does not limit the scope of the application.

[0008] For example, the method includes: a terminal generating a signal for requesting random access by performing an inverse fast Fourier transform (IFFT) on a Z4 sequence as a preamble; and the terminal transmitting the signal for requesting random access. Different terminals can choose different Z4 sequences as preambles. Based on the large capacity of the Z4 sequence, not only can the probability of collisions due to multiple terminals selecting the same preamble during random access be reduced, but also the constant modulus sequence characteristics and good autocorrelation and cross-correlation properties of the Z4 sequence can reduce interference between different Z4 sequences and improve channel estimation performance.

[0009] Secondly, a communication method is provided, which can be applied to a communication device. This device may be, for example, a network device, a component configured within the network device (such as a chip, chip system, processor, etc.), or a logic module or software capable of implementing all or part of the functions of the network device, etc. This application does not limit the scope of the application.

[0010] For example, the method includes: a network device receiving a signal for requesting random access, the signal for requesting random access being obtained by IFFT transformation of a preamble, the preamble being a Z4 sequence; and the network device processing the signal for requesting random access.

[0011] Based on the above scheme, by using the Z4 sequence as a preamble for requesting random access, the large capacity of the Z4 sequence can not only reduce the probability of collisions when multiple terminals randomly access each other due to selecting the same preamble, but also reduce interference between different Z4 sequences and improve channel estimation performance based on the constant modulus sequence characteristics and the good autocorrelation and cross-correlation characteristics of the Z4 sequence.

[0012] In some possible implementations of the first or second aspect, the preamble is determined from a plurality of Z4 sequences generated based on at least one base sequence, wherein different Z4 sequences generated based on the same base sequence have different cyclic shift values ​​and / or phase rotation values.

[0013] Multiple Z4 sequences can be generated by cyclic shifting and / or phase rotation based on the base sequence. These multiple Z4 sequences can be generated based on the same base sequence through cyclic shifting and / or phase rotation, or they can be generated based on different base sequences through cyclic shifting and / or phase rotation. Each terminal can randomly select one Z4 sequence (i.e., multiple preambles) as the currently used preamble, thereby generating a signal for requesting random access. In this way, the capacity of RACH can be improved, enabling high-capacity uplink access for multiple terminals.

[0014] In some possible implementations of the first or second aspect, the plurality of Z4 sequences includes at least one Z4 sequence generated based on a first base sequence and at least one Z4 sequence generated based on a second base sequence, wherein the primitive polynomials and / or initial values ​​of the first and second base sequences are different.

[0015] The Z4 sequence has multiple different primitive polynomials and initial values. Terminals can generate multiple different base sequences based on these different primitive polynomials and / or initial values. These base sequences have different primitive polynomials and / or initial values. This increases the capacity of RACH and enables high-capacity uplink access for multiple terminals.

[0016] In some possible implementations of the first or second aspect, the cyclic shift interval between two Z4 sequences generated based on the same base sequence is correlated with the maximum Doppler frequency offset.

[0017] It's important to understand that frequency-domain cyclic shifting and time-domain phase rotation are equivalent; therefore, the cyclic shift interval between two Z4 sequences needs to consider the maximum Doppler frequency offset. This not only reduces the probability of transmission collisions when multiple terminals randomly access the network, but also improves channel estimation performance.

[0018] In some possible implementations of the first or second aspect, the cyclic shift interval N cs，Z4 With the maximum Doppler frequency offset f d Satisfy: N cs，Z4 Greater than or equal to f d / Subcarrier spacing (SCS).

[0019] Considering frequency offset, the cyclic shift of a frequency domain signal can be equivalent to the phase rotation of a time domain signal. Therefore, multiple Z4 sequences are generated by cyclic shifting the base sequence based on the frequency domain mapping, allowing multiple terminals to access the network. The cyclic shift interval N between any two Z4 sequences is [missing information]. cs，Z4 Need to satisfy: N cs，Z4 Greater than or equal to f d / SCS. In this way, network devices can distinguish different cyclic shifts in the Z4 sequence, improving detection performance and thus further enhancing channel estimation performance.

[0020] In some possible implementations of the first or second aspect, the phase rotation value of each of the plurality of Z4 sequences is related to the cell radius.

[0021] Considering propagation delay, the cyclic shift of the time-domain signal caused by the delay can be equivalent to a phase rotation of the frequency-domain signal. The larger the cell radius, the larger the phase rotation value of the corresponding Z4 sequence needs to be. Thus, multiple Z4 sequences are obtained by phase rotation based on the base sequence. Using the Z4 sequences as preambles allows for access by multiple terminals. This not only reduces the probability of collisions when multiple terminals randomly access each other due to selecting the same preamble, but also improves channel estimation performance.

[0022] In some possible implementations of the first or second aspect, the phase rotation value θ satisfies: θ is greater than or equal to Alternatively, θ equals zero, N represents the sequence length of the Z4 sequence, M is a positive integer less than or equal to N, and M is positively correlated with the cell radius.

[0023] Considering propagation delay, the cyclic shift of the time-domain signal caused by the delay can be equivalent to the phase rotation of the frequency-domain signal. Therefore, multiple Z4 sequences are generated by phase rotation based on the base sequence, allowing multiple terminals to access the network. The phase rotation value θ needs to satisfy the following: Alternatively, θ = 0. When θ = 0, it means that the base sequence does not undergo phase rotation. Thus, using the Z4 sequence as a preamble, the Z4 sequences obtained based on different phase rotation values ​​can resist cell propagation delay, meaning that network devices can distinguish different phase rotations of the Z4 sequence, improving detection performance and further enhancing channel estimation performance.

[0024] In some possible implementations of the first or second aspect, the preamble s(n) satisfies: s(n) = αc(n+w)e jθn Where α represents a complex constant, c(n) represents a complex sequence obtained based on base sequence modulation, n is greater than or equal to zero and less than N, N represents the length of the preamble, w represents the cyclic shift value, and θ represents the phase rotation value.

[0025] Multiple Z4 sequences are generated by cyclic shifting and / or phase rotation of the base sequence. This can be understood as modulating the base sequence to obtain a complex sequence c(n), and then cyclically shifting and / or phase rotating the complex sequence to generate multiple Z4 sequences, which can serve as optional preambles. This increases the capacity of the preamble, allowing multiple terminals to reuse preambles generated from the same or different base sequences, thereby reducing the probability of collisions when multiple terminals request random access.

[0026] Thirdly, this application provides a communication device, including modules or units for implementing the method in the first aspect or any possible implementation of the first aspect. Specifically, the modules, units, or means can be implemented in software, hardware, or a combination of software and hardware.

[0027] Fourthly, this application provides a communication device including one or more processors for executing a computer program (also referred to as code or instructions) in a memory, such that the communication device implements the communication method in the first aspect or any possible implementation of the first aspect.

[0028] Optionally, the device further includes a memory for storing computer programs and data. The memory is coupled to the processor, which, when executing the computer program stored in the memory, can implement the methods described in the first aspect or any possible implementation thereof.

[0029] Optionally, the device further includes a communication interface for communicating with other devices. For example, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0030] For example, the device in the third or fourth aspect is a terminal, or a component in a terminal, such as a chip, chip system, processor, etc.

[0031] Fifthly, this application provides a chip system including at least one processor for supporting the implementation of the functions involved in the first aspect and any possible implementation of the first aspect, such as processing the information involved in the above method.

[0032] In one possible design, the chip system also includes a memory for storing computer programs and data, which may be located inside or outside the processor.

[0033] The chip system can consist of chips or include chips and other discrete components.

[0034] In one possible design, the chip system also includes a power supply circuit for supplying power to the chip system.

[0035] Sixthly, this application provides a communication device, including modules or units for implementing the method in the second aspect or any possible implementation of the second aspect. Specifically, the modules, units, or means can be implemented in software, hardware, or a combination of software and hardware.

[0036] In a seventh aspect, this application provides a communication device including one or more processors, the one or more processors being configured to execute a computer program (also referred to as code or instructions) in a memory, such that the communication device implements the communication method in the second aspect or any possible implementation of the second aspect.

[0037] Optionally, the device further includes a memory for storing computer programs and data. The memory is coupled to the processor, which, when executing the computer program stored in the memory, can implement the methods described in the second aspect or any possible implementation thereof.

[0038] Optionally, the device further includes a communication interface for communicating with other devices. For example, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0039] For example, the apparatus in the fifth or sixth aspect is a network device, or a component in a network device, such as a chip, chip system, processor, etc.

[0040] Eighthly, this application provides a chip system including at least one processor for supporting the implementation of the functions involved in the second aspect and any possible implementation of the second aspect, such as processing the information involved in the above method.

[0041] In one possible design, the chip system also includes a memory for storing computer programs and data, which may be located inside or outside the processor.

[0042] The chip system can consist of chips or include chips and other discrete components.

[0043] In one possible design, the chip system also includes a power supply circuit for supplying power to the chip system.

[0044] Ninthly, this application provides a computer-readable storage medium including a computer program that, when run on a computer, causes the computer to implement the methods of the first to second aspects and any possible implementation of the first to second aspects.

