Communication method, apparatus, and system

Abstract

The present application relates to the technical field of communications, and discloses a communication method, an apparatus, and a system. The method comprises: a first communication apparatus generating a random access signal, wherein the random access signal is obtained on the basis of a first sequence; and sending the random access signal, wherein the first sequence is obtained on the basis of a second sequence and a first cyclic shift value, the second sequence is one of M sequences, the M sequences are obtained on the basis of M1 recurrence relations and M2 initial value sequences, M1 is an integer greater than 1, M2 is an integer greater than 1, and the first cyclic shift value is an integer greater than or equal to 0. In this way, a sequence (such as a preamble) used for generating a random access signal can be expanded, thereby reducing the probability of collision between different terminal devices in accessing a network device, and satisfying the requirements of future communication scenarios.

Description

A communication method, apparatus and system

[0001] Cross Reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202410807979.7, filed on June 20, 2024, and entitled “A communication method, apparatus and system”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method, apparatus and system. BACKGROUND

[0004] The random access procedure refers to a procedure from sending a random access signal by a terminal device to establishing a basic signaling connection with a network device. The random access signal is used to initiate the random access procedure, and the random access signal is obtained based on a random access preamble, which can be referred to as a preamble.

[0005] However, the number of terminal devices accessing network devices in the future will further increase, which may cause different terminal devices to send random access signals based on the same preamble at the same random access occasion, resulting in collisions of different terminal devices. SUMMARY

[0006] The present application provides a communication method, apparatus and system for expanding the capacity of the preamble, reducing the probability of collisions of different terminal devices accessing network devices, and meeting the needs of future communication scenarios.

[0007] In a first aspect, an embodiment of the present application provides a communication method, which can be applied to a first communication apparatus. The first communication apparatus can be a terminal device or a component (such as a chip or circuit) in the terminal device. For example, in the method provided in the first aspect, the first communication apparatus generates a random access signal, the random access signal being obtained based on a first sequence; and sends the random access signal; wherein the first sequence is obtained according to a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained according to M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; and the first cyclic shift value being an integer greater than or equal to 0.

[0008] By using the above method, the capacity of the sequence (such as the preamble) used to generate the random access signal can be expanded, the probability of collisions of different terminal devices accessing network devices can be reduced, and the needs of future communication scenarios can be met.

[0009] In a possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0010] That is, the M sequences obtained according to the M1 recursive formulas and the M2 initial value sequences are not the sequences obtained by cyclically shifting each other.

[0011] In a possible design, the M sequences are all Z4 sequences.

[0012] In this way, the preamble can be expanded while ensuring the detection performance of the preamble, because the cross-correlation values between different Z4 sequences are low.

[0013] In a possible design, M=M1*M2.

[0014] In a possible design, 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.

[0015] In a possible design, the first sequence is one of M*M3 sequences, and the M*M3 sequences are obtained according to the M sequences and the M3 cyclic shift values.

[0016] In a possible design, the first sequence is obtained according to 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)mod L)

[0017] Where, cs represents the first cyclic shift value.

[0018] In a possible design, the first sequence is denoted as [y(n)], and the third sequence is denoted as [x(n)], and n=0, 1, 2, …, L-1.

[0019] Or

[0020] The random access signal is obtained based on the first sequence, and includes: the random access signal is obtained based on the third sequence.

[0021] In this way, the first sequence is modulated to obtain a third sequence (i.e., a preamble) in a natural mapping manner, so that a second highest peak of a ambiguity function of the third sequence is low, thereby facilitating guarantee of synchronization performance of the preamble.

[0022] In a possible design, the random access signal is generated by performing discrete Fourier transform (DFT) on the third sequence to obtain a fourth sequence, mapping elements in the fourth sequence to a plurality of subcarriers, and performing inverse fast Fourier transform (IFFT) processing.

[0023] In a second aspect, an embodiment of the present application provides a communication method, which can be applied to a second communication device, which can be a network device or a component (such as a chip or a circuit) in the network device. For example, in the method provided in the second aspect, the second communication device 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; and the first cyclic shift value being an integer greater than or equal to 0.

[0024] In a possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any sequence in the M sequences.

[0025] In a possible design, the M sequences are all Z4 sequences.

[0026] In a possible design, M=M1*M2.

[0027] In a possible design, 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.

[0028] In a possible design, the first sequence is one of M*M3 sequences, and the M*M3 sequences are obtained based on the M sequences and the M3 cyclic shift values.

[0029] In a 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; y(n)=z((i+cs)mod L)

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

[0031] In a possible design, the first sequence is denoted as [y(n)], and the third sequence is denoted as [x(n)], where 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 can be 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 related technical features in the second aspect can be referred to the description of the first aspect.

[0035] In a third aspect, the present application provides a communication apparatus, which has the functions of the first aspect or the second aspect, for example, the communication apparatus includes modules or units or means for performing the operations of the first aspect or the second aspect, and the functions or units or means can be implemented by software or hardware, or by executing corresponding software by hardware.

[0036] In a possible design, the communication apparatus includes a processing unit and a communication unit, where the communication unit can be configured to transceive signals to implement communication between the communication apparatus and other apparatuses; and the processing unit can be configured to perform some internal operations of the communication apparatus. The functions performed by the processing unit and the communication unit can correspond to the operations of the first aspect or the second aspect.

[0037] In a possible design, the communication apparatus includes a processor, which can be configured to be coupled with a memory. The memory can store necessary computer programs or instructions for implementing the functions of the first aspect or the second aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication apparatus can implement the method in any possible design or implementation manner of the first aspect or the second aspect.

[0038] In a possible design, the communication apparatus includes a processor and a memory, and the memory can store necessary computer programs or instructions for implementing the functions of the first aspect or the second aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication apparatus can implement the method in any possible design or implementation manner of the first aspect or the second aspect.

[0039] In a possible design of the communication apparatus, the communication apparatus includes a processor and an interface circuit, where the processor is configured to communicate with other apparatuses through the interface circuit, and perform the method in any possible design or implementation manner of the first aspect or the second aspect.

[0040] It can be understood that, in the third aspect, the processor can be implemented by hardware or software, and when implemented by hardware, the processor can be a logic circuit, an integrated circuit, or the like; when implemented by software, the processor can be a general-purpose processor, and the processor can be implemented by reading software code stored in a memory. In addition, the processor can be one or more, and the memory can be one or more. The memory can be integrated with the processor, or the memory can be arranged separately from the processor. In a specific implementation process, the memory can be integrated on the same chip as the processor, or the memory and the processor can be arranged separately on different chips, and the embodiments of the present application do not limit the type of the memory and the arrangement manner of the memory and the processor.

