Communication method, device and system

Abstract

The invention relates to the technical field of communication, and discloses a communication method, device and system. The method comprises: a first communication device generating a random access signal, the random access signal being obtained based on a first sequence; sending the random access signal; wherein the first sequence is obtained according to a second sequence and a first cyclic shift value, the second sequence is one of M sequences, the M sequences are obtained according to M1 recursion formulas and M2 initial value sequences, M1 is an integer greater than 1, and M2 is an integer greater than 1; the first cyclic shift value is an integer greater than or equal to 0. Thus, the sequence (such as a lead code) used for generating the random access signal can be expanded, the probability of collision when different terminal devices access the network device is reduced, and the requirements of future communication scenes are met.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method, apparatus and system. Background Technology

[0002] The random access procedure refers to the process from when a terminal device sends a random access signal to attempt to access the network until a basic signaling connection is established with the network device. The random access signal is used to initiate the random access procedure, and it is obtained based on the random access preamble, which can be simply referred to as the preamble.

[0003] However, the number of terminal devices accessing the network will increase further in the future, which may cause different terminal devices to send random access signals based on the same preamble at the same random access time, thus causing collisions between different terminal devices. Summary of the Invention

[0004] This application provides a communication method, apparatus, and system for expanding the capacity of preambles, reducing the probability of collisions when different terminal devices access network devices, and meeting the needs of future communication scenarios.

[0005] In a first aspect, embodiments of this application provide a communication method, which can be applied to a first communication device, which can be a terminal device or a component (such as a chip or circuit) within the terminal device. For example, in the method provided in the first aspect, the first communication device generates a random access signal, which is obtained based on a first sequence; and transmits the random access signal; wherein the first sequence is obtained based on a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained based on M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; the first cyclic shift value is an integer greater than or equal to 0.

[0006] Using the above method, it is possible to expand the sequence (such as preamble) used to generate random access signals, reduce the probability of collisions when different terminal devices access network devices, and meet the needs of future communication scenarios.

[0007] In one possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0008] In other words, the sequence is obtained by cyclically shifting M sequences obtained from M1 recursive formulas and M2 initial value sequences, without any of them being the same sequence.

[0009] In one possible design, all M sequences are Z4 sequences.

[0010] Thus, since the cross-correlation values ​​between different Z4 sequences are low, it is possible to expand the capacity of the preamble while ensuring the detection performance of the preamble.

[0011] In one possible design, M = M1 * M2.

[0012] In one possible design, the first cyclic shift value is one of M3 cyclic shift values. L represents the sequence length of the second sequence, and C represents the cyclic shift interval; L is an integer greater than 1, and C is an integer greater than or equal to 1.

[0013] In one possible design, the first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

[0014] In one possible design, the first sequence is obtained based on the second sequence and the first cyclic shift value, including: the first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2 ... L-1;

[0015] y(n)=z((i+cs)modL)

[0016] Where cs represents the first cyclic shift value.

[0017] In one possible design, the first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1;

[0018] or

[0019] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0020] Thus, by using natural mapping to modulate the first sequence to obtain the third sequence (i.e., the preamble), the second peak of the ambiguity function of the third sequence is lower, which makes it easier to ensure the synchronization performance of the preamble.

[0021] In one possible design, generating the random access signal includes: performing a Discrete Fourier Transform (DFT) on the third sequence to obtain a fourth sequence; mapping the elements of the fourth sequence onto multiple subcarriers and performing an Inverse Fast Fourier Transform (IFFT) to generate the random access signal.

[0022] Secondly, embodiments of this application provide a communication method that can be applied to a second communication device, which can be a network device or a component (such as a chip or circuit) within the network device. For example, in the method provided in the second aspect, the second communication device receives a random access signal, which is obtained based on a first sequence; in response to the random access signal, it sends a random access response; wherein the first sequence is obtained based on a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained based on M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; the first cyclic shift value is an integer greater than or equal to 0.

[0023] In one possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0024] In one possible design, all M sequences are Z4 sequences.

[0025] In one possible design, M = M1 * M2.

[0026] In one possible design, the first cyclic shift value is one of M3 cyclic shift values. L represents the sequence length of the second sequence, and C represents the cyclic shift interval; L is an integer greater than 1, and C is an integer greater than or equal to 1.

[0027] In one possible design, the first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

[0028] In one possible design, the first sequence is obtained based on the second sequence and the first cyclic shift value, including: the first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2 ... L-1;

[0029] y(n)=z((i+cs)modL)

[0030] Wherein, cs represents the first cyclic shift value, and cs is an integer greater than or equal to 0.

[0031] In one possible design, the first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1;

[0032] or

[0033] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0034] It is understood that the communication method provided in the second aspect corresponds to the communication method provided in the first aspect, and the beneficial effects of the relevant technical features in the second aspect can be referred to the description in the first aspect.

[0035] Thirdly, this application provides a communication device that has the functions involved in the first or second aspect above. For example, the communication device includes modules, units, or means corresponding to the operations involved in the first or second aspect above. The functions, units, or means can be implemented by software, or by hardware, or by hardware executing corresponding software.

[0036] In one possible design, the communication device includes a processing unit and a communication unit, wherein the communication unit can be used to transmit and receive signals to enable communication between the communication device and other devices; the processing unit can be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit can correspond to the operations involved in the first or second aspect described above.

[0037] In one possible design, the communication device includes a processor that can be coupled to a memory. The memory can store necessary computer programs or instructions for implementing the functions described in the first or second aspect above. The processor can execute the computer programs or instructions stored in the memory, causing the communication device to implement the methods in any possible design or implementation of the first or second aspect above, when executed.

[0038] In one possible design, the communication device includes a processor and a memory, the memory of which may store necessary computer programs or instructions for implementing the functions involved in the first or second aspect described above. The processor may execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, cause the communication device to implement the methods in any possible design or implementation of the first or second aspect described above.

[0039] In one possible design, the communication device includes a processor and an interface circuit, wherein the processor is configured to communicate with other devices via the interface circuit and execute the methods in any possible design or implementation of the first or second aspect described above.

[0040] Understandably, in the third aspect described above, the processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc.; when implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. Furthermore, there can be one or more processors, and one or more memories. The memory can be integrated with the processor or separated from it. In specific implementations, the memory can be integrated with the processor on the same chip or disposed on different chips. This application does not limit the type of memory or the arrangement of the memory and processor.

[0041] Fourthly, this application provides a communication system, which may include a first communication device and a second communication device; wherein the first communication device is used to perform the method described in the first aspect, and the second communication device is used to perform the method described in the second aspect.

[0042] Fifthly, this application provides a computer-readable storage medium storing a computer program (or computer-readable instructions) in which, when a computer reads and executes some or all of the computer-readable instructions, the method in any of the possible designs of the first or second aspect described above is executed.

[0043] For example, a computer-readable storage medium can be any available medium that a computer can access. This includes, but is not limited to, non-transient computer-readable media, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM or other optical disc storage, magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer.

[0044] Sixthly, this application provides a computer program product that, when read and executed by a computer, causes the method in any of the possible designs of the first or second aspect to be performed.