[0045] In a tenth aspect, this application provides a computer program product comprising: a computer program that, when run, causes a computer to perform the methods of the first to second aspects and any possible implementation thereof.

[0046] Eleventhly, embodiments of this application provide a communication system, including the aforementioned terminal and network device.

[0047] The third to eleventh aspects of this application correspond to the technical solutions of the first to second aspects of this application. The beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be repeated here. Attached Figure Description

[0048] Figure 1 is a schematic diagram of the basic structure of the feedback shift register provided in an embodiment of this application;

[0049] Figure 2 is a schematic diagram of the architecture of the communication system provided in an embodiment of this application;

[0050] Figure 3 is a schematic flowchart of the random access process provided in an embodiment of this application;

[0051] Figure 4 is a schematic diagram of the power distribution of the m-sequence scrambled ZC sequence on different resource units provided in the embodiments of this application;

[0052] Figure 5 is a schematic flowchart of the communication method provided in an embodiment of this application;

[0053] Figure 6 is a schematic diagram of the signal processing flow provided in an embodiment of this application;

[0054] Figure 7 is a schematic diagram of the terminal-side communication architecture provided in an embodiment of this application;

[0055] Figure 8 is a schematic block diagram of the device provided in an embodiment of this application;

[0056] Figure 9 is another schematic block diagram of the device provided in the embodiments of this application;

[0057] Figure 10 is a schematic diagram of the structure of the terminal device provided in an embodiment of this application;

[0058] Figure 11 is a schematic diagram of the network device provided in an embodiment of this application. Detailed Implementation

[0059] The technical solution provided in this application will now be described with reference to the accompanying drawings.

[0060] First, in the embodiments of this application, "sending" and "receiving" indicate the direction of signal transmission. Communication between different devices can refer to direct communication between different devices (i.e., without the need for relaying or forwarding by other devices), or communication between different devices through other devices (i.e., requiring relaying or forwarding by other devices), or communication between a functional unit within a device and other devices through another functional unit. That is, "sending information to a terminal" in this application can be understood as the destination of the information being the terminal, and can include sending information directly or indirectly to the terminal. "Receiving information from a network device" can be understood as the source of the information being the network device, and "receiving information from a network device" can be understood as the source of the information being the network device, and can include receiving information directly or indirectly from the network device. Information may undergo necessary processing between the source and destination of the information transmission, such as format changes, digital-to-analog conversion, etc., but the destination can understand the valid information from the source. Similar expressions in this application can be understood in a similar way, and will not be elaborated further here.

[0061] Second, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a; b; c; a and b; a and c; b and c; or a and b and c. Here, a, b, and c can be single or multiple.

[0062] Third, in the embodiments of this application, "when," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a time, nor do they require the device to make a judgment action when it is implemented, nor do they mean that there are other limitations.

[0063] Fourth, the correspondences shown in the tables of this application are merely examples and should not be construed as limiting the scope of this application. The content in each table is only illustrative and can be configured with other content; this application does not limit this. When configuring these correspondences, it is not necessarily required to configure all the correspondences shown in each table. For example, the correspondences shown in some rows may not be configured. For another example, some columns may be replaced with other forms. Furthermore, appropriate modifications and adjustments can be made to the tables shown herein, such as splitting, merging, etc.

[0064] In addition, tables are only one possible form of correspondence. In specific implementations, other data structures can also be used, such as arrays, queues, containers, stacks, linear lists, pointers, linked lists, trees, graphs, structures, classes, heaps, hash tables, or hash tables.

[0065] The technical solutions provided in this application can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink (SL) communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5th Generation (5G) mobile communication systems, or new radio access technology (NR). Among these, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems, such as 6th Generation (6G) mobile communication systems. This application does not limit these applications.

[0066] Figure 1 is a schematic diagram of the architecture of a communication system applicable to the communication method provided in this application. Figure 1 shows a schematic diagram of a possible, non-limiting system architecture. As shown in Figure 1, the communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. Optionally, the communication system 10 also includes an Internet 300. RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110) and at least one terminal (120a-120j in Figure 1, collectively referred to as 120). RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). Terminal 120 is wirelessly connected to RAN node 110. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network equipment in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device that integrates core network logical functions and radio access network logical functions.

[0067] RAN 100 can be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication systems, or future-oriented evolution systems (such as 6G mobile communication systems). RAN 100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (Wi-Fi) system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0068] RAN node 110, sometimes also referred to as access network equipment, RAN entity, or access node, is part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station. For terminals 120j accessing RAN 100 through network element 120i, network element 120i is a base station; but for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes both referred to as communication devices. For example, network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and network elements 120a-120j can be understood as communication devices with terminal functions.

[0069] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, a RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU).

[0070] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with each RAN node performing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be separate entities or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0071] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0072] A terminal can also be called a terminal device, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc.

[0073] In the embodiments of this application, the terminal and the wireless access network device can be hardware devices, or software functions running on dedicated hardware. Software functions running on general-purpose hardware, for example, are virtualization functions instantiated on a platform (e.g., a cloud platform), or are entities that include dedicated or general-purpose hardware devices and software functions. This application does not limit the specific form of the terminal and the wireless access network device.

[0074] To better understand the methods provided in the embodiments of this application, the terms involved in this application will be briefly explained below.

[0075] 1. M-sequence: Short for maximum length linear feedback shift register sequence. An M-sequence is a special type of pseudo-random sequence, the longest-period sequence generated by a shift register with linear feedback. Generally, the longest period generated by an n-stage linear feedback shift register is equal to 2. n -1.

[0076] Figure 2 is a schematic diagram of the basic structure of the feedback shift register provided in an embodiment of this application. The initialized bit data are a1, a2, ..., a n a1, a2, ..., a n It can be stored in a feedback shift register, and new values ​​can be generated and added to the feedback shift register by the feedback function. Assume the feedback function f(x) is an XOR operation on all the bits in the feedback shift register, that is... The output sequence is then in, This indicates the XOR operation.

[0077] The m-sequence can be determined by the initial bit values ​​stored in the feedback shift register and the primitive polynomial, where the order of the primitive polynomial is the highest power of the polynomial. For example, f(x) = x 7 The recurrence relation for +x+1 is: s(t)+s(t-6)+s(t-7)=0. Binary operations can be defined as modulo 2 operations, i.e., 0+1=1 (mod 2), 1+1=0 (mod 2), 1+0=1 (mod 2), 0+0=0 (mod 2). Therefore, the above recurrence relation can be converted to: s(t)=s(t-6)+s(t-7). Here, "mod 2" represents modulo 2 operation.

[0078] For a binary sequence, the primitive polynomial is generally considered to be: a i For ∈{0,1}, the recurrence formula is:

[0079] 2. Gold code sequence: also known as a gold sequence, is a pseudo-random sequence. A gold sequence can be viewed as an element-wise XOR operation obtained from two m-sequences with different primitive polynomials. Gold sequences have good autocorrelation and cross-correlation properties; moreover, the number of gold sequences is large, making it easy to carry information.

[0080] 3. Z4 sequence: For a quaternion sequence, consider the primitive polynomial as follows: a i The recurrence relation for ∈{0, 1, 2, 3} is: Among them, a i This represents the initial value. It's important to note that the results of all four arithmetic operations on a quaternion sequence require modulo-4 operations. The most common quaternion sequence is the Z4 sequence. The Z4 sequence has the same period as the binary gold sequence of the same length, and its value set is {0,1,2,3}. It can be modulated into a complex signal using quadrature phase shift keying (QPSK). Similar to the gold sequence, the Z4 sequence can be generated using a circular shift register. The generation of the Z4 sequence is similar to that of the m-sequence, except that the Z4 sequence is defined on a quaternion ring of {0,1,2,3}. Therefore, addition and subtraction require modulo-4 operations. The specific recursive formula for the sequence can be found above and will not be repeated here.

[0081] In practical applications, the Z4 sequence needs to be modulated. The mapping table is shown in Table 1.

[0082] Table 1

[0083] For an m-sequence, the m-sequences generated by different initial values ​​correspond to cyclic shifts of sequences generated by other initial values, and the sequences that differ from the m-sequences have a length of 2. n The initial values ​​of the Z4 sequence of -1 are 4. n In this case, the Z4 sequences generated under different initial values ​​are mostly cyclically shifted versions of each other. For example, for a sequence of length 63, traversing the initial values ​​yields 4095 sequences, but after removing the cyclically shifted versions, only 65 sequences remain. Therefore, different initial values ​​for the Z4 sequence can also be used to support multi-user access. Generally, for a length of L=2... n For a Z4 sequence of -1, there are L initial values ​​available.

[0084] Compared to 4G and 5G communications, the increase in connection density of future communication networks will be more significant. High-capacity communication, as an extension of massive machine-type communication (mMTC), will have applications in smart cities, transportation, logistics, healthcare, energy, environmental monitoring, agriculture, and many other fields. The International Mobile Telecommunications (IMT)-2030 standard sets new requirements for network capabilities. IMT-2020 requires a connection density of 10... 6 The IMT-2030 standard requires a connection density of 10⁶ to 10⁸ terminals per kilometer, representing a two-order-of-magnitude increase. It is currently widely believed that 6G will achieve a connection density of ten million connections per square kilometer or even greater.