[0041] In a fourth aspect, the present application provides a communication system, which can include a first communication apparatus and a second communication apparatus; where the first communication apparatus is configured to perform the method in the first aspect, and the second communication apparatus is configured to perform the method in the second aspect.

[0042] In a fifth aspect, the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program (or computer-readable instructions), and when a computer reads and executes part or all of the computer-readable instructions, the method in any possible design of the first aspect or the second aspect is performed.

[0043] For example, the computer-readable storage medium can be any available medium that can be accessed by a computer. For example, but not limited to: the computer-readable medium can include a non-transitory computer-readable medium, a random access memory (RAM), a read-only memory (ROM), an electrically EPROM (EEPROM), a CD-ROM or other optical disk storage, a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0044] In a sixth aspect, the present application provides a computer program product, when a computer reads and executes the computer program product, the method in any possible design of the first aspect or the second aspect is performed.

[0045] In a seventh aspect, the present application provides a chip (or a chip system), which comprises a processor coupled with a memory, and the memory stores a computer program; the processor is configured to invoke part or all of the computer program in the memory, so that the method in any possible design of the first aspect or the second aspect is executed. BRIEF DESCRIPTION OF DRAWINGS

[0046] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied;

[0047] FIG. 2 is a schematic diagram of a random access procedure provided by embodiments of the present application;

[0048] FIG. 3 is a schematic diagram of a basic structure of a feedback shift register provided by embodiments of the present application;

[0049] FIG. 4 is a schematic diagram of a flow corresponding to a communication method provided by embodiments of the present application;

[0050] FIG. 5 is a possible exemplary block diagram of an apparatus involved in embodiments of the present application;

[0051] FIG. 6 is a schematic diagram of a structure of a communication apparatus provided by embodiments of the present application. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. The present application will present various aspects, embodiments or features around a system which can comprise a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can comprise additional devices, components, modules, etc., and / or can not comprise all the devices, components, modules, etc. discussed in connection with the drawings. In addition, combinations of these solutions can also be used.

[0053] In the embodiments of the present application, the words “exemplarily”, “for example”, and the like are used to represent examples, illustrations or descriptions. Any embodiment or design scheme described as “example” in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word “example” is used to present the concept in a specific manner. In the embodiments of the present application, “of”, “corresponding” and “corresponding” are sometimes used interchangeably, and it should be pointed out that when their differences are not emphasized, the meanings they express are consistent.

[0054] The technical solutions of the embodiments of the present application can be applied to various wireless communication systems, such as a universal mobile telecommunications system (UMTS), a wireless local area network (WLAN), a short-range wireless communication system (such as a sidelink, wireless fidelity (Wi-Fi), Bluetooth, and the like), a wired network, a vehicle to everything (V2X) communication system, a device-to-device (D2D) communication system, a vehicle networking communication system, a 4th generation (4G) mobile communication system (such as a long term evolution (LTE) system), an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD), a worldwide interoperability for microwave access (WiMAX) communication system, a 5th generation (5G) mobile communication system (such as a new radio (NR) system), a future communication system, or other similar communication systems, and the like, without limitation. The embodiments of the present application are described by taking a communication system shown in FIG. 1 as an example, and when the technical solutions of the embodiments of the present application are applied to other communication systems, devices, components, modules, and the like in the embodiments can be replaced by corresponding devices, components, modules in other communication systems, without limitation.

[0055] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied. As shown in FIG. 1, the communication system includes an access network 100. Optionally, the communication system can also include a core network 200 and an Internet 300. The access network 100 can include at least one network device, such as 110a and 110b in FIG. 1, and at least one terminal device, such as 120a-120j in FIG. 1. Among them, 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) arranged indoors or outdoors, 120g is a notebook computer, 120h is a printer, and 120i is a drone. Among them, the same terminal device or network device can provide different functions in different application scenarios. For example, the mobile phones in FIG. 1 are 120a, 120e, 120f and 120j. The mobile phone 120a can access the base station 110a, connect to the car 120b, communicate directly with the mobile phone 120e and access the HAP. The car 120b can access the HAP and communicate directly with the mobile phone 120a. The mobile phone 120f can access the micro station 110b, connect to the notebook computer 120g and connect to the printer 120h. The mobile phone 120j can control the drone 120i.

[0056] (1) Network device

[0057] A network device is a network-side device with wireless transceiving function. The network device can be a device in a radio access network (RAN) that provides wireless communication function for a terminal device, referred to as a RAN device. The RAN can be an access network in the 3rd generation partnership project (3GPP), such as 4G, 5G or future network. The RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a communication network of two or more of the above networks.

[0058] The RAN device 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] The RAN device can also be a module or unit that completes the functions of the base station part, for example, can be a central unit (CU), can also be a distributed unit (DU), and can also be a radio unit (RU). The CU here completes the functions of the radio resource control protocol (RRC) and the PDCP of the base station, and can also complete the function of the service data adaptation protocol (SDAP); the CU can be further divided into a CU control panel (CP) (CU-CP) and a CU user panel (UP) (CU-UP). The DU completes the functions of the RLC layer and the MA layer of the base station, and can also complete part of the physical layer or all the physical layer functions. For specific descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of 3GPP. The CU and the DU can be separately arranged, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna processing unit (AAU), or a remote radio head (RRH). In different systems, the CU, the DU or the RU can also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, and the RU can also be referred to as an O-RU. Any one of the CU (or CU-CP, CU-UP), the DU and the RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. The RAN device can be a macro base station (such as 110a in FIG. 1), can also be a micro base station or an indoor station (such as 110b in FIG. 1), and can also be a relay node or a donor node, etc. The embodiments of the present application do not limit the specific technologies and specific device forms adopted by the network device.

[0060] In the embodiments of the present application, the functions of the network device can also be executed by a module (such as a chip) in the network device, or can also be executed by a control subsystem containing the functions of the network device. The control subsystem containing the functions of the network device here can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city.

[0061] (2) Terminal device

[0062] A terminal device is a user-side device with wireless transceiving function. The terminal device can also be referred to as a terminal, a user equipment (UE), a mobile station, a mobile terminal, etc. The terminal device can be widely applied 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, automatic driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiving function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. In the embodiments of the present application, the device for implementing the function of the terminal device can be the terminal device, or a device capable of supporting the terminal device to implement the function, such as a chip system or a combination device or component that can implement the function of the terminal device, which can be installed in the terminal device. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0063] In the embodiments of the present application, the function of the terminal device can also be executed by a module (such as a chip or a modem) in the terminal device, or by a device containing the function of the terminal device.

