Communication method and communication apparatus

Abstract

Embodiments of the present application provide a communication method and a communication apparatus, capable of enabling a reader / writer to generate, on the basis of a first rule, a first message to be sent to a terminal device. The method comprises: a reader / writer sends a first message to a terminal device, the first message including one or more of the following: a first paging message, an R2D signal, or a second random access message, wherein the first message is generated by the reader / writer on the basis of a first rule.

Description

Communication methods and communication devices Technical Field

[0001] This application relates to the field of communications, and more specifically, to communication methods and communication devices. Background Technology

[0002] In recent years, the Internet of Things (IoT) has received considerable attention in the field of wireless communication. With the continuous development of communication systems, IoT devices are being applied to various scenarios, including homes, industry, agriculture, and healthcare. Ambient IoT (AIoT) technology has been widely discussed. AIoT devices primarily utilize the external environment (e.g., light, radio waves, motion, heat, etc.) to obtain energy, thus eliminating the need for battery devices or requiring only low energy storage capacity (e.g., capacitors), eliminating the need for manual battery replacement or charging.

[0003] The 3rd Generation Partnership Project (3GPP) Release 19 introduced the topic of AIoT. However, many issues regarding AIoT remain unresolved. Summary of the Invention

[0004] This application provides a communication method and a communication device that enable a reader / writer to generate a first message to be sent to a terminal device according to a first rule.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] Firstly, a communication method is provided. This method can be executed by a reader / writer, or by a component of the reader / writer, such as a processor, chip, or chip system, or by a logic module or software capable of implementing all or part of the reader / writer's functions. Taking the method being executed by a reader / writer as an example, the method includes: the reader / writer sending a first message to a terminal device, the first message including one or more of the following: a first paging message, an R2D signal, or a randomly accessed second message; wherein the first message is generated by the reader / writer according to a first rule.

[0007] Secondly, a communication method is provided. This method can be executed by a terminal device, or by a component of the terminal device, such as the terminal device's processor, chip, or chip system, or by a logic module or software capable of implementing all or part of the terminal device's functions. Taking the method being executed by a terminal device as an example, the method includes: the terminal device receiving a first message, the first message including one or more of the following: a first paging message, an R2D signal, or a randomly accessed second message; the terminal device decoding the first message according to a first rule; wherein the first message is generated by the reader / writer according to the first rule.

[0008] Thirdly, a communication device is provided for implementing the various methods described above. This communication device may be the reader / writer described in the first aspect, or a device included in the reader / writer, such as a chip; or, the communication device may be the terminal device described in the second aspect, or a device included in the terminal device, such as a chip.

[0009] The communication device includes modules, units, or means that implement the above methods. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0010] In some possible designs, the communication device may include a processing module and a communication module. The communication module may include an output module (or transmitting module) and an input module (or receiving module), respectively used to implement the output (or transmitting) and input (or receiving) functions in any of the above aspects and any possible designs. The processing module can be used to implement the processing functions in any of the above aspects and any possible designs.

[0011] Optionally, the communication device also includes a storage module for storing program instructions and data.

[0012] Fourthly, a communication device is provided, comprising: at least one processor configured to execute computer programs or instructions, or to cause the communication device to perform the method described in any of the preceding aspects via logic circuitry. The communication device may be a reader / writer as described in the first aspect, or a device included in a reader / writer, such as a chip; or, the communication device may be a terminal device as described in the second aspect, or a device included in a terminal device, such as a chip.

[0013] In some possible designs, the communication device also includes a memory for storing configuration files of computer instructions and / or logic circuits. Optionally, the memory is integrated with the processor, or the memory is independent of the processor.

[0014] In one possible design, the communication device also includes a communication interface for inputting and / or outputting signals.

[0015] In some possible designs, the communication interface is an interface circuit used to read and write computer instructions. For example, the interface circuit is used to receive computer execution instructions (which are stored in memory and may be read directly from memory or may pass through other devices) and transmit them to the processor.

[0016] In some possible designs, this communication interface is used to communicate with modules outside the communication device.

[0017] In some possible designs, the communication device can be a chip system. When the communication device is a chip system, the chip system may include chips, or it may contain chips and other discrete components.

[0018] Fifthly, a communication device is provided, comprising: a logic circuit and an interface circuit; the interface circuit is used for inputting information and / or outputting information; the logic circuit is used to execute the method described in any of the preceding aspects, processing the input information and / or generating output information. The communication device may be a reader / writer as described in the first aspect, or a device included in the reader / writer, such as a chip; or, the communication device may be a terminal device as described in the second aspect, or a device included in the terminal device, such as a chip.

[0019] In a sixth aspect, a computer-readable storage medium is provided that stores a computer program or instructions that, when executed by a processor, cause the methods described in any of the preceding aspects to be performed.

[0020] In a seventh aspect, a computer program product is provided, which, when executed by a processor, causes the method described in any of the preceding aspects to be performed.

[0021] Eighthly, a communication system is provided, which includes the reader / writer of the first aspect and the terminal device of the second aspect.

[0022] It is understood that when the communication device provided by any of the third to fifth aspects is a chip, the aforementioned sending action / function can be understood as output information, and the aforementioned receiving action / function can be understood as input information.

[0023] The technical effects of any of the design methods in aspects three through five can be found in the technical effects of different design methods in aspects one or two above, and will not be repeated here. Attached Figure Description

[0024] Figure 1 is a schematic diagram of four topologies of an AIoT system;

[0025] Figure 2A is a schematic diagram of the CW signal and the sideband signal generated by the CW signal provided in the embodiments of this application;

[0026] Figure 2B is a schematic diagram of a scenario based on topology 1 / 2 and whether the CW node is within the topology;

[0027] Figure 3 is a schematic diagram of the mapping relationship between bits and chips in Manchester encoding;

[0028] Figure 4 is a schematic diagram of PIE encoding;

[0029] Figure 5 is a schematic diagram of FM0 encoding;

[0030] Figure 6 is a schematic diagram of Miller coding;

[0031] Figure 7 is a schematic diagram of the R2D start indicator;

[0032] Figure 8 is a schematic diagram of the R2D intermediate guide code;

[0033] Figure 9 is a schematic diagram of the D2R intermediate guide code;

[0034] Figure 10 is a schematic diagram of the R2D postcode;

[0035] Figure 11 is a schematic diagram of the D2R postcode;

[0036] Figure 12 is a schematic diagram of the approximate time relationship between the D2R preamble, D2R intermediate preamble, and D2R postamble.

[0037] Figure 13 is a schematic diagram of the random access process between the reader and the terminal device;

[0038] Figure 14 is a schematic diagram of TDMA, FDMA, and TDMA+FDMA provided in the embodiments of this application;

[0039] Figure 15 is a schematic diagram of the reader / writer sending an MSG2 to the terminal device according to an embodiment of this application;

[0040] Figure 16 is a schematic diagram of the MSG2 response to the terminal device provided in an embodiment of this application;

[0041] Figure 17 is a schematic diagram of MSG2 in embodiment 2 of this application;

[0042] Figure 18 is a schematic diagram of MSG2 in embodiment 3 provided in this application;

[0043] Figure 19 is a schematic diagram with the end time unit of Step A as a reference point provided in the embodiment of this application;

[0044] Figure 20 is a schematic diagram of the communication system provided in an embodiment of this application;

[0045] Figure 21 is a schematic diagram of the structure of the communication device 2100 provided in an embodiment of this application;

[0046] Figure 22 is a schematic diagram of an example of the communication method provided in an embodiment of this application;

[0047] Figure 23 is a schematic diagram of the first synchronization signal after Manchester encoding provided in an embodiment of this application for calculating the chip length;

[0048] Figure 24 is a schematic diagram of triggering the terminal device to send a first random access message according to an embodiment of this application;

[0049] Figure 25 is a schematic diagram showing that the preamble is located at the very front of the D2R signal according to an embodiment of this application;

[0050] Figure 26 is a schematic diagram of the resources for the first random access message and the third random access message provided in an embodiment of this application;

[0051] Figure 27 is a schematic diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0052] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0053] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following or similar expressions" refers to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b and / or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0054] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0055] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0056] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0057] It is understood that in this application, "...when" and "if" both refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed during implementation, nor do they imply any other limitations.

[0058] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0059] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, unless otherwise specified or there is a logical conflict, the terminology and / or descriptions between different embodiments are consistent and can be mutually referenced. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. The following descriptions of the embodiments of this application do not constitute a limitation on the scope of protection of this application.

[0060] To facilitate the reader's understanding, the embodiments of this application provide a brief introduction to the relevant technologies involved.

[0061] I. Topology of AIoT System

[0062] Figure 1 shows a schematic diagram of four topologies for an AIoT system. As shown in Figure 1, the AIoT system mainly includes four topologies: Topology 1 to Topology 4, which will be introduced below.

[0063] Topology 1:

[0064] In topology 1, the access network devices and AIoT terminals are directly connected for uplink / downlink communication. That is, the AIoT terminal sends information to the access network devices, or the AIoT terminal receives information from the access network devices.

[0065] Topology 2:

[0066] In topology 2, AIoT terminals and intermediate nodes communicate uplink / downlink, while intermediate nodes communicate uplink / downlink with access network devices. That is, AIoT terminals send or receive information from intermediate nodes, and intermediate nodes send or receive information from access network devices. Intermediate nodes can be relays, integrated access backhaul (IAB) nodes, user equipment (UE), repeaters, etc.

[0067] Topology 3:

[0068] In topology 3, the AIoT terminal communicates unidirectionally with the access network device / auxiliary node. In the left diagram, the AIoT terminal directly sends signals to the access network device but receives signals through the auxiliary node. In the right diagram, the AIoT terminal can directly receive signals from the access network device but sends signals to the auxiliary node. The auxiliary node can be a relay, IAB node, UE, repeater, etc.

[0069] Topology 4:

[0070] In topology 4, the UE and AIoT terminal are directly connected for uplink / downlink communication. That is, the AIoT terminal sends information to the UE or receives information from the UE.

[0071] In the following embodiments of this application, unless otherwise stated, the AIoT terminal is referred to as a terminal device, the access network device, the intermediate node, and the UE are referred to as a reader, the transmission direction from the terminal device to the reader is referred to as device to reader (D2R), and the transmission direction from the reader to the terminal device is referred to as reader to device (R2D).

[0072] Optionally, the access network equipment that can serve as a reader / writer can be an evolved NodeB (or eNB, or e-NodeB) in a long-term evolution (LTE) system or an enhanced LTE (LTE-A) system, such as a traditional macro base station (eNB) and a micro base station (eNB) in a heterogeneous network scenario. Alternatively, it can include a next-generation node B (gNB) in a new radio (NR) system. Alternatively, it can include a transmission reception point (TRP), a home base station (e.g., a home evolved NodeB, or a home Node B, HNB), a base band unit (BBU), a base band pool (BBU pool), or a wireless fidelity (WiFi) access point (AP), etc. Alternatively, it can include base stations in non-terrestrial networks (NTNs), i.e., those deployed on flying platforms or satellites. In NTNs, access network devices can act as Layer 1 (L1) relays, base stations, or integrated access and backhaul (IAB) nodes. Alternatively, access network devices can be devices that implement base station functions in IoT, such as those implementing base station functions in drone communication, V2X, D2D, or machine-to-machine (M2M) communication.

[0073] In some possible scenarios, access network equipment can also be modules or units capable of implementing some of the functions of a base station. For example, the first network device can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and DU can be set up separately or included in the same network element, such as in a baseband unit (BBU). The RU can be included in radio equipment or radio units, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0074] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, an access network device can be a network device or a module of a network device in an Open Radio Access Network (ORAN) system. In an ORAN system, CU can also be called open (O)-CU, DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through a software module, a hardware module, or a combination of a software module and a hardware module.

[0075] Optionally, the base station in the embodiments of this application may include various forms of base stations, such as: macro base station, micro base station (also known as small station), relay station, access point, home base station, TRP, transmitting point (TP), mobile switching center, etc., and the embodiments of this application do not specifically limit them.

[0076] Optionally, the UE that can be used as a reader / writer can be user equipment (UE), access terminal, terminal unit, user station, terminal station, mobile station, mobile station, remote station, remote terminal, user terminal equipment (TE), mobile device, wireless communication device, terminal agent, tablet computer, handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, vehicle-mounted communication module, wearable device, or terminal device in a 5G network or a public land mobile network (PLMN) evolved after 5G. The access terminal can be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, drone, robot, point of sale (POS) machine, customer-premises equipment (CPE), or wearable device, virtual reality (VR) device. Wireless terminals can be categorized into various types, including VR (Augmented Reality) terminal devices, wireless terminals in industrial control, self-driving, remote medical, smart grid, transportation safety, smart city, and smart home. Alternatively, a terminal can be a communication-enabled terminal within the Internet of Things (IoT), such as a V2X terminal (e.g., vehicle-to-everything (V2X) terminal, a D2D communication terminal, or an M2M communication terminal. Terminals can be mobile or fixed. Furthermore, this application does not limit the device form of the terminal; the apparatus used to implement the terminal device's function can be the terminal device itself, or it can be an apparatus capable of supporting the terminal device in implementing that function, such as a chip system. This apparatus can be installed in the terminal device or used in conjunction with the terminal device. In this application, the chip system can consist of chips or include chips and other discrete components.

[0077] II. Types of terminal equipment.

[0078] Terminal devices (AIoT terminals) can be broadly categorized into two types: those capable of generating their own signals and those unable to do so. The latter type receives backscattered signals from third-party signals (carrier waves, CW) and transmits them; therefore, they can also be called backscatter-based communication terminals. Because backscatter-based communication terminals cannot actively generate signals, their architecture is simpler and less expensive, resulting in lower power consumption compared to the former type. In the four topologies described in Related Technology 1, the signals sent by the terminal device to the access network device / intermediate node / UE can be either self-generated signals or backscattered signals.

[0079] The types of terminal devices can be shown in Table 1.

[0080] Table 1

[0081] It should be noted that the peak power values ​​in the embodiments of this application are merely examples, and the specific values ​​of peak power are not limited in the embodiments of this application. The embodiments of this application can also be applied to other types of AIoT terminals and are not limited to Table 1 above.

[0082] III. Carrier wave (CW).

[0083] In an AIoT system, in addition to the nodes mentioned in the related technologies above (access network devices, AIoT terminals, intermediate / auxiliary nodes), there are also nodes that transmit CW (Continuous Wave). CW can also be called a continuous wave, and this application does not limit the name.

[0084] One function of CW (Cyber-Wave) is to provide energy to AIoT devices, meaning that AIoT devices receive energy from CW. All AIoT devices can obtain energy by receiving CW signals.

[0085] Another function of CW is for backscatter communication. For example, the D2R signals of device 1 and device 2a mentioned above are backscatter signals generated by the terminal device through receiving CW.

[0086] In this embodiment, the node providing the CW can be an access network device, an intermediate node, a UE, or a third-party node. Taking topology 1 as an example, the CW can be sent by the access network device, and the AIoT terminal receives other signals (e.g., control information) and the CW sent by the access network device; the CW can also be sent by a third-party node, and the AIoT terminal receives signals (e.g., control information) sent by the access network device and the CW sent by the third-party node.

[0087] Based on the topology described in the above-mentioned related technology 1, depending on the situation, the device that sends CW (denoted as CW node) may be inside or outside the topology.

[0088] In this embodiment, the CW can be a single-tone signal or a multi-tone signal, with two-tone signals being the primary type. However, other multi-tone signals can also be used, and this embodiment does not limit the specific type. A single-tone CW signal will generate two sideband signals, a two-tone CW signal will generate four sideband signals, and so on. The sideband signals are the backscattered signals, i.e., the D2R signals of device 1 and device 2a. Figure 2A is a schematic diagram of the CW signal and the sideband signals generated by the CW signal provided in this embodiment. As shown in Figure 2A, f1 and f2 are the frequencies of the two CW signals, f1-f' and f1+f' are the frequencies of the two sideband signals generated by the CW of f1, and f2-f' and f2+f' are the frequencies of the two sideband signals generated by the CW of f2.

[0089] IV. AIoT Scenarios.

[0090] Currently, 3GPP is mainly researching Topology 1 and Topology 2. Based on Topology 1 / 2 and whether the CW node is within the topology, the following scenarios are possible, as shown in Table 2 and Figure 2B. In Topology 1, the reader / writer is an access network device; in Topology 2, the reader / writer is an intermediate node, which can be a relay, IAB node, UE, repeater, etc. The embodiments of this application are applicable to the following scenarios, and can also be applied to Topology 3 or Topology 4.

[0091] Table 2

[0092] V. AIoT Modulation and Coding.

[0093] Due to the simple structure of AIoT terminals, their signal processing methods differ from traditional communication. R2D signals use Manchester encoding or pulse-interval encoding (PIE). D2R signals use Manchester encoding, FM0 encoding, Miller encoding, or forward error correction (FEC).

[0094] Figure 3 is a schematic diagram of the mapping relationship between Manchester encoding bits and chips. As shown in Figure 3, Manchester encoding is an encoding method that uses level transitions to represent bits 0 and 1. Based on Manchester encoding, the mapping relationship between bits and chips can be as follows: bit 0 is mapped to chip {10}, which can be understood as switching from a high level to a low level; bit 1 is mapped to chip {01}, which can be understood as switching from a low level to a high level. Of course, bit 0 can also be mapped to chip {01}, and bit 1 can be mapped to chip {10}. According to the mapping relationship in the figure, the encoding efficiency of Manchester encoding is 1 / 2.

[0095] In Figure 3, the length of chip 1 in each bit is the same as the length of chip 0. The lengths of chip 1 and chip 0 can also be different. The time relationship between chip 0 and chip 1 can be represented by the duty cycle, which refers to the proportion of the on-time (high level time) to the total time in one pulse cycle.

[0096] Figure 4 is a schematic diagram of PIE encoding. As shown in Figure 4, PIE encoding represents 0 and 1 by the time interval between the falling edges of a pulse. The time interval between the falling edges of "0" and "1" pulses is different. Based on PIE encoding, the high-level duration of data 0 and data 1 can be the same; this embodiment of the application does not limit this.

[0097] Figure 5 is a schematic diagram of FM0 encoding. As shown in Figure 5, FM0 encoding is also known as biphase space encoding. The FM0 encoding rule is that a level switch occurs at the boundary of each bit window. Specifically, bit 0 undergoes a level switch at both the boundary and the middle, while bit 1 undergoes a level switch only at the boundary. That is to say, bit 0 has 3 level switches, and bit 1 has 1 level switch.

[0098] Miller coding, also known as delay modulation coding, is illustrated in Figure 6. Its coding rules are shown in Table 3 below:

[0099] Table 3

[0100] Forward error correction (FEC) codes, by adding redundant error correction codes to the sequence, can automatically correct errors through decoding under certain conditions, thereby reducing the bit error rate of the received signal. FEC codes are divided into two types: block codes and convolutional codes.

[0101] VI. Channels and signals of AIoT systems.

[0102] 1. R2D synchronization signal.

[0103] The R2D synchronization signal can also be called an R2D preamble, or any other name, which is not limited in this application. The R2D synchronization signal can be used by the terminal device to obtain time synchronization and the start time of the R2D physical channel. Typically, the R2D synchronization signal is followed by the R2D physical channel. This application does not limit the other functions of the R2D synchronization signal.

[0104] The R2D synchronization signal comprises two parts: synchronization information and start indication information. The start indication information can be used by the terminal device to determine the start time of the R2D synchronization signal or physical channel, while the synchronization information can be used by the terminal device to obtain time synchronization. This application embodiment does not limit the R2D synchronization signal to include other information. The start indication information is sent before the synchronization information.

[0105] Figure 7 is a schematic diagram of the R2D synchronization signal. For the start indication information pattern, in one possible implementation, the start indication information pattern consists of high and low levels; or, in other words, the start indication information sequence consists of a first value and a second value, which are different. For example, the first value is 0 and the second value is 1. Or, for another example, the first value is 1 and the second value is 0. In another possible implementation, the start indication information sequence consists entirely of the first value or entirely of the second value, as shown in Figure 7. In this case, the start indication information pattern consists of all low levels; in other words, the start indication information sequence consists entirely of 0s.