[0085] In terms of terminal device types, massive connectivity scenarios will involve various types of terminal devices. In addition to traditional IoT devices, new passive low-power terminal devices will also be introduced. These new terminal devices may include head-mounted displays, drones, watches, and AI assistants, among others. This application does not limit the specific types of terminal devices.

[0086] Figure 3 is a schematic flowchart of the random access process provided in an embodiment of this application. Figure 3 illustrates the method provided in this application from the perspective of the interaction between the terminal and the network device, but this should not be construed as limiting the application in any way. Furthermore, the terminal or network device in Figure 3 can be replaced with components within the terminal or network device, such as chips, chip systems, processors, etc., and can also be replaced with logic modules or software capable of implementing some or all of its functions. This application does not impose any limitations on this.

[0087] The following details each step in the random access process.

[0088] First, the network device sends the master information block (MIB) and system information block (SIB) 1. The terminal then receives the MIB and SIB 1 accordingly.

[0089] Before initial access, the terminal first decodes the MIB to obtain basic information such as the system frame number and downlink bandwidth; it then decodes the SIB1 to obtain information such as cell selection and reselection parameters, public land mobile network (PLMN) identifier and tracking area code (TAC) to determine whether it can access the cell.

[0090] Then, the network device and the terminal perform a random access procedure for messages (Msg) 1 to Msg 5.

[0091] Msg1: The terminal sends a random access preamble to the network device. This random access preamble, or simply preamble, will be referred to as such for simplicity. The terminal initiates a random access request to the network device by randomly selecting the physical random access channel (PRACH) corresponding to its coverage level and the preamble. During Msg1, the terminal may also send a preamble index and a random access radio network temporary identifier (RA-RNTI) to the network device. The preamble index can be used by the network side to distinguish random access requests from different terminals, and the RA-RNTI can be used to identify the terminal in subsequent random access processes.

[0092] Msg2: In response to the preamble sent by the terminal, the network device can send a random access response (RAR) to the terminal via the physical downlink shared channel (PDSCH) to reply to the random access request. The network device can generate a RA-RNTI based on the time-frequency position and index of the preamble. The network device sends scheduling information on the physical downlink control channel (PDCCH) to instruct the terminal to receive the RAR on the PDSCH. The scheduling information in the PDCCH includes the RA-RNTI. The network device can also send the RAR on the PDSCH.

[0093] Msg3: The terminal receives and detects the RAR containing its Random Access Preamble (RAPID) on the PDSCH, adjusts the uplink timing based on the time alignment command in the RAR, and can also obtain the Temporary Cell Radio Network Temporary Identifier (TC-RNTI) from the RAR and scramble Msg3 using the TC-RNTI. The terminal can then send a Radio Resource Control (RRC) connection request on the Physical Uplink Shared Channel (PUSCH) according to the uplink resources allocated in the RAR.

[0094] Msg4: The network device can detect RRC connection requests based on TC-RNTI, parse the RRC connection requests to obtain information such as the service type and capability indication reported by the terminal, and allocate time-frequency resources for user data transmission to the terminal based on the service type and capability indication reported by the terminal. The network device can generate a radio resource control (RRC) connection establishment message, and then send scheduling information on the PDCCH to instruct the terminal to receive the RRC connection establishment message on the PDSCH. The network device then sends the RRC connection establishment message to the terminal on the PDSCH.

[0095] Msg5: The terminal can detect the RRC connection establishment message on the PDSCH based on TC-RNTI. Once the terminal confirms that the RRC connection has been successfully established, it can send an RRC connection establishment completion message to the network device. The RRC connection establishment completion message includes information such as the terminal's capability reporting. The terminal sends the RRC connection establishment completion message on the PUSCH or physical uplink control channel (PUCCH) according to the uplink resources allocated by the base station.

[0096] The preamble for PRACH can be a ZC sequence, transmitted using a discrete Fourier transform (DFT) to spread the OFDM (DFT-spread OFDM, DFT-s-OFDM) waveform. The formula for generating the ZC sequence used in PRACH is:

[0097] Among them, X u (i) represents the i-th element of the ZC sequence, L RA The sequence length is represented by u, which is a parameter that determines specific characteristics of the ZC sequence, and i represents the index of the sequence.

[0098] ZC sequences, based on different cyclic shifts and root indices, can enable multiple users to access the same time-frequency resources. Without considering time-domain cyclic shifts, or time-domain multipath propagation, the cross-correlation value between ZC sequences obtained based on the same root index is 0, while the cross-correlation value between ZC sequences obtained based on different root indices is [missing value]. N is the length of the ZC sequence.

[0099] Currently, in the Msg1 process described above, sending the message carried in the PRACH channel can be represented as sending PRACH. The PRACH sending process includes the following steps:

[0100] Step 1: By parsing the SIB1 message, the terminal can obtain PRACH configuration parameters, including the PRACH root sequence index, PRACH subcarrier spacing, and the number of frequency-domain random access opportunities (ROs). The PRACH root sequence index is used to determine the starting preamble index for the current cell's 64 preambles. Specifically, a random access channel opportunity (PRACH occasion) requires 64 preambles. If the number of preambles generated by a root index (the number of available cyclic shifts) is less than 64, then the next root index is used to continue generating preambles.

[0101] Step 2: The terminal can select the PRACH transmission timing, i.e., select RO, based on the parsed synchronization signal and PBCH block (SS / PBCH block, or SSB) beam index information, and randomly select any one of the above preamble sets on RO.

[0102] The number of elements in the aforementioned preamble set is not necessarily 64, as the 64 preambles can be subdivided according to their intended use. For example, among all preambles used for contention-based random access, the network device's RRC can selectively divide them into two groups: Group A and Group B. When a terminal triggers random access, the preamble set needs to be determined based on the size of the Msg3 signal to be transmitted and the path loss. Group B can be used in scenarios where Msg3 is large and path loss is small, while Group A can be used in other situations where Group B is not suitable.

[0103] The magnitude of Msg3 and path loss can be measured based on the threshold parameters notified to the terminal by the network device in SIB1. After determining whether to use set A or B for the preamble, the terminal can randomly select a preamble code from that set to send. For example, the preamble set can be further subdivided based on whether Msg3 is repeated. Therefore, the number of sequences in the preamble set determined by the terminal must be less than 64.

[0104] Step 3: The terminal sends the preamble using the DFT-s-OFDM waveform.

[0105] The PRACH reception process is as follows: The base station obtains the preamble at the corresponding RO and performs precise time synchronization. Since the base station does not know the preamble used by the UE, it needs to traverse all available preambles in the sequence set for cross-correlation detection. The preamble with the largest cross-correlation value corresponds to the one actually transmitted. It is important to understand that the synchronization position and the preamble are determined simultaneously, which is a two-dimensional detection process.

[0106] Currently, a scheme based on scrambling ZC sequences with m-sequences has been proposed to increase the capacity of RACH access, achieving a 100-fold increase and improving the frequency offset resistance of the preamble to some extent. Alternatively, different cyclic shifts and root indices of the ZC sequence can enable multiple users to access the same time-frequency resources.

[0107] As the number of users accessing the network continues to increase, the probability of collisions during user access will also increase. Furthermore, to support terminal access in high-speed mobile scenarios, it is necessary to further limit the number of cyclic shift bits available for the preamble. Therefore, the PRACH capacity is further constrained.

[0108] PRACH can improve its own detection performance for channel estimation, and in small packet transmission, the channel estimation result can assist PUSCH demodulation and decoding. Figure 4 is a schematic diagram of the power distribution of the m-sequence scrambled ZC sequence on different resource elements (REs) provided in the embodiments of this application. The horizontal axis represents REs, and the vertical axis represents power, with the unit being decibels (dB). It can be seen that when expanding based on the current sequence, the frequency domain of the sequence is not flat, which leads to a decrease in channel estimation accuracy.

[0109] In view of this, this application provides a method that uses a Z4 sequence as a preamble. By performing an IFFT transform on the preamble, a time-domain signal for requesting random access can be obtained; that is, the preamble is mapped onto OFDM symbols for transmission. A terminal can then request network access based on this signal. Correspondingly, after receiving the signal from the terminal requesting random access, the network device can demodulate the signal to obtain the preamble for the random access request. Using the Z4 sequence as a preamble for random access requests not only reduces the probability of collisions due to multiple terminals selecting the same preamble when randomly accessing the network, leveraging the large capacity of the Z4 sequence, but also improves channel estimation performance based on the constant mode property and good autocorrelation and cross-correlation characteristics of the Z4 sequence.

[0110] The methods provided in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0111] Figure 5 is a schematic flowchart of the communication method provided in an embodiment of this application. Figure 5 describes the method provided in this application from the perspective of interaction between a terminal and a network device, but this should not be construed as limiting this application in any way. Furthermore, the terminal in Figure 5 can be replaced by components within the terminal, such as chips, chip systems, processors, etc., and can also be replaced by logic modules or software capable of implementing some or all of its functions; similarly, the network device in Figure 5 can be replaced by components within the network device, such as chips, chip systems, processors, etc., and can also be replaced by logic modules or software capable of implementing some or all of its functions. This application does not impose any limitations in this regard.