[0064] The network device and the terminal device can be fixed in position or movable. The network device and the terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface; can also be deployed on an airplane, a balloon and a man-made satellite in the air. The embodiments of the present application do not limit the application scenarios of the network device and the terminal device.

[0065] The roles of the network device and the terminal device can be relative, for example, the helicopter or the unmanned aerial vehicle 120i in FIG. 1 can be configured as a mobile network device, and for those terminal devices 120j that access the wireless access network 100 through 120i, the terminal device 120i is a network device; but for the network device 110a, 120i is a terminal device, that is, 110a communicates with 120i through a wireless air interface protocol. Of course, 110a and 120i can also communicate through an interface protocol between network devices and network devices, at this time, 120i is also a network device relative to 110a. Therefore, the network device and the terminal device can be collectively referred to as a communication apparatus, 110a and 110b in FIG. 1 can be referred to as a communication apparatus with a network device function, and 120a-120j in FIG. 1 can be referred to as a communication apparatus with a terminal device function.

[0066] The network device and the terminal device, the network device and the network device, and the terminal device and the terminal device can communicate through an authorized frequency spectrum, or through an unlicensed frequency spectrum, or through both the authorized frequency spectrum and the unlicensed frequency spectrum, without limitation.

[0067] The network architecture and the service scenario described in the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems as the network architecture evolves and new service scenarios appear.

[0068] The related terms or technical features involved in the embodiments of the present application will be explained first. These explanations are to make the embodiments of the present application easier to understand, and should not be regarded as a strict limitation on the terms in the claimed scope of the present application.

[0069] (1) Sequence

[0070] The "sequence" in the embodiments of the present application includes one or more elements. Among them, the element can be represented as a complex number, including a real part and an imaginary part; or the element can also be represented as a real number, without specific limitation.

[0071] For example, the sequence [s(n)] includes L elements, and L is an integer greater than 1. n belongs to [0, …, L-1], that is, n∈[0, …, L-1]. "…" in [0, …, L-1] represents the integers 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) respectively; in other words, the element with the number n in [s(n)] can be s(n).

[0072] It can be understood that the embodiment of the present application takes the numbering mode of starting from 0 and increasing by 1 as an example, but is not limited thereto. For example, the numbering mode can also be starting from 1 and increasing by 1. For another example, the numbering mode can also be starting from X and decreasing by 1, X being an integer greater than 1. The “[·]” and “{·}” can be used interchangeably, and are used to represent multiple elements, which can be understood as a set, a group, or a sequence, and are not limited.

[0073] (2) Cross-correlation between sequences

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

[0075] Wherein, c(s1,s2)' represents the cross-correlation value (i.e., the cross-correlation value before normalization) between [s1(n)] and [s2(n)], c(s1,s2) represents the cross-correlation value (i.e., the cross-correlation value after normalization) between [s1(n)] and [s2(n)], the value range of τ is [-L, L], and abs represents taking the absolute value.

[0076] The cross-correlation value between [s1(n)] and [s2(n)] satisfies the following formula without considering the time domain cyclic shift:

[0077] Wherein, c(s1,s2)' represents the cross-correlation value (i.e., the cross-correlation value before normalization) between [s1(n)] and [s2(n)], and c(s1,s2) represents the cross-correlation value (i.e., the cross-correlation value after normalization) between [s1(n)] and [s2(n)].

[0078] (3) Random access procedure

[0079] The random access procedure refers to a procedure from sending a random access signal by a terminal device to establishing a basic signaling connection with a network device. The random access signal is used to initiate the random access procedure, for example, the random access signal is obtained based on a random access preamble, which can be referred to as a random access preamble sequence, or a preamble sequence, or a preamble. The random access signal is carried in a physical random access channel (PRACH). The terminal device can interact with the network device through the random access procedure, achieve uplink synchronization with the network device, and optionally, also perform resource request or data transmission through the random access procedure.

[0080] According to whether the preamble is selected by the terminal device itself, the random access procedure can be divided into a contention-based random access procedure and a non-contention-based random access procedure. Hereinafter, a possible implementation of the random access procedure is described by taking the contention-based random access procedure as an example.

[0081] FIG. 2 is a schematic diagram of a random access procedure provided by an embodiment of the present application. As shown in FIG. 2, the random access procedure includes the following steps:

[0082] S200, the network device sends configuration information of random access to the terminal device, and correspondingly, the terminal device can receive the configuration information from the network device. This step can be used for preparation before performing the random access procedure, and does not belong to the steps included in the random access procedure.

[0083] Exemplarily, the network device can send the configuration information of random access to the terminal device through a system message. The configuration information can include information 1, which is used to configure a plurality of PRACH occasions (ROs). One RO can be understood as a block of time-frequency resources, which is used to transmit a random access signal once.

[0084] The configuration information can also include information 2, for example, the information 2 is a logical root index number, which is used to determine a sequence set (or a preamble set) of a current cell. For details, refer to the description below.

[0085] In addition, the configuration information can also be used to configure other possible information, such as a correspondence between a plurality of ROs and a synchronization signal block (SS) / physical broadcast channel (PBCH) block (SS / PBCH block).

[0086] S201, the terminal device sends a random access signal to the network device. Wherein, the random access signal can be referred to as the first message of the random access process or message 1 (Msg1).

[0087] Specifically, the terminal device can receive multiple SS / PBCH blocks sent by the network device, and select a target SS / PBCH block from the multiple SS / PBCH blocks according to the measurement 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, and generates a random access signal based on the sequence a, and then sends the random access signal on the RO corresponding to the target SS / PBCH block.

[0088] S202, after the network device detects the random access signal sent by the terminal device, the network device sends a random access response (RAR) to the terminal device. Wherein, the random access response can be referred to as the second message of the random access process or message 2 (Msg2).

[0089] Exemplarily, after the network device receives the random access signal on the RO corresponding to the target SS / PBCH block, the network device can determine that the downlink beam for communication 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 the RAR to the terminal device.

[0090] Exemplarily, the RAR includes timing advance (TA), and the TA is used for uplink synchronization between the terminal device and the network device.

[0091] S203, the terminal device sends uplink signaling to the network device according to the TA. Wherein, the uplink signaling can be referred to as the third message of the random access process or message 3 (Msg3).