[0106] 2. R2D physical channel.

[0107] The R2D physical channel can be called PRDCH, or other names, which are not limited to in this application. The R2D physical channel can be used to carry data, payloads from higher layers, or control information from Layer 1 (L1). The payloads from higher layers include control information from higher layers.

[0108] 3.D2R preamble.

[0109] The D2R preamble can also be called by other names, and this application embodiment does not limit this. The D2R preamble can be used by the reader to obtain time synchronization and the start time of the D2R physical channel. This application embodiment does not limit other functions of the D2R preamble.

[0110] 4. D2R physical channel.

[0111] The D2R physical channel may be called PDRCH, or other names, which are not limited to in this application. The D2R physical channel can be used to carry data, payloads from higher layers, or control information from Layer 1 (L1). The payloads from higher layers include control information from higher layers.

[0112] 5. R2D intermediate guide code.

[0113] The R2D intermediate preamble is an intermediate preamble between two adjacent R2D physical channels, or between two adjacent segments of a single R2D physical channel. The R2D intermediate preamble is used by the terminal device to obtain time synchronization. An R2D intermediate preamble can be shown in Figure 8. This application does not limit its name in its embodiments. This application does not limit other functions of the R2D intermediate preamble in its embodiments.

[0114] 6. D2R intermediate guide code.

[0115] The D2R intermediate preamble is the intermediate preamble between two adjacent D2R physical channels, or between two adjacent segments of a single D2R physical channel. The D2R intermediate preamble is used by the reader / writer for time synchronization. A D2R intermediate preamble can be shown in Figure 9. This application does not limit its name in its embodiments. This application does not limit other functions of the D2R intermediate preamble in its embodiments.

[0116] 7. R2D postcode.

[0117] The R2D postcode follows the R2D physical channel and is used to determine the end time position of the R2D physical channel. The R2D postcode can be as shown in Figure 10. This application does not limit its name in its embodiments. This application does not limit other functions of the R2D postcode in its embodiments.

[0118] 8. D2R postcode.

[0119] The D2R postcode follows the D2R physical channel and is used to determine the end time position of the D2R physical channel. The D2R postcode can be as shown in Figure 11. This application does not limit its name in its embodiments. This application does not limit other functions of the D2R postcode in its embodiments. It should be noted that the intermediate preamble and / or postcode are optional and may not necessarily exist.

[0120] Taking D2R as an example, the approximate time relationship between the D2R preamble, D2R intermediate preamble, and D2R postamble is shown in Figure 12.

[0121] 7. AIoT Transmission Process.

[0122] 1. AIoT technology can be used indoors or outdoors, with main application scenarios including inventory, command, positioning, and sensing. The main research scenarios for the 3GPP Release 19 AIoT project are inventory and command; therefore, the DO-DTT (Device-originated–device-terminated triggered) service type is prioritized. This means that the terminal device initiates a session only after receiving a signal from the reader / writer. Therefore, AIoT terminals do not actively initiate sessions like traditional terminals (e.g., NR BSR / SR). The process between the reader / writer and the terminal device is shown in Figure 13.

[0123] Step A: The reader sends a trigger message, triggering a response from one or more terminal devices. Step A can also be understood as AIoT paging. The content of Step A may include device ID, device group ID, etc. Step A may also include resource information. Step A may also include the type of random access, which includes at least one of the following: 2-step random access, 3-step (or 4-step) random access, contention-based random access, and non-contention-based random access. Step A may also include other content, which is not limited in this embodiment. Optionally, Step A can be transmitted via PRDCH. It should be noted that Step A may involve one or more transmissions.

[0124] Step B: The terminal device will initiate random access. Step B can include one or more interaction processes. The random process in AIoT can also include contention-based random access and non-contention-based random access.

[0125] Step C: Optionally, considering different application scenarios, in some scenarios, the terminal device will send data or control information to the reader, such as the terminal device ID or higher-level information; or the reader will send data or control information to the terminal device. Step C and Step B may not be distinguished, and part or all of the process in Step C may be included in Step B, that is, the random access process may include the transmission of data / control information. Step C may include one or more interaction processes, which is not limited in this embodiment.

[0126] 2. Random access procedures can be divided into contention-based random access and contention-free random access. Contention-based random access can include at least one of the following types: 2-step random access, 3-step (or 4-step) random access. These will be described in detail below.

[0127] 2.1, 3-step (or 4-step) contention-based random access.

[0128] The random access process is roughly as follows:

[0129] Msg1 (also known as the first random access message): The terminal device sends a random access sequence (also known as a random ID) to the reader. Msg1 can be transmitted via D2R preamble and / or PDRCH.

[0130] Msg2 (also known as the second random access message): After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the terminal device. This response message may contain the random access sequence or other types of acknowledgment information. Msg2 can be transmitted using R2Dpreamble and / or PRDCH.

[0131] Msg3 (also known as Random Access Third Message): After receiving Msg2, the terminal device can send data (e.g., device ID, higher-level information) or control information to the reader. Msg3 can be transmitted via D2R preamble and / or PDRCH.

[0132] Msg4 (also known as the Random Access Fourth Message) is an optional step whereby the reader sends information to the terminal device, for example, an acknowledgment message. Msg4 can be transmitted using R2D preamble and / or PRDCH.

[0133] 2.2 Two-step contention-based random access.

[0134] Msg1 (also known as the first random access message): The terminal device sends data (e.g., device ID, higher-level information) or control information to the reader. Msg1 can be transmitted via D2R preamble and / or PDRCH.

[0135] Msg2 (also known as the second random access message): After receiving Msg1, the reader sends a response message (also known as an acknowledgment message) to the terminal device. This response message may contain the random access sequence or other types of acknowledgment information. Msg2 can be transmitted using R2Dpreamble and / or PRDCH.

[0136] 2.3 The non-contention-based random access process is roughly as follows:

[0137] (Random Access) First Message (also known as MSG1 or MSG3): The terminal device sends data (e.g., device ID, higher-layer information) or control information to the reader. The first message can be transmitted via D2R preamble and / or PDRCH.

[0138] (Random Access) Second Message (also known as MSG2 or MSG4): After receiving the first message, the reader sends a response message (also known as an acknowledgment message) to the terminal device. The second message can be transmitted using R2D preamble and / or PRDCH.

[0139] In contention-based random access methods, multiple terminal devices may transmit MSG1 on the same time-frequency resource, resulting in a collision and causing random access failure. In non-contention-based random access procedures, the reader pre-allocates MSG1 resources, preventing collisions between different terminal devices.

[0140] For AIoT terminals, random access can be implemented using Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), or Code Division Multiplexing (CDM). Msg1 and / or Msg3 can be transmitted using TDM, FDM, or CDM, and this application embodiment does not limit this. Specifically, TDM random access means that different terminal devices can initiate random access at different times; FDM random access means that different terminal devices can initiate random access on different frequency resources; and CDM random access means that different terminal devices can initiate random access using different sequences. Terminal devices can also initiate random access using two or three combinations of the above methods, for example, TDM + FDM, and this application embodiment does not limit this.

[0141] 3. For MSG1 of the AIoT system, the content carried by MSG1 shall include at least one of the following:

[0142] A terminal device identifier is used by the reader to distinguish different terminal devices. The terminal device identifier can be a random ID or other forms of ID; this application embodiment does not limit this. The terminal device identifier can be randomly generated by the terminal device, generated according to predefined rules, assigned to the terminal device by the reader, or obtained through other means; this application embodiment does not limit this. The length of the random ID can be 16 bits. If it is another form of ID, the ID length may be longer; this application embodiment does not limit this.

[0143] Energy status is used to indicate the energy status of terminal devices.

[0144] Other high-level information.

[0145] In this embodiment of the application, as described above, the MSG1 of multiple terminal devices can be transmitted using TDM and / or FDM. When the reader triggers X resources (where X is greater than or equal to 1) for MSG1 transmission, the X resources can be TDM, FDM, or a combination of TDM and FDM. The terminal device can randomly select one of the X resources to transmit MSG1, which can be considered as a contention-based random access method (CBRA). Alternatively, the reader allocates specific resources to the terminal device, and the terminal device uses those resources to transmit MSG1, which can be considered as a non-contention-based random access method (CFRA). Step A (also known as a trigger message or AIoT paging message) can indicate the resources for MSG1, including the number of time-domain resources X, the start time / offset of each MSG1 resource, and the length. The resources for MSG1 can also include the number of frequency-domain resources and the location of the frequency-domain resources. The frequency domain resource set of MSG1 can be obtained through BLF (backscatter link frequency) and line code repetition number.

[0146] Figure 14 is a schematic diagram of TDMA, FDMA, and TDMA+FDMA provided in the embodiments of this application. As shown in Figure 14, X is greater than or equal to 1, meaning the reader / writer can trigger one or more MSG1 resources. As shown in Figure 14, R2D is similar to Step A described above. For TDM, a time gap needs to be reserved between temporally adjacent MSG1 resources to address the impact of SFO. This time gap may or may not be included in each MSG1 resource. If it is included in the resource, then each MSG1 resource should include the actual MSG1 transmission resource plus a time gap, and no further time gap needs to be reserved between adjacent resources; if it is not included in the resource, then each MSG1 resource is the actual MSG1 transmission resource, and a time gap is reserved between adjacent resources. For FDM, a guard band also needs to be reserved between frequency-adjacent MSG1 resources.

[0147] In a contention-based random access method, different terminals can randomly select one MSG1 resource to send MSG1.

[0148] 4. For MSG2 in the AIoT system, MSG2 serves as a response message to MSG1, and the content carried by MSG2 must include at least one of the following:

[0149] Terminal device identifier. After receiving MSG2, if the identifier carried in MSG2 matches its own identifier, the terminal device indicates successful access; otherwise, access has failed. Depending on the implementation, MSG2 can carry one or more terminal device identifiers. When an MSG2 carries multiple terminal device identifiers, one of the following methods can be used: Other forms of acknowledgment information, such as ACK or NACK. The terminal device uses this acknowledgment information to determine whether access was successful. Depending on the implementation, MSG2 can carry acknowledgment information for one or more terminal devices.

[0150] MSG3 resource scheduling information. The terminal device sends MSG3 to the reader / writer based on this scheduling information.

[0151] When a reader needs to send MSG2 to multiple terminal devices, it can use one or more of the following methods:

[0152] Method 1: The reader sends an MSG2 to the terminal device to respond to multiple terminal devices. As shown in Figure 15, it is a schematic diagram of the reader sending an MSG2 to the terminal device according to the embodiment of this application.

[0153] When an MSG2 carries multiple terminal identifiers or confirmation information from multiple terminals, as shown in Figure 16, which is a schematic diagram of the MSG2 responding to a terminal device according to an embodiment of this application, it can be done in at least one of the following ways:

[0154] In one possible implementation, each part of MSG2 corresponds to a response from a terminal device.

[0155] In another possible implementation, one part of MSG2 corresponds to the responses of multiple terminal devices. MSG2 can also adopt a combination of the two methods described above, and this application embodiment does not limit this approach.

[0156] Method 2: TDM.

[0157] Figure 17 shows a schematic diagram of MSG2 mode 2 provided in this application embodiment. There are multiple MSG2 resources. The reader sends MSG2 on multiple resources. The multiple resources are in different time units. The terminal device receives its own MSG2 on the corresponding resource.

[0158] Method 3: FDM.

[0159] For some terminal devices, MSG2 can be transmitted using FDM. Figure 18 shows a schematic diagram of MSG2 mode 3 provided in this embodiment. There are multiple MSG2 resources, and the reader transmits MSG2 on multiple resources. These multiple resources are located in different frequency domain units, and the terminal device receives its own MSG2 on the corresponding resource.

[0160] It should be noted that the transmission timing of MSG2 should fall within the range of [TD2R_min, TD2R_max], where TD2R_min represents the minimum time interval between the R2D signal and the previous D2D signal, and TD2R_max represents the maximum time interval between the R2D signal and the previous D2D signal. For the above methods, the protocol needs to specify the resource location of MSG2, including the start time of the terminal device receiving MSG2 and the resource size of MSG2.

[0161] The start time of MSG2 shall be determined using at least one of the following methods:

[0162] For method 1, different terminal devices begin receiving MSG2 at the same time unit.

[0163] For method 2, one MSG2 corresponds to one terminal device. Different MSG2s have different start times, and different terminal devices start receiving MSG2s at different time units; or, different terminal devices start receiving MSG2s at the same time unit, for example, these MSG2s are within a time window, and the terminal device receives MSG2s within that time window.

[0164] The reference point for the start time of MSG2 can be determined in several ways:

[0165] This reference point is the end time unit of the terminal device's own MSG1;

[0166] In MSG1 TDM mode, the reference point is the end time unit of the last resource among X MSG1 resources;

[0167] This reference point is the end time unit of Step A;

[0168] This reference point is the end time unit of other MSG2 resources, such as the end time unit of the previous MSG2 resource.

[0169] For example, Figure 19 is a schematic diagram with the end time unit of Step A as a reference point provided in an embodiment of this application.

[0170] The duration of MSG2 resources shall be determined using at least one of the following methods:

[0171] Predefined rules, for example, determined by TD2R_min and / or TD2R_max;

[0172] Instructions are given to the terminal device via Step A.

[0173] 5. MSG3 for AIoT systems.

[0174] MSG3 carries at least one of the following:

[0175] The terminal device identifier in MSG3 differs from that in MSG1. The terminal device identifier in MSG1 can be a temporary ID, while the terminal device identifier in MSG3 can be a permanent or long-term ID. The lengths of the terminal device identifiers in MSG1 and MSG3 also differ.

[0176] Energy status is used to indicate the energy status of terminal devices.

[0177] Other high-level information.

[0178] It should be noted that, similar to MSG1, MSG3 can also be transmitted using TDM and / or FDM. MSG3 resources can be obtained explicitly and / or implicitly, including:

[0179] MSG3 has the same resources or resource indexes as MSG1;

[0180] MSG3 has the same frequency domain resources or resource index as MSG1, while the time domain resources are indicated by MSG2.

[0181] The time-domain resources or resource index of MSG3 are the same as those of MSG1, while the frequency-domain resources are indicated by MSG2.

[0182] The time-domain and frequency-domain resources of MSG3 are indicated by MSG2.

[0183] The communication method provided in the embodiments of this application will be described below. First, Figure 20 is a schematic diagram of the communication system provided in the embodiments of this application.

[0184] As shown in Figure 20, the communication system includes a reader / writer and a terminal device.

[0185] In this embodiment of the application, the reader / writer is used to send a first message to the terminal device.

[0186] In this embodiment of the application, the terminal device is used to receive a first message from the reader and decode the first message according to a first rule.

[0187] The first message includes one or more of the following: a first paging message, an R2D signal, or a random access second message. The first message is generated by the reader / writer according to a first rule.

[0188] The functions of the reader and terminal device involved in the embodiments of this application can be implemented by the communication device 2100 in FIG21. FIG21 is a schematic diagram of the structure of the communication device 2100 provided in the embodiments of this application. The communication device 2100 includes one or more processors 2101, communication lines 2102, and at least one communication interface (FIG21 is only an example illustrating the inclusion of a communication interface 2104 and a processor 2101), and optionally may also include a memory 2103.

[0189] The processor 2101 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application.

[0190] The communication line 2102 may include a path for connecting different components.

[0191] The communication interface 2104 can be a transceiver module used to communicate with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (WLAN), etc. For example, the transceiver module can be a transceiver or a similar device. Optionally, the communication interface 2104 can also be a transceiver circuit located within the processor 2101, used to implement the processor's signal input and signal output.

[0192] The memory 2103 can be a device with storage function. For example, it can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions; random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions; it can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices; or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory can exist independently and be connected to the processor via communication line 2102. The memory can also be integrated with the processor.

[0193] The memory 2103 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 2101. The processor 2101 executes the computer execution instructions stored in the memory 2103, thereby implementing the communication method provided in the embodiments of this application.

[0194] Alternatively, in this embodiment of the application, the processor 2101 may execute the processing-related functions in the communication method provided in the following embodiments of the application, and the communication interface 2104 may be responsible for communicating with other devices or communication networks. This embodiment of the application does not specifically limit this.

[0195] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0196] In a specific implementation, as one example, processor 2101 may include one or more CPUs, such as CPU0 and CPU1 in FIG21.

[0197] In a specific implementation, as one embodiment, the communication device 2100 may include multiple processors, such as processors 2107 and 2101 in FIG. 21. Each of these processors may be a single-core processor or a multi-core processor. The processors here may include, but are not limited to, at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, etc., and various computing devices that run software. Each computing device may include one or more cores for executing software instructions to perform calculations or processing.

[0198] In a specific implementation, as one embodiment, the communication device 2100 may further include an output device 2105 and an input device 2106. The output device 2105 communicates with the processor 2101 and can display information in various ways. For example, the output device 2105 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 2106 communicates with the processor 2101 and can receive user input in various ways. For example, the input device 2106 may be a mouse, keyboard, touchscreen device, or sensing device, etc.

[0199] The aforementioned communication device 2100 may sometimes be referred to as a communication device, which can be a general-purpose device or a special-purpose device. For example, the communication device 2100 may be a desktop computer, a portable computer, a web server, a handheld computer (personal digital assistant, PDA), a mobile phone, a tablet computer, a wireless AIoT device, an embedded device, or a device with a similar structure to that in Figure 21. The embodiments of this application do not limit the type of communication device 2100.

[0200] Furthermore, the composition shown in Figure 21 does not constitute a limitation on the communication device. In addition to the components shown in Figure 21, the communication device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0201] It should be noted that in the following embodiments of this application, the message names, parameter names, or information names between network elements are just examples. Other names may also be used in other embodiments. The communication method provided in this application does not specifically limit these names.

[0202] It is understood that in the embodiments of this application, each network element can execute some or all of the steps in the embodiments of this application. These steps or operations are merely examples, and the embodiments of this application can also perform other operations or variations of various operations. Furthermore, the steps can be executed in different orders as presented in the embodiments of this application, and it is not necessary to execute all the operations in the embodiments of this application.

[0203] The communication method provided in the embodiments of this application will be described below with reference to Figures 22 to 26.

[0204] It should be noted that the embodiments of this application can be applied not only to AIoT devices, but also to other similar low-power devices, which will be collectively referred to as terminal devices below.

[0205] Figure 22 is a schematic diagram of an example of the communication method provided in this application embodiment. This method can be applied to the communication system shown in Figure 20, and is illustrated using the interaction between a reader and a terminal device as an example. Of course, the entity executing the reader's actions in this method can also be a device / module within the reader, such as a chip, processor, or processing module within the reader; similarly, the entity executing the terminal device's actions in this method can also be a device / module within the terminal device, such as a chip, processor, or processing module within the terminal device. This application embodiment does not specifically limit this. In this application embodiment, a single executing entity (e.g., the processing performed by the reader or terminal device) can also be divided into multiple executing entities, which can be logically and / or physically separated. For example, as shown in Figure 22, method 2200 includes at least one of the following steps:

[0206] S2210, the reader sends the first message to the terminal device. Correspondingly, the terminal device receives the first message from the reader.

[0207] In this embodiment, the first message is generated by the reader / writer according to a first rule. The first message includes one or more of the following: a first paging message, an R2D signal, a random access second message, or other messages sent by the reader / writer to the terminal device; this embodiment does not limit the specific message. The R2D signal may or may not be the first R2D signal.

[0208] Optionally, the first rule includes spread spectrum orthogonal frequency division multiplexing (DFT-s-OFDM) based on discrete Fourier transform, or the first rule may also include CP-OFDM, which is not limited in this embodiment of the application.

[0209] In this embodiment of the application, the first rule includes one or more of the following:

[0210] Generate a first time-domain OOK signal; perform an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal to obtain a first frequency-domain signal; map the first frequency-domain signal onto X subcarriers; perform an N-point Inverse Discrete Fourier Transform (IDFT) or Inverse Fast Fourier Transform (IFFT) to obtain the first time-domain signal; obtain the first message based on the first time-domain signal.