[0045] In a seventh aspect, this application provides a chip (or chip system) including a processor coupled to a memory storing a computer program; the processor is configured to invoke part or all of the computer program in the memory, such that the method in any of the possible designs of the first or second aspect described above is executed. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the architecture of the communication system used in the embodiments of this application;

[0047] Figure 2 This is a schematic diagram of the random access process provided in an embodiment of this application;

[0048] Figure 3 This is a schematic diagram of the basic structure of the feedback shift register provided in the embodiments of this application;

[0049] Figure 4 A flowchart illustrating the communication method provided in the embodiments of this application;

[0050] Figure 5 The following are possible exemplary block diagrams of the apparatus involved in the embodiments of this application;

[0051] Figure 6 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0052] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings. This application will focus on various aspects, embodiments, or features of a system that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the accompanying drawings. Furthermore, combinations of these solutions may also be used.

[0053] In the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as an "example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "example" is intended to present concepts in a concrete manner. In the embodiments of this application, "of," "corresponding, relevant," and "corresponding" may sometimes be used interchangeably, and it should be noted that their intended meanings are consistent unless their distinction is emphasized.

[0054] The technical solutions of this application can be applied to various wireless communication systems, such as Universal Mobile Telecommunications System (UMTS), Wireless Local Area Network (WLAN), short-range wireless communication systems (such as sidelink, Wireless Fidelity (Wi-Fi), Bluetooth, etc.), wired networks, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, 4th generation (4G) mobile communication systems (such as Long Term Evolution (LTE) systems), LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Worldwide Interoperability for Microwave Access (WiMAX) communication systems, 5th generation (5G) mobile communication systems (such as New Radio (NR) systems), Future Communications systems, or other similar communication systems, and are not limited thereto. The embodiments of this application use... Figure 1 The communication system shown is used as an example for description. When the technical solutions of the embodiments of this application are applied to other communication systems, the devices, components, modules, etc. in the embodiments can be replaced with corresponding devices, components, modules in other communication systems without limitation.

[0055] Figure 1 This is a schematic diagram of the architecture of the communication system used in the embodiments of this application. Figure 1 As shown, the communication system includes an access network 100. Optionally, the communication system may also include a core network 200 and an Internet 300. The access network 100 may include at least one network device, such as... Figure 1 110a and 110b may also include at least one terminal device, such as Figure 1The series consists of 120a-120j. Specifically, 110a is a base station, 110b is a micro-station, 120a, 120e, 120f, and 120j are mobile phones, 120b is a car, 120c is a fuel dispenser, 120d is a home access point (HAP) deployed indoors or outdoors, 120g is a laptop, 120h is a printer, and 120i is a drone. The same terminal device or network device can provide different functions in different application scenarios. For example... Figure 1 The mobile phones included are 120a, 120e, 120f, and 120j. Mobile phone 120a can access base station 110a, connect to car 120b, communicate directly with mobile phone 120e, and access HAP. Car 120b can access HAP and communicate directly with mobile phone 120a. Mobile phone 120f can connect to micro-station 110b, connect to laptop 120g, and connect to printer 120h. Mobile phone 120j can control drone 120i.

[0056] (1) Network equipment

[0057] A network device is a network-side device with wireless transceiver capabilities. A network device can be a device in a radio access network (RAN) that provides wireless communication capabilities to terminal devices; this is called RAN equipment. The RAN can be an access network within the 3rd Generation Partnership Project (3GPP), such as 4G, 5G, or future networks. The RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a communication network combining two or more of these.

[0058] RAN equipment can also be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc.

[0059] RAN equipment can also be modules or units that perform some of the functions of a base station. For example, it can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). The CU performs the functions of the radio resource control (RRC) and PDCP protocols of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The CU can be further divided into a CU control plane (CP) (i.e., CU-CP) and a CU user plane (UP) (i.e., CU-UP). The DU performs the functions of the RLC and MA layers of the base station, and can also perform some or all of the physical layer functions. For specific descriptions of the above protocol layers, please refer to the relevant 3GPP technical specifications. CU and DU can be set up separately, or they can be included in the same network element, such as in a baseband unit (BBU). The RU can be included in radio frequency equipment or radio frequency units, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radiohead (RRH). In different systems, CU, 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, and RU can also be called O-RU. Any of the CU (or CU-CP, CU-UP), DU, and RU units in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. RA equipment can be a macro base station (such as...) Figure 1 110a in the text), can also be a micro base station or an indoor station (such as... Figure 1 In 110b), it can also be a relay node or a donor node, etc. The embodiments of this application do not limit the specific technology or device form used in the network equipment.

[0060] In the embodiments of this application, the functions of the network device can be executed by modules (such as chips) within the network device, or by a control subsystem that includes the functions of the network device. This control subsystem, which includes the functions of the network device, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities.

[0061] (2) Terminal equipment

[0062] A terminal device is a user-side device with wireless transceiver capabilities. Terminal devices can also be called terminals, user equipment (UE), mobile stations, mobile terminals, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, intelligent transportation, and smart cities. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. In the embodiments of this application, the device used to implement the functions of the terminal device can be the terminal device itself, or it can be a device that supports the terminal device in implementing that function, such as a chip system or a combination of devices or components that can implement the functions of the terminal device. This device can be installed in the terminal device. The embodiments of this application do not limit the specific technology or specific device form used in the terminal device.

[0063] In this embodiment of the application, the functions of the terminal device can also be performed by modules (such as chips or modems) in the terminal device, or by a device containing the functions of the terminal device.

[0064] Network devices and terminal devices can be fixed in location or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and artificial satellites. The embodiments of this application do not limit the application scenarios of the network devices and terminal devices.

[0065] The roles of network devices and terminal devices can be relative, for example, Figure 1 The helicopter or drone 120i can be configured as a mobile network device. For terminal devices 120j that access the wireless access network 100 via 120i, terminal device 120i is a network device; however, for network device 110a, 120i is a terminal device, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a network device-to-network device interface protocol; in this case, 120i is also a network device relative to 110a. Therefore, both network devices and terminal devices can be collectively referred to as communication devices. Figure 1110a and 110b can be referred to as communication devices with network equipment functions. Figure 1 The 120a-120j in the text can be referred to as communication devices with terminal equipment functions.

[0066] Network devices and terminal devices, network devices and network devices, and terminal devices can communicate through licensed spectrum, unlicensed spectrum, or both simultaneously, without limitation.

[0067] The network architecture and business scenarios described in this application are intended to more clearly illustrate the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0068] The relevant terms and technical features involved in the embodiments of this application will be explained below. These explanations are intended to make the embodiments of this application easier to understand and should not be regarded as strict limitations on the terms in the scope of protection claimed by this application.

[0069] (1) Sequence

[0070] In this application's embodiments, the "sequence" includes one or more elements. Each element can be represented as a complex number, including a real part and an imaginary part; alternatively, elements can also be represented as real numbers, without any specific limitation.

[0071] For example, the sequence [s(n)] contains L elements, where L is an integer greater than 1. n belongs to [0, ..., L-1], that is, n∈[0, ..., L-1]. In [0, ..., L-1], "..." represents an integer between 0 and L-1. For example, when L=5, n∈[0, 1, 2, 3, 4, ...]. The L elements in [s(n)] can be s(0), ..., s(L-1); in other words, the element numbered n in [s(n)] can be s(n).

[0072] It is understood that this application embodiment uses a numbering method with a starting number of 0 and incrementing by a step size of 1 as an example, but it is not limited to this. For example, the numbering method can also be: starting number of 1 and incrementing by a step size of 1. Another example is that the numbering method can also be: starting number of X and decrementing by a step size of 1, where X is an integer greater than 1. "[·]" and "{·}" can be used interchangeably to represent multiple elements, which can be understood as a set, group, or sequence, etc., and are not limited thereto.