[0092] S204, the network device sends a contention resolution message to the terminal device, and accordingly, the terminal device can receive the contention resolution message from the network device, and if it is determined that the random access conflict is won according to the contention resolution message, it is determined that the random access is successful; otherwise, the terminal device determines that the random access fails. Wherein, the contention resolution message can be referred to as the fourth message of the random access process or message 4 (Msg4).

[0093] It can be understood that the random access procedure illustrated in FIG. 2 is only one possible example, and the embodiments of the present application do not limit this.

[0094] (4) Preamble set

[0095] In a wireless communication system (such as LTE or NR), the preamble set of each cell can include 64 preambles, i.e. 64 sequences, which are cyclically shifted from at least one root sequence, and the root sequence is a Zadoff-Chu (ZC) sequence.

[0096] Exemplarily, 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 a scenario where the data amount of MSG3 is large and the path loss is small, and Group A is used for other scenarios that are not suitable for Group B. Therefore, for the contention-based random access illustrated in FIG. 2, the terminal device can determine whether to use Group A or Group B according to the data amount of MSG3 and the size of the path loss; if it is determined to use Group A, a sequence is randomly selected from Group A, and a random access signal is generated based on the selected sequence, and if it is determined to use Group B, a sequence is randomly selected from Group B, and a random access signal is generated based on the selected sequence.

[0097] The implementation of the terminal device obtaining the preamble set will be described in combination with the following two steps (i.e. step 1 and step 2).

[0098] Step 1: The terminal device generates a root sequence [X u (n)] as a reference sequence.

[0099] Exemplarily, after the terminal device receives a logical root index number (denoted as i) from the network device, the terminal device can query a predefined table to obtain a physical root index number (denoted as u) according to the logical root index number, and then generate a root sequence according to the physical root index number. The specific generation formula (i.e. the generation formula of the ZC sequence) is as follows:

[0100] Wherein, L is the length of the root sequence. For example, the length of the root sequence is 139 or 839.

[0101] When the length of the root sequence is 139, the value range of the physical root index number is 1 to 138. The predefined table is shown in Table 1.

[0102] Table 1: Correspondence table of logical root index number and physical root index number

[0103] 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.

[0104] Wherein, sequence [X] u,v [n] can be generated by the following formula: X u,v (n)=X u ((n+C v )mod L RA

[0105] 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 of which can be configured by the network device.

[0106] The following example, with a root sequence length of 139, illustrates how to obtain 64 sequences from the preamble set.

[0107] 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.

[0108] 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)];

[0109] Second sequence: v = 1, C v =vN CS =4,X 11,1 (n)=X 11 ((n+4) mod 139;

[0110] The third sequence: v = 2, C v =vN CS =8,X 11,2 (n)=X11 ((n+8) mod 139;

[0111] and so on.

[0112] The 35th sequence: v = 34, C v = vN CS = 136, X 11,34 (n) = X 11 ((n+136) mod 139.

[0113] Since the number of sequences generated by cyclically shifting the root sequence [X 11 (n)] is less than 64, the next root sequence is generated and cyclically shifted. The physical root index number of the next root sequence is 128 (i.e., the logical root index number is 21), and thus the next root sequence is [X 128 (n)].

[0114] The 36th sequence: v = 0, C v = vN CS = 0, X 128,0 (n) = X 128 (n), i.e., the 36th sequence is the root sequence [X 128 (n)].

[0115] The 37th sequence: v = 1, C v = vN CS = 4, X 128,1 (n) = X 128 ((n+4) mod 139;

[0116] and so on.

[0117] The 64th sequence: v = 28, C v = vN CS = 112, X 128,28 (n) = X 128 ((n+112) mod 139, and thus 64 sequences are obtained.

[0118] It can be understood that the above is described by taking the terminal device generating 64 sequences as an example. In other examples, the terminal device can also determine the physical root index number and the cyclic shift value corresponding to each sequence of the 64 sequences without actually generating the sequences; after the terminal device selects one sequence (such as sequence a), the sequence a is generated according to the physical root index number and the cyclic shift value corresponding to the sequence a.

[0119] 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.

[0120] 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.

[0121] In the future, the number of terminal devices accessing network devices will further increase, and the PRACH capacity is further limited, so the probability of collision of different terminal devices accessing network devices is relatively large. For example, for the scenario of competing random access, it is assumed that multiple terminal devices determine to use Group A and select a preamble in Group A. When the number of terminal devices is large and the number of preambles in Group A is small, the preambles selected by different terminal devices may be the same, for example, the preambles selected by terminal device 1 and terminal device 2 are the same. If terminal device 1 and terminal device 2 send random access signals on the same RO, collision will occur, thereby causing the random access of terminal device 1 and terminal device 2 to fail. Therefore, generating a preamble based on a ZC sequence may not meet the needs of future communication scenarios.

[0122] Therefore, based on this, the embodiment of the present application provides a communication method for expanding the capacity of the preamble and reducing the probability of collision of different terminal devices accessing network devices, thereby meeting the needs of future communication scenarios.

[0123] Exemplarily, in the embodiment of the present application, a preamble is generated based on a Z4 sequence to expand the capacity of the preamble. Here, the related technical features of the Z4 sequence are introduced first.

[0124] (1) Z4 sequence

[0125] Since the Z4 sequence has a certain relationship with the m sequence / Gold sequence, for the convenience of understanding, the m sequence and the Gold sequence are introduced first.

[0126] m sequence: The m sequence is the abbreviation of the longest linear feedback shift register sequence, which is a sequence with the longest period generated by a shift register with linear feedback. Generally, the longest period generated by a v-level linear feedback shift register is equal to 2 v -1. FIG. 3 is the basic structure of a feedback shift register, and the bit data used for initialization is stored in a memory, and a new value is generated through a feedback function and supplemented to the memory. It is assumed that the feedback function is an XOR operation on all the bits in the memory, that is , then a1, a2, …, a n are the initial value sequence, and the output sequence is The length of the output sequence is 2 v -1.

[0127] It can be understood that the m sequence is determined by the initial value sequence stored in the register and the primitive polynomial, the value set of the initial value is {0, 1}, and the order of the primitive polynomial is the highest power in the polynomial. For example, the primitive polynomial f(x) = x 7The recursive formula corresponding to +x+1 is s(t)+s(t-6)+s(t-7)=0. Since the binary addition is defined as modulo 2 addition, the recursive formula can be converted to s(t)=s(t-6)+s(t-7), that is, the primitive polynomial f(x)=x 7 The recursive formula corresponding to +x+1 is s(t)=s(t-6)+s(t-7).

[0128] Gold sequence: The Gold sequence can be regarded as the element-wise XOR of two m sequences with different primitive polynomials.