[0112] The method 500 shown in Figure 5 may include steps 510 to 530, and the steps in method 500 are described in detail below.

[0113] In step 510, the terminal generates a signal for requesting random access, which is obtained by IFFT transformation of a preamble, and the preamble is a Z4 sequence.

[0114] The preamble can be generated based on the base sequence of the Z4 sequence, such as by cyclic shifting and / or phase rotation of the base sequence. The base sequence can be generated based on the primitive polynomial and initial value of the Z4 sequence.

[0115] Generally, a terminal device can randomly select a preamble from multiple preambles corresponding to the terminal device, and generate a signal for requesting random access based on that preamble. In this embodiment, the preamble can be determined from multiple Z4 sequences, which are generated based on at least one base sequence. These multiple Z4 sequences can be included in a sequence pool (or sequence set). Of course, this application does not exclude the possibility that the sequence pool includes a single Z4 sequence, in which case the preamble is that single Z4 sequence in the sequence pool.

[0116] To improve RACH capacity and prevent collisions during random access by terminal devices, the diversity of sequences in the sequence pool can be increased, or in other words, the number of sequences in the sequence pool can be increased. On the one hand, different Z4 sequences generated based on the same base sequence have different cyclic shift values ​​and / or phase rotation values. In other words, multiple Z4 sequences can be obtained based on a single base sequence by adjusting the cyclic shift values ​​and / or phase rotation values. On the other hand, different primitive polynomials and / or initial values ​​of Z4 sequences can generate different base sequences, and thus different Z4 sequences can be generated based on different base sequences.

[0117] As an example, multiple different basis sequences are generated based on different primitive polynomials and / or initial values. Multiple Z4 sequences in the sequence pool can be generated based on the same basis sequence or on different basis sequences, with different primitive polynomials and / or initial values ​​between the different basis sequences.

[0118] For example, a set of primitive polynomials of the Z4 sequence satisfies: x(n+7)=mod(2x(n+4)+3x(n+1)+x(n),4). Here, "mod" represents the modulo operation.

[0119] The Z4 sequence can include, for example, the following 128 initial values: [x(0), x(1), x(2), x(3), x(4), x(5), x(6)] = [1,0,0,0,0,0,0], [3,0,0,0,0,0,0], [1,0,0,0,2,2,2], [3,2,0,0,0,0,0], [1,2,2,2,0,0,0], [1,0,0,0,0,0,2], [3,0,0,0,0,0,2], [3,2,2,2,0,0,0], [1,2,0,0,0,0,0], [3,0,0,0,2,2,2], [1,2,0,2,0,2,0], [3,2,2,0,0,0,0] ,[1,2,2,2,2,2,2],[1,2,2,0,0,2,2],[3,0,2,2,0,0,0],[1,2,0,2,0,0,0],[1,0,2,0,0,0,0],[1,0,2,0,0,0,0],[1,0,2,0,2,0,2],[1,0,0,0,2,0,2],[3,2,0,0,2,2 [1,0,2,2,2,2,0],[1,0,0,0,0,2,0],[3,0,0,0,0,2,0],[3,2,2,2,0,0,2],[3,2,0,0,0,0,2],[3,0,0,0,2,2,0],[1,0,0,0,0,2,2],[3,0,0,0, 0,2,2],[1,0,0,0,2,2,0],[1,2,0,0,0,0,2],[1,2,2,2,0,0,2],[3,2,2,2,2,2,2],[1,2,2,0,0,0,0],[3,2,0,2,0,2,0],[3,0,2,2,2,2,0],[1,2,0 ,0,2,2,2],[3,0,0,0,2,0,2],[3,0,2,0,2,0,2],[3,0,2,0,0,0,0],[3,2,0,2,0,0,0],[1,0,2,2,0,0,0],[3,2,2,0,0,2,2],[1,0,0,2,0,2,2],[1, 0,0,2,0,0,0],[1,2,0,2,2,0,2],[1,0,2,2,0,0,2],[3,2,2,0,2,0,2],[3,2,0,0,2,2,0],[3,0,2,0,2,2,2],[3,2,2,2,2,2,0],[3,2,2,0,2,2,2], [3,2,0,0,2,0,2],[3,0,0,2,0,2,2],[1,2,0,2,2,2,2],[1,2,0,0,2,2,0],[3,0,0,2,0,2,0],[1,0,2,2,2,2,2],[1,2,2,2,0,2,0],[1,2,2,2,2,0]2],[1,2,2,0,2,0,0],[3,0,2,2,2,2,2],[3,0,2,0,2,0,0],[3,2,2,0,0,0,2],[1,0,2,0,2,2,2],[3,0,0,2,0,0,0],[1,0,2,0,0,2,0],[3,2,0,0,0,2,2],[1,0,0,0,2,0,0],[3,0,2,0,0,2,2],[3,2,2,0,2,0,0],[3,0,0,0,2,0,0],[3,2,2,2,0,2,2],[3,2,0,0,0,2,0],[1,2,0,0,0,2,0],[1,2,2,2,0,2,2],[1,0,2,0,2,0,0],[3,2,0,2,0,0,2],[3,2,2,0,0,2,0],[1,2,0,2,0,2,2],[1,0,2,0,0,0,2],[1,2,2,2,2,2,0],[3,2,2,2,0,2,0],[1,2,0,0,0,2,2],[1,2,2,0,0,0,2],[3,0,2,2,0,0,2],[3,0,2,0,0,0,2],[3,2,0,2,0,2,2],[1,2,2,0,0,2,0],[1,2,0,2,0,0,2],[1,2,2,0,2,0,2],[3,2,0,2,2,0,2],[1,0,0,2,0,2,0],[1,0,2,0,0,2,2],[3,0,2,0,0,2,0],[3,2,0,2,2,2,2],[3,2,2,2,2,0,2],[1,2,0,0,2,0,2],[1,2,2,0,2,2,2],[3,0,0,2,2,2,2],[3,2,2,2,2,0,0],[1,2,2,2,2,0,0],[3,0,2,2,0,2,0],[1,2,2,0,2,2,0],[3,2,0,0,2,0,0],[3,0,2,2,2,0,2],[1,0,0,2,2,0,0],[1,2,0,2,2,2,0],[3,0,0,2,2,0,2],[3,0,0,2,0,0,2],[1,0,0,2,2,2,2],[3,2,0,2,2,0,0],[1,0,0,2,2,2,0],[3,0,0,2,2,0,0],[1,0,2,2,2,0,0],[1,0,2,2,0,2,2],[3,0,2,2,2,0,0],[3,0,2,2,0,2,2],[3,2,0,2,2,2,0],[3,2,2,0,2,2,0],[1,0,0,2,0,0,2],[1,2,0,0,2,0,0],[1,0,2,2,2,0,2],[3,0,2,0,2,2,0],[1,2,0,2,2,0,0],[1,0,2,0,2,2,0],[1,0,0,2,2,0,2],[3,0,0,2,2,2,0],[1,0,2,2,0,2,0].

[0120] Based on the primitive polynomial of the Z4 sequence and any set of initial values, multiple different basis sequences can be generated, each with different initial values.

[0121] It should be understood that the primitive polynomial and initial value of the Z4 sequence are merely examples and should not constitute any limitation on this application. The primitive polynomial and initial value of the aforementioned Z4 sequence may be pre-configured, predefined by the protocol, etc., and this application does not impose any limitations on them.

[0122] Another example is generating multiple different base sequences based on different cyclic shift values ​​and / or phase rotation values.

[0123] It should be noted that multiple Z4 sequences can be generated by cyclic shifting and / or phase rotation based on the base sequence. This can be understood as modulating the base sequence (i.e., the Z4 sequence) to obtain the complex sequence corresponding to the base sequence, and then cyclic shifting and / or phase rotation of the complex sequence to obtain multiple Z4 sequences. These multiple Z4 sequences can be used as preambles that can be selected by different terminals.

[0124] For example, based on different primitive polynomials and different initial values ​​of the Z4 sequence, the terminal can determine different basis sequences, denoted as x(n), with the set of values ​​for the basis sequence being {0, 1, 2, 3}. Modulating this basis sequence yields a complex sequence, denoted as c(n), with the set of values ​​for this complex sequence being {1, -1, j, -j}. The modulated c(n) obtained from x(n) satisfies: This modulation process can be called natural mapping.

[0125] Since the set of element values ​​for the complex sequence obtained after modulation of the base sequence is {1, -1, j, -j}, when the network device receives the Z4 sequence (i.e., the preamble) and performs element-wise multiplication of the received Z4 sequence and the local sequence in the frequency domain, it needs to perform element-wise multiplication of the local sequence and the Z4 sequence (i.e., the preamble) in the frequency domain. Typically, multiplying complex sequences such as the ZC sequence in the current standard is quite complex. However, multiplying the Z4 sequence and the local sequence can be viewed as a sign change, such as multiplying by -1; or as a phase rotation, such as multiplying by j or -j. Therefore, the complexity of the element-wise multiplication can be ignored.