[0073] (2) Cross-correlation between sequences

[0074] For two sequences of length L, such as [s1(n)] and [s2(n)], considering all time-domain cyclic shifts, the cross-correlation value between [s1(n)] and [s2(n)] satisfies the following formula:

[0075]

[0076] Where c(s1,s2)' represents the cross-correlation value between [s1(n)] and [s2(n)] (i.e., the cross-correlation value before normalization), c(s1,s2) represents the cross-correlation value between [s1(n)] and [s2(n)] (i.e., the cross-correlation value after normalization), τ takes values ​​in the range of [-L,L], and abs represents taking the absolute value.

[0077] Without considering time-domain cyclic shift, the cross-correlation value between [s1(n)] and [s2(n)] satisfies the following formula:

[0078]

[0079] Where c(s1,s2)' represents the cross-correlation value between [s1(n)] and [s2(n)] (i.e., the cross-correlation value before normalization), and c(s1,s2) represents the cross-correlation value between [s1(n)] and [s2(n)] (i.e., the cross-correlation value after normalization).

[0080] (3) Random access procedure

[0081] A random access procedure refers to the process from when a terminal device sends a random access signal to attempt to access the network, until a basic signaling connection is established with the network device. The random access signal is used to initiate the random access procedure; for example, the random access signal is derived from a random access preamble, which can be called a random access preamble sequence, preamble sequence, or preamble. The random access signal is carried on the physical random access channel (PRACH). The terminal device can interact with the network device through the random access procedure to achieve uplink synchronization with the network device. Optionally, it can also request resources or transmit data through the random access procedure.

[0082] Based on whether the preamble is selected by the terminal device itself, random access procedures can be divided into contention-based random access procedures and non-contention-based random access procedures. The following description uses a contention-based random access procedure as an example to illustrate one possible implementation of the random access procedure.

[0083] Figure 2 This is a schematic diagram of a random access procedure provided in an embodiment of this application. Figure 2 As shown, it includes the following steps:

[0084] In step S200, the network device sends random access configuration information to the terminal device, and the terminal device can correspondingly receive the configuration information from the network device. This step can be considered preparatory work before performing the random access procedure and is not part of the random access procedure itself.

[0085] For example, a network device can send random access configuration information to a terminal device via system messages. This configuration information may include Message 1, which configures multiple PRACH occasions (ROs). An RO can be understood as a time-frequency resource used to transmit a random access signal once.

[0086] The configuration information may also include information 2, such as the logical root index number. The logical root index number is used to determine the sequence set (or preamble set) of the current cell, as described below.

[0087] In addition, the configuration information can also be used to configure other possible information, such as the correspondence between multiple ROs and (synchronization signal block, SS) / physical broadcast channel (PBCH) blocks (SS / PBCH block).

[0088] S201, the terminal device sends a random access signal to the network device. This random access signal can be referred to as the first message or message 1 (Msg1) of the random access procedure.

[0089] Specifically, the terminal device can receive multiple SS / PBCH blocks sent by the network device and select a target SS / PBCH block from among them based on the measured values ​​of the multiple SS / PBCH blocks (such as the reference signal receiving power (RSRP) of the multiple SS / PBCH blocks). Further, the terminal device selects a preamble (such as sequence a) from the preamble set of the current cell, generates a random access signal based on sequence a, and then transmits the random access signal on a RO corresponding to the target SS / PBCH block.

[0090] S202, after detecting the random access signal sent by the terminal device, the network device sends a random access response (RAR) to the terminal device. This random access response can be referred to as message 2 or message 2 (Msg2) in the random access procedure.

[0091] For example, after receiving a random access signal on the RO corresponding to the target SS / PBCH block, the network device can determine that the downlink beam communicating with the terminal device is the beam corresponding to the target SS / PBCH block, and then use the beam corresponding to the target SS / PBCH block to send a RAR to the terminal device.

[0092] For example, RAR includes timing advance (TA), which is used for uplink synchronization between terminal devices and network devices.

[0093] S203, the terminal device sends an uplink signaling message to the network device according to the TA. This uplink signaling message can be referred to as message 3 or message 3 (Msg3) of the random access procedure.

[0094] In S204, the network device sends a contention resolution message to the terminal device. Correspondingly, the terminal device can receive the contention resolution message from the network device. If the contention resolution message determines that the random access conflict has been won, the random access is considered successful; otherwise, the terminal device determines that the random access has failed. The contention resolution message can be referred to as message 4 or message 4 (Msg4) in the random access procedure.

[0095] It is understandable that the above Figure 2 The random access procedure shown is only one possible example, and the embodiments of this application do not limit it.

[0096] (4) Preamble set

[0097] In wireless communication systems (such as LTE or NR), the preamble set of each cell can include 64 preambles, that is, 64 sequences. These 64 sequences are obtained by cyclic shifting based on at least one root sequence, which is the Zadoff-Chu (ZC) sequence.

[0098] For example, the 64 sequences in the preamble set can be divided into sequences for contention-based random access and sequences for non-contention-based random access. The sequences for contention-based random access can be further divided into Group A and Group B. Group B is used for scenarios where MSG3 has a large data volume and low path loss, while Group A is used for other scenarios unsuitable for Group B. Therefore, for... Figure 2 In the contention-based random access scenario, the terminal device can determine whether to use Group A or Group B based on the data volume of MSG3 and the magnitude of path loss. If Group A is selected, a sequence is randomly chosen from Group A, and a random access signal is generated based on the selected sequence. If Group B is selected, a sequence is randomly chosen from Group B, and a random access signal is generated based on the selected sequence.

[0099] The implementation of obtaining the preamble set by the terminal device is described below in two steps (i.e., step 1 and step 2).

[0100] Step 1: The terminal device generates a root sequence [X] u [(n)] serves as a baseline sequence.

[0101] For example, after receiving the logical root index number (denoted as i) from the network device, the terminal device can look up the physical root index number (denoted as u) in a predefined table based on the logical root index number, and then generate the root sequence based on the physical root index number. The specific generation formula (i.e., the generation formula of the ZC sequence) is as follows:

[0102]

[0103] Where L is the length of the root sequence. For example, the length of the root sequence is 139 or 839.

[0104] When the length of the root sequence is 139, the physical root index number ranges from 1 to 138. The predefined table is shown in Table 1.

[0105] Table 1: Correspondence between Logical Root Index Number and Physical Root Index Number

[0106]

[0107] Step 2: The terminal device processes the root sequence [X] u Perform a cyclic shift on [n] to generate a 64-sequence [X]. u,v (n)]. If for the root sequence [X] u If the number of sequences generated by cyclic shifting (n) is less than 64, then continue to generate the next root sequence and perform cyclic shifting on the next root sequence until 64 sequences are generated.

[0108] Wherein, sequence [X] u,v [n] can be generated using the following formula:

[0109] X u,v (n)=X u ((n+C v )mod LRA

[0110] The above C v For cyclic shift values, such as C v =vN CS , Indicates L / N CS Round down; N CS The cyclic shift interval is the specific value that can be configured by the network device.

[0111] The following example, with a root sequence length of 139, illustrates how to obtain 64 sequences from the preamble set.

[0112] The terminal device receives a logical root index number of 20, obtains a physical root index number of 11 by looking up Table 1, and can then generate the root sequence [X]. 11 (n)]. Further, assume N CS If the value is 4, then v = 0, 1, 2...34.