[0211] Each OFDM symbol includes M chips, and each chip can be sampled L times, corresponding to L sampling points. M, L, N', X, and N are positive integers greater than 1. The frequency domain resources corresponding to the X subcarriers are greater than or equal to B_tx,R2D, where B_tx,R2D is the downlink transmission bandwidth.

[0212] Optionally, after generating the first time-domain OOK signal, the amplitude or phase may be randomized. For example, the amplitude or phase may be randomized before or after the DFT transform. The randomization of the amplitude or phase may include randomization of the amplitude or phase of the frequency-domain signal or the time-domain signal, and is not limited here.

[0213] The communication method provided in this application embodiment further includes:

[0214] The first time-domain OOK signal is processed to generate a second time-domain OOK signal. The first processing includes one or more of the following: scrambling, spreading, or a first operation; wherein, performing an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal includes performing a Z-point DFT transform on each OFDM symbol of the second time-domain OOK signal.

[0215] In one possible implementation, the first time-domain OOK signal is subjected to a first processing, which includes: using a first sequence and the baseband sequence of the first time-domain OOK signal to perform a first processing to generate a second time-domain OOK signal;

[0216] In another possible implementation, the first time-domain OOK signal is subjected to a first processing, including: performing a first processing on a first sequence and a baseband sequence of the first time-domain OOK signal to generate a second sequence; performing a first processing on the second sequence and the baseband sequence to generate the second time-domain OOK signal; wherein, the type of the first sequence includes one or more of the following: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

[0217] It should be noted that when the first sequence is an all-1 sequence, it indicates that the baseband sequence is spread. When the second sequence is a ZC sequence, M sequence, machine-selected sequence, or Gold sequence, it indicates that the sequence that has been spread by the first sequence is scrambled.

[0218] In this embodiment of the application, the first operation may be, for example, generating a first time-domain OOK signal and then randomizing the frequency domain amplitude according to the amplitude-phase modulation method; or, for example, the first operation may be intermittent scrambling of the bits of the first time-domain OOK signal; or, for example, the first operation may be selecting different sequences and lengths according to the terminal device type and frame structure; or, the first operation may be selecting the scrambling sequence type and sequence length according to the mathematical relationship between the preceding and following bits of the bit to be transmitted.

[0219] In this embodiment, the type or length of the first sequence is determined based on the size of the Physical Resource Blocks (PRBs) corresponding to M or X subcarriers. For example, if M = 6 corresponds to 2 PRBs to 4 PRBs, then a ZC sequence is used with a length not less than the sampling point M*L or the sequence length of M or L.

[0220] In another possible implementation, the first time-domain OOK signal is subjected to a first processing, including: multiplying the baseband sequence of the first time-domain OOK signal with a preprocessed first matrix to generate a second time-domain signal.

[0221] The first matrix includes the following features: the amplitude and / or phase of the elements included in the first matrix increases; the amplitude and / or phase of the elements included in the first matrix decreases; the elements included in the first matrix are related to the level of the first time-domain OOK signal; or the size of the first matrix is ​​related to the number of symbols of the first time-domain OOK signal, and / or the number of sampling points, and / or the M value.

[0222] For example, ON can use any element from amplitude set 1 and phase set 1, and OFF can use any element from amplitude set 2 and phase set 2. This application does not limit this.

[0223] For example, when an OFDM symbol corresponds to 16 chips, the size of the first matrix is ​​16*1, 1*16, or 16*16.

[0224] In this embodiment of the application, the first matrix may also be called the preprocessing matrix, and the name is not limited in this embodiment of the application.

[0225] In this embodiment of the application, the frequency domain amplitude or phase can also be randomized during DFT or truncation processing. For example, a first sequence is used for scrambling in the above steps, and specific implementations can be found in the two possible implementations described above. Alternatively, any implementation method that randomizes the amplitude or phase can be used, which will not be elaborated further in this embodiment of the application.

[0226] For the above N', X, and M, they satisfy the following relationship:

[0227] In a possible implementation, N' is equal to X, and a specific M value can be used to generate a baseband OOK signal, where M is a value in a first set, and the first set satisfies one or more of the following:

[0228] Values in the first set are multiples of A. For example, A may be 4, and M may be 4, 8, 16, 24, etc.; or, for another example, A may be 8, and M may be 8, 16, 32, etc.; or A may also be another positive integer, which is not limited in the embodiments of the present application.

[0229] Values in the first set are values smaller than a first threshold, and the first threshold is a positive integer. For example, the first threshold is 16, and M may be 1, 2, 4, 8, 12, etc.

[0230] Alternatively, values in the first set are fixed values, and the fixed values are positive integers. For example, M may be 8, or 16, or 24.

[0231] In another possible implementation, N' is greater than X. For example, by truncating the length of N' to X, a specific M value can be used to generate a baseband OOK signal, where M is a value in a second set, and the second set satisfies one or more of the following:

[0232] Values in the second set are multiples of A. For example, A may be 4, and M may be 4, 8, 16, 24, etc.; or, for another example, A may be 8, and M may be 8, 16, 32, etc.; or A may also be another positive integer, which is not limited in the embodiments of the present application.

[0233] Values in the second set are values smaller than a first threshold, and the first threshold is a positive integer. For example, the first threshold is 16, and M may be 1, 2, 4, 8, 12, etc.

[0234] Values in the second set are fixed values, and the fixed values are positive integers. For example, M may be 8, or 16, or 24.

[0235] Alternatively, values in the second set are values greater than a second threshold, and the second threshold is a positive integer. For example, T=8, that is, due to the truncation operation, the M value can be specified to be greater than the second threshold.

[0236] Alternatively, as a possible implementation, N' is greater than X, and M is a value in a third set, where the third set is a subset of the second set. For example, only M values that are multiples of 4 and M<16 are used, for example, M=4 / 8 / 12 / 16; only M values that are multiples of 8 and M≤16 are used, for example, M=8 / 16; only M values with M<T are used, for example, T=8, then M values such as M=1, or 2, or 4 can be used; only a fixed M value is used, for example, M=6, or 12, or 16.

[0237] For N', M, L, N' and X satisfying the first relation, baseband scrambling is performed, and / or truncation is performed, where the length of the scrambling sequence is T, T is a positive integer, and N' = M * L; the first relation includes one or more of the following: N' is equal to X, or N' is greater than X.

[0238] For example, if N' = M*L = X, no baseband scrambling or truncation is performed; or, if N' = M*L > X, no baseband scrambling is performed, but truncation is performed; or, if N' = M*L*T = X, baseband scrambling is performed with a scrambling sequence length of T, and no truncation is performed; or, if N' = M*L*T > X, baseband scrambling is performed with a scrambling sequence length of T, and truncation is performed.

[0239] Regarding the mapping of the first frequency domain signal to X subcarriers as described above:

[0240] One possible implementation involves mapping the first frequency domain signal onto X subcarriers, including:

[0241] Mapping can begin from the middle position of B_tx,R2D; or from the smallest PRB position of B_tx,R2D; or from the largest PRB position of B_tx,R2D; or from the Nth PRB position of B_tx,R2D; the Bth PRB is associated with one or more of SFO, intermodulation interference, or harmonic interference.

[0242] In this case, the mapping method is chip-based mapping, and the mapped resources are continuous in both the time and frequency domains. Alternatively, for symbol-based mapping, the mapped resources can also be continuous in both the time and frequency domains.

[0243] Another possible implementation includes mapping the first frequency domain signal onto X subcarriers in the following ways:

[0244] Uniformly mapped to B_tx, R2D, with each adjacent input point having B time or frequency unit intervals; or, non-uniformly mapped to B_tx, R2D, with each adjacent input point having N1, N2, N3... time or frequency units, where N1>N2>N3, or N1 <N2<N3。

[0245] In this method, the mapping is chip-based, and the mapped resources are discontinuous in the time and frequency domains. This mapping method can also be called sparse mapping on the transmission bandwidth B_tx, R2D, which can avoid intermodulation interference. Alternatively, for symbol-based mapping, the mapped resources can also be discontinuous in the time and frequency domains, or a distributed mapping can be used.

[0246] In this embodiment of the application, obtaining a first message based on a first time-domain signal includes: adding a first prefix to the first time-domain signal to generate a second time-domain signal, and obtaining the first message based on the second time-domain signal.

[0247] The first prefix includes the complete first and second values. Optionally, the first value is high (ON) and the second value is low (OFF). Alternatively, the first value is low (OFF) and the second value is high (ON).

[0248] In this embodiment of the application, before adding a first prefix to the first time-domain signal, in order to ensure that the terminal device accurately detects the first message, a cyclic shift within the OFDM symbol can be performed on the OFDM symbol of the first time-domain signal. This cyclic shift satisfies:

[0249] The cyclic shift can start from the end of the first prefix, or if the first prefix is ​​an incomplete first and second value (i.e., the first prefix includes both the first and second values), the cyclic shift can start from the second value of the first prefix.

[0250] Cyclic shifting begins with an odd number of chips, using Manchester encoding. For example, when the first message undergoes Manchester encoding, cyclic shifting starting with an odd number of chips ensures the integrity of a single bit of information. For instance, if the OFDM symbol before the cyclic shift transmitted 6 chips (corresponding to ON-OFF-OFF-ON-ON-OFF, and bit information 010), then the cyclic shift would begin with the third chip (OFF-ON-ON-OFF-ON-OFF) or the fifth chip (ON-OFF-ON-OFF-OFF-ON) to guarantee information integrity.

[0251] The cyclic shift begins from any chip, where the encoding method is not Manchester encoding. For example, the starting position of the cyclic shift can be the second chip, a middle chip, or the last chip.

[0252] Alternatively, the position of the cyclic shift can be determined based on the length of the first prefix, where the cyclic shift position is either the start or end position of the chip. For example, to ensure there are no level spikes or dips within the length of the first prefix, the start position of the cyclic shift should be set at the start or end position of the chip within the OFDM symbol, ensuring that the level within the length of the first prefix is ​​OFF-ON or ON-OFF, i.e., a complete high and low level.

[0253] In this embodiment, when the OFDM symbol after cyclic shifting includes incomplete first and second values, to ensure the orthogonality of the subcarriers, there may be instances where the pattern of the first prefix after cyclic shifting is OFF-ON (ON-OFF) within the length of the first prefix, but the end position of the OFDM symbol after cyclic shifting is not OFF-ON (ON-OFF). In this case, redundant levels need to be added to ensure that the end position of the OFDM symbol is OFF-ON (ON-OFF). It should be specifically noted that OFF is the first value, such as 0; and ON is the second value, such as 1. Redundant levels can also be called redundant values ​​or redundant lengths, which are not limited in this embodiment. Adding redundant lengths requires ensuring that the levels of the last n chips are consistent or inconsistent with those of the chips within the length of the first prefix. Based on this, the communication method provided in this embodiment further includes:

[0254] Add a redundant length at the end of an incomplete OFDM symbol; wherein, the OFDM symbol after adding the redundant length includes complete first and second values, and the redundant length satisfies the following conditions: the length of the redundant length is less than the length of one chip; the redundant length is all first values, or, the redundant length is all second values, or, the redundant length is complete first and second values; the redundant length is determined according to SFO, or, the number of sampling points; the level corresponding to the redundant length is the same as or opposite to the level of the last chip before adding the redundant level; or, the level corresponding to the redundant length is the same as or opposite to the level of the first chip or the first prefix after the next OFDM symbol is cyclically shifted.

[0255] In this embodiment, to ensure inter-carrier orthogonality, when the last chip in an OFDM symbol of the first message is copied to the first prefix, the copying is considered to be either the last chip, or the last bit (which is two chips if Manchester encoded), or the last few chips. One embodiment is that if the last two chips in the OFDM symbol are ON-OFF, then the first prefix is ​​also ON-OFF; if the last two chips in the OFDM symbol are OFF-ON, then the first prefix is ​​also OFF-ON.

[0256] Therefore, in order to ensure that there are no level spikes or dips within the CP length, the protocol can predefine that the level values ​​of the first prefix and the last two chips of the OFDM symbol of the first time domain signal are the same (e.g., OFF-ON, or ON-OFF). Alternatively, the protocol can predefine the first prefix as a first value and a second value. In order to ensure the orthogonality between the start and end positions of the first prefix, a redundant length needs to be added to ensure that the end position of the OFDM symbol is OFF-ON (ON-OFF).

[0257] The addition of redundancy length primarily ensures that the voltage levels of the last n chips are consistent with those of the chips within the first prefix length. Therefore, the length of redundancy length is less than or equal to one chip length, or the redundancy length can be all ON, all OFF, ON-OFF, or OFF-ON.

[0258] In this embodiment of the application, in order to ensure that only transition edges appear at the beginning or end of the first prefix, and no transition edges appear during the first prefix, and in order to achieve the last chip of symbol n = the first chip of symbol n+1 = the last chip of symbol n+1, it is necessary to consider the case where the level of the last chip of symbol n+1 is not equal to that of the first chip. Therefore, before adding the first prefix to the first time-domain signal, the communication method provided in this embodiment of the application further includes:

[0259] The OFDM symbols of the first time-domain signal are cyclically shifted; the cyclic shift satisfies:

[0260] Cyclic shifting begins with an odd number of chips, using Manchester encoding. For example, when the first message undergoes Manchester encoding, cyclic shifting starting with an even number of chips ensures the integrity of a single bit of information detection. For instance, if the preceding OFDM symbol transmitted 6 chips (corresponding to ON-OFF-OFF-ON-ON-OFF, and bit information 010), the cyclic shift would begin with the third chip (OFF-ON-ON-OFF-ON-OFF) or the fifth chip (ON-OFF-ON-OFF-OFF-ON) to guarantee information integrity.

[0261] The cyclic shift begins from any chip, where the encoding method is not the Manchester encoding described above. For example, the starting position of the cyclic shift can be the second chip, a middle chip, or the last chip; this application embodiment does not limit this.

[0262] Perform a cyclic shift from the start or end position of any chip;

[0263] Alternatively, the cyclic shift can begin from the middle chip, where the first OFDM symbol comprises an odd number of chips.

[0264] Redundancy length can also be added to OFDM symbols. This redundancy length ensures that the voltage levels of the last n chips are consistent with those of the chips within the first prefix length. The redundancy length must satisfy the following conditions: its length is less than or equal to one chip length; and it can be all ON, all OFF, ON-OFF, or OFF-ON.

[0265] The redundancy length can take into account the effects of SFO (Site Optimization Forecast) and the number of sampling points. For example, if the redundancy length is 1 chip, the number of sampling points is affected by SFO, resulting in a decrease in the number of sampling points. Ultimately, the redundancy length can be set to less than 1 chip.

[0266] In one possible implementation, when an odd number of PRDCH chips are transmitted in the first OFDM symbol, while keeping the M value unchanged in the remaining OFDM symbols, the reader can add a redundant length of one chip in the first OFDM symbol, and the terminal device will actively discard the chip after recognizing it.

[0267] It should be noted that the above methods for adding a first prefix to the OFDM symbol of the first time-domain signal can form an independent scheme.

[0268] In this embodiment of the application, the first message may include a first synchronization signal. The description of the first synchronization signal can be found in the above-mentioned related technologies, and will not be repeated here.

[0269] In one possible implementation, the transition edge of the second sequence included in the first synchronization signal can be used by the terminal device to determine the chip length of the first message, wherein the second sequence includes a complete first value and a complete second value, for example, the second sequence can be OFF->ON, or the second sequence can be ON->OFF.

[0270] It should be noted that the transition edge can be understood through Figure 23, and the transition edge can also be called other names, which are not limited in this application embodiment.

[0271] Optionally, the first time length of two consecutive second sequences detected by the terminal device is used to determine that the chip length of the first message is half of the first time length. For example, if the first time length is T, the time interval between two consecutive ON-OFF or OFF-ON events detected by the terminal device is T, and the chip length is T / 2.

[0272] Alternatively, one possible implementation is to not specify the transition edge between two consecutive identical ON-OFF or OFF-ON, and the time interval between any two consecutive ON-OFF or OFF-ON detected by the terminal device is T, with a chip length of T / 2.

[0273] Figure 23 is a schematic diagram of the first synchronization signal after Manchester encoding provided in an embodiment of this application for calculating the chip length.

[0274] For example, in case (a) of Figure 23, the first synchronization signal is encoded using Manchester (one bit of information is encoded into two chips), and two consecutive identical bits (or ON-OFF-ON-OFF / OFF-ON-OFF-ON) are used to calculate the chip length. If the duration of two consecutive identical transition edges (ON->OFF or OFF->ON) is T, then the chip length = T / 2.

[0275] For example, in case (b) of Figure 23, the first synchronization signal is encoded by Manchester (1 bit of information is encoded into two chips), and two consecutive different bits (or ON-OFF-OFF-ON / OFF-ON-ON-OFF) are used to calculate the chip length, and the third bit is the same as the second bit. If the duration of two consecutive identical transition edges (ON->OFF or OFF->ON) is T, then chip duration = T / 3.

[0276] For example, as shown in case (c) of Figure 23, the first synchronization signal is encoded by Manchester (1 bit of information is encoded into two chips), and two consecutive different bits (or ON-OFF-OFF-ON / OFF-ON-ON-OFF) are used to calculate the chip to be transmitted to you for reading, and the third bit is different from the second bit. If the duration of two consecutive identical transition edges (ON->OFF or OFF->ON) is T, then the chip length = T / 4.

[0277] Alternatively, the terminal device may detect Y discontinuous second sequences to determine the chip length of a message, where Y is greater than or equal to 3. For example, with at most Y OFF->ON or ON->OFF transition edges (discontinuous second sequences), such as N=3 or N=4, the terminal device detects the first ON-OFF and the third ON-OFF in the first synchronization signal to obtain the chip length.

[0278] In one possible implementation of this application embodiment, the first synchronization signal includes a first prefix, which can be used by the terminal device to determine the chip length of the first message.

[0279] Optionally, the first prefix is ​​a single level, i.e., the first prefix is ​​a first value, or the first prefix is ​​a second value; when the first prefix is ​​considered, the first prefix and three chips of the first synchronization signal are used to determine the chip length of the first message; or, when the first prefix is ​​not considered, four chips greater than or equal to the first synchronization signal are used to determine the chip length of the first message.

[0280] Optionally, the first prefix may be multiple levels, i.e., the first prefix includes multiple first values ​​and second values; the length of the first prefix is ​​an integer multiple of the chip of the first synchronization signal, and the first prefix and at least two chips of the first synchronization signal are used to determine the chip length of the first message; or, the length of the first prefix is ​​a non-integer multiple of the chip of the first synchronization signal, and at least four chips of the first synchronization signal are used to determine the chip length of the first message.

[0281] Alternatively, in another possible implementation of this application, the first prefix can be used as a symbol for determining the chip length regardless of whether its length is greater or less than the chip length. For example, when the first prefix level is high, the sequence pattern of the first synchronization signal is ON(first prefix)+OFF(chip)+ON(chip)+OFF(chip)+..., then the terminal device can determine the chip length based on the first prefix and the first three chips.

[0282] As another possible implementation, the sequence pattern of the first synchronization signal is used to enable the terminal device to determine the chip length of the first message. The sequence pattern of the first synchronization signal includes at least one of the following: The sequence of the first synchronization signal sequentially includes a first value, a second value, and a third value, for example, ON-OFF-ON or OFF-ON-OFF. Alternatively, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the second value, for example, OFF-ON-ON, wherein this implementation corresponds to the case where the second value is OFF and the first value is ON. Alternatively, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the third value, for example, OFF-ON-ON, wherein this implementation corresponds to the case where the first value is OFF and the second value is ON. Alternatively, the first synchronization signal is a repetition of the above sequence, for example, ON-OFF-ON repeated twice is: ON-OFF-ON-ON-OFF-ON.

[0283] When determining the chip length using the sequence pattern of the first synchronization signal, it can be predefined that the terminal device detects at least two consecutive ON-OFF or OFF-ON signals to determine the chip length. Specifically, if the time interval between the terminal device detecting two consecutive ON-OFF or OFF-ON signals is T, then the chip length is T / 3.