[0126] Further, the complex sequence c(n) can be circularly shifted and / or phase-rotated to obtain multiple different Z4 sequences, that is, multiple preambles, denoted as preamble s(n), where s(n) satisfies: s(n) = αc(n + w)e jθn .

[0127] where s(n) represents the nth element of the generated preamble, n represents the index of the preamble, α represents a complex constant, c(n) represents a sequence modulated based on a base sequence (i.e., a complex sequence), n is greater than or equal to zero and less than N, that is, 0 ≤ n < N, N represents the length of the preamble, w represents the circular shift value, and θ represents the phase rotation value. The length of the preamble s(n) can also be expressed as 2 q - 1, q represents the number of stages of the shift register, and N = 2 q - 1.

[0128] When w = 0, s(n) satisfies: s(n) = αc(n)e jθn . That is, multiple Z4 sequences can be obtained by phase-rotating based on the base sequence. When θ = 0, s(n) satisfies: s(n) = αc(n + w). That is, multiple Z4 sequences can be obtained by circularly shifting based on the base sequence. When both w and θ are not 0, the preamble s(n) can be obtained by circularly shifting and phase-rotating based on the base sequence.

[0129] It can be understood that the preamble s(n) can be predefined by the protocol, preconfigured, etc., and this application does not limit this.

[0130] The multiple Z4 sequences in the sequence pool can be known sequences to the network device and the terminal, and each sequence corresponds to an index, that is, a preamble index, or the terminal generates the multiple Z4 sequences in the sequence pool based on the method in the above example. This application does not limit this.

[0131] Exemplarily, the multiple Z4 sequences in the sequence pool are predefined by the protocol, that is, they can be pre-stored; or the parameters used to generate the multiple Z4 sequences can be predefined or preconfigured by the protocol. For example, the protocol predefines or preconfigures at least one of the following parameters: primitive polynomial, initial value, circular shift value, or phase rotation value. The network device and the terminal can generate multiple Z4 sequences based on at least one parameter predefined or preconfigured by the protocol, that is, they can generate the multiple Z4 sequences in real time.

[0132] After receiving a downlink broadcast message, the terminal can determine the starting preamble index of multiple preambles for the cell for which it is currently requesting random access, i.e., determine the sequence pool, based on the PRACH root sequence index carried in the downlink broadcast message. Each sequence pool can include one or more Z4 sequences, and the Z4 sequences in the sequence pool are the preambles. For example, a sequence pool can include 64 preambles, or it can include more or fewer preambles, etc., and this application does not limit this.

[0133] The terminal can randomly select a Z4 sequence from a defined sequence pool as a preamble, and then perform an IFFT transformation on the preamble to generate a signal for requesting random access. This signal is a time-domain signal. In other words, the terminal can map the preamble onto at least one OFDM symbol to generate the signal for requesting random access. An OFDM symbol can consist of multiple subcarriers, each carrying a portion of data.

[0134] It's important to understand that the Z4 sequence is a constant-modulus sequence, meaning that the amplitude of all elements in the Z4 sequence is the same and constant. Constant-modulus sequences, transmitted using OFDM symbols (or OFDM waveforms), can achieve superior channel estimation performance.

[0135] In other words, the Z4 sequences included in the sequence pool differ in at least one of the following parameters: primitive polynomial, initial value, cyclic shift value, or phase rotation value. In other words, multiple terminals can be enabled to request random access on the same time-frequency resources based on at least one of the following parameters of the base sequence: primitive polynomial, initial value, cyclic shift value, and phase rotation value. That is, based on at least one of the above parameters, multiple different preambles can be generated, further expanding the number of Z4 sequences.

[0136] For example, a terminal can expand the number of Z4 sequences based on different cyclic shifts of the base sequence, different phase rotations of the base sequence, different primitive polynomials and / or initial values ​​of the base sequence, and so on, without further elaboration. In this way, different terminals can request random access based on different preambles, thereby achieving high-capacity uplink random access for the terminal.

[0137] The following sections will provide detailed explanations of cyclic shifting and phase rotation based on base sequences.

[0138] Cyclic shift: When w is not 0, the terminal can perform cyclic shift based on the base sequence to generate multiple Z4 sequences, each with a different cyclic shift value.

[0139] The difference between the cyclic shift values ​​of any two Z4 sequences among the plurality of Z4 sequences is the cyclic shift interval between those two Z4 sequences; or, the difference between the cyclic shift values ​​of the Z4 sequences obtained from two adjacent cyclic shifts is the cyclic shift interval between those two Z4 sequences. For example, cyclically shifting the base sequence yields Z4 sequence #1, with the cyclic shift value denoted as w1; cyclically shifting Z4 sequence #1 again yields Z4 sequence #2, with the cyclic shift value denoted as w2. The cyclic shift interval between Z4 sequence #1 and Z4 sequence #2 is |w2 - w 1| .

[0140] For example, if the base sequence is a four-part sequence [a,b,c,d], and the Doppler frequency offset f d Since the subcarrier spacing is 1, the selectable cyclic shift values ​​w are 0 and 2. The Z4 sequence generated based on w=0 is [a,b,c,d], and the Z4 sequence generated based on w=2 is [c,d,a,b].

[0141] Among multiple Z4 sequences generated based on the base sequence, the cyclic shift interval between two Z4 sequences generated based on the same base sequence is correlated with the maximum Doppler frequency offset.

[0142] Considering the effects of channel propagation delay and frequency offset, since the frequency offset in the time domain represents a phase rotation of the time-domain signal, correspondingly, the frequency-domain signal undergoes a cyclic shift. This cyclic shift interval N cs，Z4 The maximum Doppler frequency offset f of the terminal d It can satisfy: N cs，Z4 Greater than or equal to f d / SCS, which is N cs，Z4 ≥f d / SCS. Here, SCS is the difference between the center frequencies of the different subcarriers used to carry the preamble in the aforementioned OFDM symbol.

[0143] One possibility is that the cyclic shift interval is equal, and the cyclic shift interval between any two adjacent Z4 sequences obtained by cyclic shifts satisfies: N cs，Z4 ≥f d / SCS; Another possibility is that the cyclic shift interval is unequal, and the minimum value of the cyclic shift interval between two adjacent cyclic shifts of the Z4 sequence satisfies: N cs，Z4 ≥f d / SCS.

[0144] Optionally, N cs，Z4 with f d It can also satisfy: N cs，Z4 =2×f d / SCS.

[0145] Phase rotation: When θ is not 0, the terminal can perform phase rotation based on the base sequence to generate multiple Z4 sequences, and each Z4 sequence has a different phase rotation value.

[0146] Perform phase rotation e based on the base sequence jθn The multiple generated Z4 sequences can distinguish different terminals. n represents the subcarrier index, n = 0, 1, 2, 3,..., N, and different terminals select Z4 sequences with different phase rotation values.

[0147] The phase rotation values of the multiple Z4 sequences are related to the cell radius. Considering the channel propagation delay, since the time-domain cyclic shift caused by the delay of the signal in the time domain can be equivalent to the phase rotation of the frequency-domain signal, when the base sequence generates multiple Z4 sequences based on phase rotation to enable multiple terminals to request random access, the phase rotation value θ can satisfy: θ is greater than or equal to Or, θ is equal to zero, that is, Or, θ = 0, N represents the sequence length of the Z4 sequence, M is less than or equal to N, and M is positively correlated with the cell radius.

[0148] Exemplarily, the value of θ can be 0, and so on, not listed one by one. It can be understood that when θ = 0, it means that the base sequence does not perform phase rotation.

[0149] That is, the larger the cell radius, the larger M; on the contrary, the smaller the cell radius, the smaller M. The cell radius can be the cell radius of the cell to which the terminal is currently accessing, or the cell radius of the target cell, where the target cell refers to the cell to which the terminal requests random access, or it can also be the cell radius of any other cell, etc., and this application does not limit this.

[0150] The Z4 sequence has strong anti-frequency offset ability. Generally, the anti-frequency offset ability can be evaluated based on the secondary peak and the peak of the ambiguity function. The ambiguity function can include the auto-ambiguity function and the cross-ambiguity function. The anti-frequency offset ability of the Z4 sequence will be described below for the auto-ambiguity function and the cross-ambiguity function respectively.

[0151] Auto-ambiguity function A(f d , τ) The expression is:

[0152] Among them, s(n) represents the Z4 sequence, s * (n) represents the complex conjugate sequence of s(n), L represents the length of the Z4 sequence, and this Z4 sequence length is the sequence length of the Z4 sequence before oversampling, 0 ≤ n < L, τ represents the time offset value (or, delay), f dRepresents the Doppler frequency offset value. Considering that the length of the cyclic prefix is 1 / 10 of the length of the Z4 sequence, so the value range of τ is τ ∈ [0:L / 10 - 1], f d The value range of is f d ∈ [0:L - 1]. It should be understood that when f d = 0, A(f d ,τ) corresponds to the non-periodic autocorrelation. The larger the secondary peak of the ambiguity function, the weaker the frequency offset resistance ability of the sequence, that is, the weaker the synchronization ability when there is a frequency offset. Generally, it is necessary to normalize the secondary peak of the ambiguity function, that is where, A(0,0) represents the ambiguity function when fd = 0 and τ = 0.