[0113] The first sequence: v = 0, C v =vN CS =0,X 11,0 (n)=X 11 (n), that is, the first sequence is the root sequence [X] 11 (n)];

[0114] Second sequence: v = 1, C v =vN CS =4,X 11,1 (n)=X 11 ((n+4) mod 139;

[0115] The third sequence: v = 2, C v =vN CS =8,X 11,2 (n)=X 11 ((n+8) mod 139;

[0116] And so on;

[0117] The 35th sequence: v = 34, C v =vN CS =136, X 11,34 (n)=X 11 ((n+136)mod 139.

[0118] Due to the root sequence [X] 11If the number of sequences generated by the cyclic shift of [n] is less than 64, then the next root sequence is generated and cyclically shifted. The physical root index of the next root sequence is 128 (i.e., the logical root index is 21), therefore, the next root sequence is [X]. 128 (n)].

[0119] The 36th sequence: v = 0, C v =vN CS =0,X 128,0 (n)=X 128 (n), that is, the 36th sequence is the root sequence [X] 128 (n)];

[0120] The 37th sequence: v = 1, C v =vN CS =4,X 128,1 (n)=X 128 ((n+4) mod 139;

[0121] And so on;

[0122] The 64th sequence: v = 28, C v =vN CS =112, X 128,28 (n)=X 128 ((n+112)mod 139, thus obtaining 64 sequences.

[0123] It is understandable that the above description is based on the example of a terminal device generating 64 sequences. In other examples, the terminal device can also determine the physical root index number and cyclic shift value corresponding to each of the 64 sequences without actually generating the sequence. After the terminal device selects one of the sequences (such as sequence a), it generates sequence a according to the physical root index number and cyclic shift value corresponding to sequence a.

[0124] For ZC sequences, the cross-correlation value between multiple ZC sequences obtained by cyclic shifting the same root sequence (ignoring time-domain cyclic shift) is 0, while the cross-correlation value between multiple ZC sequences obtained by cyclic shifting different root sequences (ignoring time-domain cyclic shift) is... Therefore, when the preamble uses the ZC sequence, in a contention-based random access scenario, multiple terminal devices can transmit random access signals based on different preambles on the same time-frequency resource (i.e., RO). For example, terminal device 1 transmits random access signal 1 on RO1 (random access signal 1 is based on the preamble [X... 11,1 (n)] generated), terminal device 2 sends random access signal 2 on RO1 (random access signal 2 is based on preamble [X 11,2(n)] generated), terminal device 3 sends random access signal 3 on RO1 (random access signal 3 is based on preamble [X 128,1 (n)] generated), due to [X 11,1 (n)]、[X 11,2 (n)] and [X 128,1 The cross-correlation value between [n] is small, which ensures the detection performance of the preamble and facilitates successful access of terminal device 1, terminal device 2 and terminal device 3 to the network device.

[0125] However, on the one hand, massive communication, as an extension of massive machine-type communication (mMTC), places new demands on network capabilities, such as requiring a network connection density of 10. 6 -10 8 Each device per kilometer (10) 6 -10 8 Therefore, the number of terminal devices accessing network devices will further increase in the future. On the other hand, in high-speed mobile scenarios such as high-speed trains (speed approximately 1000 km / h) and low-orbit satellite communication (speed approximately 7.56 km / s), terminal devices also need to access network devices. In order to support the access of terminal devices in high-speed mobile scenarios, the cyclic shift interval needs to be increased, which leads to a reduction in the number of preambles generated for each root sequence (for example, when the length of the root sequence is 139, assuming N...). CS The value is 15, and each root sequence can generate 10 sequences, for a total of 15 sequences. A preamble; assuming N CS If the value is increased to 30, each root sequence can generate 5 cyclic shift sequences, and a total of 690 preambles can be generated. This may result in the number of preambles in the preamble set of each cell being less than 64, further limiting the PRACH capacity.

[0126] As the number of terminal devices accessing network devices increases further in the future, while PRACH capacity becomes increasingly limited, the probability of collisions when different terminal devices access network devices is high. For example, in a scenario of contention for random access, assuming multiple terminal devices all choose Group A and select a preamble from Group A, when the number of terminal devices is large and the number of preambles in Group A is small, different terminal devices may select the same preamble, such as terminal device 1 and terminal device 2 selecting the same preamble. If terminal device 1 and terminal device 2 send random access signals on the same RO, a collision will occur, causing random access failure for terminal device 1 and terminal device 2. Therefore, generating preambles based on ZC sequences may not meet the needs of future communication scenarios.

[0127] Based on this, embodiments of this application provide a communication method for expanding the capacity of the preamble, reducing the probability of collisions when different terminal devices access network devices, and meeting the needs of future communication scenarios.

[0128] For example, in this embodiment of the application, a preamble is generated based on a Z4 sequence to expand the capacity of the preamble. The relevant technical features of the Z4 sequence are introduced here first.

[0129] (1) Z4 sequence

[0130] Since the Z4 sequence and the m / Gold sequence are related, for ease of understanding, we will first introduce the m sequence and the Gold sequence.

[0131] m-sequence: An m-sequence is short for Longest Linear Feedback Shift Register Sequence, which is the longest-period sequence generated by a shift register with linear feedback. Generally, the longest period generated by a V-stage linear feedback shift register is equal to 2. v -1. Figure 3 The basic structure of a feedback shift register involves storing initialization bit data in memory, and then generating new values ​​through a feedback function and adding them back to memory. Assume the feedback function performs an XOR operation on all bits in memory, i.e. Then a1, a2, ..., a n Given the initial value sequence, the output sequence is: The length of the output sequence is 2. v -1.

[0132] This can be understood as follows: the m-sequence is determined by the initial value sequence stored in the register and the primitive polynomial. The set of initial values ​​is {0,1}, and the order of the primitive polynomial is the highest power of the polynomial. For example, the primitive polynomial f(x) = x 7The recurrence relation for +x+1 is s(t)+s(t-6)+s(t-7)=0. Since binary addition is defined as modulo-2 addition, the above recurrence relation can be transformed into s(t)=s(t-6)+s(t-7), that is, the primitive polynomial f(x)=x 7 +x+1 corresponds to the recursive formula s(t)=s(t-6)+s(t-7).

[0133] Gold sequence: The Gold sequence can be seen as the result of XORing two m-sequences with different primitive polynomials element by element.

[0134] Z4 Sequence: The period of a Z4 sequence is the same as that of a binary Gold sequence of the same length, and the initial value set is {0, 1, 2, 3}. Z4 sequences can be generated using a circular shift register. The generation of Z4 sequences is very similar to that of m-sequences, except that Z4 sequences are defined on a four-element ring {0, 1, 2, 3}, therefore addition and subtraction must be modulo 4. For example, the primitive polynomial of a Z4 sequence is f(x) = x. 7 +2x 4 +x+3, the primitive polynomial can also be expressed as 10020013, and the recursive formula corresponding to the primitive polynomial is s(t)=2s(t-3)+3s(t-6)+s(t-7).

[0135] (2) Cross-correlation between different Z4 sequences

[0136] As mentioned above, for ZC sequences: since the cross-correlation value between multiple ZC sequences obtained by cyclic shifting the same root sequence is 0, the cross-correlation value between multiple ZC sequences obtained by cyclic shifting different root sequences is 0. Therefore, generating a preamble based on the ZC sequence can guarantee the detection performance of the preamble.

[0137] Regarding the Z4 sequence: Since the cross-correlation values ​​between multiple Z4 sequences obtained by the same recursive formula are relatively low, and the cross-correlation values ​​between multiple Z4 sequences obtained by different recursive formulas are also relatively low, generating a preamble based on the Z4 sequence can also guarantee the detection performance of the preamble.