[0284] S2220, the terminal device decodes the first message according to the first rule.

[0285] It should be added that if the start position of the SIP is not aligned with the start position of the OFDM symbol, and the M value is small (e.g., 4), the protocol specifies that SIP selects a single ON-OFF as the SIP pattern for transmission. If the start position of the SIP is aligned with the start position of the OFDM symbol, and the M value is relatively large (e.g., 16), the protocol specifies that SIP selects multiple ON-OFF as the SIP pattern for transmission.

[0286] The communication method provided in this application embodiment enables the reader to encode the first message according to the first rule, and then the terminal device to decode the received first message according to the first rule.

[0287] In this embodiment of the application, the first paging message can trigger multiple groups or multiple terminal devices. Specifically, the first paging message contains one or more identifiers (IDs) for triggering multiple groups or multiple terminal devices. For example, the first paging message contains one ID, which is used to indicate multiple terminal devices or a group of terminal devices; or, for another example, the first paging message contains multiple IDs, each ID being used to indicate multiple terminal devices or a group of terminal devices.

[0288] Figure 24 is a schematic diagram of triggering a terminal device to send a random access first message according to an embodiment of this application. As shown in Figure 24, the reader / writer indicates the resources for the random access first message in different ways.

[0289] In one possible implementation, the first paging message includes first indication information, which is used to indicate information for random access to the first message.

[0290] The information in the random access first message includes time-domain information of the random access first message resource set. This information may be the start time position of the random access first message resource set, or the index of the random access first message resource set, or other information, which is not limited in this embodiment. The random access first message resource set refers to the collective name of one or more resources for random access first message, and this name is not limited in this embodiment.

[0291] It should be noted that the starting time position of the first message resource set indicated by the aforementioned first indication information can be a time-domain offset of the starting time position of the first message resource set indicated by the first indication information relative to a reference point. That is, the terminal device can determine the starting time position of the first message resource set based on the first indication information. This application embodiment does not limit the specific indication method of the first indication information. The reference point can be the start or end time unit of the first paging message, or the start or end time unit of other R2D signals. The time unit can be a symbol, time slot, frame, subframe, etc., and this application embodiment does not limit it in this respect.

[0292] Optionally, the first paging message further includes second indication information, which is used to instruct the terminal device to receive or the reader to send the first R2D signal in the time domain, and the first R2D signal is used to trigger random access of the terminal device.

[0293] The time-domain information of the first R2D signal may be the start time position of the first R2D signal, the transmission time period of the first R2D signal, or the index information of the first R2D signal, or it may be other information. This application embodiment does not limit this.

[0294] It should be noted that the second indication information indicating the start time position of the first R2D signal can be the time-domain offset of the start time position of the first R2D signal relative to the reference point. That is, the terminal device can determine the start time position of the first R2D signal based on the second indication information. This application embodiment does not limit the specific indication method of the second indication information. The reference point can be the start or end time unit of the first paging message, or the start or end time unit of other R2D signals. The time unit can be a symbol, time slot, frame, subframe, etc., and this application embodiment does not limit it.

[0295] For example, taking the second indication information used to instruct the terminal device to receive the first R2D signal in the time domain as an example, after receiving the first paging message, the terminal device determines the timing for receiving the first R2D signal based on the second indication information in the first paging message. This first R2D signal is used to trigger random access. For example, if the transmission time of the first R2D signal indicated by the second indication information is the time of R2Dtrigger#2 in the figure, then the terminal device will continue to receive the first R2D signal at the time of R2D trigger#2 to further obtain the parameters of random access (e.g., the resource location information of the first random access message), and does not need to attempt to receive the R2D signal before R2D trigger#2.

[0296] Alternatively, the indication information (e.g., ID) in the first paging message can be associated with the time-domain information of the terminal device receiving the first R2D signal or the time-domain information of randomly accessing the first message resource set. For example, the ID in the first paging message is associated with the time-domain information of the terminal device associated with that ID receiving the first R2D signal or the time-domain information of randomly accessing the first message resource set. For instance, the ID in the first paging message is sequentially associated with the time-domain information of the first R2D signal or the time-domain information of randomly accessing the first message resource set. It should be understood that this method can be considered an implicit indication method.

[0297] It should be noted that in the first paging message, one ID can correspond to one first indication information or one second indication information, or multiple IDs can correspond to one first indication information or one second indication information, or one ID can correspond to multiple first indication information or multiple second indication information. Taking one ID corresponding to one first indication information or one second indication information as an example, the terminal device associated with this ID determines the time domain information for receiving the first R2D signal or the time domain information for randomly accessing the first message resource set based on the associated first indication information or second indication information.

[0298] In another possible implementation, after the first paging message, the communication method provided in this application embodiment includes at least one of the following steps:

[0299] S2230, the reader sends a first R2D signal to the terminal device. Correspondingly, the terminal device receives the first R2D signal from the reader.

[0300] In this embodiment of the application, the first R2D signal includes third indication information, which is used to trigger random access of the terminal device, that is, the terminal device determines whether to perform random access based on the third indication information.

[0301] S2240, the terminal device sends a random access first message to the reader / writer according to the third instruction information. Correspondingly, the reader / writer receives the random access first message from the terminal device.

[0302] The terminal device determines whether it will send a random access first message in this instance (i.e., after the first R2D signal) based on the third indication information in the first R2D signal. It should be noted that in this implementation, the terminal device attempts to receive multiple R2D signals.

[0303] Optionally, the third indication information can be expressed as present / absent (i.e., whether the first R2D signal carries the third indication information), or the third indication information can indicate different values, such as bit 0 or bit 1.

[0304] For example, if the first R2D signal carries third indication information, the terminal device will select a random access first message resource from the current random access first message resource set to send the random access first message. Conversely, if the third indication information indicates bit 0, the terminal device will select a random access first message resource from the current random access first message resource set to send the random access first message.

[0305] Furthermore, the third instruction information instructs the terminal device to perform random access in this instance (i.e., after the first R2D signal), and the terminal device can continue to obtain random access parameters through the first R2D signal. Otherwise, the terminal device will not send the first random access message and will continue to receive the first R2D signal.

[0306] The third indication information can be active, non-active, first flag, second flag, 0, 1, resource reuse mode (TDM or FDM), etc., and this application embodiment does not limit it.

[0307] In another possible implementation, after the first paging message, the communication method provided in this application embodiment includes at least one of the following steps:

[0308] S2250, the reader sends a first R2D signal to the terminal device. Correspondingly, the terminal device receives the first R2D signal from the reader.

[0309] In this embodiment of the application, the first R2D signal includes fourth indication information, which is used to indicate the time domain information of the terminal device receiving or the reader sending the second R2D signal. The second R2D signal is used to trigger random access of the terminal device.

[0310] S2260, the terminal device determines the time domain information of the second R2D signal based on the fourth instruction information.

[0311] Specifically, after receiving the first paging message, the terminal device receives the first R2D signal (e.g., R2D trigger#1). The fourth indication information in the first R2D signal indicates the time domain information of the second R2D signal (e.g., R2D trigger#x) to the terminal device. The terminal device will continue to receive R2D signals at the time of R2D trigger#x to further obtain the parameters of random access (e.g., the resource location information of the first random access message). Before R2D trigger#x, there is no need to attempt to receive R2D signals.

[0312] Alternatively, as a possible implementation, a time offset can be defined for the R2D signal relative to the preceding random access first message resource set or resource. The terminal device receives the R2D signal after this offset.

[0313] Taking Figure 24 as an example, the terminal device can receive R2D trigger#2 after the first random access first message resource. The terminal device will further obtain the parameters of random access (e.g., the resource location information of the random access first message) from R2D trigger#2. Specifically, the time offset can be: the offset between the R2D signal and the start or end position of its previous random access first message resource set, or the offset between the R2D signal and the start or end position of its most recent random access first message resource, or the offset between the R2D signal and the start or end position of the first random access first message resource in its previous random access first message resource set. This time offset is greater than or equal to the minimum time interval (TR2Dmin) between adjacent R2D signals and D2R signals, which is not limited in this embodiment.

[0314] It should be noted that the communication methods shown in Figure 24 can form independent schemes.

[0315] Optionally, the communication method provided in this application embodiment further includes:

[0316] S2270, the terminal device sends a first D2R signal to the reader / writer. Correspondingly, the reader / writer receives the first D2R signal from the terminal device.

[0317] In this embodiment of the application, the first D2R signal includes a random access first message and / or a random access third message.

[0318] In this embodiment, the first D2R signal can be an M-sequence or a Gray sequence, which will be described in detail below.

[0319] For an M-sequence, the order of the generator polynomial or primitive polynomial P(x) of the M-sequence is n. The maximum length of the M-sequence is related to the following factors:

[0320] The length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal. For example, the maximum length of the M-sequence (2^n-1) is less than or equal to the length of at least one first D2R preamble.

[0321] Alternatively, the length of the truncated or weighted M-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal. It should be noted that this assumes the correlation of the sequence can still be guaranteed after truncation. It should also be noted that this factor applies to terminal devices of type 2a or 2b, or to terminal devices of type 1, 2a, or 2b.

[0322] The first guide can be a preamble, a postamble, or a midamble.

[0323] In this embodiment of the application, the initial sequences of the M sequences included in the first D2R signal may be the same or different, and may include at least one of the following:

[0324] A sequence that is not all zeros, a sequence of all ones, a sequence of cyclic coded bits 0 and 1 ([1,0,1,0,1,0...1,0]), or a sequence of cyclic coded bits 0 and 1 ([0,1,0,1,0,1...0,1]).

[0325] In this embodiment of the application, the feedback value corresponding to the M sequence included in the first D2R signal is calculated by: XOR, OR, or multiplication.

[0326] In this embodiment of the application, the shift mechanism corresponding to the M sequence included in the first D2R signal includes:

[0327] Shift the entire value in the register to the right by N bits (for example, N = 1...L-1, where L is the sequence length, L = 2^n-1), and output the value from the leftmost position.

[0328] Alternatively, shift the entire value in the register to the left by N bits (e.g., N = 1...L-1, where L is the sequence length, L = 2^n-1), and output the value from the rightmost position.

[0329] The aforementioned N value is related to D2R TBS, or to the first D2R guide code.

[0330] In this embodiment of the application, the modulation mechanism corresponding to the M sequence includes: modulation after cyclic shift.

[0331] The modulation includes BPSK modulation, for example, mapping a binary sequence to {1} and {-1}, such as sequence element 1 corresponding to modulation bit {1} and sequence element {0} corresponding to bit {-1}; or, the modulation includes OOK modulation, for example, mapping a binary sequence to {1} and {-1}, such as sequence element 1 corresponding to modulation bit {1} and sequence element {0} corresponding to bit {0}.

[0332] In this embodiment of the application, the M sequence included in the first D2R signal can be predefined. For example, the reader can pre-configure a set of M sequences. The reader can instruct the terminal device to use the sequence according to the capabilities of the terminal device and the configured D2R resources. For example, when n=3, the M sequence of the terminal device is 0011011.

[0333] It should be noted that the aforementioned content related to the M sequence can be extended to the Gold sequence, and this application embodiment does not limit this. It should also be noted that when generating the Gold sequence, the operations on the two M sequences include bitwise XOR, bitwise XOR, bitwise multiplication, etc.

[0334] For a Gray sequence, generate Golay complementary pairs or binary sequences of length N that satisfy one of the following requirements:

[0335] The sum of the autocorrelation functions corresponding to the two sequences is 0 under all non-zero delays;

[0336] The recursive formula satisfies: ak+1=[ak,bk], bk+1=[ak,-bk], where k represents the number of recursions.

[0337] In this embodiment of the application, the length of the Gray sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal. For example, the maximum length of the Gray sequence (2^k) is less than or equal to the length of the first preamble of at least one D2R signal.

[0338] Regarding the number of recursions for the Gray sequence, in one possible implementation, the number of recursions is indicated by the reader to the terminal device; in another possible implementation, the number of recursions for the Gray sequence is determined by the terminal device based on a first factor.

[0339] The first factor includes: the size of the TBS, the resource size of the first preamble of the first D2R signal configured by the reader, or the frame structure configured by the reader.

[0340] In this embodiment of the application, the modulation mechanism corresponding to the Gray sequence included in the first D2R signal includes: modulation after cyclic shift.

[0341] The modulation includes BPSK modulation, for example, mapping a binary sequence to {1} and {-1}, where sequence element 1 corresponds to modulation bit {1} and sequence element {0} corresponds to bit {-1}; or, the modulation includes OOK modulation, mapping a binary sequence to {1} and {-1}, where sequence element 1 corresponds to modulation bit {1} and sequence element {0} corresponds to bit {0}.

[0342] For the two sequences mentioned above, in one possible implementation, the reader can indicate the type of the sequence to the terminal device. Optionally, the communication method provided in this application embodiment further includes:

[0343] The reader sends a fifth instruction message to the terminal device. Correspondingly, the terminal device receives the fifth instruction message from the reader.

[0344] In this embodiment of the application, the fifth indication information is used to indicate the type of sequence included in the first D2R signal, and the type of sequence includes m-sequence or Gray sequence.

[0345] In another possible implementation, the type of sequence is determined by the reader based on the frame structure of the first D2R signal and / or the purpose of the first D2R signal;

[0346] The first D2R signal is used for SFO estimation, and the sequence type is m-sequence; the first D2R signal is used for channel estimation, and the sequence type is m-sequence or Gray sequence; the first D2R signal is used for interference estimation, and the sequence type is Gray sequence.

[0347] Alternatively, in another possible implementation, the type of the sequence is determined by the reader based on the size of TBS; where TBS is less than or equal to N, the type of the sequence is an m-sequence; TBS is greater than N, the type of the sequence is a Gray sequence; or, TBS is greater than N, the type of the sequence is an m-sequence; TBS is less than or equal to N, the type of the sequence is a Gray sequence.

[0348] It should be noted that, in the embodiments of this application, the method of using Gray sequence or m sequence to construct the first D2R signal can form a separate scheme.

[0349] In this embodiment of the application, as shown in FIG25, the preamble is located at the very beginning of the D2R signal, and the intermediate preamble can be an intermediate preamble between different first uplink channels (also referred to as PDRCH), or an intermediate preamble between two adjacent segments of a first uplink channel. Furthermore, the intermediate preamble can also be placed at the end of the first uplink channel to indicate the end of the PDRCH, as shown in position 3 in FIG2.

[0350] The D2R intermediate preamble has different functions when located at different positions in the first uplink channel, and its corresponding sequence type can also be different.

[0351] Optionally, the intermediate guide is located in the middle of the first uplink channel. The intermediate guide is used for SFO estimation or channel estimation. The sequence of the intermediate guide is an m-sequence or a fixed binary sequence.

[0352] Optionally, the intermediate guide is located in the middle of the first uplink channel. The intermediate guide is used for interference estimation. The sequence of the intermediate guide is a Gray sequence, an m-sequence, or a fixed binary sequence.

[0353] Optionally, the intermediate guide is located at the end of the first uplink channel. The intermediate guide is used for SFO estimation or channel estimation. The sequence of the intermediate guide is an m-sequence, or the sequence of the intermediate guide is a fixed binary sequence.

[0354] Optionally, the intermediate guide is located at the end of the first uplink channel. The intermediate guide is used to indicate the end of the first uplink channel. The sequence of the intermediate guide is an m-sequence, or a Gray sequence, or a fixed binary sequence.

[0355] The fixed binary sequence includes one or more of the following: a sequence of all 1s, a sequence of all 0s, or a fixed binary sequence including at least F 1s, where F is greater than or equal to half the sequence length of the intermediate preamble at the end position of the first uplink channel, and F is a positive integer.

[0356] In this embodiment, the intermediate preamble at the end of the first uplink channel satisfies one or more of the following: the intermediate preamble at the end of the first uplink channel is separated from the previous intermediate preamble by M time-domain units. This avoids excessively dense intermediate preambles that would consume too much D2R resource. The time-domain units include bits, symbols, chips, etc., which are not limited in this embodiment. Alternatively, the intermediate preamble at the end of the first uplink channel can be used to indicate the end of data transmission on the first uplink channel. For example, if the data reported by the terminal device is less than the number of resources configured for the first uplink channel, this means that the terminal device may have finished transmitting the required data ahead of schedule. In this case, there is a certain time-domain resource gap between the D2R intermediate preamble (indicated by R2D control information) at the end of the first uplink channel and the actual end of the D2R transmission. Therefore, in one possible implementation, it can be predefined that if the data sent by the terminal device only occupies a small portion of the configured first uplink channel resources, the terminal device, after sending the data, actively sends a predefined D2R intermediate guide at the end position of the first uplink channel to indicate the end position of the first uplink channel to the reader. This predefined D2R intermediate guide can include a sequence of all 1s or all 0s of length H, where H is a positive integer.

[0357] In one possible implementation of this application, the length of the intermediate preamble at the end position of the first uplink channel and / or the sequence type are indicated by the reader to the terminal device. For example, the L1 information of R2D indicates the length of the D2R intermediate preamble, the sequence type, etc. at the end position of the first uplink channel, and this indication method can be considered as an explicit indication method.

[0358] In another possible implementation of the embodiments of the present application, the length and / or sequence type of the mid-amble at the end position of the first uplink channel is determined by the terminal device according to a predefined rule. For example, the frame structure of the D2R signal is preamble + first uplink channel + mid-amble. When TBS < K, the terminal device sends the D2R signal through the frame structure of preamble + first uplink channel + mid-amble; or, for another example, when the data to be transmitted by the terminal device is less than the configured time-domain resource of the first uplink channel, the terminal device sends the D2R signal through the frame structure of preamble + first uplink channel + mid-amble. This method can be considered as an implicit or predefined indication method. Alternatively, the terminal device may also determine the length or sequence type of the mid-amble at the end position of the first uplink channel according to other rules, which is not limited in the embodiments of the present application.

[0359] It should be noted that the method for indicating the end position of the first uplink channel by using the mid-amble can form an independent solution.

[0360] Optionally, in the embodiments of the present application, it needs to be supplemented that the configuration of the frequency-domain resource of the D2R signal is related to one or more of the following factors: maximum D2R transmission bandwidth, maximum repetition factor of Manchester encoding of the D2R signal, size of guard band between adjacent D2R signals, or harmonic components.

[0361] Optionally, the maximum repetition factor of the Manchester encoding of the D2R signal refers to the number of different ON-OFF / FF-ON within the same time period. For example, when the number of ON-OFF / FF-ON is 2 or 4 within the same time period, the maximum repetition factor is 2 or 4; the harmonic component is a harmonic component generated when the terminal device generates the D2R signal according to the carrier signal CW and R2D indication information, including third-order harmonic components and fifth-order harmonic components.

[0362] Wherein, the configuration of the frequency-domain resource of the D2R signal may also be referred to as the configuration of small frequency offset, or may have other names, which is not limited in the embodiments of the present application.

[0363] Exemplarily, the maximum D2R transmission bandwidth may also be occupied bandwidth, or may have other descriptions, which is not limited in the embodiments of the present application. For example, the maximum D2R transmission bandwidth may be 180 KHz or an integer multiple thereof, and the maximum value of the small frequency offset does not exceed the maximum D2R transmission bandwidth, i.e., the occupied bandwidth; or the maximum value of the small frequency offset does not exceed half of the maximum D2R transmission bandwidth, i.e., the occupied bandwidth.

[0364] Exemplarily, the guard band between adjacent D2R signals is used to avoid the influence of SFO and the influence of harmonic components, for example, the small frequency offset is not configured at the position of the third-order harmonic.

[0365] In one possible implementation, the small frequency offset can be an integer multiple of SCS. For example, the small frequency offset can be 2 times SCS, or 3 times SCS, or 4 times SCS, or other multiples. This application does not limit this.

[0366] It should be noted that the configuration methods for small frequency offsets can be combined into independent solutions.

[0367] This application also provides a scheme for adding Cyclic Redundancy Check (CRC) to the D2R signal in the terminal device. Accordingly, the reader / writer can also determine the length of the CRC of the D2R signal according to certain rules and then perform CRC verification.