[0153] At the same time, it is also necessary to consider the cross ambiguity function between different Z4 sequences. The cross ambiguity function characterizes the cross-correlation of any two Z4 sequences under the condition of frequency offset.

[0154] The expression of the cross ambiguity function C(f d ,τ) is:

[0155] where, s1(n) and s2(n) represent two different Z4 sequences, s2 * (n) represents the complex conjugate sequence of s2(n), L represents the length of the Z4 sequence, which is the sequence length of the Z4 sequence without oversampling, 0 ≤ n < L, τ represents the time offset value (or, time delay), the value range of τ is τ ∈ [0:L / 10 - 1], f d represents the Doppler frequency offset value, f d The value range of is f d ∈ [0:L - 1]. It should be understood that when fd = 0, A(f d ,τ) corresponds to the non-periodic cross-correlation. The larger the highest peak of the cross ambiguity function, the weaker the frequency offset resistance ability of the sequences in the sequence set, that is, the weaker the synchronization ability when there is a frequency offset. Generally, it is necessary to normalize the highest peak of the cross ambiguity function, that is

[0156] Table 2 shows the performance parameters of the ambiguity function and the cross ambiguity function based on three different sequences.

[0157] Table 2

[0158] It can be seen that, with 127 different sequences and a supplementary cumulative distribution function (CCDF) of 1e⁻⁴, the performance of the self-ambiguity function and cross-ambiguity function of the proposed Z4 sequence can approach that of the current scheme of scrambling the ZC sequence onto the m sequence. Furthermore, compared to the current m sequence, the proposed Z4 sequence scheme only increases the maximum autocorrelation sidelobe (i.e., the second peak of AF) to twice that of the m sequence, while the maximum cross-correlation (i.e., the highest peak of CF) is close to that of the m sequence, and the peak-to-average power ratio (PAPR) is only improved by about 0.5 dB compared to the m sequence.

[0159] In summary, the Z4 sequence exhibits good autocorrelation and cross-correlation properties. Using the Z4 sequence as a preamble to generate a signal requesting random access can improve channel estimation performance.

[0160] In step 520, the terminal sends the signal requesting random access. Correspondingly, the network device receives the signal requesting random access.

[0161] For example, the terminal can carry the signal for requesting random access via PRACH and send it to the network device. Based on the aforementioned step 610, the signal for requesting random access is obtained based on a preamble IFFT transform. That is, the signal for requesting random access carries a preamble, and the terminal can request random access based on this preamble.

[0162] In step 530, the network device processes the signal used to request random access.

[0163] The network device can generate a sequence pool, i.e., generate multiple Z4 sequences, based on at least one of the following parameters predefined or preconfigured by the protocol: primitive polynomial, initial value, cyclic shift value, or phase rotation value; or, the network device can also preconfigure the sequence pool in advance, which includes multiple Z4 sequences, etc., and this application does not limit this.

[0164] Different terminals can choose different preambles to request random access. Network devices identify the preamble index to determine that a preamble has been received, and can then determine the terminal that initiated the random access based on the preamble, thereby distinguishing the access requests of each terminal.

[0165] For example, after receiving the signal requesting random access, the network device can demodulate the signal to obtain the preamble index corresponding to the preamble carried by the signal. Then, based on this preamble index and the sequence pool, it can determine which Z4 sequence in the sequence pool the preamble received by the network device belongs to.

[0166] Network devices can respond to random access of terminals based on received preambles, or determine uplink synchronization positions based on received preambles, etc. This application does not limit this.

[0167] As an example, a network device can respond to a preamble index corresponding to a preamble sent by a terminal by sending Msg2 via PDSCH, replying to the random access request. The preamble index also helps the network device with resource allocation and scheduling. Based on the received preamble index, the network device can allocate appropriate uplink resources to the terminal for subsequent data transmission.

[0168] For details regarding the network device's response to the terminal's random access request, please refer to the detailed content in step 430 above, or refer to the detailed content of the network device's response to the terminal's random access request during the current random access process, which will not be repeated here.

[0169] In another example, the network device can traverse all available preambles (i.e., the multiple Z4 sequences) in the sequence pool and perform correlation detection on the available preambles and the received signal for requesting random access; the network device can also perform channel estimation based on the received signal for requesting random access, and then eliminate the influence of the channel on the received signal based on the channel estimation result; the network device can also perform correlation detection again on the preamble carried in the received signal for requesting random access and the available preambles stored locally to improve detection performance, etc., which are not limited in this application.

[0170] Another example is Figure 6, which is a schematic diagram of the signal processing flow provided in an embodiment of this application. The preamble is typically used as a synchronization signal. After receiving the synchronization signal, the network device first performs filtering to remove noise and interference. Then, the filtered signal is downsampled to reduce the amount of data and simplify processing. Further, time-frequency offset estimation can be performed to determine the signal's time and frequency deviation. Finally, through these steps, time-frequency synchronization between the terminal and the network device is achieved, ensuring accurate data transmission and reception.

[0171] Figure 7 is a schematic diagram of the terminal-side communication architecture provided in an embodiment of this application. It can be seen that the terminal may include a transceiver, a processor (or controller), and a memory. The processor and transceiver can be interconnected via a bus. The processor is coupled to the memory and is used to execute instructions stored in the memory to control the transceiver to send and / or receive signals.

[0172] It should be noted that the communication architecture on the terminal side can also be the communication architecture on the network side. That is, network devices can also include transceivers, processors (or controllers), and memory, which will not be elaborated further.

[0173] It is understandable that this communication architecture can be a chip architecture. If the chip architecture is a terminal-side chip architecture, the processor needs to further generate a signal for requesting random access based on the generated preamble, and then send this signal for requesting random access in the transceiver. If the chip architecture is a network device-side chip architecture, the processor needs to determine the time synchronization position based on the detected preamble and send the RAR.

[0174] Optionally, when the communication architecture is a terminal-side communication architecture, the terminal may further include a modem processor. The modem may include an encoder, modulator, demodulator, and decoder, and can be used for processing such as modulation of the preamble.

[0175] Based on the above technical solution, by using the Z4 sequence as a preamble and processing it, a signal for requesting random access can be obtained. The terminal can then request network access based on this signal. Correspondingly, after receiving the signal from the terminal requesting random access, the network device can demodulate it to obtain the preamble for the request. Using the Z4 sequence as a preamble for random access not only reduces the probability of transmission collisions when multiple terminals attempt random access but also improves channel estimation performance.

[0176] The methods provided in the embodiments of this application have been described in detail above with reference to several accompanying drawings. The apparatus provided in the embodiments of this application will now be described with reference to the accompanying drawings.

[0177] Figures 8 to 11 are schematic block diagrams of possible devices provided in the embodiments of this application. These devices can be used to implement the functions of the terminal or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the device can be the terminal or network device in the method embodiment shown in Figure 5, or it can be a component configured in the terminal or network device (such as a chip, chip system, processor, etc.), or it can be a logic module or software capable of implementing some or all of the functions of the terminal or network device.

[0178] The device provided in this application is shown in FIG8. The device 800 includes a transceiver unit 810 and a processing unit 820.

[0179] One possible design is that the device 800 is used to implement the functions of the terminal in the method embodiment shown in FIG5 above. For example, the device 800 may correspond to the terminal in FIG5.

[0180] For example, the processing unit 820 is used to generate a signal for requesting random access, which is obtained by transforming a preamble through an inverse fast Fourier transform (IFFT), and the preamble is a Z4 sequence; the transceiver unit 810 is used to transmit the signal for requesting random access.

[0181] Optionally, the preamble is determined from a plurality of Z4 sequences, which are generated based on at least one base sequence, and the cyclic shift values ​​and / or phase rotation values ​​of different Z4 sequences generated based on the same base sequence are different.

[0182] Optionally, the plurality of Z4 sequences includes at least one Z4 sequence generated based on a first base sequence and at least one Z4 sequence generated based on a second base sequence, wherein the primitive polynomials and / or initial values ​​of the first base sequence and the second base sequence are different.

[0183] Optionally, among the plurality of Z4 sequences, the cyclic shift interval between two Z4 sequences generated based on the same base sequence is correlated with the maximum Doppler frequency offset.

[0184] Optionally, the cyclic shift interval N cs，Z4 With the maximum Doppler frequency offset f d Satisfy: N cs，Z4 Greater than or equal to f d / SCS.

[0185] Optionally, the phase rotation value of each of the plurality of Z4 sequences is related to the cell radius.

[0186] Optionally, the phase rotation value θ satisfies: θ is greater than or equal to Alternatively, θ equals zero, N represents the sequence length of the Z4 sequence, M is a positive integer less than or equal to N, and M is positively correlated with the cell radius.

