Communication method and communication apparatus

Abstract

The present application relates to the field of communications, and specifically relates to a communication method and a communication apparatus. The communication characteristics of NTN are that a relatively long signal propagation distance causes a relatively large path loss, and a search space-based receiving mode for downlink control information deteriorates the link budget of the downlink control information. In the present application, first downlink control information may be sent by a network device (e.g., a satellite) in NTN; by receiving a plurality of pieces of repeated first downlink control information, a terminal may combine the first downlink control information received multiple times and decode same, thereby improving the decoding success rate, and further improving transmission reliability of downlink control information in NTN. In addition, in the present embodiment, since the time domain position where the first downlink control information is located is definite, the terminal does not need to perform blind detection in the search space, which also improves transmission reliability of downlink control information.

Description

Communication method and communication apparatus

[0001] The present application claims priority to the Chinese patent application No. 202411098154.9, filed on August 9, 2024, and entitled "Communication method and communication apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication, in particular to a communication method and a communication apparatus. BACKGROUND

[0003] Non-terrestrial network (NTN) refers to a network for communication based on aerial devices such as satellites, unmanned aircraft systems (UAS) or high altitude platform stations (HAPS). NTN has the characteristics of wide coverage, low latency, wide bandwidth and low cost. As a supplement and extension of ground networks, NTN can achieve wide-area seamless coverage that cannot be achieved by wired telephone networks and ground mobile communication networks, and effectively solve the problem of Internet access in areas where communication infrastructure is scarce.

[0004] The communication characteristics of NTN are that the signal propagation distance is far, resulting in large path loss, and the downlink control information receiving mode based on search space makes the link budget of downlink control information worse. How to improve the transmission reliability of downlink control information in NTN is a problem to be solved at present. SUMMARY

[0005] Embodiments of the present application provide a communication method, a communication apparatus, a communication system, a computer readable storage medium and a computer program product, which can improve the transmission reliability of downlink control information in NTN.

[0006] In a first aspect, embodiments of the present application provide a communication method applicable to a terminal side, an execution subject of the method can be a terminal or a communication module in the terminal, or a circuit or chip (such as a Modem chip, also known as a baseband chip, or a System on Chip (SoC) chip or a System in Package (SIP) chip containing a modem core) of the terminal, which is described below with the execution subject being a terminal as an example. The method comprises: determining a repetition number M and a first time domain position in a time slot n0 for carrying first downlink control information, the first downlink control information being used to indicate (or configure) time-frequency resources of a broadcast message, and M being an integer greater than 1; receiving the first downlink control information at the first time domain position and M-1 times of retransmitted first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

[0007] In the embodiments, the first downlink control information can be sent by a network device (such as a satellite) in an NTN, and the terminal can combine and decode the first downlink control information received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, in the embodiments, the time domain position of the first downlink control information is determined, and the terminal does not need to perform blind detection in a search space, which also improves the transmission reliability of the downlink control information.

[0008] In an optional implementation of the first aspect, the first downlink control information in the time slot n0+j is used to indicate the time-frequency resources of the broadcast message in the time slot n0+j, where j = {0, 1, 2, …, M-1}; the method further comprises: receiving M broadcast messages in the M time slots from the time slot n0 to the time slot n0+M-1, and the M broadcast messages being the same.

[0009] The above broadcast message carries information for terminal access, and the terminal can combine and decode the broadcast message received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the access information in the NTN.

[0010] In an optional implementation of the first aspect, determining the repetition number M and the first time domain position in the time slot n0 for carrying the first downlink control information comprises: receiving a synchronization signal block, the synchronization signal block comprising a first index, the first index being an index in a predefined first table; determining the repetition number M and the first time domain position in the first table according to the first index, and determining the time slot n0 according to a part of parameters corresponding to the first index in the first table.