[0138] Specifically, taking the recursive formula s(t) = 2s(t-3) + 3s(t-6) + s(t-7) with a length of 127 as an example, assuming the initial value sequence 1 is [s(6), s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,0,0,0,1], then according to the initial value sequence 1 and the recursive formula, sequence b can be obtained. Further, sequence b is cyclically shifted, assuming the cyclic shift interval is 1 (i.e., the cyclic shift value is 0,1,2…126), then a total of 127 sequences can be obtained (such as sequences b1 to b127); the initial value sequence 2 is [s(6), s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,1]. Given the initial value sequence [s(6), s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,0,0,0,3], we can obtain sequence c based on the initial value sequence 2 and the recursive formula. Furthermore, we can perform a cyclic shift on sequence d, assuming the cyclic shift interval is 1 (i.e., the cyclic shift value is 0,1,2…126), resulting in 127 sequences (e.g., sequences c1 to c127). The initial value sequence 2 is [s(6), s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,0,0,0,3]. Based on the initial value sequence 3 and the recursive formula, we can obtain sequence d. Further, we perform a cyclic shift on sequence d, assuming the cyclic shift interval is 1 (i.e., the cyclic shift value is 0,1,2…126), resulting in 127 sequences (e.g., sequences d1 to d127). In other words, based on the three initial value sequences and 127 cyclic shift values, we can obtain a total of 3 * 127 = 381 sequences. Calculations revealed that the maximum cross-correlation value among these 381 sequences was 0.0948, the minimum cross-correlation value was 0.0078, and the median cross-correlation value was 0.0837. When the preamble uses a ZC sequence, assuming the root sequence length is 138, the cross-correlation value among multiple ZC sequences obtained by cyclically shifting different root sequences is... That is, the cross-correlation values ​​between multiple Z4 sequences obtained based on the same recursive formula are relatively close to the cross-correlation values ​​between ZC sequences obtained from different root sequences.

[0139] Furthermore, calculations revealed that when the number of recursive formulas is 2, the maximum cross-correlation value among multiple Z4 sequences obtained based on 2 recursive formulas is 0.3174; when the number of recursive formulas is 3, the maximum cross-correlation value among multiple Z4 sequences obtained based on 3 recursive formulas is also 0.3174; further numbers of recursive formulas are not listed here. Although the maximum cross-correlation value among multiple Z4 sequences obtained based on multiple recursive formulas is slightly greater than that among multiple Z4 sequences obtained based on the same recursive formula, the maximum cross-correlation value among multiple Z4 sequences obtained based on multiple recursive formulas is still relatively low. Therefore, generating a preamble based on Z4 sequences can ensure that the preamble has good detection performance.

[0140] (3) Comparison of the number of preambles

[0141] As mentioned above, for ZC sequences: when the length of the ZC sequence is 139, since there are 138 physical root index numbers, 138 root sequences can be generated based on these 138 physical root index numbers; further, assuming N CS =15, then a total of 15 can be generated. There are 1380 preambles for each sequence (for example, 1380 sequences are equivalent to 1380 preambles).

[0142] For an m-sequence: for the same recursive formula, m-sequences generated from different initial value sequences are cyclically shifted versions of each other. For example, if the length of an m-sequence is 63, there are 64(2) sequences. 6 Given 64 initial value sequences, for the same recursive formula, the m-sequences generated by these 64 initial value sequences are mutually cyclically shifted sequences. For example, initial value sequence 1 is [s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,0,0,1]. Based on initial value sequence 1 and the recursive formula, m-sequence 1 is generated. Initial value sequence 2 is [s(5), s(4), s(3), s(2), s(1), s(0)] = [0,0,0,0,1,0]. Based on initial value sequence 2 and the recursive formula, m-sequence 2 is generated. m-sequence 1 and m-sequence 2 are mutually cyclically shifted sequences, that is, cyclically shifting m-sequence 1 yields m-sequence 2. Therefore, it can be considered that the m-sequence has only one initial value sequence.

[0143] When the length of the m-sequence is 127 (i.e., taking a value close to 139 as an example), if the m-sequence has 18 recursive formulas, then 18 sequences can be generated based on an initial value sequence; further, assuming N CS =15, then a total of 15 can be generated. There are 180 preambles in the sequence.

[0144] For the Z4 sequence: for example, if the length of the Z4 sequence is 64, there are a total of 4096 (4 6 Given 4096 initial value sequences, for the same recursive formula, the Z4 sequences generated by 65 of these 65 initial value sequences are not cyclically shifted versions of each other, while the Z4 sequences generated by the other initial value sequences are cyclically shifted versions of the Z4 sequences generated by these 65 initial value sequences. For example, if the length of the Z4 sequence is 127, there are 4... 7 4 initial value sequences, for the same recursive formula, 7 The Z4 sequences generated by the 129 initial value sequences are not cyclically shifted sequences of each other, while the Z4 sequences generated by the other initial value sequences are cyclically shifted sequences of the Z4 sequences generated by these 129 initial value sequences.

[0145] When the length of the Z4 sequence is 127 (i.e., taking a value close to 139 as an example), if the m sequence has 18 recursive formulas, and the ratio of the number of recursive formulas in the Z4 sequence to the number of recursive formulas in the m sequence is γ, then based on 129 initial value sequences, 18γ*129 sequences can be generated; where γ is a value greater than or equal to 1, such as γ being 1, 1.1, or 1.2. Further, assume N... CS =15, then a total of 15 can be generated. There are 23220γ sequences, corresponding to 23220γ preambles (for example, 23220γ preambles are obtained by modulating 23220γ sequences).

[0146] This shows that when the lengths of the ZC and Z4 sequences are similar, the number of preambles corresponding to the Z4 sequence is much greater than the number of preambles corresponding to the ZC sequence (more than 20 times the expansion). Therefore, generating preambles based on the Z4 sequence can effectively expand the preamble.

[0147] The communication method provided in this application is described below with reference to specific embodiments. The communication method provided in this application involves a first communication device and a second communication device. The first communication device is the transmitting side of a random access signal, and the second communication device is the receiving side of the random access signal. For example, the first communication device is a terminal device or a component of a terminal device, such as a chip or chip system disposed in the terminal device; the second communication device is a network device or a component of a network device, such as a chip or chip system disposed in the network device. In this application embodiment, the example of "the first communication device being a terminal device and the second communication device being a network device" is used for description.

[0148] Figure 4 This is a flowchart illustrating the communication method provided in an embodiment of this application. Figure 4As shown, the process may include:

[0149] S401, the terminal device generates a random access signal.

[0150] For example, the terminal device generates a random access signal based on a first sequence. Alternatively, the terminal device generating the random access signal based on a first sequence can be replaced by generating the random access signal based on a third sequence, where the third sequence is a preamble obtained from the first sequence, for example, the third sequence is a preamble obtained by modulating the first sequence.

[0151] The terminal device generates a random access signal based on a third sequence (i.e., a preamble). Specifically, the terminal device performs a Discrete Fourier Transform (DFT) on the third sequence to obtain a fourth sequence; then, it maps the elements of the fourth sequence onto multiple subcarriers and performs an Inverse Fast Fourier Transform (IFFT) to generate the random access signal. In other words, the random access signal is a signal of a Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveform.