[0368] In this embodiment of the application, the terminal device can add a CRC to the D2R signal between adjacent first preambles, wherein the length of the CRC can be 0 bits, or the length of the CRC can be 6 bits, or the length of the CRC can be 16 bits.

[0369] Optionally, the number of information bits of the D2R signal between adjacent first preambles may be the same or different, and this application embodiment does not limit this.

[0370] The number of information bits depends on the position of the intermediate preamble. The terminal device determines the CRC length of the D2R signal segment and adds CRC based on the number of information bits of the D2R signal between adjacent first preambles.

[0371] For example, if the number of information bits in the D2R signal between adjacent first preambles is less than or equal to Y bits, then the CRC length of the D2R signal segment is 0 bits; as another example, if the number of information bits in the D2R signal between adjacent first preambles is greater than Y bits and less than or equal to X bits, then the CRC length of the D2R signal segment is 6 bits; and as yet another example, if the number of information bits in the D2R signal between adjacent first preambles is greater than X bits, then the CRC length of the D2R signal segment is 16 bits.

[0372] In this embodiment of the application, the D2R signal between adjacent first precodes includes at least one of the following cases:

[0373] D2R signal between adjacent preamble and intermediate preamble; D2R signal between adjacent intermediate preambles; D2R signal between adjacent intermediate preambles and postambles.

[0374] It should be noted that the intermediate preamble can also be located at the end of the first uplink channel.

[0375] Optionally, in one possible implementation, the communication method provided in this application embodiment further includes:

[0376] S2280, the terminal device determines the CRC length of the D2R signal between adjacent first preambles based on the number of information bits of the D2R signal between adjacent first preambles.

[0377] In another possible implementation, the terminal device can determine the CRC length of the segmented D2R signal of the first uplink channel based on the total number of information bits in the first uplink channel. That is, the first uplink channel can be divided into multiple segments, and each segment of information bits is called a segmented D2R signal. The number of information bits in each segmented D2R signal can be the same or different.

[0378] For example, if the total number of information bits in the first uplink channel exceeds the first threshold Q, the terminal device can segment the total number of information bits in the first uplink channel and add CRC to the segmented D2R signals respectively.

[0379] In one possible implementation, when The value is an integer, and the number of D2R signal information bits in each segment after the first uplink channel segmentation is M.

[0380] In another possible implementation, when The number of information bits is not an integer. The number of information bits of the D2R signal in at least one segment after the first uplink channel segmentation is less than M, and the number of information bits of the D2R signal in the remaining segments is M.

[0381] For example, taking the maximum number of bits M of a segmented D2R signal as an example, the number of segments in the first uplink channel can be... in, This indicates rounding up to the nearest integer.

[0382] if If the value is divisible, then the number of information bits in each segment of the D2R signal is M. The terminal device determines the CRC length of the D2R signal segment and adds CRC based on the value of M.

[0383] For example, if M is less than or equal to Y bits, the CRC length of the D2R signal segment is 0 bits; if M is greater than Y bits and less than or equal to X bits, the CRC length of the D2R signal segment is 6 bits; and if M is greater than X bits, the CRC length of the D2R signal segment is 16 bits.

[0384] if If the number of information bits is not divisible by M, then at least one segment of the D2R signal has less than M information bits, while the other segments of the D2R signal have M information bits.

[0385] For example, if one segment of the D2R signal has M1 information bits (M1 is less than M), and other segments of the D2R signal have M information bits, the terminal device determines the CRC length of each segment of the D2R signal and adds a CRC based on the number of information bits (M1 or M). Segments with fewer than M bits can be placed at the beginning or end of the first uplink channel.

[0386] Optionally, Q is predefined in the protocol; alternatively, Q is indicated by the reader to the terminal device, and this embodiment of the application does not limit this.

[0387] It should be noted that the above-mentioned schemes for adding cyclic redundancy check (CRC) to the D2R signal can form an independent scheme.

[0388] Optionally, embodiments of this application also provide a scheme for determining the frequency domain resources of a random access third message, as shown in Figure 26.

[0389] In one possible implementation of this application, the frequency domain position of the random access first message is the same as one of the frequency domain positions of the random access third message. The frequency domain position may or may not include a guard bandwidth. The size of the guard bandwidth may be related to the size of the SFO (Signal Default Frequency). For example, the guard bandwidth may include the frequency domain offset caused by the SFO; this invention does not limit this.

[0390] The first random access message can use TDM, and the third random access message can use FDM. Different terminal devices can send the third random access message at different frequency domain positions.

[0391] Optionally, the frequency domain position of the random access third message can be predefined, or the reader / writer can indicate to the terminal device that the frequency domain position of the random access first message is the same as that of the random access first message. As shown in Figure 26 (taking a single sideband as an example), the frequency domain resource position of the random access third message is the same as that of the random access first message. It can be the lowest frequency domain position, the highest frequency domain position, or an intermediate frequency domain position that is the same as the frequency domain resource of the random access first message, or the Lth frequency domain resource position of the random access third message is the same as the frequency domain resource of the random access first message. This application embodiment does not limit this.

[0392] Optionally, the frequency domain range of a random access third message can be predefined, or the reader can indicate to the terminal device the frequency domain location of the random access first message. Due to factors such as SFO, the actual transmission location of the random access third message may be offset; therefore, the frequency domain range of a random access third message is greater than or equal to the resource size of the random access third message. The frequency domain range of the random access third message may include the resource size for transmitting the random access third message and the protection bandwidth.

[0393] In another possible implementation of this application embodiment, the frequency domain position of the random access third message can be indicated by the random access second message, and the frequency domain position may or may not include the guard bandwidth. That is, the communication method provided in this application embodiment further includes:

[0394] The reader sends a second random access message to the terminal device. Correspondingly, the terminal device receives the second random access message from the reader.

[0395] In this embodiment of the application, the second random access message is used to indicate the frequency domain offset of the frequency domain position of the third random access message relative to the frequency domain position of the first random access message.

[0396] The frequency domain offset may include the frequency domain offset caused by the SFO. The guard bandwidth may include the frequency domain offset caused by the SFO. In one possible implementation, the reader can estimate the SFO of the random access third message based on the SFO of the random access first message.

[0397] It should be noted that the two possible implementation methods mentioned above can also be combined. For example, the protocol predefines or the reader indicates that the frequency domain position of one of the random access third messages is the same as the frequency domain position of the random access first message. The frequency domain position of the resource in the random access third message is used as a reference point, and the random access second message indicates the offset of the frequency domain position of other random access third messages relative to the reference point.

[0398] It should be noted that the methods described above for determining the frequency domain resources for random access third messages can form an independent scheme.

[0399] It should be noted that the aforementioned random access first message can be MSG1 as described in the related technologies, or MSGA as described in the related technologies, or other names. This application embodiment does not limit this.

[0400] It should be noted that the aforementioned random access second message may also be MSG2 as described in the related art, or MSGB as described in the related art, or other names, and the embodiments of this application do not limit this.

[0401] It should be noted that the aforementioned random access third message can be MSG3 as described in related technologies, or it can be other names, and this application embodiment does not limit it in this regard.

[0402] The above mainly describes the solutions provided by the embodiments of this application from the perspective of the interaction between the reader / writer and the terminal device. Correspondingly, the embodiments of this application also provide a communication device for implementing the various methods described above. This communication device can be the reader / writer in the above method embodiments, or a device containing the reader / writer, or a component usable in the reader / writer; or, this communication device can be the terminal device in the above method embodiments, or a device containing the terminal device, or a component usable in the terminal device. It is understood that, in order to achieve the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0403] For example, Figure 27 is a schematic diagram of a communication device provided in an embodiment of this application, wherein the communication device includes a transceiver module 2710 and a processing module 2720. The transceiver module 2710, also known as a transceiver unit, is used to implement the transceiver function, and may be a transceiver circuit, transceiver, transceiver device, or communication interface.

[0404] Taking the communication device as an example, which is the reader / writer in the above method embodiment (which may be the reader / writer chip, the reader / writer module, or an internal device of the reader / writer):

[0405] In this embodiment of the application, the processing module is used to determine the first message.

[0406] In this embodiment of the application, the transceiver module is used to send a first message, which includes one or more of the following: a first paging message, an R2D signal, or a randomly accessed second message; wherein the first message is generated by the communication device according to a first rule.

[0407] In one possible implementation of this application, the first rule includes spread spectrum orthogonal frequency division multiplexing (DFT-s-OFDM) based on discrete Fourier transform.

[0408] In one possible implementation of this application, the first rule includes one or more of the following: generating a first time-domain binary on / off keying (OOK) signal; performing an N'-point discrete Fourier transform (DFT) on each OFDM symbol of the first time-domain OOK signal to obtain a first frequency-domain signal; mapping the first frequency-domain signal onto X subcarriers; performing an N-point inverse discrete Fourier transform (IDFT) or inverse fast Fourier transform (IFFT) to obtain the first time-domain signal; and obtaining the first message based on the first time-domain signal. Each OFDM symbol includes M chips, each chip consists of L sampling points, and M, L, N', X, and N are positive integers greater than 1. The frequency-domain resources corresponding to the X subcarriers are greater than or equal to B_tx,R2D, where B_tx,R2D is the downlink transmission bandwidth.

[0409] In one possible implementation of this application embodiment, after generating the first time-domain OOK signal, the method further includes: performing a first processing on the first time-domain OOK signal to generate a second time-domain OOK signal, wherein the first processing includes one or more of the following: scrambling, spreading, or a first operation; wherein performing an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal includes: performing a Z-point DFT transform on each OFDM symbol of the second time-domain OOK signal.

[0410] In one possible implementation of this application, the first processing of the first time-domain OOK signal includes: using a first sequence and the baseband sequence of the first time-domain OOK signal to perform the first processing to generate a second time-domain OOK signal; wherein, the type of the first sequence includes one or more of the following: ZC sequence, M sequence, machine-selected sequence, or Gold sequence.

[0411] In one possible implementation of this application, the first processing of the first time-domain OOK signal includes: performing the first processing on a first sequence and a baseband sequence of the first time-domain OOK signal to generate a second sequence; performing the first processing on the second sequence and the baseband sequence to generate the second time-domain OOK signal; wherein the type of the first sequence includes one or more of the following: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

[0412] In one possible implementation of this application, the type or length of the first sequence is determined based on the size of the physical resource block (PRB) corresponding to the M or X subcarriers.

[0413] In one possible implementation of this application, the first processing of the first time-domain OOK signal includes: multiplying the baseband sequence of the first time-domain OOK signal with a first matrix to generate the second time-domain signal; wherein the first matrix includes one or more of the following features: the amplitude and / or phase of the elements included in the first matrix increases, the amplitude and / or phase of the elements included in the first matrix decreases, the elements included in the first matrix are related to the level of the first time-domain OOK signal, or the size of the first matrix is ​​related to the number of symbols, and / or the number of sampling points, and / or the M value of the first time-domain OOK signal.

[0414] In one possible implementation of this application, N' is equal to X, and M is a value in a first set, wherein the first set satisfies one or more of the following: the value in the first set is a multiple of A; the value in the first set is less than a first threshold, wherein the first threshold is a positive integer; or, the value in the first set is a fixed value, wherein the fixed value is a positive integer.

[0415] In one possible implementation of this application embodiment, N' is greater than X, and M is a value in a second set, the second set satisfying one or more of the following: the value in the second set is a multiple of A; the value in the second set is less than a first threshold, the first threshold being a positive integer; the value in the second set is a fixed value, the fixed value being a positive integer; or, the value in the second set is greater than a second threshold, the second threshold being a positive integer.

[0416] In one possible implementation of this application embodiment, N' is greater than X, and M is a value in a third set, wherein the third set is a subset of the second set.

[0417] In one possible implementation of this application, A includes one or more of the following: 4, or 8.

[0418] In one possible implementation of this application, N' and X satisfy a first relationship, baseband scrambling is performed, and / or a truncation operation is performed, wherein the length of the scrambling sequence is T, T is a positive integer, and N' = M*L; the first relationship includes one or more of the following: N' is equal to X, or N' is greater than X.

[0419] In a possible implementation manner of the embodiment of the present application, the mapping mode for mapping the first frequency-domain signal onto X subcarriers comprises: starting mapping from a middle position of said B_tx,R2D; starting mapping from a minimum PRB position of said B_tx,R2D; or starting mapping from a maximum PRB position of said B_tx,R2D; or starting mapping from an N-th PRB position of said B_tx,R2D; said B-th PRB is related to one or more of SFO, intermodulation interference or harmonic interference. Wherein, said mapping mode is chip-based mapping, and mapped resources are continuous in time domain and frequency domain.

[0420] In a possible implementation manner of the embodiment of the present application, the mapping mode for mapping the first frequency-domain signal onto X subcarriers comprises: uniformly mapping to said B_tx,R2D, with each adjacent input point having an interval of B time units or frequency units; or non-uniformly mapping to said B_tx,R2D, with each adjacent input point having N1, N2, N3... time units or frequency units, where N1>N2>N3, or N1<N2<N3; wherein, said mapping mode is chip-based mapping, and mapped resources are discontinuous in time domain and frequency domain.

[0421] In a possible implementation manner of the embodiment of the present application, said obtaining the first message based on the first time-domain signal comprises: adding a first prefix to the first time-domain signal to generate a second time-domain signal, and obtaining the first message based on the second time-domain signal; wherein the first prefix comprises a complete first value and a complete second value, the first value is a high level and the second value is a low level, or the first value is a low level and the second value is a high level.

[0422] In a possible implementation manner of the embodiment of the present application, before adding the first prefix to the first time-domain signal, the method further comprises: performing cyclic shift on an OFDM symbol of the first time-domain signal; said cyclic shift satisfies: performing the cyclic shift starting from an odd number of chips, wherein the coding mode is Manchester coding; performing the cyclic shift starting from any chip, wherein the coding mode is non-Manchester coding; or determining a position of the cyclic shift according to a length of the first prefix, wherein the position of the cyclic shift is a start position or an end position of a chip.

[0423] In one possible implementation of this application embodiment, when the OFDM symbol after cyclic shift includes incomplete first and second values, the method further includes: adding a redundant length to the incomplete OFDM symbol at its end position; wherein, the OFDM symbol after adding the redundant length includes complete first and second values, and the redundant length satisfies: the length of the redundant length is less than one chip length; the redundant length is all first values, or, the redundant length is all second values, or, the redundant length is complete first and second values; the redundant length is determined according to SFO, or, the number of sampling points; the level corresponding to the redundant length is the same as or opposite to the level of the last chip before adding the redundant length; or, the level corresponding to the redundant length is the same as or opposite to the level of the first chip or the first prefix after the next OFDM symbol cyclic shift.

[0424] In one possible implementation of this application embodiment, the protocol predefines the first prefix to be the same as the level value of the last two chips of the OFDM symbol of the first time domain signal, or the protocol predefines the first prefix to be the first value and the second value.

[0425] In one possible implementation of this application, before adding the first prefix to the first time-domain signal, the method further includes: cyclically shifting the OFDM symbols of the first time-domain signal; the cyclic shift satisfying the following conditions: starting the cyclic shift from an odd number of chips, wherein the encoding method is Manchester encoding; starting the cyclic shift from any chip, wherein the encoding method is not Manchester encoding; starting the cyclic shift from the start or end position of any chip; or starting the cyclic shift from an intermediate chip, wherein the first OFDM symbol comprises an odd number of chips.

[0426] In one possible implementation of this application, the first message includes a first synchronization signal, and the transition edge of the second sequence included in the first synchronization signal is used by the terminal device to determine the chip length of the first message. The second sequence includes a complete first value and a complete second value.

[0427] In one possible implementation of this application embodiment, the first time length of two consecutive second sequences detected by the terminal device is used to determine that the chip length of the first message is half of the first time length; or, the terminal device detects Y second sequences non-continuously to determine the chip length of the first message, wherein Y is greater than or equal to 3.

[0428] In one possible implementation of this application, the first message includes a first synchronization signal, the first synchronization signal includes a first prefix, and the first prefix is ​​used by the terminal device to determine the chip length of the first message.

[0429] In one possible implementation of this application, the first prefix is ​​the first value, or the first prefix is ​​the second value; the first prefix and three chips of the first synchronization signal are used to determine the chip length of the first message; or, four chips greater than or equal to the first synchronization signal are used to determine the chip length of the first message.

[0430] In one possible implementation of this application, the first prefix includes multiple first values ​​and second values; the length of the first prefix is ​​an integer multiple of the chip of the first synchronization signal, and the first prefix and at least two chips of the first synchronization signal are used to determine the chip length of the first message; or, the length of the first prefix is ​​a non-integer multiple of the chip of the first synchronization signal, and at least four chips of the first synchronization signal are used to determine the chip length of the first message.

[0431] In one possible implementation of this application embodiment, the first message includes a first synchronization signal, and the sequence pattern of the first synchronization signal is used by the terminal device to determine the chip length of the first message; the sequence pattern of the first synchronization signal includes at least one of the following: the sequence of the first synchronization signal sequentially includes the first value, the second value, and the first value; or, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the second value; or, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the first value.

[0432] In one possible implementation of this application, the first paging message includes first indication information, which is used to indicate information about random access to the first message.

[0433] In one possible implementation of this application embodiment, the first paging message further includes second indication information, which is used to instruct the terminal device to receive or the communication device to send time-domain information of a first R2D signal, and the first R2D signal is used to trigger random access of the terminal device.

[0434] In one possible implementation of this application embodiment, after the first paging message, the transceiver module is further configured to send a first R2D signal, the first R2D signal including third indication information, the third indication information being used to trigger random access of the terminal device.

[0435] In one possible implementation of this application embodiment, after the first paging message, the transceiver module is further configured to send a first R2D signal. The first R2D signal includes fourth indication information, which is used to instruct the terminal device to receive or the communication device to send time-domain information of a second R2D signal. The second R2D signal is used to trigger random access of the terminal device. The transceiver module is further configured to receive a first D2R signal from the terminal device. The first D2R signal includes a first random access message and / or a third random access message. The length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; or, the truncated length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; wherein, the first preamble is a preamble, or a postamble, or an intermediate preamble.

[0436] In one possible implementation of this application, the initial sequence of the m-sequence included in the first D2R signal includes one or more of the following: a non-all-zero sequence, an all-one sequence, a sequence of cyclic encoded bits 0 and 1, or a sequence of cyclic encoded bits 0 and 1.

[0437] In one possible implementation of this application embodiment, the feedback value corresponding to the m sequence included in the first D2R signal is calculated by: XOR, OR, or multiplication.

[0438] In one possible implementation of this application, the shift mechanism corresponding to the m-sequence included in the first D2R signal includes: shifting the value in the register to the right by N bits and outputting the value from the leftmost position; or shifting the value in the register to the left by N bits and outputting the value from the rightmost position.

[0439] In one possible implementation of this application embodiment, the modulation mechanism corresponding to the m sequence included in the first D2R signal includes: modulation after cyclic shifting.

[0440] In one possible implementation of this application embodiment, the modulation includes one or more of the following: BPSK modulation, or OOK modulation.

[0441] In one possible implementation of this application, the set of m sequences included in the first D2R signal is predefined.

[0442] In one possible implementation of this application embodiment, the transceiver module is further configured to receive a first D2R signal from the terminal device, the first D2R signal including a random access first message and / or a random access third message; the length of the Gray sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; wherein the first preamble is a preamble, or a postamble, or an intermediate preamble.

[0443] In one possible implementation of this application embodiment, the number of recursions of the Gray sequence included in the first D2R signal is indicated by the communication device to the terminal device.

[0444] In one possible implementation of this application embodiment, the number of recursions of the Gray sequence included in the first D2R signal is determined by the terminal device based on a first factor; the first factor includes one or more of the following:

[0445] The size of the transport block (TBS), the resource size of the first preamble of the first D2R signal configured by the communication device, or the frame structure configured by the communication device; the first preamble includes one or more of the following: preamble, intermediate preamble, or postamble.

[0446] In one possible implementation of this application embodiment, the modulation mechanism corresponding to the Gray sequence included in the first D2R signal includes: modulation after cyclic shift.