[0011] The repetition number M, the first time domain position and the time slot n0 are indicated by combining the first index with a predefined table, and the network device only needs to transmit a small amount of transmission resources to transmit the first index, thereby reducing the information overhead of the transmission resources for indicating the first downlink control information.

[0012] In an optional implementation of the first aspect, the broadcast message is: a system information block (SIB) 1, or a combination of the SIB 1 and SIB 19.

[0013] In the NTN, some access information is carried in the SIB 19, and if the SIB 1 or the SIB 19 is transmitted alone, the SIB 19 also needs to be repeated multiple times to improve transmission reliability. In this embodiment, the network device in the NTN can compress the SIB 1 and the SIB 19 and repeatedly transmit them as one broadcast message, and the terminal does not need to wait for the scheduling of the SIB 1 to receive the SIB 19, thereby improving the access rate of the terminal.

[0014] In the second aspect, the embodiments of the present application provide a communication method, which can be applied to the network side, the execution subject of the method can be a network device or a component implementing a communication function in the network device, or a circuit or chip of the network device, and the following will be described by taking the network device as an example. The method comprises the following steps: determining a repetition number M and a first time domain position in a time slot n0 for carrying first downlink control information, the first downlink control information being used for indicating (or configuring) time-frequency resources of a broadcast message, and M being an integer greater than 1; transmitting the first downlink control information at the first time domain position, and transmitting M-1 first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

[0015] In this embodiment, the first downlink control information can be transmitted by the network device (such as a satellite) in the NTN, the network device transmits multiple repeated first downlink control information, and the terminal can combine and decode the multiple received first downlink control information to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, in this embodiment, the time domain position of the first downlink control information is determined, and the terminal does not need to perform blind detection in the search space, which also improves the transmission reliability of the downlink control information.

[0016] In an optional implementation of the second aspect, the first downlink control information in the time slot n0+j is used to indicate the time-frequency resources of the broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; the method further comprises the following steps: transmitting M broadcast messages in M time slots from the time slot n0 to the time slot n0+M-1, and the M broadcast messages being the same.

[0017] The broadcast message carries information for terminal access, the network device transmits a plurality of repeated broadcast messages, and the terminal can combine and decode the broadcast messages received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the access information in the NTN.

[0018] In an optional implementation of the second aspect, the method further includes: transmitting a synchronization signal block, the synchronization signal block including a first index, the first index being an index in a predefined first table, parameters corresponding to the first index in the first table including the repetition number M and the first time domain position, and part of the parameters corresponding to the first index in the first table being used to determine the slot n0.

[0019] The repetition number M, the first time domain position, and the slot n0 are indicated by the first index in combination with the predefined table, and the network device in the NTN only needs to transmit a small amount of transmission resource to transmit the first index, thereby reducing the information overhead of the transmission resource for indicating the first downlink control information.

[0020] In an optional implementation of the second aspect, the broadcast message is: an SIB1, or a combination of an SIB1 and an SIB19.

[0021] In the NTN, some access information is carried in the SIB19, and if the SIB1 or the SIB19 is transmitted alone, the SIB19 also needs to be repeated multiple times to improve the transmission reliability. In this embodiment, the network device in the NTN can compress the SIB1 and the SIB19 and repeatedly transmit them as one broadcast message, and the terminal does not need to wait for the scheduling of the SIB1 to receive the SIB19, thereby improving the access rate of the terminal.

[0022] In a third aspect, embodiments of the present application provide a communication method, which can be applied to a terminal side, the execution subject of the method can be a terminal or a communication module in the terminal, or a circuit or chip applied to the terminal, and the following will be described taking the execution subject as a terminal. The method includes: determining a repetition number M1 and a slot n0 for carrying first downlink control information, the first downlink control information being used to indicate (or configure) a time-frequency resource of a broadcast message, M1 being an integer greater than 1; determining, according to the first repetition number M1, a symbol number A of the first downlink control information, and a maximum symbol number B for carrying downlink control information in one slot, receiving M1 first downlink control information in continuous N slots starting from the slot n0, the M1 first downlink control information being the same, A being a positive integer, B being a positive integer greater than or equal to A, and N being a positive integer less than or equal to M1; wherein N, M1, A, and B satisfy:

[0023] In the embodiment, the first downlink control information can be sent by a network device (e.g., a satellite) in the NTN, and the terminal can combine and decode the first downlink control information received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, in the embodiment, the time domain position of the first downlink control information is determined, and the terminal does not need to perform blind detection in the search space, which also improves the transmission reliability of the downlink control information. In addition, in the case where B is greater than or equal to 2A, the plurality of first downlink control information can be located in one time slot, and the terminal can decode the first downlink control information as soon as possible to improve the access efficiency.

[0024] In an optional implementation of the third aspect, the first downlink control information further indicates a second repetition number M2 of the broadcast message; the method further includes: receiving M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, and M2 being a positive integer greater than or equal to M1.

[0025] The broadcast message carries information for terminal access, and the terminal can combine and decode the broadcast message received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the access information in the NTN. Alternatively, M2 can also be a positive integer less than M1, and the network device can flexibly indicate or configure the repetition number M2 of the broadcast message according to actual conditions.

[0026] In an optional implementation of the third aspect, determining the repetition number M1 and the time slot n0 for carrying the first downlink control information includes: receiving a synchronization signal block, the synchronization signal block including a second index, the second index being an index in a predefined second table; determining the repetition number M1 in the second table according to the second index, and determining the time slot n0 according to a part of parameters corresponding to the second index in the second table.

[0027] The repetition number M1 and the time slot n0 are indicated by the combination of the second index and the predefined table, and the network device only needs to transmit a small amount of transmission resource to transmit the second index, thereby reducing the information overhead of the transmission resource for indicating the first downlink control information.

[0028] In an optional implementation of the third aspect, the broadcast message is: an SIB1, or a combination of an SIB1 and an SIB19.

[0029] In the NTN, some access information is carried in the SIB19. If the SIB1 or the SIB19 is sent alone, the SIB19 also needs to be repeated multiple times to improve transmission reliability. In the embodiment, the network device in the NTN can compress the SIB1 and the SIB19 and repeatedly send them as one broadcast message. The terminal does not need to wait for the scheduling of the SIB1 to receive the SIB19, thereby improving the access rate of the terminal.

[0030] In a fourth aspect, the embodiments of the present application provide a communication method, which can be applied to a network side. The execution subject of the method can be a network device or a component implementing a communication function in the network device, or a circuit or chip of the network device. Hereinafter, the execution subject is taken as an example for description. The method comprises the following steps: determining a repetition number M1 and a time slot n0 used for carrying first downlink control information, the first downlink control information being used for indicating a time-frequency resource of a broadcast message, M1 being an integer greater than 1; determining, according to the first repetition number M1, a symbol number A of the first downlink control information, and a maximum symbol number B used for carrying downlink control information in one time slot, M1 pieces of first downlink control information being sent in N consecutive time slots starting from the time slot n0, the M1 pieces of first downlink control information being the same, A being a positive integer, B being a positive integer greater than or equal to A, and N being a positive integer less than or equal to M1; wherein N, M1, A, and B satisfy the following conditions:

[0031] In the embodiment, the first downlink control information can be sent by a network device (such as a satellite) in the NTN. The network device sends multiple repeated first downlink control information. The terminal can combine and decode the multiple received first downlink control information to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, in the embodiment, the time domain position of the first downlink control information is determined. The terminal does not need to perform blind detection in the search space, which also improves the transmission reliability of the downlink control information. In addition, in the case where B is greater than or equal to 2A, the multiple first downlink control information can be located in one time slot. The terminal can decode the first downlink control information as soon as possible to improve the access efficiency.