[0152] It is understood that in a contention-based random access scenario, the third sequence can be a preamble selected by the terminal device from the preamble set of the cell. This application embodiment does not limit the specific implementation of the terminal device determining the preamble set. In a non-contention-based random access scenario, the third sequence can be a preamble indicated by the network device to the terminal device. This application embodiment does not limit the specific indication method of the network device. Furthermore, this application embodiment will use "the preamble is the third sequence" as an example for description. In other examples, the preamble can also be the first sequence. In this case, the terminal device generating a random access signal based on the first sequence (i.e., the preamble) means: the terminal device modulates the first sequence to obtain the third sequence, performs DFT processing on the third sequence to obtain the fourth sequence; then maps the elements in the fourth sequence onto multiple subcarriers and performs IFFT processing to generate the random access signal.

[0153] (1) Describe the first sequence.

[0154] The first sequence is obtained based on the second sequence and the first cyclic shift value. The first cyclic shift value is one of M3 cyclic shift values. or This represents rounding up L / C, where L represents the length of the second sequence and C represents the cyclic shift interval; L is an integer greater than 1, and C is an integer greater than or equal to 1. For example, in M3 cyclic shift values, the first cyclic shift value is 0, the second cyclic shift value is C, the third cyclic shift value is 2C, the fourth cyclic shift value is 3C, and so on, with the M3th cyclic shift value being... For example, if L is 127 and C = 15, then... The M3 cyclic shift values ​​are 0, 15, 30, 45, 60, 75, 90, 105, and 120.

[0155] For example, let the first sequence be denoted as y(n) and the second sequence as z(n), where n = 0, 1, 2, ..., L-1. The first and second sequences satisfy the following formula:

[0156] y(n)=z((i+cs)modL)

[0157] Where cs represents the first cyclic shift value.

[0158] (2) Describe the modulation method.

[0159] There are various modulation methods for modulating the first sequence, such as quadrature phase shift keying (QPSK) modulation. When QPSK modulation uses Gray mapping, the complex values ​​mapped to the elements in the first sequence are shown in Table 2; when QPSK modulation uses natural mapping, the complex values ​​mapped to the elements in the first sequence are shown in Table 3 or Table 4.

[0160] Table 2: QPSK modulation of Gray map

[0161] element Complex values 0 1+1j 1 -1+1j 2 1-1j 3 -1-1j

[0162] Table 3: QPSK modulation of natural mapping

[0163] element Complex values 0 1 1 j 2 -1 3 -j

[0164] Table 4: QPSK modulation of natural mapping

[0165] element Complex values 0 1 1 -j 2 -1 3 j

[0166] When using QPSK modulation with natural mapping, the third sequence is denoted as [x(n)], and the third sequence and the first sequence satisfy the following formula:

[0167] (corresponding to Table 3), or (Corresponding to Table 4)

[0168] Therefore, when using QPSK modulation with natural mapping, the third sequence can be represented as:

[0169] or

[0170] For example, since the preamble is used to achieve uplink synchronization between the terminal device and the network device, considering the impact of noise, the synchronization point may mistakenly appear at the second peak position of the ambiguity function of the preamble (i.e., the third sequence). Therefore, the smaller the second peak, the better the synchronization performance of the third sequence. Thus, the specific mapping method can be selected based on the second peak of the ambiguity function of the third sequence corresponding to different mapping methods. Here, the second peak is the second largest ambiguity function value. In this application embodiment, the second peak refers to the normalized second peak. Furthermore, considering the possible frequency offset during synchronization, in this application embodiment, the second peak of the ambiguity function is defined as when the frequency offset is ±0.5 / ±1 / ±2 (considering the crystal oscillator frequency offset present in actual communication systems, the maximum frequency offset is twice the subcarrier interval; the frequency offset value is iterated with a granularity of 0.5 times the subcarrier interval; therefore, f...). d The value of can be ±0.5 / ±1 / ±2) and the normalized second peak under all cyclic shifts in the time domain.

[0171] The fuzzy function of the third sequence conforms to the following formula:

[0172]

[0173] Among them, A(f) d ,τ) is the fuzzy function of the third sequence, f d Let y be the frequency offset value, τ be the time-domain multipath delay, and y be the frequency offset value. * (n+τ) is the conjugate of y(n+τ). For example, if the main peak of the fuzzy function of the third sequence is A(0,0), then A(f d ,τ)′=A(f d ,τ) / A(0,0),A(f d ,τ)′ is a pair of A(f d The result is obtained by normalizing τ.

[0174] When the first sequence (or the second sequence) is a Z4 sequence, simulations show that the second peak of the ambiguity function of the third sequence obtained by modulating the first sequence with natural mapping QPSK modulation is smaller than the second peak of the ambiguity function of the third sequence obtained by modulating the first sequence with Gray mapping QPSK modulation, as shown in Table 4. Therefore, in this embodiment, natural mapping QPSK modulation can be used to modulate the first sequence to ensure the synchronization performance of the preamble.

[0175] Table 4: Examples of the normalized secondary peaks of the third sequence obtained by modulation when the first sequence is a ZC sequence or a Z4 sequence

[0176]

[0177] (3) Describe the second sequence.

[0178] The second sequence is one of the M sequences. The M sequences are obtained according to M1 recurrence formulas and M2 initial value sequences. M1 is an integer greater than 1, and M2 is an integer greater than 1. The lengths of the M sequences are the same, for example, all are of length L. Among them, the recurrence formula can be obtained according to the primitive polynomial, and the recurrence formula corresponds to the primitive polynomial one by one. In the embodiments of the present application, the "recurrence formula" can be replaced by the "primitive polynomial".

[0179] Since the M sequences are obtained according to M1 recurrence formulas and M2 initial value sequences, and M2 is an integer greater than 1, therefore, the M sequences can be Z4 sequences, or other possible sequences, such as Gold sequences. Among them, since the cross-correlation values between different Z4 sequences are relatively low, the detection performance of the preamble can be guaranteed, while the cross-correlation values between different Gold sequences are relatively high. Therefore, in the embodiments of the present application, the Z4 sequence is mainly used as an example for description. That is to say, in the embodiments of the present application, the preamble is generated based on the Z4 sequence, so that while ensuring the detection performance of the preamble, the preamble can be expanded.

[0180] Among them, M1*M2 sequences can be obtained according to M1 recurrence formulas and M2 initial value sequences. The M sequences can be M1*M2 sequences (i.e., M = M1*M2), or the M sequences can also be partial sequences of the M1*M2 sequences (i.e., M < M1*M2). In the embodiments of the present application, M = M1*M2 is taken as an example. When the first cyclic shift value is greater than 0, the first sequence is different from any of the M sequences. That is to say, the M sequences obtained according to M1 recurrence formulas and M2 initial value sequences are not cyclic shift sequences of each other.

[0181] For example, when the length of the second sequence is 63, M2 = 65, and when the length of the second sequence is 127, M2 = 129. M1 = γ*M4, where M4 represents the number of recurrence formulas of the m sequence of the same length.

[0182] In addition, M*M3 sequences can be obtained according to the M sequences and M3 cyclic shift values. The first sequence can be one of the M*M3 sequences.

[0183] S402. The terminal device sends a random access signal to the network device; correspondingly, the network device receives the random access signal.

[0184] It is understandable that the random access signal is generated by the baseband chip of the terminal device. The terminal device sending the random access signal includes the baseband chip transmitting the random access signal to the radio frequency chip. The terminal device also sends the random access signal to the network device via its radio frequency chip.

[0185] For example, after receiving a random access signal, the network device processes the random access signal to obtain a sequence r. Then, based on the cross-correlation value between the sequence in the preamble set of the current cell and sequence r (considering time-domain cyclic shift), the device determines the sequence with the largest cross-correlation value between the preamble set and sequence r as the sequence actually transmitted by the terminal device. Simultaneously with determining the sequence actually transmitted by the terminal device, the network device can also determine the time-domain multipath delay, and then determine the TA of the current cell based on the time-domain multipath delay.