[0129] Z4 sequence: The period of the Z4 sequence is the same as that of the binary Gold sequence with the same length, and the initial value is taken from the set {0, 1, 2, 3}. The Z4 sequence can be generated by a cyclic shift register, and the generation of the Z4 sequence is extremely similar to that of the m sequence. The difference is that the Z4 sequence is defined on the four-element ring {0, 1, 2, 3}, and therefore the addition and subtraction are modulo 4. For example, the primitive polynomial of the Z4 sequence is f(x)=x 7 +2x 4 +x+3, which can also be expressed as 10020013. The recursive formula corresponding to the primitive polynomial is s(t)=2s(t-3)+3s(t-6)+s(t-7).

[0130] (2) Cross-correlation between different Z4 sequences

[0131] As described above, for the ZC sequence: the cross-correlation values between multiple ZC sequences obtained by cyclically shifting the same root sequence are 0, and the cross-correlation values between multiple ZC sequences obtained by cyclically shifting different root sequences are Therefore, generating the preamble based on the ZC sequence can ensure the detection performance of the preamble.

[0132] For the Z4 sequence: 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. Therefore, generating the preamble based on the Z4 sequence can also ensure the detection performance of the preamble.

[0133] Specifically, taking the "recursive formula s(t) = 2s(t-3) + 3s(t-6) + s(t-7), length 127" as an example, assuming that 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, the sequence b can be obtained, and further, the sequence b is cyclically shifted, assuming that the cyclic shift interval is 1 (that is, the cyclic shift values are 0, 1, 2,..., 126), then a total of 127 sequences (such as sequence b1 to sequence b127) can be obtained; 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, 2], then according to the initial value sequence 2 and the recursive formula, the sequence c can be obtained, and further, the sequence c is cyclically shifted, assuming that the cyclic shift interval is 1 (that is, the cyclic shift values are 0, 1, 2,..., 126), then a total of 127 sequences (such as sequence c1 to sequence c127) can be obtained; 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], then according to the initial value sequence 3 and the recursive formula, the sequence d can be obtained, and further, the sequence d is cyclically shifted, assuming that the cyclic shift interval is 1 (that is, the cyclic shift values are 0, 1, 2,..., 126), then a total of 127 sequences (such as sequence d1 to sequence d127) can be obtained. That is, according to the three initial value sequences and 127 cyclic shift values, a total of 3*127 = 381 sequences can be obtained. Through calculation, it is found that the maximum cross-correlation value between the 381 sequences is 0.0948, the minimum cross-correlation value is 0.0078, and the intermediate cross-correlation value is 0.0837. When the preamble adopts a ZC sequence, assuming that the length of the root sequence is 138, then the cross-correlation values between the multiple ZC sequences obtained by cyclically shifting different root sequences are That is, the cross-correlation values between the multiple Z4 sequences obtained based on the same recursive formula are relatively close to the cross-correlation values between the ZC sequences obtained by different root sequences.

[0134] Further, it is found by calculation that when the number of recursive formulas is 2, the maximum cross-correlation value between the plurality of Z4 sequences based on the 2 recursive formulas is 0.3174; when the number of recursive formulas is 3, the maximum cross-correlation value between the plurality of Z4 sequences based on the 3 recursive formulas is 0.3174; and more numbers of recursive formulas are not listed one by one. Although the maximum cross-correlation value between the plurality of Z4 sequences based on the plurality of recursive formulas is slightly larger than the maximum cross-correlation value between the plurality of Z4 sequences based on the same recursive formula, the maximum cross-correlation value between the plurality of Z4 sequences based on the plurality of recursive formulas is also relatively low, and therefore, the preamble based on the Z4 sequence can ensure that the preamble has good detection performance.

[0135] (3) Preamble quantity comparison

[0136] As described above, for the ZC sequence: when the length of the ZC sequence is 139, since there are 138 physical root index numbers in total, 138 root sequences can be generated according to the 138 physical root index numbers; further, assuming that N CS = 15, a total of sequences can be generated, corresponding to 1380 preambles (for example, 1380 sequences are 1380 preambles).

[0137] For the m sequence: for the same recursive formula, the m sequences generated by different initial value sequences are each other's cyclically shifted sequences. For example, the length of the m sequence is 63, and there are 64 (2 6 ) initial value sequences, and for the same recursive formula, the m sequences generated by the 64 initial value sequences are each other's cyclically shifted sequences. For example, the initial value sequence 1 is [s(5), s(4), s(3), s(2), s(1), s(0)] = [0, 0, 0, 0, 0, 1], and the m sequence 1 is generated according to the initial value sequence 1 and the recursive formula; the initial value sequence 2 is [s(5), s(4), s(3), s(2), s(1), s(0)] = [0, 0, 0, 0, 1, 0], and the m sequence 2 is generated according to the initial value sequence 2 and the recursive formula; the m sequence 1 and the m sequence 2 are each other's cyclically shifted sequences, that is, the m sequence 2 can be obtained by cyclically shifting the m sequence 1. Therefore, it can be considered that the m sequence has only one initial value sequence.

[0138] When the length of the m sequence is 127 (that is, taking a number close to 139 as an example), if the m sequence has 18 recursive formulas, then according to one initial value sequence, 18 sequences can be generated; further, assuming that N CS = 15, a total of sequences can be generated, corresponding to 180 preambles.

[0139] 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.

[0140] 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).

[0141] 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.

[0142] 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.

[0143] Figure 4 is a flowchart illustrating the communication method provided in this embodiment. As shown in Figure 4, the process may include:

[0144] S401, the terminal device generates a random access signal.

[0145] Exemplarily, the terminal device generates the random access signal based on the first sequence. For example, the terminal device generates the random access signal based on the first sequence can be replaced with: the terminal device generates the random access signal based on a third sequence, the third sequence being a preamble obtained based on the first sequence, for example, the third sequence being a preamble obtained by modulating the first sequence.

[0146] The terminal device generates the random access signal based on the third sequence (i.e., the preamble), which can specifically be: the terminal device performs discrete fourier transformation (DFT) processing on the third sequence to obtain a fourth sequence; and then maps elements in the fourth sequence to a plurality of subcarriers and performs inverse fast fourier transformation (IFFT) processing to generate the random access signal. That is, the random access signal is a signal of a discrete fourier transformation-spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveform.