[0187] Optionally, the preamble s(n) satisfies: s(n) = αc(n+w)e jθn Where α represents a complex constant, c(n) represents a complex sequence obtained based on base sequence modulation, n is greater than or equal to zero and less than N, N represents the length of the preamble, w represents the cyclic shift value, and θ represents the phase rotation value.

[0188] One possible design is that the device 800 is used to implement the functions of the network device in the method embodiment shown in FIG5 above. For example, the device 800 may correspond to the network device in FIG5.

[0189] For example, the transceiver unit 810 is used to receive a signal for requesting random access, which is obtained by transforming a preamble through an inverse fast Fourier transform (IFFT) and the preamble is a Z4 sequence; the processing unit 820 is used to process the signal for requesting random access.

[0190] Optionally, the preamble is determined from a plurality of Z4 sequences, which are generated based on at least one base sequence, and the cyclic shift values ​​and / or phase rotation values ​​of different Z4 sequences generated based on the same base sequence are different.

[0191] Optionally, the plurality of Z4 sequences includes at least one Z4 sequence generated based on a first base sequence and at least one Z4 sequence generated based on a second base sequence, wherein the primitive polynomials and / or initial values ​​of the first base sequence and the second base sequence are different.

[0192] Optionally, among the plurality of Z4 sequences, the cyclic shift interval between two Z4 sequences generated based on the same base sequence is correlated with the maximum Doppler frequency offset.

[0193] Optionally, the cyclic shift interval N cs，Z4 With the maximum Doppler frequency offset f d Satisfy: N cs，Z4 Greater than or equal to f d / SCS.

[0194] Optionally, the phase rotation value of each of the plurality of Z4 sequences is related to the cell radius.

[0195] Optionally, the phase rotation value θ satisfies: θ is greater than or equal to Alternatively, θ equals zero, N represents the sequence length of the Z4 sequence, M is a positive integer less than or equal to N, and M is positively correlated with the cell radius.

[0196] Optionally, the preamble s(n) satisfies: s(n) = αc(n+w)e jθn Where α represents a complex constant, c(n) represents a complex sequence obtained based on base sequence modulation, n is greater than or equal to zero and less than N, N represents the length of the preamble, w represents the cyclic shift value, and θ represents the phase rotation value.

[0197] A more detailed description of the transceiver unit 810 and the processing unit 820 can be obtained directly from the relevant description in any of the embodiments shown in Figure 5, and will not be repeated here.

[0198] In one possible design, when the device 800 is a network device or a communication module within a network device, the functionality of the processing unit 820 can be implemented by one or more processors. Specifically, the processor may include a modem chip, or a system-on-a-chip (SoC) or SIP chip containing a modem core. The functionality of the transceiver unit 810 can be implemented by transceiver circuitry.

[0199] In one possible design, when the device 800 is a circuit or chip responsible for communication functions in a network device, such as a modem chip or a system-on-a-chip (SoC) or SIP chip containing a modem core, the function of the processing unit 820 can be implemented by a circuit system in the aforementioned chip that includes one or more processors or processor cores. The function of the transceiver unit 810 can be implemented by the interface circuitry or data transceiver circuitry on the aforementioned chip.

[0200] It should also be understood that the transceiver unit in the communication device 800 can also be called a communication unit. This transceiver unit 810 may include a transmitting unit but not a receiving unit. Alternatively, the transceiver unit 810 may include a receiving unit but not a transmitting unit. Specifically, it depends on whether the above-described scheme performed by the device 800 includes both transmitting and receiving actions. The receiving unit can be used to perform the receiving action in the above-described scheme, and the transmitting unit can be used to perform the transmitting action in the above-described scheme.

[0201] It is understood that the division of units in the above-described device is merely a logical functional division. Each function can correspond to a functional unit, or two or more functions can be integrated into one functional unit. In actual implementation, all or some units can be integrated into a single physical entity, or they can be distributed across different physical entities. Furthermore, the aforementioned functional units can be implemented in hardware, software, or a combination of both. Whether a function is executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0202] Figure 9 is another schematic block diagram of the device provided in an embodiment of this application. As shown in Figure 9, the device 900 includes one or more processors 910. The processor 910 can be a general-purpose processor or a special-purpose processor, etc. For example, it can be a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the device (e.g., a vehicle or a chip), execute software programs, and process data from the software programs.

[0203] Alternatively, in one design, processor 910 may include a computer program (also referred to as code or instructions) that can be run on processor 910, causing device 900 to perform the methods executed by the terminal or network device in the above method embodiments. In yet another possible design, device 900 includes circuitry (not shown in FIG9) for implementing the functions of the terminal or network device in the above method embodiments.

[0204] For example, processor 910 can be used to execute a computer program in memory to implement the steps performed by a terminal or network device in the method embodiment shown in FIG5.

[0205] Optionally, the device 900 may include one or more memories 920 storing computer programs (sometimes referred to as code or instructions) that can be run on the processor 910, causing the device 900 to perform the methods performed by the terminal or network device in the above embodiments.

[0206] Optionally, the processor 910 and / or memory 920 may also store data. The processor and memory may be configured separately or integrated together.

[0207] Optionally, the device 900 may also include a communication interface 930. The processor 910, sometimes referred to as a processing unit, controls the device (e.g., a terminal or network device). The communication interface 930, sometimes referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver, is used to implement the device's transceiver functions.

[0208] Optionally, the device 900 also includes a communication interface 930. The processor 910 and the communication interface 930 are coupled to each other. It is understood that the communication interface 930 can be a transceiver or an input / output interface.

[0209] When device 900 is used to implement the method shown in FIG. 5, processor 910 can be used to execute the functions of processing unit 820, and communication interface 930 can be used to execute the functions of transceiver unit 810. Whether communication interface 930 is used for sending or receiving depends on whether the scheme executed by device 900 is used to perform a sending action or a receiving action.

[0210] When the aforementioned device 900 is a chip applied to a terminal, the chip implements the functions of the terminal in the above method embodiments. The terminal's chip receives signals from other modules (such as radio frequency modules or antennas) in the terminal, and these signals may be sent to the terminal by network devices; or, the terminal's chip sends signals to other modules (such as radio frequency modules or antennas) in the terminal, and these signals may be sent to network devices by the terminal.

[0211] When the aforementioned device 900 is a chip applied to a network device, the chip implements the functions of the network device in the above method embodiments. The chip of the network device receives signals from other modules in the network device, which may be signals sent by a terminal to the network device; or, the chip of the network device sends signals to other modules in the network device, which may be signals sent by the network device to a terminal.

[0212] It is understood that when the device 900 is a terminal or network device, the communication interface 930 can be a transceiver, specifically including a transmitter and a receiver, with the transmitter used to send signals and the receiver used to receive signals. When the device 900 is a chip applied to a terminal or network device, the communication interface 930 can be an input / output circuit, wherein the input circuit can be used for receiving and the output interface can be used for sending.

[0213] Optionally, the device 900 also includes a power supply circuit for supplying power to the device 900.

[0214] Figure 10 is a schematic diagram of the terminal device provided in an embodiment of this application. As shown in Figure 10, the terminal device 1000 can be applied to the system shown in Figure 1 to perform the functions of the terminal in the method embodiment shown in Figure 5. As shown, the terminal device 1000 includes a processor 1001 and a transceiver 1002. Optionally, the terminal device 1000 also includes a memory 1003. The processor 1001, transceiver 1002, and memory 1003 can communicate with each other through an internal connection path to transmit control and / or data signals. The memory 1003 is used to store computer programs, and the processor 1001 is used to call and run the computer programs from the memory 1003 to control the transceiver 1002 to transmit and receive signals. Optionally, the terminal device 1000 may also include an antenna 1004 for transmitting uplink data or uplink control signaling output by the transceiver 1002 via wireless signals.

[0215] The processor 1001 and memory 1003 can be combined into a single processing device. The processor 1001 executes the program code stored in the memory 1003 to achieve the aforementioned functions. In specific implementations, the memory 1003 can be integrated into the processor 1001 or be independent of the processor 1001. The processor 1001 can correspond to the processing unit in FIG8 or the processor in FIG9.

[0216] The transceiver 1002 described above can correspond to the transceiver unit in Figure 8 or the communication interface in Figure 9. The transceiver 1002 may include a receiver (or receiver circuit) and a transmitter (or transmitter circuit). The receiver is used to receive signals, and the transmitter is used to transmit signals.

[0217] It should be understood that the terminal device 1000 shown in Figure 10 can implement the various processes involving the terminal or network device in the method embodiment shown in Figure 5. The operation and / or function of each module in the terminal device 1000 are respectively for implementing the corresponding processes in the above method embodiments. For details, please refer to the description in the above method embodiments; to avoid repetition, detailed descriptions are appropriately omitted here.

[0218] The processor 1001 described above can be used to execute the actions implemented internally by the terminal or network device as described in the preceding method embodiments, while the transceiver 1002 can be used to execute the actions described in the preceding method embodiments whereby the network device sends data to the terminal or the terminal receives data from the network device. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0219] Optionally, the terminal device 1000 may also include a power supply 1005 for providing power to various devices or circuits in the terminal.