[0186] S403, the network device sends a random access response to the terminal device; correspondingly, the terminal device receives the random access response.

[0187] For example, the random access response includes the TA of the current cell, and the terminal device can obtain the TA of the current cell from the random access response and perform uplink synchronization with the network device based on the TA of the current cell.

[0188] The above Figure 4 The illustrated method can be applied to both contention-based and non-contention-based random access. When Figure 4 The illustrated method flow can be applied to contention-based random access. The method flow may also include other possible steps, such as the terminal device sending uplink signaling to the network device according to the current cell's TA, and the network device sending a contention resolution message to the terminal device.

[0189] In this embodiment, multiple sequences for generating random access signals are generated based on multiple cyclic shift values, multiple recursive formulas, and multiple initial value sequences. This enables the expansion of the sequences used to generate random access signals (such as preambles), reduces the probability of collisions when different terminal devices access network devices, and meets the needs of future communication scenarios.

[0190] Regarding the above embodiments, it is understood that:

[0191] (1) In the embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions in different examples or implementations are consistent and can be referenced by each other. The technical features in different examples or implementations can be combined to form new embodiments according to their inherent logical relationships. In addition, different implementations or different examples can be referenced or referenced by each other.

[0192] (2) The various numerical designations used in this application are merely for descriptive convenience and are not intended to limit the scope of this application. The step numbers in the above flowcharts are only examples of the execution process and do not constitute a restriction on the order of execution of the steps. That is, the size of each step number does not imply the order of execution; the execution order of each step should be determined by its function and internal logic. Furthermore, not all steps shown in the flowcharts are mandatory steps; some steps may be added or deleted based on actual needs.

[0193] The above mainly describes the solution provided by the embodiments of this application from the perspective of the interaction between the first communication device and the second communication device. It is understood that, in order to achieve the above functions, the first communication device and the second communication device may include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware 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.

[0194] In this application embodiment, the first communication device and the second communication device can be divided into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0195] When using integrated units, Figure 5 A possible exemplary block diagram of the apparatus involved in an embodiment of this application is shown. For example... Figure 5 As shown, the device 500 may include a processing unit 502 and a communication unit 503. The processing unit 502 is used to control and manage the operation of the device 500. The communication unit 503 is used to support communication between the device 500 and other devices. Optionally, the communication unit 503 is also called a transceiver unit, and may include a receiving unit and / or a transmitting unit, respectively used to perform receiving and transmitting operations. The device 500 may also include a storage unit 501 for storing the program code and / or data of the device 500.

[0196] (1) The device 500 can be the first communication device in the above embodiments. The processing unit 502 can support the device 500 in performing the actions of the first communication device in the above method embodiments. Alternatively, the processing unit 502 mainly performs the internal actions of the first communication device in the method embodiments, and the communication unit 503 can support communication between the device 500 and other devices.

[0197] For example, in one embodiment, the processing unit 502 is used to: generate a random access signal, the random access signal being obtained based on a first sequence; the communication unit 503 is used to: transmit the random access signal; wherein, the first sequence is obtained based on a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained based on M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; the first cyclic shift value is an integer greater than or equal to 0.

[0198] In one possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0199] In one possible design, all M sequences are Z4 sequences.

[0200] In one possible design, M = M1 * M2.

[0201] In one possible design, the first cyclic shift value is one of M3 cyclic shift values. L represents the sequence length of the second sequence, and C represents the cyclic shift interval; L is an integer greater than 1, and C is an integer greater than or equal to 1.

[0202] In one possible design, the first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

[0203] In one possible design, the first sequence is obtained based on the second sequence and the first cyclic shift value, including: the first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2 ... L-1;

[0204] y(n)=z((i+cs)modL)

[0205] Where cs represents the first cyclic shift value.

[0206] In one possible design, the first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1;

[0207]

[0208] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0209] In one possible design, the processing unit 502 is specifically used to: perform Discrete Fourier Transform (DFT) processing on the third sequence to obtain a fourth sequence; map the elements in the fourth sequence onto multiple subcarriers and perform Inverse Fast Fourier Transform (IFFT) processing to generate the random access signal.

[0210] (2) The device 500 can be the second communication device in the above embodiments. The processing unit 502 can support the device 500 in performing the actions of the second communication device in the above method embodiments. Alternatively, the processing unit 502 mainly performs the internal actions of the second communication device in the method embodiments, and the communication unit 503 can support communication between the device 500 and other devices.

[0211] For example, in one embodiment, the communication unit 503: receives a random access signal, the random access signal being obtained based on a first sequence; and in response to the random access signal, sends a random access response; wherein the first sequence is obtained based on a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained based on M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; the first cyclic shift value being an integer greater than or equal to 0.

[0212] In one possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0213] In one possible design, all M sequences are Z4 sequences.

[0214] In one possible design, M = M1 * M2.

[0215] In one possible design, the first cyclic shift value is one of M3 cyclic shift values. L represents the sequence length of the second sequence, and C represents the cyclic shift interval; L is an integer greater than 1, and C is an integer greater than or equal to 1.

[0216] In one possible design, the first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

[0217] In one possible design, the first sequence is obtained based on the second sequence and the first cyclic shift value, including: the first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2 ... L-1;

[0218] y(n)=z((i+cs)modL)

[0219] Wherein, cs represents the first cyclic shift value, and cs is an integer greater than or equal to 0.

[0220] In one possible design, the first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1;

[0221]

[0222] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0223] It should be understood that the division of units in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, all units in the device can be implemented entirely through software calls from processing elements; all units can be implemented entirely in hardware; or some units can be implemented through software calls from processing elements, and some units can be implemented in hardware. For example, each unit can be a separate processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as a program in memory, called and executed by a processing element of the device. Moreover, these units can be fully or partially integrated together, or implemented independently. The processing element mentioned here can also be called a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, the operations of the above methods or the various units can be implemented through integrated logic circuits in the processor element or through software calls from processing elements.

[0224] In one example, a unit in any of the above devices can be one or more integrated circuits configured to implement the methods described above, such as: one or more application-specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these forms of integrated circuits. As another example, when a unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (CPU), or other processor capable of calling programs. Furthermore, these units can be integrated together and implemented as a System-on-a-Chip (SoC).

[0225] The receiving unit described above is an interface circuit of the device, used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit for the chip to receive signals from other chips or devices. The transmitting unit described above is an interface circuit of the device, used to transmit signals to other devices. For example, when the device is implemented as a chip, the transmitting unit is an interface circuit for the chip to transmit signals to other chips or devices.

[0226] Based on the same technical concept, embodiments of this application also provide a communication device, which is used to implement the functions of the first or second communication device in the above embodiments. For example... Figure 6 As shown, the device can be a communication device or a chip within a communication device. The device includes a processor 601 and a communication interface 602, and optionally, a memory 603. Figure 6 Only the main components of the communication device are shown. In addition to the processor 601 and the communication interface 602, the communication device may further include a memory 603 and input / output devices (not shown).

[0227] The processor 601 is used to execute the program code stored in the memory 603, specifically to perform the actions of the processing unit 502 described above, which will not be described in detail here. The communication interface 602 is specifically used to perform the actions of the communication unit 503 described above, which will not be described in detail here.