[0147] It can be understood that in the contention-based random access scenario, the third sequence can be a preamble selected by the terminal device from a preamble set of the cell, and the specific implementation of the terminal device determining the preamble set is not limited in the embodiments of the present application. In the non-contention-based random access scenario, the third sequence can be a preamble indicated by the network device to the terminal device, and the specific indication manner of the network device is not limited in the embodiments of the present application. In addition, the embodiments of the present application will be described taking "the preamble as the third sequence" as an example, and in other examples, the preamble can also be the first sequence, in which case, the terminal device generates the random access signal based on the first sequence (i.e., the preamble) means that: the terminal device modulates the first sequence to obtain the third sequence, performs DFT processing on the third sequence to obtain the fourth sequence; and then maps elements in the fourth sequence to a plurality of subcarriers and performs IFFT processing to generate the random access signal.

[0148] (1) The first sequence is described.

[0149] The first sequence is obtained according to the second sequence and a first cyclic shift value. The first cyclic shift value is one of M3 cyclic shift values, or represents up-rounding of the L / C, 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. For example, the first cyclic shift value in the M3 cyclic shift values 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, and the M3 cyclic shift value is For example, L is 127, and C is 15, and thus The M3 cyclic shift values are 0, 15, 30, 45, 60, 75, 90, 105, and 120, respectively.

[0150] For example, the first sequence is denoted as y(n), and the second sequence is denoted as z(n), and n = 0, 1, 2, …, L-1. The first sequence and the second sequence satisfy the following formula: y(n) = z((i+cs)mod L)

[0151] where cs represents the first cyclic shift value.

[0152] (2) Describing the modulation mode.

[0153] There are multiple modulation modes for modulating the first sequence, for example, the modulation mode is quadrature phase shift keying (QPSK) modulation. When the QPSK modulation adopts Gray mapping, the complex value mapped by the element in the first sequence is as shown in Table 2; when the QPSK modulation adopts natural mapping, the complex value mapped by the element in the first sequence is as shown in Table 3 or Table 4.

[0154] Table 2: QPSK modulation of Gray mapping

[0155] Table 3: QPSK modulation of natural mapping

[0156] Table 4: QPSK modulation of natural mapping

[0157] When the QPSK modulation of natural mapping is adopted, the third sequence is denoted as [x(n)], and the third sequence and the first sequence satisfy the following formula:

[0158] (corresponding to Table 3), or (corresponding to Table 4)

[0159] Therefore, when the QPSK modulation of natural mapping is adopted, the third sequence can be expressed as:

[0160] or

[0161] Exemplarily, since the preamble is used to realize uplink synchronization between the terminal device and the network device, considering the influence of noise, the synchronization point may be wrongly located at the position of the second peak of the ambiguity function of the third sequence, that is, the third sequence. Therefore, the smaller the second peak is, the better the synchronization performance of the third sequence is, and then the mapping mode actually used can be selected according to the second peak of the ambiguity function of the third sequence corresponding to different mapping modes. The second peak is the second largest value of the ambiguity function, and the second peak involved in the embodiments of the present application refers to the normalized second peak. In addition, considering the possible frequency offset value during synchronization, the second peak of the ambiguity function in the embodiments of the present application is defined as the normalized second peak under the frequency offset values of ±0.5 / ±1 / ±2 (considering the crystal oscillator frequency offset existing in the actual communication system, the maximum frequency offset is twice the subcarrier spacing, and the frequency offset value is traversed in the granularity of 0.5 times the subcarrier spacing, therefore, f d may be ±0.5 / ±1 / ±2) and all cyclic shifts in the time domain.

[0162] The ambiguity function of the third sequence conforms to the following formula:

[0163] wherein A(f d ,τ) is the ambiguity function of the third sequence, f d is a frequency offset value, τ is a time-domain multipath delay, y * (n+τ) is the conjugate of y(n+τ). For example, the main peak of the ambiguity function of the third sequence is A(0,0), and A(f d ,τ) ′ =A(f d ,τ) / A(0,0), A(f d ,τ) ′ is obtained by normalizing A(f d ,τ).

[0164] When the first sequence (or the second sequence) is a Z4 sequence, it is found through simulation that the second peak of the ambiguity function of the third sequence obtained by modulating the first sequence by using the natural mapping QPSK modulation is smaller than the second peak of the ambiguity function of the third sequence obtained by modulating the first sequence by using the Gray mapping QPSK modulation, as shown in Table 5. Therefore, in the embodiments of the present application, the first sequence can be modulated by using the natural mapping QPSK modulation, so as to facilitate guaranteeing the synchronization performance of the preamble.

[0165] Table 5: Examples of normalized second peaks of third sequences obtained by modulation when the first sequence is a ZC sequence or a Z4 sequence

[0166] (3) The second sequence is described.

[0167] The second sequence is one of M sequences, the M sequences are obtained according to M1 recursive formulas and M2 initial value sequences, M1 is an integer greater than 1, M2 is an integer greater than 1, and the M sequences have the same length, such as L.

[0168] Since the M sequences are obtained according to M1 recursive formulas and M2 initial value sequences, and M2 is an integer greater than 1, the M sequences can be Z4 sequences or other possible sequences, such as Gold sequences. Since the cross-correlation values between different Z4 sequences are relatively low, the detection performance of the preamble can be ensured, and the cross-correlation values between different Gold sequences are relatively high, the Z4 sequences are mainly taken as examples for description in the embodiments of the present application. That is, the preamble is generated based on the Z4 sequences in the embodiments of the present application, so that the preamble can be expanded while the detection performance of the preamble is ensured.

[0169] The M1*M2 sequences can be M sequences (that is, M=M1*M2) or part of the M1*M2 sequences (that is, M

[0170] 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, and M4 represents the number of recursive formulas of m sequences with the same length.

[0171] In addition, M*M3 sequences can be obtained according to the M sequences and M3 cyclic shift values, and the first sequence can be one of the M*M3 sequences.

[0172] S402, the terminal device sends a random access signal to the network device; correspondingly, the network device receives the random access signal.

[0173] It can be understood 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 of the terminal device sending the random access signal to the radio frequency chip of the terminal device. The terminal device sending the random access signal also includes the radio frequency chip of the terminal device sending the random access signal to the network device.

[0174] Exemplarily, after receiving the random access signal, the network device processes the random access signal to obtain a sequence r, and then determines, according to a cross-correlation value between a sequence in a preamble set of the current cell and the sequence r (considering time domain cyclic shift), a sequence in the preamble set with the maximum cross-correlation value with the sequence r as the sequence actually transmitted by the terminal device. While 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 according to the time domain multipath delay.

[0175] S403, the network device sends a random access response to the terminal device; correspondingly, the terminal device receives the random access response.