[0032] In an optional implementation of the fourth aspect, the first downlink control information further indicates a second repetition number M2 of the broadcast message; the method further comprises the following steps: sending M2 pieces of broadcast messages in M2 time slots, the M2 pieces of broadcast messages being the same, and M2 being a positive integer greater than or equal to M1.

[0033] The broadcast message carries information for terminal access, and the terminal can combine and decode the broadcast messages received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the access information in the NTN. Alternatively, M2 can also be a positive integer less than M1, and the network device can flexibly indicate or configure the number of repetitions M2 of the broadcast message according to actual conditions.

[0034] In an optional implementation of the fourth aspect, the method further includes: transmitting a synchronization signal block, the synchronization signal block including a second index, the second index being an index in a predefined second table, and a parameter corresponding to the second index in the second table including the number of repetitions M1 and a part of the parameter corresponding to the second index in the second table being used to determine the slot n0.

[0035] The number of repetitions M1 and the slot n0 are indicated by the second index in combination with the predefined table, and the network device only needs to transmit a small amount of transmission resource to transmit the second index, thereby reducing the information overhead of the transmission resource for indicating the first downlink control information.

[0036] In an optional implementation of the fourth aspect, the broadcast message is: an SIB1, or a combination of an SIB1 and an SIB19.

[0037] In the NTN, some access information is carried in the SIB19, and if the SIB1 or the SIB19 is transmitted alone, the SIB19 also needs to be repeated multiple times to improve the transmission reliability. In this embodiment, the network device in the NTN can compress the SIB1 and the SIB19 and repeatedly transmit them as one broadcast message, so that the terminal can receive the SIB19 without waiting for the scheduling of the SIB1, thereby improving the access rate of the terminal.

[0038] In the fifth aspect, the embodiments of the present application provide a communication apparatus. The communication apparatus can include a processing unit and a transceiver unit, and be configured to perform: any one of the methods in the first aspect and the optional implementations thereof, or any one of the methods in the second aspect and the optional implementations thereof, or any one of the methods in the third aspect and the optional implementations thereof, or any one of the methods in the fourth aspect and the optional implementations thereof; wherein the transceiver unit is a transmitting unit when performing the transmitting step, and the transceiver unit is a receiving unit when performing the receiving step.

[0039] In the sixth aspect, the embodiments of the present application provide a communication apparatus, which can be a terminal or a communication module in the terminal, or a circuit or a chip applied to the terminal. The communication apparatus can include a processor configured to perform: any one of the methods in the first aspect and the optional implementations thereof, or any one of the methods in the third aspect and the optional implementations thereof.

[0040] Optionally, when the communication apparatus is a terminal, the processor is, for example, a central processing unit (CPU), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA); when the communication apparatus is a chip, the processor is, for example, a core, which can include at least one execution unit, for example, an arithmetic and logic unit (ALU).

[0041] Optionally, the communication apparatus can further include a transceiver. When the communication apparatus is a terminal, the transceiver can be a transceiver circuit, an antenna, etc.; when the communication apparatus is a chip, the transceiver can be an input / output interface, a pin, a circuit, etc.

[0042] Optionally, the communication apparatus can further include a memory for storing a computer program or instructions, and the processor executes the computer program or instructions stored in the memory, so that the communication apparatus performs any one of the methods in the first aspect and the optional embodiments thereof, or so that the communication apparatus performs any one of the methods in the third aspect and the optional embodiments thereof. When the communication apparatus is a terminal, the memory can be a read-only memory, a random access memory, etc.; when the communication apparatus is a chip, the memory can be a register, a cache, etc.

[0043] In a seventh aspect, an embodiment of the present application provides a communication apparatus, which can be a network device or a component in a network device that implements a communication function, or can be a circuit or a chip applied to a network device. The communication apparatus can include a processor configured to perform: any one of the methods in the second aspect and the optional embodiments thereof, or any one of the methods in the fourth aspect and the optional embodiments thereof.