[0447] In one possible implementation of this application embodiment, the modulation includes one or more of the following: BPSK modulation, or OOK modulation.

[0448] In one possible implementation of this application, the transceiver module is further configured to send fifth indication information, which indicates the type of sequence included in the first D2R signal, and the type of sequence includes m-sequence or Gray sequence.

[0449] In one possible implementation of this application embodiment, the type of the sequence is determined by the communication device based on the frame structure of the first D2R signal and / or the purpose of the first D2R signal; wherein, the purpose of the first D2R signal is SFO estimation, and the type of the sequence is an m-sequence; the purpose of the first D2R signal is channel estimation, and the type of the sequence is an m-sequence or a Gray sequence; the purpose of the first D2R signal is interference estimation, and the type of the sequence is a Gray sequence.

[0450] In one possible implementation of this application embodiment, the type of the sequence is determined by the communication device based on the size of the transport block byte (TBS); wherein, if the TBS is less than or equal to N, the type of the sequence is an m-sequence; if the TBS is greater than N, the type of the sequence is a Gray sequence; or, if the TBS is greater than N, the type of the sequence is an m-sequence; if the TBS is less than or equal to N, the type of the sequence is a Gray sequence.

[0451] In one possible implementation of this application embodiment, the intermediate preamble is located at the end of the first uplink channel, the intermediate preamble is used for SFO estimation or channel estimation, the sequence of the intermediate preamble is an m-sequence, or the sequence of the intermediate preamble is a fixed binary sequence.

[0452] In one possible implementation of this application embodiment, the intermediate guide is located at the end position of the first uplink channel, the intermediate guide is used to indicate the end of the first uplink channel, the sequence of the intermediate guide is an m-sequence, or the sequence of the intermediate guide is a Gray sequence, or the sequence of the intermediate guide is a fixed binary sequence.

[0453] In one possible implementation of this application embodiment, the fixed binary sequence includes one or more of the following: an all-1 sequence, an all-0 sequence, or the fixed binary sequence includes at least F 1s, wherein F is greater than or equal to half the sequence length of the intermediate preamble at the end position of the first uplink channel.

[0454] In one possible implementation of this application embodiment, the intermediate preamble at the end position of the first uplink channel satisfies one or more of the following: the intermediate preamble at the end position of the first uplink channel is separated from the previous intermediate preamble by M time domain units; or, the intermediate preamble at the end position of the first uplink channel is used to indicate the end of data transmission on the first uplink channel.

[0455] In one possible implementation of this application embodiment, the length of the intermediate preamble at the end position of the first uplink channel and / or the sequence type are indicated by the communication device to the terminal device.

[0456] In one possible implementation of this application embodiment, the length of the intermediate preamble at the end position of the first uplink channel and / or the sequence type are determined by the terminal device according to predefined rules.

[0457] In one possible implementation of this application, the cyclic redundancy check (CRC) length of the D2R signal between adjacent first precodes is determined based on the number of information bits of the D2R signal between the adjacent first precodes.

[0458] In one possible implementation of this application, the cyclic redundancy check (CRC) length of the segmented D2R signal is determined based on the number of information bits of the segmented D2R signal.

[0459] In one possible implementation of this application, when the total number of information bits in the first uplink channel is greater than or equal to the first threshold Q, if Q is an integer, the number of information bits in each segment after segmentation of the first uplink channel is M; if Q is not an integer, the number of information bits in the D2R signal of at least one segment after segmentation of the first uplink channel is less than M, and the number of information bits in the D2R signal of the remaining segments is M.

[0460] In one possible implementation of this application embodiment, Q is predefined by the protocol, or Q is indicated by the communication device to the terminal device.

[0461] In one possible implementation of this application embodiment, the frequency domain position of the first random access message is the same as the frequency domain position of the third random access message; wherein, the first random access message uses time division multiplexing (TDM), and the third random access message uses frequency division multiplexing (FDM).

[0462] In one possible implementation of this application, the frequency domain position of the first random access message being the same as the frequency domain position of the third random access message is either predefined by the protocol or indicated by the communication device to the terminal device.

[0463] In one possible implementation of this application, the transceiver module is further configured to send a second random access message to the terminal device, wherein the second random access message is used to indicate the frequency domain offset of the frequency domain position of the third random access message relative to the frequency domain position of the first random access message.

[0464] In one possible implementation of this application, the configuration of the frequency domain resources of the D2R signal is related to one or more of the following factors: the maximum D2R transmission bandwidth, the maximum repetition factor of the Manchester code of the D2R signal, the size of the guard band between adjacent D2R signals, or harmonic components.

[0465] Optionally, the communication device may further include a storage module 2730, which can be used to store instructions and / or data, and the processing module 2720 can read the instructions and / or data in the storage module 2730.

[0466] In this embodiment, the reader / writer is presented as an integrated unit divided into functional modules. Here, "module" can refer to a specific ASIC, circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices that can provide the aforementioned functions. In a simplified embodiment, those skilled in the art will recognize that the communication device can take the form of the communication device 2100 shown in FIG. 21.

[0467] For example, the processor 2101 in the communication device 2100 shown in FIG21 can call the computer execution instructions stored in the memory 2103 to make the communication device 2100 execute the communication method in the above method embodiment.

[0468] Specifically, the functions / implementation processes of the transceiver module 2710 and processing module 2720 in Figure 27 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103. Alternatively, the functions / implementation processes of the processing module 2720 in Figure 27 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103, and the functions / implementation processes of the transceiver module 2710 in Figure 27 can be implemented by the communication interface 2104 in the communication device 2100 shown in Figure 21.

[0469] Taking the communication device as an example, which is the terminal device in the above method embodiment (which may be a chip of the terminal device, a module of the terminal device, or an internal device of the terminal device):

[0470] In this embodiment of the application, the transceiver module is used to receive a first message, which includes one or more of the following: a first paging message, an R2D signal, or a randomly accessed second message;

[0471] In this embodiment of the application, the processing module is used to decode the first message according to a first rule; wherein the first message is generated by the reader / writer according to the first rule.

[0472] In one possible implementation of this application, the first rule includes spread spectrum orthogonal frequency division multiplexing (DFT-s-OFDM) based on discrete Fourier transform.

[0473] In one possible implementation of this application embodiment, the first rule includes one or more of the following:

[0474] Generate the first time-domain binary on / off keying OOK signal;

[0475] Perform an N'-point Discrete Fourier Transform (DFT) on each OFDM symbol of the first time-domain OOK signal to obtain the first frequency-domain signal;

[0476] Map the first frequency domain signal onto X subcarriers;

[0477] Perform an N-point Inverse Discrete Fourier Transform (IDFT) or an Inverse Fast Fourier Transform (IFFT) to obtain the first time-domain signal;

[0478] The first message is obtained based on the first time-domain signal;

[0479] Each OFDM symbol comprises M chips, each chip consists of L sampling points, where M, L, N', X, and N are positive integers greater than 1, the frequency domain resources corresponding to the X subcarriers are greater than or equal to B_tx,R2D, and B_tx,R2D is the downlink transmission bandwidth.

[0480] In one possible implementation of this application embodiment, after generating the first time-domain OOK signal, the first rule further includes:

[0481] The first time-domain OOK signal is subjected to a first processing to generate a second time-domain OOK signal. The first processing includes one or more of the following: scrambling, spreading, or a first operation.

[0482] The step of performing an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal includes:

[0483] Perform a Z-point DFT transform on each OFDM symbol of the second time-domain OOK signal.

[0484] In one possible implementation of this application embodiment, the first processing of the first time-domain OOK signal includes:

[0485] The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second time-domain OOK signal;

[0486] The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

[0487] In one possible implementation of this application embodiment, the first processing of the first time-domain OOK signal includes:

[0488] The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second sequence;

[0489] The second time-domain OOK signal is generated by performing the first processing on the second sequence and the baseband sequence.

[0490] The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

[0491] In one possible implementation of this application, the type or length of the first sequence is determined based on the size of the physical resource block (PRB) corresponding to the M or X subcarriers.

[0492] In one possible implementation of this application embodiment, the first processing of the first time-domain OOK signal includes:

[0493] The second time-domain signal is generated by multiplying the baseband sequence of the first time-domain OOK signal with the first matrix;

[0494] The first matrix includes one or more of the following features:

[0495] The amplitude and / or phase of the elements included in the first matrix increase, the amplitude and / or phase of the elements included in the first matrix decrease, the elements included in the first matrix are related to the level of the first time-domain OOK signal, or the size of the first matrix is ​​related to the number of symbols of the first time-domain OOK signal, and / or the number of sampling points, and / or the M value.

[0496] In one possible implementation of this application embodiment, N' is equal to X, and M is a value in a first set, wherein the first set satisfies one or more of the following:

[0497] The values ​​in the first set are multiples of A;

[0498] The values ​​in the first set are values ​​less than a first threshold, where the first threshold is a positive integer;

[0499] Alternatively, the values ​​in the first set may be fixed values, where the fixed values ​​are positive integers.

[0500] In one possible implementation of this application embodiment, N' is greater than X, and M is a value in a second set, the second set satisfying one or more of the following: the value in the second set is a multiple of A; the value in the second set is less than a first threshold, the first threshold being a positive integer; the value in the second set is a fixed value, the fixed value being a positive integer; or, the value in the second set is greater than a second threshold, the second threshold being a positive integer.

[0501] In a possible implementation manner of the embodiment of the present application, said N' is greater than said X, and M is a value in a third set, wherein the third set is a subset of the second set.

[0502] In a possible implementation manner of the embodiment of the present application, said A comprises one or more of the following: 4, or 8.

[0503] In a possible implementation manner of the embodiment of the present application, said N' and said X satisfy a first relationship, baseband scrambling is performed, and / or a truncation operation is performed, wherein the length of the scrambling sequence is T, T is a positive integer, and N'=M*L; the first relationship comprises one or more of the following: N' is equal to X, or N' is greater than X.

[0504] In a possible implementation manner of the embodiment of the present application, characterized in that the mapping manner for mapping the first frequency-domain signal to X subcarriers comprises: starting mapping from a middle position of said B_tx,R2D; starting mapping from a minimum PRB position of said B_tx,R2D; or starting mapping from a maximum PRB position of said B_tx,R2D; or starting mapping from an N-th PRB position of said B_tx,R2D; the B-th PRB is related to one or more of SFO, intermodulation interference, or harmonic interference. Wherein, the mapping manner is chip-based mapping, and mapping resources are continuous in time domain and frequency domain.

[0505] In a possible implementation manner of the embodiment of the present application, the mapping manner for mapping the first frequency-domain signal to X subcarriers comprises: uniformly mapping to said B_tx,R2D, with each adjacent input point having an interval of B time units or frequency units; or non-uniformly mapping to said B_tx,R2D, with each adjacent input point having N1, N2, N3... time units or frequency units, where N1>N2>N3, or N1<N2<N3; wherein the mapping manner is chip-based mapping, and mapping resources are discontinuous in time domain and frequency domain.

[0506] In a possible implementation manner of the embodiment of the present application, said obtaining the first message based on the first time-domain signal comprises: adding a first prefix to the first time-domain signal to generate a second time-domain signal, and obtaining the first message based on the second time-domain signal; wherein the first prefix comprises a complete first value and a complete second value, the first value is a high level and the second value is a low level, or the first value is a low level and the second value is a high level.

[0507] In one possible implementation of this application embodiment, before adding the first prefix to the first time-domain signal, the first rule further includes: cyclically shifting the OFDM symbols of the first time-domain signal; the cyclic shift satisfying the following conditions: starting the cyclic shift from an odd number of chips, wherein the encoding method is Manchester encoding; or starting the cyclic shift from any chip, wherein the encoding method is not Manchester encoding; or, determining the position of the cyclic shift according to the length of the first prefix, wherein the position of the cyclic shift is the start or end position of a chip.

[0508] In one possible implementation of this application embodiment, when the OFDM symbol after cyclic shift includes incomplete first and second values, the first rule further includes: adding a redundant length to the incomplete OFDM symbol at its end position; wherein, the OFDM symbol after adding the redundant length includes complete first and second values, and the redundant length satisfies: the length of the redundant length is less than one chip length; the redundant length is all first values, or, the redundant length is all second values, or, the redundant length is complete first and second values; the redundant length is determined according to SFO, or, the number of sampling points; the level corresponding to the redundant length is the same as or opposite to the level of the last chip before adding the redundant length; or, the level corresponding to the redundant length is the same as or opposite to the level of the first chip or the first prefix after the next OFDM symbol cyclic shift.

[0509] In one possible implementation of this application embodiment, the protocol predefines the first prefix to be the same as the level value of the last two chips of the OFDM symbol of the first time domain signal, or the protocol predefines the first prefix to be the first value and the second value.

[0510] In one possible implementation of this application embodiment, before adding the first prefix to the first time-domain signal, the first rule further includes: cyclically shifting the OFDM symbols of the first time-domain signal; the cyclic shift satisfies: starting the cyclic shift from an odd number of chips, wherein the encoding method is Manchester encoding; starting the cyclic shift from any chip, wherein the encoding method is not Manchester encoding; starting the cyclic shift from the start or end position of any chip; or, starting the cyclic shift from an intermediate chip, wherein the first OFDM symbol comprises an odd number of chips.

[0511] In one possible implementation of this application, the first message includes a first synchronization signal, and the transition edge of the second sequence included in the first synchronization signal is used by the communication device to determine the chip length of the first message. The second sequence includes a complete first value and a complete second value.

[0512] In one possible implementation of this application embodiment, the first time length of two consecutive second sequences detected by the communication device is used to determine that the chip length of the first message is half of the first time length; or, the communication device detects Y second sequences non-continuously to determine the chip length of the first message, wherein Y is greater than or equal to 3.

[0513] In one possible implementation of this application, the first message includes a first synchronization signal, the first synchronization signal includes a first prefix, and the first prefix is ​​used by the communication device to determine the chip length of the first message.

[0514] In one possible implementation of this application, the first prefix is ​​the first value, or the first prefix is ​​the second value; the first prefix and three chips of the first synchronization signal are used to determine the chip length of the first message; or, four chips greater than or equal to the first synchronization signal are used to determine the chip length of the first message.

[0515] In one possible implementation of this application, the first prefix includes multiple first values ​​and second values; the length of the first prefix is ​​an integer multiple of the chip of the first synchronization signal, and the first prefix and at least two chips of the first synchronization signal are used to determine the chip length of the first message; or, the length of the first prefix is ​​a non-integer multiple of the chip of the first synchronization signal, and at least four chips of the first synchronization signal are used to determine the chip length of the first message.

[0516] In one possible implementation of this application embodiment, the first message includes a first synchronization signal, and the sequence pattern of the first synchronization signal is used by the communication device to determine the chip length of the first message; the sequence pattern of the first synchronization signal includes at least one of the following: the sequence of the first synchronization signal sequentially includes the first value, the second value, and the first value; or, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the second value; or, the sequence of the first synchronization signal sequentially includes the second value, the first value, and the first value.

[0517] In one possible implementation of this application, the first paging message includes first indication information, which is used to indicate information about random access to the first message.

[0518] In one possible implementation of this application embodiment, the first paging message further includes second indication information, which is used to indicate the time domain information of the communication device receiving or the reader sending a first R2D signal, and the first R2D signal is used to trigger random access of the communication device.

[0519] In one possible implementation of this application embodiment, after the first paging message, the transceiver module is further configured to receive a first R2D signal, the first R2D signal including third indication information, the third indication information being used to trigger random access of the communication device.

[0520] In one possible implementation of this application embodiment, after the first paging message, the transceiver module is further configured to receive a first R2D signal. The first R2D signal includes fourth indication information, which is used to indicate the time domain information of the communication device receiving or the reader sending a second R2D signal. The second R2D signal is used to trigger random access of the communication device.

[0521] In one possible implementation of this application embodiment, the transceiver module is further configured to send a first D2R signal, the first D2R signal including a random access first message and / or a random access third message; the length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; or, the truncated length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; wherein, the first preamble is a preamble, or a postamble, or an intermediate preamble.

[0522] In one possible implementation of this application, the initial sequence of the m-sequence included in the first D2R signal includes one or more of the following: a non-all-zero sequence, an all-one sequence, a sequence of cyclic encoded bits 0 and 1, or a sequence of cyclic encoded bits 0 and 1.

[0523] In one possible implementation of this application embodiment, the feedback value corresponding to the m sequence included in the first D2R signal is calculated by: XOR, OR, or multiplication.

[0524] In one possible implementation of this application, the shift mechanism corresponding to the m-sequence included in the first D2R signal includes: shifting the value in the register to the right by N bits and outputting the value from the leftmost position; or shifting the value in the register to the left by N bits and outputting the value from the rightmost position.

[0525] In one possible implementation of this application embodiment, the modulation mechanism corresponding to the m sequence included in the first D2R signal includes: modulation after cyclic shifting.

[0526] In one possible implementation of this application embodiment, the modulation includes one or more of the following: BPSK modulation, or OOK modulation.

[0527] In one possible implementation of this application, the set of m sequences included in the first D2R signal is predefined.

[0528] In one possible implementation of this application, the transceiver module is further configured to send a first D2R signal, the first D2R signal including a random access first message and / or a random access third message; the length of the Gray sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; wherein the first preamble is a preamble, or a postamble, or an intermediate preamble.

[0529] In one possible implementation of this application embodiment, the number of recursions of the Gray sequence included in the first D2R signal is indicated by the reader to the communication device.

[0530] In one possible implementation of this application embodiment, the number of recursions of the Gray sequence included in the first D2R signal is determined by the communication device according to a first factor; the first factor includes one or more of the following: the size of the transport block TBS, the resource size of the first preamble of the first D2R signal configured by the reader, or the frame structure configured by the reader; the first preamble includes one or more of the following: a preamble, an intermediate preamble, or a postamble.

[0531] In one possible implementation of this application embodiment, the modulation mechanism corresponding to the Gray sequence included in the first D2R signal includes: modulation after cyclic shift.

[0532] In one possible implementation of this application embodiment, the modulation includes one or more of the following: BPSK modulation, or OOK modulation.

[0533] In one possible implementation of this application embodiment, the transceiver module is further configured to receive fifth indication information, the fifth indication information being used to indicate the type of sequence included in the first D2R signal, the type of sequence including m-sequence or Gray sequence.

[0534] In one possible implementation of this application, the type of the sequence is determined by the reader based on the frame structure of the first D2R signal and / or the purpose of the first D2R signal; wherein, the purpose of the first D2R signal is SFO estimation, and the type of the sequence is an m-sequence; the purpose of the first D2R signal is channel estimation, and the type of the sequence is an m-sequence or a Gray sequence; the purpose of the first D2R signal is interference estimation, and the type of the sequence is a Gray sequence.

[0535] In one possible implementation of this application, the type of the sequence is determined by the reader based on the size of the Transport Block Size (TBS). Wherein, if the TBS is less than or equal to N, the type of the sequence is an m-sequence; if the TBS is greater than N, the type of the sequence is a Gray sequence; or, if the TBS is greater than N, the type of the sequence is an m-sequence; if the TBS is less than or equal to N, the type of the sequence is a Gray sequence.

[0536] In one possible implementation of this application embodiment, the intermediate preamble is located at the end of the first uplink channel, the intermediate preamble is used for SFO estimation or channel estimation, the sequence of the intermediate preamble is an m-sequence, or the sequence of the intermediate preamble is a fixed binary sequence.

[0537] In one possible implementation of this application embodiment, the intermediate guide is located at the end position of the first uplink channel, the intermediate guide is used to indicate the end of the first uplink channel, the sequence of the intermediate guide is an m-sequence, or the sequence of the intermediate guide is a Gray sequence, or the sequence of the intermediate guide is a fixed binary sequence.

[0538] In one possible implementation of this application embodiment, the fixed binary sequence includes one or more of the following: an all-1 sequence, an all-0 sequence, or the fixed binary sequence includes at least F 1s, wherein F is greater than or equal to half the sequence length of the intermediate preamble at the end position of the first uplink channel.