[0176] Exemplarily, the random access response includes the TA of the current cell, and then the terminal device can obtain the TA of the current cell from the random access response, and perform uplink synchronization with the network device according to the TA of the current cell.

[0177] The method flow illustrated in FIG. 4 can be applied to contention-based random access, or can also be applied to non-contention-based random access. When the method flow illustrated in FIG. 4 can be applied to contention-based random access, the method flow can also include other possible steps, such as that the terminal device sends uplink signaling to the network device according to the TA of the current cell, and the network device sends a contention resolution message to the terminal device.

[0178] In the embodiments of the present application, a plurality of sequences for generating random access signals are generated based on a plurality of cyclic shift values, a plurality of recursive formulas and a plurality of initial value sequences, so that the sequences (such as preambles) for generating random access signals can be expanded, the probability of collision when different terminal devices access the network device can be reduced, and the needs of future communication scenarios can be met.

[0179] For the above embodiments, it can be understood that:

[0180] (1) In the embodiments of the present application, the terms and / or descriptions in different examples or implementation manners are consistent and can be referred to each other without special description and logical conflict, and the technical features in different examples or implementation manners can be combined to form new embodiments according to their inherent logical relationship. In addition, different implementation manners or different examples can refer to or refer to each other.

[0181] (2) The various numbers referred to in the present application are only used for distinguishing convenience, and do not limit the scope of the present application. The step numbers of the above-mentioned flowcharts are only an example of the execution flow, and do not limit the execution sequence of the steps, i.e., the size of the step numbers does not mean the execution sequence, and the execution sequence of the steps should be determined according to the function and inherent logic. In addition, the steps shown in the various flowcharts are not all the steps that must be executed, and some steps can be added or deleted based on the various flowcharts according to actual needs.

[0182] The above mainly introduces the scheme provided by the embodiments of the present application from the perspective of the interaction between the first communication device and the second communication device. It can be understood that, in order to realize the above functions, the first communication device and the second communication device can include corresponding hardware structures and / or software modules for executing various functions. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed in the present application, the embodiments of the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0183] The embodiments of the present application can divide the functional units of the first communication device and the second communication device according to the above method examples, for example, each functional unit can be divided according to each function, or two or more functions can be integrated in one unit. The integrated unit can be realized in the form of hardware or software functional unit.

[0184] In the case of using an integrated unit, FIG. 5 shows a possible exemplary block diagram of the device involved in the embodiments of the present application. As shown in FIG. 5, the device 500 can include a processing unit 502 and a communication unit 503. The processing unit 502 is used to control and manage the actions of the device 500. The communication unit 503 is used to support the communication of the device 500 with other devices. Optionally, the communication unit 503, also called a transceiver unit, can include a receiving unit and / or a sending unit, which are used to perform receiving and sending operations, respectively. The device 500 can also include a storage unit 501 for storing the program code and / or data of the device 500.

[0185] (1) The apparatus 500 can be the first communication apparatus in the above embodiments. The processing unit 502 can enable the apparatus 500 to perform the actions of the first communication apparatus in the above method embodiments. Alternatively, the processing unit 502 mainly performs the internal actions of the first communication apparatus in the method embodiments, and the communication unit 503 can enable the apparatus 500 to communicate with other devices.

[0186] For example, in an embodiment, the processing unit 502 is configured to generate a random access signal, the random access signal being based on a first sequence; and the communication unit 503 is configured to transmit the random access signal; wherein the first sequence is derived based on a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being derived based on M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, M2 being an integer greater than 1; and the first cyclic shift value being an integer greater than or equal to 0.

[0187] In a possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any of the M sequences.

[0188] In a possible design, the M sequences are all Z4 sequences.

[0189] In a possible design, M = M1*M2.

[0190] In a possible design, 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.

[0191] In a possible design, the first sequence is one of M*M3 sequences, the M*M3 sequences being derived based on the M sequences and the M3 cyclic shift values.

[0192] In a possible design, the first sequence is derived 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; y(n) = z((i+cs)mod L)

[0193] Wherein, cs represents the first cyclic shift value.

[0194] In a possible design, the first sequence is denoted as [y(n)], and the third sequence is denoted as [x(n)], n = 0, 1, 2,..., L-1.

[0195] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0196] In a possible design, the processing unit 502 is specifically configured to: perform discrete Fourier transform (DFT) processing on the third sequence to obtain a fourth sequence; and map elements in the fourth sequence onto a plurality of subcarriers and perform inverse fast Fourier transform (IFFT) processing to generate the random access signal.

[0197] (2) The apparatus 500 can be the second communication apparatus in the above embodiments. The processing unit 502 can enable the apparatus 500 to perform the actions of the second communication apparatus in the above method embodiments. Alternatively, the processing unit 502 mainly performs the internal actions of the second communication apparatus in the method embodiments, and the communication unit 503 can enable the apparatus 500 to communicate with other devices.

[0198] For example, in an embodiment, the communication unit 503: receives a random access signal, the random access signal being obtained based on a first sequence; and sends a random access response in response to the random access signal; wherein the first sequence is obtained according to a second sequence and a first cyclic shift value, the second sequence being one of M sequences, the M sequences being obtained according to M1 recursive formulas and M2 initial value sequences, M1 being an integer greater than 1, and M2 being an integer greater than 1; and the first cyclic shift value being an integer greater than or equal to 0.

[0199] In a possible design, the first cyclic shift value is greater than 0, and the first sequence is different from any sequence in the M sequences.

[0200] In a possible design, the M sequences are all Z4 sequences.

[0201] In a possible design, M=M1*M2.

[0202] In a possible design, 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.

[0203] In a possible design, the first sequence is one of M*M3 sequences, and the M*M3 sequences are obtained according to the M sequences and the M3 cyclic shift values.

[0204] In a possible design, the first sequence is obtained according to 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; y(n)=z((i+cs)mod L)

[0205] where cs represents the first cyclic shift value, and cs is an integer greater than or equal to 0.

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

[0207] The random access signal is obtained based on the first sequence, including: the random access signal is obtained based on the third sequence.

[0208] It should be understood that the division of units in the above apparatus is only a logical function division, and all or part of the units can be integrated into one physical entity, or can be physically separated. The units in the apparatus can all be implemented in the form of software invoked by a processing element; or all can be implemented in the form of hardware; or part of the units can be implemented in the form of software invoked by a processing element, and part of the units can be implemented in the form of hardware. For example, each unit can be a separately established processing element, or can be integrated into a chip of the apparatus, in addition, the unit can also be stored in the form of a program in a memory, and the function of the unit is invoked and executed by a processing element of the apparatus. In addition, all or part of the units can be integrated together, or can be independently implemented. The processing element mentioned herein can be a processor, which can be an integrated circuit with signal processing capability. In the implementation process, each operation of the above method or each unit can be implemented by an integrated logic circuit of hardware in the processing element, or in the form of software invoked by the processing element.