[0044] Optionally, when the communication apparatus is a network device, the processor is, for example, a CPU, an ASIC, or an FPGA; when the communication apparatus is a chip, the processor is, for example, a core, which can include at least one execution unit, for example, an ALU.

[0045] Optionally, the communication apparatus can further include a transceiver. When the communication apparatus is a network device, the transceiver can be a transceiver circuit, an antenna, etc.; when the communication apparatus is a chip, the transceiver can be an input / output interface, a pin, a circuit, etc.

[0046] Optionally, the communication apparatus further comprises a memory for storing a computer program or instructions, and the processor executes the computer program or instructions stored in the memory to enable the communication apparatus to perform any of the methods in the second aspect and the optional embodiments thereof, or to enable the communication apparatus to perform any of the methods in the fourth aspect and the optional embodiments thereof. When the communication apparatus is a network device, the memory can be a read-only memory, a random access memory, etc.; when the communication apparatus is a chip, the memory can be a register, a cache, etc.

[0047] It should be understood that the circuit or chip in the above aspects can be a Modem chip, also known as a baseband chip; or the circuit or chip in the above aspects can be a System on Chip (SoC) chip or a System in Package (SIP) chip containing a modem core, etc.

[0048] In an eighth aspect, embodiments of the present application provide a communication system, comprising: a communication apparatus for performing any of the methods in the first aspect and the optional embodiments thereof, and a communication apparatus for performing any of the methods in the second aspect and the optional embodiments thereof; or a communication apparatus for performing any of the methods in the third aspect and the optional embodiments thereof, and a communication apparatus for performing any of the methods in the fourth aspect and the optional embodiments thereof.

[0049] In a ninth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program, when the computer program is executed on a communication apparatus, causing the communication apparatus to perform: any of the methods in the first aspect and the optional embodiments thereof, or any of the methods in the second aspect and the optional embodiments thereof, or any of the methods in the third aspect and the optional embodiments thereof, or any of the methods in the fourth aspect and the optional embodiments thereof.

[0050] In a tenth aspect, embodiments of the present application provide a computer program product, comprising: computer program code or computer program instructions, when the computer program code or computer program instructions are run on a communication apparatus, causing the communication apparatus to perform: any of the methods in the first aspect and the optional embodiments thereof, or any of the methods in the second aspect and the optional embodiments thereof, or any of the methods in the third aspect and the optional embodiments thereof, or any of the methods in the fourth aspect and the optional embodiments thereof. BRIEF DESCRIPTION OF DRAWINGS

[0051] FIG. 1 is a schematic diagram of an architecture of a communication system to which embodiments of the present application are applied;

[0052] FIG. 2 is a structural diagram of a radio access network node according to an embodiment of the present application;

[0053] FIG. 3 is a schematic diagram of an NTN architecture including a transmissive mode satellite according to an embodiment of the present application;

[0054] FIG. 4 is a schematic diagram of a synchronization signal block according to an embodiment of the present application;

[0055] FIG. 5 is a schematic diagram of a cell search method according to an embodiment of the present application;

[0056] FIG. 6 is a schematic diagram of an NTN link according to an embodiment of the present application;

[0057] FIG. 7 is a schematic flowchart of a communication method according to an embodiment of the present application;

[0058] FIG. 8 is a schematic diagram of a time domain position relationship between a first downlink control information and a broadcast message according to an embodiment of the present application;

[0059] FIG. 9 is a schematic diagram of another time domain position relationship between a first downlink control information and a broadcast message according to an embodiment of the present application;

[0060] FIG. 10 is a schematic flowchart of another communication method according to an embodiment of the present application;

[0061] FIG. 11 is a schematic diagram of another time domain position relationship between a first downlink control information and a broadcast message according to an embodiment of the present application;

[0062] FIG. 12 is a schematic diagram of another time domain position relationship between a first downlink control information and a broadcast message according to an embodiment of the present application;