[0539] In one possible implementation of this application embodiment, the intermediate preamble at the end position of the first uplink channel satisfies one or more of the following: the intermediate preamble at the end position of the first uplink channel is separated from the previous intermediate preamble by M time domain units; or, the intermediate preamble at the end position of the first uplink channel is used to indicate the end of data transmission on the first uplink channel.

[0540] In one possible implementation of this application embodiment, the length of the intermediate preamble at the end position of the first uplink channel and / or the sequence type are indicated by the reader to the communication device.

[0541] In one possible implementation of this application embodiment, the length of the intermediate preamble at the end position of the first uplink channel and / or the sequence type are determined by the communication device according to predefined rules.

[0542] In one possible implementation of this application, the cyclic redundancy check (CRC) length of the D2R signal between adjacent first precodes is determined based on the number of information bits of the D2R signal between the adjacent first precodes.

[0543] In one possible implementation of this application, the cyclic redundancy check (CRC) length of the segmented D2R signal is determined based on the number of information bits of the segmented D2R signal.

[0544] In one possible implementation of this application, when the total number of information bits in the first uplink channel is greater than or equal to the first threshold Q, if Q is an integer, the number of information bits in each segment after segmentation of the first uplink channel is M; if Q is not an integer, the number of information bits in the D2R signal of at least one segment after segmentation of the first uplink channel is less than M, and the number of information bits in the D2R signal of the remaining segments is M.

[0545] In one possible implementation of this application embodiment, Q is predefined by the protocol, or Q is indicated by the reader to the communication device.

[0546] In one possible implementation of this application embodiment, the frequency domain position of the first random access message is the same as the frequency domain position of the third random access message; wherein, the first random access message uses time division multiplexing (TDM), and the third random access message uses frequency division multiplexing (FDM).

[0547] In one possible implementation of this application, the frequency domain position of the first random access message being the same as the frequency domain position of the third random access message is either predefined by the protocol or indicated by the reader to the communication device.

[0548] In one possible implementation of this application, the transceiver module is further configured to receive a second random access message, wherein the second random access message is used to indicate the frequency domain offset of the frequency domain position of the third random access message relative to the frequency domain position of the first random access message.

[0549] In one possible implementation of this application, the configuration of the frequency domain resources of the D2R signal is related to one or more of the following factors: the maximum D2R transmission bandwidth, the maximum repetition factor of the Manchester code of the D2R signal, the size of the guard band between adjacent D2R signals, or harmonic components.

[0550] Optionally, the communication device may further include a storage module 2730, which can be used to store instructions and / or data, and the processing module 2720 can read the instructions and / or data in the storage module 2730.

[0551] In this embodiment, the terminal device is presented in an integrated manner, divided into various functional modules. Here, "module" can refer to a specific ASIC, circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices that can provide the aforementioned functions. In a simplified embodiment, those skilled in the art will recognize that the communication device can take the form of the communication device 2100 shown in FIG. 21.

[0552] For example, the processor 2101 in the communication device 2100 shown in FIG21 can call the computer execution instructions stored in the memory 2103 to make the communication device 2100 execute the communication method in the above method embodiment.

[0553] Specifically, the functions / implementation processes of the transceiver module 2710 and processing module 2720 in Figure 27 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103. Alternatively, the functions / implementation processes of the processing module 2720 in Figure 27 can be implemented by the processor 2101 in the communication device 2100 shown in Figure 21 calling computer execution instructions stored in the memory 2103, and the functions / implementation processes of the transceiver module 2710 in Figure 27 can be implemented by the communication interface 2104 in the communication device 2100 shown in Figure 21.

[0554] It should be understood that one or more of the above modules or units can be implemented by software, hardware, or a combination of both. When any of the above modules or units are implemented by software, the software exists as computer program instructions and is stored in memory. The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into a SoC (System-on-a-Chip) or ASIC, or it can be a separate semiconductor chip. In addition to the core that executes software instructions for computation or processing, the processor may further include necessary hardware accelerators, such as field-programmable gate arrays (FPGAs), PLDs (Programmable Logic Devices), or logic circuits that implement dedicated logic operations.

[0555] When the above modules or units are implemented in hardware, the hardware can be any one or any combination of a CPU, microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, application-specific digital circuit, hardware accelerator, or non-integrated discrete device, which can run the necessary software or perform the above method flow independently of software.

[0556] Optionally, embodiments of this application also provide a communication device (e.g., the communication device may be a chip or a chip system), which includes a processor for implementing the methods in any of the above method embodiments. In one possible design, the communication device further includes a memory. The memory is used to store necessary program instructions and data, and the processor can call the program code stored in the memory to instruct the communication device to execute the methods in any of the above method embodiments. Of course, the memory may not be included in the communication device. When the communication device is a chip system, it may be composed of chips or may include chips and other discrete devices; embodiments of this application do not specifically limit this.

[0557] Optionally, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions that, when run on a communication device, enable the communication device to execute the methods described in any of the above method embodiments or any implementation thereof.

[0558] Optionally, embodiments of this application also provide a communication system, which includes the communication device described in the above method embodiments.

[0559] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0560] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0561] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A communication method, characterized in that, Applications in readers and writers include: The reader sends a first message, which includes one or more of the following: a first paging message, an R2D signal, or a random access second message; wherein the first message is generated by the reader according to a first rule.

2. The method according to claim 1, characterized in that, The first rule includes spread spectrum orthogonal frequency division multiplexing (DFT-s-OFDM) based on discrete Fourier transform.

3. The method according to claim 1 or 2, characterized in that, The first rule includes one or more of the following: Generate the first time-domain binary on / off keying OOK signal; Perform an N'-point Discrete Fourier Transform (DFT) on each OFDM symbol of the first time-domain OOK signal to obtain the first frequency-domain signal; Map the first frequency domain signal onto X subcarriers; Perform an N-point Inverse Discrete Fourier Transform (IDFT) or an Inverse Fast Fourier Transform (IFFT) to obtain the first time-domain signal; The first message is obtained based on the first time-domain signal; Each OFDM symbol comprises M chips, each chip consists of L sampling points, where M, L, N', X, and N are positive integers greater than 1, the frequency domain resources corresponding to the X subcarriers are greater than or equal to B_tx,R2D, and B_tx,R2D is the downlink transmission bandwidth.

4. The method according to claim 3, characterized in that, After generating the first time-domain OOK signal, the method further includes: The first time-domain OOK signal is subjected to a first processing to generate a second time-domain OOK signal. The first processing includes one or more of the following: scrambling, spreading, or a first operation. The step of performing an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal includes: Perform a Z-point DFT transform on each OFDM symbol of the second time-domain OOK signal.

5. The method according to claim 4, characterized in that, The first processing of the first time-domain OOK signal includes: The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second time-domain OOK signal; The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

6. The method according to claim 4, characterized in that, The first processing of the first time-domain OOK signal includes: The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second sequence; The second time-domain OOK signal is generated by performing the first processing on the second sequence and the baseband sequence. The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

7. The method according to claim 5 or 6, characterized in that, The type or length of the first sequence is determined based on the size of the physical resource block (PRB) corresponding to the M or X subcarriers.

8. The method according to claim 4, characterized in that, The first processing of the first time-domain OOK signal includes: The second time-domain signal is generated by multiplying the baseband sequence of the first time-domain OOK signal with the first matrix; The first matrix includes one or more of the following features: The amplitude and / or phase of the elements included in the first matrix increase, the amplitude and / or phase of the elements included in the first matrix decrease, the elements included in the first matrix are related to the level of the first time-domain OOK signal, or the size of the first matrix is ​​related to the number of symbols of the first time-domain OOK signal, and / or the number of sampling points, and / or the M value.

9. The method according to any one of claims 3 to 8, characterized in that, The N' is equal to the X, and the M is a value in the first set, which satisfies one or more of the following: The values ​​in the first set are multiples of A; The values ​​in the first set are values ​​less than a first threshold, where the first threshold is a positive integer; Alternatively, the values ​​in the first set may be fixed values, where the fixed values ​​are positive integers.

10. The method according to any one of claims 3 to 8, characterized in that, The N' is greater than the X, and the M is a value in the second set, which satisfies one or more of the following: The values ​​in the second set are multiples of A; The values ​​in the second set are less than the first threshold, where the first threshold is a positive integer; The values ​​in the second set are fixed values, and these fixed values ​​are positive integers. Alternatively, the value in the second set is greater than the second threshold, which is a positive integer.

11. The method according to claim 10, characterized in that, The N' is greater than the X, and the M is a value in the third set, wherein the third set is a subset of the second set.

12. The method according to any one of claims 9 to 11, characterized in that, The A includes one or more of the following: 4, or 8.

13. The method according to any one of claims 3 to 12, characterized in that, The N' and the X satisfy a first relationship, and baseband scrambling and / or truncation are performed, wherein the length of the scrambling sequence is T, where T is a positive integer, and N' = M*L; The first relationship includes one or more of the following: N' is equal to X, or N' is greater than X.

14. The method according to any one of claims 3 to 13, characterized in that, The mapping method for mapping the first frequency domain signal onto X subcarriers includes: Mapping begins from the middle position of B_tx,R2D; Mapping begins from the minimum PRB position of the B_tx,R2D; Mapping begins from the maximum PRB position of the B_tx,R2D; Alternatively, mapping can begin from the Nth PRB position of the B_tx,R2D; The Bth PRB is related to one or more of SFO, intermodulation interference, or harmonic interference; The mapping method is chip-based mapping, and the mapping resources are continuous in the time domain and frequency domain.

15. The method according to any one of claims 3 to 13, characterized in that, The mapping method for mapping the first frequency domain signal onto X subcarriers includes: The input points are uniformly mapped to B_tx,R2D, and each adjacent input point has B time units or frequency units between them. Alternatively, a non-uniform mapping can be applied to B_tx,R2D, where each adjacent input point has N1, N2, N3... time units or frequency units, where N1>N2>N3, or N1 <N2<N3; The mapping method is chip-based mapping, and the mapping resources are discontinuous in the time domain and frequency domain.

16. The method according to any one of claims 3 to 15, characterized in that, The step of obtaining the first message based on the first time domain signal includes: adding a first prefix to the first time domain signal to generate a second time domain signal, and obtaining the first message based on the second time domain signal; Wherein, the first prefix includes a complete first value and a second value, wherein the first value is high level and the second value is low level, or the first value is low level and the second value is high level.

17. The method according to claim 16, characterized in that, Before adding the first prefix to the first time-domain signal, the method further includes: The OFDM symbols of the first time-domain signal are cyclically shifted; the cyclic shift satisfies: The cyclic shift is performed starting from an odd number of chips, wherein the encoding method is Manchester encoding; The cyclic shift is performed starting from any chip, wherein the encoding method is not the Manchester encoding. Alternatively, the position of the cyclic shift can be determined based on the length of the first prefix, wherein the position of the cyclic shift is the start or end position of the chip.

18. The method according to claim 17, characterized in that, If the OFDM symbol after the cyclic shift includes incomplete first and second values, the method further includes: Add redundant length to the incomplete OFDM symbol at its end position; wherein, the OFDM symbol after adding the redundant length includes the complete first value and second value, and the redundant length satisfies: The length of the redundancy length is less than the length of a chip. The redundancy length is either all of the first value, or all of the second value, or a combination of both the first and second values. The redundancy length is determined based on SFO, or the number of sampling points; The level corresponding to the redundancy length is the same as or opposite to the level of the last chip before the redundancy length was added. Alternatively, the level corresponding to the redundancy length is the same as or opposite to the level of the first chip or the first prefix after the next OFDM symbol is cyclically shifted.

19. The method according to claim 16, characterized in that, The protocol predefines the first prefix to be the same as the level value of the last two chips of the OFDM symbol of the first time domain signal, or the protocol predefines the first prefix to be the first value and the second value.

20. The method according to claim 16, characterized in that, Before adding the first prefix to the first time-domain signal, the method further includes: The OFDM symbols of the first time-domain signal are cyclically shifted; the cyclic shift satisfies: The cyclic shift is performed starting from an odd number of chips, wherein the encoding method is Manchester encoding; The cyclic shift is performed starting from any chip, wherein the encoding method is not the Manchester encoding. The cyclic shift is performed from the start or end position of any chip; Alternatively, the cyclic shift can begin from an intermediate chip, wherein the first OFDM symbol comprises an odd number of chips.

21. The method according to any one of claims 16 to 20, characterized in that, The first message includes a first synchronization signal, the first synchronization signal including a transition edge of a second sequence for the terminal device to determine the chip length of the first message, the second sequence including a complete first value and a complete second value.

22. The method according to claim 21, characterized in that, The first time length of two consecutive second sequences detected by the terminal device is used to determine that the chip length of the first message is half of the first time length; Alternatively, the terminal device may detect Y second sequences discontinuously to determine the chip length of the first message, wherein Y is greater than or equal to 3.

23. The method according to any one of claims 16 to 20, characterized in that, The first message includes a first synchronization signal, the first synchronization signal includes a first prefix, and the first prefix is ​​used by the terminal device to determine the chip length of the first message.

24. The method according to claim 23, characterized in that, The first prefix is ​​the first value, or the first prefix is ​​the second value; The first prefix and the three chips of the first synchronization signal are used to determine the chip length of the first message; Alternatively, four chips greater than or equal to the first synchronization signal can be used to determine the chip length of the first message.

25. The method according to claim 23, characterized in that, The first prefix includes multiple first values ​​and second values; The length of the first prefix is ​​an integer multiple of the chip length of the first synchronization signal, and the first prefix and at least two chips of the first synchronization signal are used to determine the chip length of the first message. Alternatively, the length of the first prefix is ​​a non-integer multiple of the chip length of the first synchronization signal, and at least four chips of the first synchronization signal are used to determine the chip length of the first message.

26. The method according to any one of claims 16 to 20, characterized in that, The first message includes a first synchronization signal, and the sequence pattern of the first synchronization signal is used by the terminal device to determine the chip length of the first message; The sequence pattern of the first synchronization signal includes at least one of the following: The sequence of the first synchronization signal includes the first value, the second value, and the first value in sequence; Alternatively, the sequence of the first synchronization signal may include the second value, the first value, and the second value in sequence; Alternatively, the sequence of the first synchronization signal may include the second value, the first value, and the first value in sequence.

27. The method according to any one of claims 1 to 26, characterized in that, The first paging message includes first indication information, which is used to indicate information about random access to the first message.

28. The method according to claim 27, characterized in that, The first paging message also includes second indication information, which is used to instruct the terminal device to receive or the reader to send the first R2D signal in the time domain, and the first R2D signal is used to trigger random access of the terminal device.

29. The method according to any one of claims 1 to 26, characterized in that, The method further includes: Following the first paging message, the reader sends a first R2D signal, which includes third indication information used to trigger random access of the terminal device.

30. The method according to any one of claims 1 to 26, characterized in that, The method further includes: Following the first paging message, the reader sends a first R2D signal, which includes fourth indication information. The fourth indication information is used to indicate the time domain information of the terminal device receiving or the reader sending a second R2D signal. The second R2D signal is used to trigger random access of the terminal device.

31. The method according to any one of claims 1 to 30, characterized in that, The method further includes: The reader receives a first D2R signal from the terminal device, the first D2R signal including a random access first message and / or a random access third message; The length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; Alternatively, the length of the truncated m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal. Wherein, the first preamble is either a preamble, a postamble, or an intermediate preamble.

32. The method according to claim 31, characterized in that, The initial sequence of the m-sequence included in the first D2R signal includes one or more of the following: A sequence that is not all zeros, a sequence of all one bits, a sequence of cyclical encoded bits 0 and 1, or a sequence of cyclical encoded bits 0 and 1.

33. The method according to claim 31 or 32, characterized in that, The feedback value corresponding to the m-sequence included in the first D2R signal is calculated by: XOR, OR, or multiplication.

34. The method according to any one of claims 31 to 32, characterized in that, The shift mechanism corresponding to the m-sequence included in the first D2R signal includes: Shift the entire value in the register to the right by N bits and output the value starting from the leftmost position. Alternatively, shift the entire value in the register to the left by N bits and output the value from the rightmost position.

35. The method according to any one of claims 31 to 34, characterized in that, The modulation mechanism corresponding to the m-sequence included in the first D2R signal includes: Modulation is performed after cyclic shifting.

36. The method according to claim 35, characterized in that, The modulation includes one or more of the following: BPSK modulation, or OOK modulation.

37. The method according to any one of claims 1 to 36, characterized in that, The set of m sequences included in the first D2R signal is predefined.

38. The method according to any one of claims 1 to 30, characterized in that, The method further includes: The reader receives a first D2R signal from the terminal device, the first D2R signal including a random access first message and / or a random access third message; The length of the Gray sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; Wherein, the first preamble is either a preamble, a postamble, or an intermediate preamble.

39. The method according to claim 37, characterized in that, The number of recursions of the Gray sequence included in the first D2R signal is indicated by the reader to the terminal device.

40. The method according to claim 37, characterized in that, The number of recursions of the Gray sequence included in the first D2R signal is determined by the terminal device based on a first factor; the first factor includes one or more of the following: The size of the transport block (TBS), the resource size of the first preamble of the first D2R signal configured by the reader, or the frame structure configured by the reader; The first preamble includes one or more of the following: preamble, intermediate preamble, or postamble.

41. The method according to claim 39 or 40, characterized in that, The modulation mechanism corresponding to the Gray sequence included in the first D2R signal includes: Modulation is performed after cyclic shifting.

42. The method according to claim 41, characterized in that... The modulation includes one or more of the following: BPSK modulation, or OOK modulation.

43. The method according to any one of claims 38 to 42, characterized in that, The method includes: The reader sends a fifth indication message to the terminal device. The fifth indication message is used to indicate the type of sequence included in the first D2R signal. The type of sequence includes an m-sequence or a Gray sequence.

44. The method according to claim 43, characterized in that, The type of the sequence is determined by the reader based on the frame structure of the first D2R signal and / or the purpose of the first D2R signal; The first D2R signal is used for SFO estimation, and the sequence type is an m-sequence. The first D2R signal is used for channel estimation, and the sequence type is an m-sequence or a Gray sequence; The first D2R signal is used for interference estimation, and the sequence type is a Gray sequence.

45. The method according to claim 43, characterized in that, The type of the sequence is determined by the reader / writer based on the size of the transport block (TBS). Wherein, TBS is less than or equal to N, and the sequence type is m-sequence; The TBS is greater than the N, and the sequence type is a Gray sequence; Alternatively, the TBS is greater than N, and the sequence type is an m-sequence; The TBS is less than or equal to the N, and the sequence type is a Gray sequence.

46. ​​The method according to any one of claims 32 to 45, characterized in that, The intermediate guide is located at the end of the first uplink channel. The intermediate guide is used for SFO estimation or channel estimation. The sequence of the intermediate guide is an m-sequence, or the sequence of the intermediate guide is a fixed binary sequence.

47. The method according to any one of claims 32 to 45, characterized in that, The intermediate guide is located at the end of the first uplink channel. The intermediate guide is used to indicate the end of the first uplink channel. The sequence of the intermediate guide is an m-sequence, or a Gray sequence, or a fixed binary sequence.

48. The method according to claim 47, characterized in that, The fixed binary sequence includes one or more of the following: The sequence can be an all-1 sequence, an all-0 sequence, or the fixed binary sequence can include at least F 1s, where F is greater than or equal to half the sequence length of the intermediate preamble at the end position of the first uplink channel.

49. The method according to any one of claims 46 to 48, characterized in that, The intermediate preamble at the end position of the first uplink channel satisfies one or more of the following: The intermediate preamble at the end position of the first uplink channel is separated from the previous intermediate preamble by M time domain units; Alternatively, the intermediate preamble at the end position of the first uplink channel is used to indicate the end of data transmission on the first uplink channel.

50. The method according to any one of claims 46 to 49, characterized in that, The length of the intermediate preamble at the end position of the first uplink channel, and / or the sequence type, are as indicated by the reader to the terminal device.

51. The method according to any one of claims 46 to 49, characterized in that, The length of the intermediate preamble at the end position of the first uplink channel, and / or the sequence type, are determined by the terminal device according to predefined rules.