[0220] In addition, to make the terminal more functional, the terminal device 1000 may also include one or more of the following: an input unit 1006, a display unit 1007, an audio circuit 1008, a camera 1009, and a sensor 1010. The audio circuit may also include a speaker 1008a, a microphone 1008b, etc.

[0221] Figure 11 is a schematic diagram of the network device provided in an embodiment of this application, such as a schematic diagram of a base station. The base station 1100 can be applied to the system shown in Figure 1, performing the functions of the network device in the method embodiment shown in Figure 5. As shown, the base station 1100 may include one or more of the following: one or more (DU+RU) 1110s and one or more CUs 1120s. CU 1120 can communicate with the next-generation core (NG core). The DU may include at least one antenna 1111, at least one radio frequency unit 1112, at least one processor 1113, and at least one memory 1114. The DU is mainly used for transmitting and receiving radio frequency signals, converting radio frequency signals to baseband signals, and performing some baseband processing. CU 1120 may include at least one processor 1122 and at least one memory 1121. CU 1120 and DU can communicate through an interface. The control plane (CP) interface can be Fs-C, such as F1-C, and the user plane (UP) interface can be Fs-U, such as F1-U. DUs and RUs can work together to implement the functions of the physical (PHY) layer. A DU can be connected to one or more RUs. The functions of DUs and RUs can be configured in various ways depending on the design. For example, a DU can be configured to implement baseband functions, and an RU can be configured to implement mid-RF functions. Another example is that a DU can be configured to implement higher-level functions in the PHY layer, and an RU can be configured to implement lower-level and RF functions in the PHY layer. Higher-level functions in the PHY layer may include a portion of the PHY layer's functions, which are closer to the medium access control (MAC) layer, while lower-level functions in the PHY layer may include another portion of the PHY layer's functions, which are closer to the mid-RF side.

[0222] The CU 1120 is mainly used for baseband processing and base station control. The DU and CU 1120 can be physically installed together or separately, i.e., a distributed base station. The CU 1120 is the control center of the base station, corresponding to the processing unit in Figure 8 or the processor in Figure 9, and can also be called a processing unit, mainly used to complete baseband processing functions. For example, the CU 1120 can be used to control the base station to execute the network device operation procedures described in the above method embodiments.

[0223] Specifically, baseband processing on the CU and DU can be divided according to the protocol layers of the wireless network. For example, the functions of the Packet Data Convergence Protocol (PDCP) layer and above are set in the CU, while the functions of protocol layers below PDCP, such as the Radio Link Control (RLC) layer and the MAC layer, are set in the DU. Alternatively, the CU may implement the functions of the RRC and PDCP layers, while the DU may implement the functions of the RLC, MAC, and PHY layers.

[0224] Alternatively, base station 1100 may include one or more radio frequency units (RU), one or more DUs, and one or more CUs. A DU may include at least one processor 1113 and at least one memory 1114, an RU may include at least one antenna 1111 and at least one radio frequency unit 1112, and a CU may include at least one processor 1122 and at least one memory 1121.

[0225] In one example, the CU 1120 can be composed of one or more single boards. These boards can collectively support a single access-indicating radio access network (such as a 5G network), or they can each support radio access networks with different access standards (such as LTE, 5G, or other networks). The memory 1121 and processor 1122 can serve one or more single boards. That is, each single board can have its own memory and processor, or multiple single boards can share the same memory and processor. Furthermore, each single board can also have necessary circuitry. Similarly, the DU can be composed of one or more single boards. These boards can collectively support a single access-indicating radio access network (such as a 5G network), or they can each support radio access networks with different access standards (such as LTE, 5G, or other networks). The memory 1114 and processor 1113 can serve one or more single boards. That is, each single board can have its own memory and processor, or multiple single boards can share the same memory and processor. Furthermore, each single board can also have necessary circuitry.

[0226] It should be understood that the base station 1100 shown in Figure 11 can implement the various processes involving the network device in the method embodiment shown in Figure 5. The operation and / or function of each module in the base station 1100 are respectively for implementing the corresponding processes in the above method embodiment. For details, please refer to the description in the above method embodiment; to avoid repetition, detailed descriptions are appropriately omitted here.

[0227] It should be understood that the base station 1100 shown in Figure 11 is only one possible architecture for network devices and should not be construed as limiting this application in any way. The method provided in this application can be applied to network devices with other architectures, such as network devices including CU, DU, and AAU. This application does not limit the specific architecture of the network device.

[0228] It should be understood that Figure 11 is merely an example and not a limitation, and the network device may not depend on the structure shown in Figure 11. For example, the network device may also include an AAU, a CU and / or a DU, or a BBU and an adaptive radio unit (ARU). This application does not limit this.

[0229] The aforementioned CU and / or DU can be used to perform the actions implemented internally by the network device as described in the preceding method embodiments, while the AAU can be used to perform the actions described in the preceding method embodiments whereby the network device sends data to the terminal device or the terminal device receives data from the network device. Please refer to the descriptions in the preceding method embodiments for details, which will not be repeated here.

[0230] It should be noted that the above method embodiments can be applied to a processor, or implemented by a processor. A processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by software instructions.

[0231] The aforementioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0232] The steps of the method disclosed in the embodiments of this application can be directly manifested as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in mature storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0233] The memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0234] This application also provides a chip system including at least one processor for supporting the implementation of the functions of the terminal or network device involved in any of the above method embodiments, such as receiving, transmitting, or processing signals involved in the above methods.

[0235] In one possible design, the chip system also includes a memory for storing computer program instructions and data, which may be located inside or outside the processor.

[0236] The chip system can consist of chips or include chips and other discrete components.

[0237] This application also provides a computer program product, which includes a computer program (also referred to as code or instructions), wherein when the computer program is run, the method executed by the terminal in the embodiment shown in FIG5 is executed, or the method executed by the network device is executed.

[0238] This application also provides a computer-readable storage medium storing a computer program (also referred to as code or instructions). When the computer program is run, the method executed by the terminal in the embodiment shown in FIG5 is executed, or the method executed by the network device is executed.

[0239] This application also provides a communication system, which includes the aforementioned terminal and network equipment.

[0240] The methods provided in the above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any combination thereof. When implemented in software, they can be implemented, in whole or in part, in the form of a computer program product. This computer program product may include one or more computer instructions. When these 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 may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic disk), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0241] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0242] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0243] 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.

[0244] The unit described as a separate component may or may not be physically separate. The component shown as a unit may or may not be a physical unit; that is, it 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.

[0245] 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.

[0246] If this function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, or part of it, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

Claims

1. A communication method, characterized in that, The method includes: A signal for requesting random access is generated, wherein the signal for requesting random access is obtained by inverse fast Fourier transform (IFFT) of a preamble, and the preamble is a Z4 sequence. Send the signal used to request random access.

2. A communication method, characterized in that, The method includes: Receive a signal for requesting random access, the signal for requesting random access being obtained by inverse fast Fourier transform (IFFT) of a preamble, the preamble being a Z4 sequence; Process the signal used to request random access.

3. The method as described in claim 1 or 2, characterized in that, The preamble is determined from a plurality of Z4 sequences, which are generated based on at least one base sequence, and the cyclic shift values ​​and / or phase rotation values ​​of different Z4 sequences generated based on the same base sequence are different.

4. The method according to claim 3, characterized in that, The plurality of Z4 sequences include at least one Z4 sequence generated based on a first base sequence and at least one Z4 sequence generated based on a second base sequence, wherein the primitive polynomials and / or initial values ​​of the first base sequence and the second base sequence are different.

5. The method as described in claim 3 or 4, characterized in that, Among the multiple Z4 sequences, the cyclic shift interval between two Z4 sequences generated based on the same base sequence is related to the maximum Doppler frequency offset.

6. The method as described in claim 5, characterized in that, The cyclic shift interval N cs，Z4 With the maximum Doppler frequency offset f d Satisfy: N cs， Z4 Greater than or equal to f d / Subcarrier spacing (SCS).

7. The method according to any one of claims 3 to 6, characterized in that, The phase rotation value of each of the plurality of Z4 sequences is related to the cell radius.

8. The method as described in claim 7, characterized in that, The phase rotation value θ satisfies: θ is greater than or equal to Alternatively, θ is zero, N represents the sequence length of the Z4 sequence, M is a positive integer less than or equal to N, and M is positively correlated with the cell radius.

9. The method according to any one of claims 1 to 8, characterized in that, The preamble s(n) satisfies: s(n)=αc(n+w)e jθn ; Where α represents a complex constant, c(n) represents a complex sequence obtained based on base sequence modulation, n is greater than or equal to zero and less than N, N represents the length of the preamble, w represents the cyclic shift value, and θ represents the phase rotation value.

10. A communication device, characterized in that, Includes units for performing the method as described in any one of claims 1 to 9.

11. A communication device, characterized in that, It includes one or more processors, said one or more processors for executing computer programs or instructions in memory, causing said communication device to perform the method as described in any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it causes the method as described in any one of claims 1 to 9 to be performed.

13. A computer program product, characterized in that, Includes a computer program that, when run, causes the method as described in any one of claims 1 to 9 to be performed.

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