[0209] In one example, the units in any of the above apparatuses can be one or more integrated circuits configured to implement one or more of the above methods, for example, one or more application specific integrated circuits (ASICs), or, one or more digital singnal processors (DSPs), or, one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. In another example, when the units in the apparatuses 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 invoking a program. In yet another example, the units can be integrated together to be implemented in the form of a SoC.

[0210] The above receiving unit is an interface circuit of the apparatus for receiving signals from other apparatuses. For example, when the apparatus is implemented in the form of a chip, the receiving unit is an interface circuit of the chip for receiving signals from other chips or apparatuses. The above transmitting unit is an interface circuit of the apparatus for transmitting signals to other apparatuses. For example, when the apparatus is implemented in the form of a chip, the transmitting unit is an interface circuit of the chip for transmitting signals to other chips or apparatuses.

[0211] Based on the same technical concept, the embodiments of the present application further provide a communication apparatus, which is configured to implement the functions of the first communication apparatus or the second communication apparatus in the above embodiments. As shown in FIG. 6, the apparatus can be a communication device or a chip in a communication device. The apparatus includes a processor 601 and a communication interface 602, and optionally further includes a memory 603. FIG. 6 only shows the main components of the communication apparatus. In addition to the processor 601 and the communication interface 602, the communication apparatus can further include the memory 603 and an input / output device (not shown in the figure).

[0212] The processor 601 is configured to execute the program code stored in the memory 603, and specifically configured to execute the actions of the processing unit 502 described above, which will not be repeated here. The communication interface 602 is specifically configured to execute the actions of the communication unit 503 described above, which will not be repeated here.

[0213] The processor 601 can be a CPU, or a digital processing unit, etc. The processor 601 can be used to process communication protocols and communication data, control the whole communication device, execute software programs, process data of the software programs, such as but not limited to baseband related processing. The communication interface 602 can be used to transceive signals, such as but not limited to radio frequency transceiving. The above-mentioned devices can be respectively arranged on independent chips, or at least partially or entirely arranged on the same chip. For example, the processor 601 can be further divided into an analog baseband processor and a digital baseband processor. The analog baseband processor can be integrated on the same chip as the transceiver, and the digital baseband processor can be arranged on an independent chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip, for example, the digital baseband processor can be integrated on the same chip as various application processors, such as but not limited to a graphics processor, a multimedia processor, etc. Such a chip can be referred to as a system on chip. Whether to arrange the devices independently on different chips or to integrate them on one or more chips often depends on the specific needs of product design. The embodiments of the present application do not limit the specific implementation forms of the above-mentioned devices.

[0214] The communication interface 602 can be a transceiver, an interface circuit such as a transceiving circuit, etc., or a transceiving chip, etc. Optionally, the communication interface 602 can include a radio frequency circuit and an antenna, the radio frequency circuit being mainly used for conversion between a baseband signal and a radio frequency signal and processing of the radio frequency signal. The antenna is mainly used for transceiving radio frequency signals in the form of electromagnetic waves. Input and output devices, such as a touch screen, a display screen, a keyboard, etc., are mainly used to receive user input data and output data to the user.

[0215] The memory 603 is used to store programs executed by the processor 601. The memory 603 can be a non-volatile memory, such as a hard disk (HDD) or a solid-state drive (SSD), etc., and can also be a volatile memory, such as a random-access memory (RAM). The memory 603 is any other medium that can be used to carry or store desired program codes in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0216] 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.

[0217] 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.

[0218] This embodiment does not limit the specific connection medium between the communication interface 602, processor 601, and memory 603. In Figure 6, the memory 603, processor 601, and communication interface 602 are connected via a bus 604, which is represented by a thick line. The connection methods between other components are merely illustrative and not intended to be limiting. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is used in Figure 6, but this does not imply that there is only one bus or one type of bus.

[0219] Optionally, the communication device described above can be a standalone device or part of a larger device. For example, the communication device can be:

[0220] (1) An independent integrated circuit (IC), or chip, or chip system or subsystem;

[0221] (2) A collection of one or more ICs, optionally including a storage component for storing data and instructions;

[0222] (3) Application-specific integrated circuit (ASIC), such as modem;

[0223] (4) Modules that can be embedded in other devices;

[0224] (5) Receivers, smart terminals, wireless devices, handheld devices, mobile units, vehicle-mounted devices, cloud devices, artificial intelligence devices, etc.;

[0225] (6) Others, etc.

[0226] In the embodiments of the present application, "multiple" can mean two or more. In view of this, "multiple" can also be understood as "at least two" in the embodiments of the present application. "At least one" can be understood as one or more, for example, 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, and the included can be A, B, C, A and B, A and C, B and C, or A, B and C. "And / or" describes the association relationship of the associated objects, and specifically can exist in three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. In addition, the character " / ", if not specially stated, generally represents that the associated objects before and after are in an "or" relationship.

[0227] In addition, the terms "system" and "network" in the embodiments of the present application can be used interchangeably, and "according to" and "based on" can be used interchangeably. The ordinal numbers "first", "second" and the like mentioned in the embodiments of the present application are generally used to distinguish different objects, and are not used to limit the order, time sequence, priority or importance of multiple objects. For example, the first communication device and the second communication device in the embodiments of the present application are used to distinguish two communication devices, and do not limit the priority or importance of the two communication devices.

[0228] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0229] The present application is described with reference to flowcharts and / or block diagrams according to the method, device (system) and computer program product of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of flows and / or blocks in the flowchart and / or block diagram. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flows of the flowchart and / or one or more blocks of the block diagram.

[0230] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart or flowsheets and / or block or blocks of the block diagrams.

[0231] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flowsheets and / or block or blocks of the block diagrams.

[0232] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A communication method, characterized in that, 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 according to claim 1, characterized in that, 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 the 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.

6. The method according to claim 5, characterized in that, 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)mod L) 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 according to claim 8, characterized in that, 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 in that, 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 according to claim 10, characterized in that, 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 the 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.

15. The method according to claim 14, characterized in that, 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)mod L) 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 communication device, characterized in that, Includes units for performing the method as described in any one of claims 1 to 17.

19. A communication device, characterized in that, 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 in that, 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.

Images