52. The method according to any one of claims 32 to 51, characterized in that, The cyclic redundancy check (CRC) length of the D2R signal between adjacent first preambles is determined based on the number of information bits of the D2R signal between the adjacent first preambles.

53. The method according to any one of claims 32 to 52, characterized in that, The cyclic redundancy check (CRC) length of the segmented D2R signal is determined based on the number of information bits in the segmented D2R signal.

54. The method according to claim 53, characterized in that, When the total number of information bits in the first uplink channel is greater than or equal to the first threshold Q. when The number of information bits in each segment of the D2R signal after the first uplink channel segmentation is an integer, M; when The number of information bits is not an integer. The number of information bits of the D2R signal in at least one segment after the first uplink channel segmentation is less than M, and the number of information bits of the D2R signal in the remaining segments is M.

55. The method according to claim 54, characterized in that, The Q is either predefined by the protocol, or the Q is indicated by the reader to the terminal device.

56. The method according to any one of claims 33 to 55, characterized in that, The frequency domain position of the first random access message is the same as one of the frequency domain positions of the third random access message; wherein the first random access message uses time division multiplexing (TDM) and the third random access message uses frequency division multiplexing (FDM).

57. The method according to claim 56, characterized in that, The frequency domain position of the random access third message is either predefined by the protocol or indicated by the reader to the terminal device.

58. The method according to any one of claims 32 to 56, characterized in that, The method further includes: The reader sends a second random access message to the terminal device. The second random access message is used to indicate the frequency domain offset of the frequency domain position of the third random access message relative to the frequency domain position of the first random access message.

59. The method according to any one of claims 1 to 58, characterized in that, The configuration of the frequency domain resources of the D2R signal is related to one or more of the following factors: Maximum D2R transmission bandwidth, the maximum repetition factor of the Manchester encoding of the D2R signal, the size of the guard band between adjacent D2R signals, or, harmonic components.

60. A communication method, characterized in that, Applied to terminal devices, including: The terminal device receives a first message, which includes one or more of the following: a first paging message, an R2D signal, or a random access second message; The terminal device decodes the first message according to the first rule; The first message is generated by the reader / writer according to the first rule.

61. The method according to claim 60, characterized in that, The first rule includes spread spectrum orthogonal frequency division multiplexing (DFT-s-OFDM) based on discrete Fourier transform.

62. The method according to claim 60 or 61, characterized in that, The first rule includes one or more of the following: Generate the first time-domain binary on / off keying OOK signal; Perform an N'-point Discrete Fourier Transform (DFT) on each OFDM symbol of the first time-domain OOK signal to obtain the first frequency-domain signal; Map the first frequency domain signal onto X subcarriers; Perform an N-point Inverse Discrete Fourier Transform (IDFT) or an Inverse Fast Fourier Transform (IFFT) to obtain the first time-domain signal; The first message is obtained based on the first time-domain signal; Each OFDM symbol comprises M chips, each chip consists of L sampling points, where M, L, N', X, and N are positive integers greater than 1, the frequency domain resources corresponding to the X subcarriers are greater than or equal to B_tx,R2D, and B_tx,R2D is the downlink transmission bandwidth.

63. The method according to claim 62, characterized in that, After generating the first time-domain OOK signal, the first rule further includes: The first time-domain OOK signal is subjected to a first processing to generate a second time-domain OOK signal. The first processing includes one or more of the following: scrambling, spreading, or a first operation. The step of performing an N'-point DFT transform on each OFDM symbol of the first time-domain OOK signal includes: Perform a Z-point DFT transform on each OFDM symbol of the second time-domain OOK signal.

64. The method according to claim 63, characterized in that, The first processing of the first time-domain OOK signal includes: The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second time-domain OOK signal; The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

65. The method according to claim 63, characterized in that, The first processing of the first time-domain OOK signal includes: The first sequence and the baseband sequence of the first time-domain OOK signal are used to perform the first processing to generate the second sequence; The second time-domain OOK signal is generated by performing the first processing on the second sequence and the baseband sequence. The first sequence may be of one or more of the following types: ZC sequence, M sequence, randomly selected sequence, or Gold sequence.

66. The method according to claim 64 or 65, characterized in that, The type or length of the first sequence is determined based on the size of the physical resource block (PRB) corresponding to the M or X subcarriers.

67. The method according to claim 63, characterized in that, The first processing of the first time-domain OOK signal includes: The second time-domain signal is generated by multiplying the baseband sequence of the first time-domain OOK signal with the first matrix; The first matrix includes one or more of the following features: The amplitude and / or phase of the elements included in the first matrix increase, the amplitude and / or phase of the elements included in the first matrix decrease, the elements included in the first matrix are related to the level of the first time-domain OOK signal, or the size of the first matrix is ​​related to the number of symbols of the first time-domain OOK signal, and / or the number of sampling points, and / or the M value.

68. The method according to any one of claims 62 to 67, characterized in that, The N' is equal to the X, and the M is a value in the first set, which satisfies one or more of the following: The values ​​in the first set are multiples of A; The values ​​in the first set are values ​​less than a first threshold, where the first threshold is a positive integer; Alternatively, the values ​​in the first set may be fixed values, where the fixed values ​​are positive integers.

69. The method according to any one of claims 62 to 67, characterized in that, The N' is greater than the X, and the M is a value in the second set, which satisfies one or more of the following: The values ​​in the second set are multiples of A; The values ​​in the second set are less than the first threshold, where the first threshold is a positive integer; The values ​​in the second set are fixed values, and these fixed values ​​are positive integers. Alternatively, the value in the second set is greater than the second threshold, which is a positive integer.

70. The method according to claim 69, characterized in that, The N' is greater than the X, and the M is a value in the third set, wherein the third set is a subset of the second set.

71. The method according to any one of claims 68 to 70, characterized in that, The A includes one or more of the following: 4, or 8.

72. The method according to any one of claims 62 to 71, characterized in that, The N' and the X satisfy a first relationship, and baseband scrambling and / or truncation are performed, wherein the length of the scrambling sequence is T, where T is a positive integer, and N' = M*L; The first relationship includes one or more of the following: N' is equal to X, or N' is greater than X.

73. The method according to any one of claims 62 to 72, characterized in that, The mapping method for mapping the first frequency domain signal onto X subcarriers includes: Mapping begins from the middle position of B_tx,R2D; Mapping begins from the minimum PRB position of the B_tx,R2D; Alternatively, mapping can begin from the maximum PRB position of the B_tx,R2D; Alternatively, mapping can begin from the Nth PRB position of the B_tx,R2D; The Bth PRB is related to one or more of SFO, intermodulation interference, or harmonic interference; The mapping method is chip-based mapping, and the mapping resources are continuous in the time domain and frequency domain.

74. The method according to any one of claims 62 to 72, characterized in that, The mapping method for mapping the first frequency domain signal onto X subcarriers includes: The input points are uniformly mapped to B_tx,R2D, and each adjacent input point has B time units or frequency units between them. Alternatively, a non-uniform mapping can be applied to B_tx,R2D, where each adjacent input point has N1, N2, N3... time units or frequency units, where N1>N2>N3, or N1 <N2<N3; The mapping method is chip-based mapping, and the mapping resources are discontinuous in the time domain and frequency domain.

75. The method according to any one of claims 62 to 74, characterized in that, The step of obtaining the first message based on the first time domain signal includes: adding a first prefix to the first time domain signal to generate a second time domain signal, and obtaining the first message based on the second time domain signal; Wherein, the first prefix includes a complete first value and a second value, wherein the first value is high level and the second value is low level, or the first value is low level and the second value is high level.

76. The method according to claim 75, characterized in that, Before adding the first prefix to the first time-domain signal, the first rule further includes: The OFDM symbols of the first time-domain signal are cyclically shifted; the cyclic shift satisfies: The cyclic shift is performed starting from an odd number of chips, wherein the encoding method is Manchester encoding; The cyclic shift is performed starting from any chip, wherein the encoding method is not the Manchester encoding. Alternatively, the position of the cyclic shift can be determined based on the length of the first prefix, wherein the position of the cyclic shift is the start or end position of the chip.

77. The method according to claim 76, characterized in that, In the case that the OFDM symbol after the cyclic shift includes incomplete first and second values, the first rule further includes: Add redundant length to the incomplete OFDM symbol at its end position; wherein, the OFDM symbol after adding the redundant length includes the complete first value and second value, and the redundant length satisfies: The length of the redundancy length is less than the length of a chip. The redundancy length is either all of the first value, or all of the second value, or a combination of both the first and second values. The redundancy length is determined based on SFO, or the number of sampling points; The level corresponding to the redundancy length is the same as or opposite to the level of the last chip before the redundancy length was added. Alternatively, the level corresponding to the redundancy length is the same as or opposite to the level of the first chip or the first prefix after the next OFDM symbol is cyclically shifted.

78. The method according to claim 75, characterized in that, The protocol predefines the first prefix to be the same as the level value of the last two chips of the OFDM symbol of the first time domain signal, or the protocol predefines the first prefix to be the first value and the second value.

79. The method according to claim 75, characterized in that, Before adding the first prefix to the first time-domain signal, the first rule further includes: The OFDM symbols of the first time-domain signal are cyclically shifted; the cyclic shift satisfies: The cyclic shift is performed starting from an odd number of chips, wherein the encoding method is Manchester encoding; The cyclic shift is performed starting from any chip, wherein the encoding method is not the Manchester encoding. The cyclic shift is performed from the start or end position of any chip; Alternatively, the cyclic shift can begin from an intermediate chip, wherein the first OFDM symbol comprises an odd number of chips.

80. The method according to any one of claims 75 to 79, characterized in that, The first message includes a first synchronization signal, the first synchronization signal including a transition edge of a second sequence for the terminal device to determine the chip length of the first message, the second sequence including a complete first value and a complete second value.

81. The method according to claim 80, characterized in that, The first time length of two consecutive second sequences detected by the terminal device is used to determine that the chip length of the first message is half of the first time length; Alternatively, the terminal device may detect Y second sequences discontinuously to determine the chip length of the first message, wherein Y is greater than or equal to 3.

82. The method according to any one of claims 75 to 79, characterized in that, The first message includes a first synchronization signal, the first synchronization signal includes a first prefix, and the first prefix is ​​used by the terminal device to determine the chip length of the first message.

83. The method according to claim 82, characterized in that, The first prefix is ​​the first value, or the first prefix is ​​the second value; The first prefix and the three chips of the first synchronization signal are used to determine the chip length of the first message; Alternatively, four chips greater than or equal to the first synchronization signal can be used to determine the chip length of the first message.

84. The method according to claim 82, characterized in that, The first prefix includes multiple first values ​​and second values; The length of the first prefix is ​​an integer multiple of the chip length of the first synchronization signal, and the first prefix and at least two chips of the first synchronization signal are used to determine the chip length of the first message. Alternatively, the length of the first prefix is ​​a non-integer multiple of the chip length of the first synchronization signal, and at least four chips of the first synchronization signal are used to determine the chip length of the first message.

85. The method according to any one of claims 75 to 79, characterized in that, The first message includes a first synchronization signal, and the sequence pattern of the first synchronization signal is used by the terminal device to determine the chip length of the first message; The sequence pattern of the first synchronization signal includes at least one of the following: The sequence of the first synchronization signal includes the first value, the second value, and the first value in sequence; Alternatively, the sequence of the first synchronization signal may include the second value, the first value, and the second value in sequence; Alternatively, the sequence of the first synchronization signal may include the second value, the first value, and the first value in sequence.

86. The method according to any one of claims 59 to 85, characterized in that, The first paging message includes first indication information, which is used to indicate information about random access to the first message.

87. The method according to claim 86, characterized in that, The first paging message also includes second indication information, which is used to instruct the terminal device to receive or the reader to send the first R2D signal in the time domain, and the first R2D signal is used to trigger random access of the terminal device.

88. The method according to any one of claims 59 to 85, characterized in that, The method further includes: Following the first paging message, the terminal device receives a first R2D signal, which includes third indication information used to trigger random access for the terminal device.

89. The method according to any one of claims 59 to 85, characterized in that, The method further includes: After the first paging message, the terminal device receives a first R2D signal, which includes fourth indication information. The fourth indication information is used to indicate the time domain information of the terminal device receiving or the reader sending a second R2D signal. The second R2D signal is used to trigger random access of the terminal device.

90. The method according to any one of claims 59 to 89, characterized in that, The method further includes: The terminal device sends a first D2R signal, the first D2R signal including a random access first message, and / or a random access third message; The length of the m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; Alternatively, the length of the truncated m-sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal. Wherein, the first preamble is either a preamble, a postamble, or an intermediate preamble.

91. The method according to claim 90, characterized in that, The initial sequence of the m-sequence included in the first D2R signal includes one or more of the following: A sequence that is not all zeros, a sequence of all one bits, a sequence of cyclical encoded bits 0 and 1, or a sequence of cyclical encoded bits 0 and 1.

92. The method according to claim 90 or 91, characterized in that, The feedback value corresponding to the m-sequence included in the first D2R signal is calculated by: XOR, OR, or multiplication.

93. The method according to any one of claims 90 to 91, characterized in that, The shift mechanism corresponding to the m-sequence included in the first D2R signal includes: Shift the entire value in the register to the right by N bits and output the value starting from the leftmost position. Alternatively, shift the entire value in the register to the left by N bits and output the value from the rightmost position.

94. The method according to any one of claims 90 to 93, characterized in that, The modulation mechanism corresponding to the m-sequence included in the first D2R signal includes: Modulation is performed after cyclic shifting.

95. The method according to claim 94, characterized in that, The modulation includes one or more of the following: BPSK modulation, or OOK modulation.

96. The method according to any one of claims 59 to 95, characterized in that, The set of m sequences included in the first D2R signal is predefined.

97. The method according to any one of claims 59 to 89, characterized in that, The method further includes: The terminal device sends a first D2R signal, the first D2R signal including a random access first message, and / or a random access third message; The length of the Gray sequence included in the first D2R signal is less than or equal to the length of the first preamble of the first D2R signal; Wherein, the first preamble is either a preamble, a postamble, or an intermediate preamble.

98. The method according to claim 96, characterized in that, The number of recursions of the Gray sequence included in the first D2R signal is indicated by the reader to the terminal device.

99. The method according to claim 96, characterized in that, The number of recursions of the Gray sequence included in the first D2R signal is determined by the terminal device based on a first factor; the first factor includes one or more of the following: The size of the transport block (TBS), the resource size of the first preamble of the first D2R signal configured by the reader, or the frame structure configured by the reader; The first preamble includes one or more of the following: preamble, intermediate preamble, or postamble.

100. The method according to claim 98 or 99, characterized in that, The modulation mechanism corresponding to the Gray sequence included in the first D2R signal includes: Modulation is performed after cyclic shifting.

101. The method according to claim 100, characterized in that... The modulation includes one or more of the following: BPSK modulation, or OOK modulation.

102. The method according to any one of claims 97 to 101, characterized in that, The method includes: The terminal device receives a fifth indication information, which is used to indicate the type of sequence included in the first D2R signal. The type of sequence includes an m-sequence or a Gray sequence.

103. The method according to claim 102, characterized in that, The type of the sequence is determined by the reader based on the frame structure of the first D2R signal and / or the purpose of the first D2R signal; The first D2R signal is used for SFO estimation, and the sequence type is an m-sequence. The first D2R signal is used for channel estimation, and the sequence type is an m-sequence or a Gray sequence; The first D2R signal is used for interference estimation, and the sequence type is a Gray sequence.

104. The method according to claim 102, characterized in that, The type of the sequence is determined by the reader / writer based on the size of the transport block (TBS). Wherein, TBS is less than or equal to N, and the sequence type is m-sequence; The TBS is greater than the N, and the sequence type is a Gray sequence; Alternatively, the TBS is greater than N, and the sequence type is an m-sequence; The TBS is less than or equal to the N, and the sequence type is a Gray sequence.

105. The method according to any one of claims 91 to 104, characterized in that, The intermediate guide is located at the end of the first uplink channel. The intermediate guide is used for SFO estimation or channel estimation. The sequence of the intermediate guide is an m-sequence, or the sequence of the intermediate guide is a fixed binary sequence.

106. The method according to any one of claims 91 to 104, characterized in that, The intermediate guide is located at the end of the first uplink channel. The intermediate guide is used to indicate the end of the first uplink channel. The sequence of the intermediate guide is an m-sequence, or a Gray sequence, or a fixed binary sequence.

107. The method according to claim 106, characterized in that, The fixed binary sequence includes one or more of the following: The sequence can be an all-1 sequence, an all-0 sequence, or the fixed binary sequence can include at least F 1s, where F is greater than or equal to half the sequence length of the intermediate preamble at the end position of the first uplink channel.

108. The method according to any one of claims 105 to 107, characterized in that, The intermediate preamble at the end position of the first uplink channel satisfies one or more of the following: The intermediate preamble at the end position of the first uplink channel is separated from the previous intermediate preamble by M time domain units; Alternatively, the intermediate preamble at the end position of the first uplink channel is used to indicate the end of data transmission on the first uplink channel.

109. The method according to any one of claims 105 to 108, characterized in that, The length of the intermediate preamble at the end position of the first uplink channel, and / or the sequence type, are as indicated by the reader to the terminal device.

110. The method according to any one of claims 105 to 108, characterized in that, The length of the intermediate preamble at the end position of the first uplink channel, and / or the sequence type, are determined by the terminal device according to predefined rules.

111. The method according to any one of claims 91 to 110, characterized in that, The cyclic redundancy check (CRC) length of the D2R signal between adjacent first preambles is determined by the terminal device based on the number of information bits of the D2R signal between adjacent first preambles.

112. The method according to any one of claims 91 to 111, characterized in that, The cyclic redundancy check (CRC) length of the segmented D2R signal is determined by the terminal device based on the number of information bits of the segmented D2R signal.

113. The method according to claim 112, characterized in that, When the total number of information bits in the first uplink channel is greater than or equal to the first threshold Q. when The number of information bits in each segment of the D2R signal after the first uplink channel segmentation is an integer, M; when The number of information bits is not an integer. The number of information bits of the D2R signal in at least one segment after the first uplink channel segmentation is less than M, and the number of information bits of the D2R signal in the remaining segments is M.

114. The method according to claim 113, characterized in that, The Q is either predefined by the protocol, or the Q is indicated by the reader to the terminal device.

115. The method according to any one of claims 92 to 114, characterized in that, The frequency domain position of the first random access message is the same as one of the frequency domain positions of the third random access message; wherein the first random access message uses time division multiplexing (TDM) and the third random access message uses frequency division multiplexing (FDM).

116. The method according to claim 115, characterized in that, The frequency domain position of the first random access message being the same as that of the third random access message is either predefined by the protocol or indicated by the reader to the terminal device.

117. The method according to any one of claims 91 to 114, characterized in that, The method further includes: The terminal device receives a second random access message, which indicates the frequency domain offset of the frequency domain position of the third random access message relative to the frequency domain position of the first random access message.

118. The method according to any one of claims 60 to 117, characterized in that, The configuration of the frequency domain resources of the D2R signal is related to one or more of the following factors: Maximum D2R transmission bandwidth, the maximum repetition factor of the Manchester encoding of the D2R signal, the size of the guard band between adjacent D2R signals, or, harmonic components.

119. A communication device, characterized in that, The communication device includes a module for performing the method according to any one of claims 1 to 59, or includes a module for performing the method according to any one of claims 60 to 118.

120. A communication device, characterized in that, The communication device includes a processor; the processor is configured to perform the method according to any one of claims 1 to 59, or to cause the communication device to perform the method according to any one of claims 60 to 118.

121. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes instructions that, when executed, cause the method according to any one of claims 1 to 59 to be implemented, or cause the method according to any one of claims 60 to 118 to be implemented.

122. A computer program product, characterized in that, The computer program product includes instructions that, when executed, cause the method according to any one of claims 1 to 59 to be implemented, or cause the method according to any one of claims 60 to 118 to be implemented.

123. A communication system, characterized in that, The communication system includes the communication apparatus as described in claims 119 and 120.

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