[0228] Processor 601 can be a CPU, a digital processing unit, etc. Processor 601 can be used to process communication protocols and communication data, control the entire communication device, execute software programs, and process software program data, such as, but not limited to, baseband-related processing. Communication interface 602 can be used for transmitting and receiving signals, such as, but not limited to, radio frequency transceiver. The above-mentioned devices can be disposed on separate chips, or at least partially or entirely on the same chip. For example, processor 601 can be further divided into an analog baseband processor and a digital baseband processor. The analog baseband processor can be integrated with the transceiver on the same chip, while the digital baseband processor can be disposed on a separate chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, a digital baseband processor can be integrated with multiple application processors (such as, but not limited to, graphics processors, multimedia processors, etc.) on the same chip. Such a chip can be called a system-on-a-chip (SoC). Whether to dispose of the devices independently on different chips or integrate them on one or more chips often depends on the specific needs of the product design. This embodiment of the invention does not limit the specific implementation of the above-mentioned devices.

[0229] The communication interface 602 can be a transceiver, an interface circuit such as a transceiver circuit, or a transceiver chip, etc. Optionally, the communication interface 602 may include radio frequency (RF) circuitry and an antenna. The RF circuitry is mainly used for converting baseband signals to RF signals and processing RF signals. The antenna is mainly used for transmitting and receiving RF signals in the form of electromagnetic waves. Input / output devices, such as touch screens, displays, and keyboards, are mainly used for receiving user input data and outputting data to the user.

[0230] Memory 603 is used to store programs executed by processor 601. Memory 603 can be non-volatile memory, such as a hard disk drive (HDD) or solid-state drive (SSD), or it can be volatile memory, such as random-access memory (RAM). Memory 603 can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited to this.

[0231] When the communication device is powered on, the processor 601 can read the software program in the memory 603, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 601 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit then performs RF processing on the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor 601. The processor 601 converts the baseband signal into data and processes the data.

[0232] In another implementation, the radio frequency circuitry and antenna can be set up independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuitry and antenna can be arranged remotely, independent of the communication device.

[0233] This application embodiment does not limit the specific connection medium between the communication interface 602, processor 601, and memory 603. This application embodiment... Figure 6 The memory 603, processor 601, and communication interface 602 are connected via a bus 604. Figure 6 The connections between other components are shown in bold lines only and are not intended to be limiting. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0234] Optionally, the communication device described above can be a standalone device or part of a larger device. For example, the communication device can be:

[0235] (1) An independent integrated circuit (IC), or chip, or chip system or subsystem;

[0236] (2) A collection of one or more ICs, optionally including a storage component for storing data and instructions;

[0237] (3) Application-specific integrated circuit (ASIC), such as modem;

[0238] (4) Modules that can be embedded in other devices;

[0239] (5) Receivers, smart terminals, wireless devices, handheld devices, mobile units, vehicle-mounted devices, cloud devices, artificial intelligence devices, etc.;

[0240] (6) Others, etc.

[0241] In this application embodiment, "multiple" can refer to two or more. Therefore, in this application embodiment, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, such as one, two, or more. For example, "including at least one" means including one, two, or more. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A, B, and C. "And / or" describes the association relationship between related objects. Specifically, there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0242] Furthermore, the terms "system" and "network" in the embodiments of this application can be used interchangeably, as can "according to" and "based on". The ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are generally used to distinguish different objects and are not used to limit the order, sequence, priority, or importance of multiple objects. For example, the first communication device and the second communication device in the embodiments of this application are used to distinguish between two communication devices, and do not limit the priority or importance of these two communication devices.

[0243] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0244] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0245] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0246] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0247] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A communication method characterized by comprising: The method includes: A random access signal is generated, which is obtained based on a first sequence; Send the random access signal; The first sequence is obtained based on the second sequence and the first cyclic shift value. The second sequence is one of M sequences, which are obtained based on M1 recursive formulas and M2 initial value sequences, where M1 is an integer greater than 1 and M2 is an integer greater than 1. The first cyclic shift value is an integer greater than or equal to 0.

2. The method of claim 1, wherein, The first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

3. The method according to claim 1 or 2, characterized in that, All M sequences are Z4 sequences.

4. The method according to any one of claims 1 to 3, characterized in that, M = M1 * M2.

5. The method according to any one of claims 1 to 4, characterized in that, the first cyclic shift value is one of M3 cyclic shift values, L represents a sequence length of the second sequence, and C represents a cyclic shift interval. L is an integer greater than 1, and C is an integer greater than or equal to 1.

6. The method of claim 5, wherein, The first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

7. The method according to any one of claims 1 to 6, characterized in that, The first sequence is obtained based on the second sequence and the first cyclic shift value, and includes: The first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2, ..., L-1; y(n)=z((i+cs)modL) Where cs represents the first cyclic shift value.

8. The method according to any one of claims 1 to 7, characterized in that, The first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1; or The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

9. The method of claim 8, wherein, Generating the random access signal includes: The third sequence is processed by Discrete Fourier Transform (DFT) to obtain the fourth sequence; The elements in the fourth sequence are mapped onto multiple subcarriers and processed by inverse fast Fourier transform (IFFT) to generate the random access signal.

10. A communication method characterized by comprising: The method includes: Receive a random access signal, which is obtained based on a first sequence; In response to the random access signal, a random access response is sent; The first sequence is obtained based on the second sequence and the first cyclic shift value. The second sequence is one of M sequences, which are obtained based on M1 recursive formulas and M2 initial value sequences, where M1 is an integer greater than 1 and M2 is an integer greater than 1. The first cyclic shift value is an integer greater than or equal to 0.

11. The method of claim 10, wherein, The first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

12. The method according to claim 10 or 11, characterized in that, All M sequences are Z4 sequences.

13. The method according to any one of claims 10 to 12, characterized in that, M = M1 * M2.

14. The method according to any one of claims 10 to 13, characterized in that, the first cyclic shift value is one of M3 cyclic shift values, L represents a sequence length of the second sequence, and C represents a cyclic shift interval. L is an integer greater than 1. C is an integer greater than or equal to 1.

15. The method of claim 14, wherein, The first sequence is one of M*M3 sequences, which are obtained from the M sequences and the M3 cyclic shift values.

16. The method according to any one of claims 10 to 15, characterized in that, The first sequence is obtained based on the second sequence and the first cyclic shift value, and includes: The first sequence is denoted as [y(n)], the second sequence is denoted as [z(n)], and n = 0, 1, 2, ..., L-1; y(n)=z((i+cs)modL) Wherein, cs represents the first cyclic shift value, and cs is an integer greater than or equal to 0.

17. The method according to any one of claims 10 to 16, characterized in that, The first sequence is denoted as [y(n)], the third sequence is denoted as [x(n)], and n = 0, 1, 2, ..., L-1; or The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

18. A communications device, characterized by Includes units for performing the method as described in any one of claims 1 to 17.

19. A communications device, characterized by The device includes a processor coupled to a memory in which a computer program is stored; the processor is configured to invoke part or all of the computer program in the memory such that the method as described in any one of claims 1 to 17 is executed.

20. A communication system, characterized by The communication system includes a first communication device and a second communication device, wherein the first communication device is used to perform the method as described in any one of claims 1 to 9, and the second communication device is used to perform the method as described in any one of claims 10 to 17.

21. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when some or all of the computer program is executed by a computer, causes the method described in any one of claims 1 to 17 to be performed.

22. A computer program product, characterized in that, When the computer reads and executes the computer program product, the method described in any one of claims 1 to 17 is performed.

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