[0063] FIG. 13 is a structural diagram of a communication apparatus according to an embodiment of the present application;

[0064] FIG. 14 is a structural diagram of another communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0065] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0066] FIG. 1 is a schematic diagram of an architecture of a communication system 1000 to which embodiments of the present application are applied. As shown in FIG. 1, the communication system includes a radio access network (RAN) 100, wherein the RAN 100 includes at least one RAN node (e.g., 110a-110e, collectively referred to as 110 in FIG. 1), and can further include at least one terminal (e.g., 120a-120d, collectively referred to as 120 in FIG. 1). The RAN 100 can further include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 1). The terminals 120 are connected to the RAN nodes 110 in a wireless manner. Terminals and terminals, and RAN nodes and RAN nodes can be connected to each other in a wired or wireless manner. The communication system 1000 can further include a core network 200. The RAN nodes 110 are connected to the core network 200 in a wireless or wired manner. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 can be independent and different physical devices, or can be the same physical device integrated with the logical functions of the core network devices and the logical functions of the RAN nodes. The communication system 1000 can further include the Internet 300.

[0067] The RAN 100 can be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, or a future wireless access system defined in the 3rd generation partnership project (3GPP). The RAN 100 can also include two or more different wireless access systems. The RAN 100 can also be an open RAN (O-RAN).

[0068] The RAN node, also referred to as a network device, a radio access network device, a RAN entity, or an access node, is configured to help the terminal to access the communication system in a wireless manner.

[0069] In one application scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, a base station in a future communication network, an access node (AP) in a Wi-Fi system, an AP in a long range radio (LoRa) system, or an AP in a vehicle-to-everything (V2X) system. The RAN node can be a macro base station (e.g., 110a in FIG. 1), a micro base station or an indoor station (e.g., 110e in FIG. 1), or a relay node (e.g., 110b and 110c in FIG. 1).

[0070] In another application scenario, a terminal can access a wireless network through cooperation of a plurality of RAN nodes, and different RAN nodes implement part of functions of a base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). The CU here implements functions of a radio resource control (RRC) protocol and a packet data convergence protocol (PDCP) of a base station, and can also implement a function of a service data adaptation protocol (SDAP). The DU implements functions of a radio link control (RLC) layer and a medium access control (MAC) layer of a base station, and can also implement part or all of functions of a physical (PHY) layer. Details of the protocol layers can be referred to related technical specifications of the 3GPP. The RU can be used to implement functions of transmitting and receiving radio frequency signals. The CU and the DU can be two independent RAN nodes, or can be integrated in the same RAN node, for example, integrated in a baseband unit (BBU). The RU can be included in a radio frequency device, for example, included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0071] In different systems, the RAN node can have different names, for example, in an O-RAN system, the CU can be referred to as an open CU (O-CU), the DU can be referred to as an open DU (O-DU), and the RU can be referred to as an open RU (O-RU).

[0072] FIG. 2 is a schematic diagram of an architecture of an O-RAN according to an embodiment of the present application.

[0073] As shown in FIG. 2, the O-RAN 200 includes a CU 210, a DU 220, and an RU 230. Optionally, the CU 210 and the DU 220 can be integrated in a BBU 240, and the BBU 240 can be co-located or non-co-located with the RU 230. The CU 210 can communicate with a core network 250 through a backhaul link, the CU 210 and the DU 220 can communicate through a midhaul link, the DU 220 and the RU 230 can communicate through a fronthaul link, and the RU 230 and a UE 260 can communicate through an air interface.

[0074] The RAN node in the embodiments of the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node can be a server loaded with a corresponding software module. The embodiments of the present application do not limit the specific technology and specific device form of the RAN node. For ease of description, a base station is taken as an example of the RAN node in the following description.

[0075] A terminal is a device with wireless transceiving function, which can send signals to a base station or receive signals from a base station. The terminal can also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. The terminal can be widely applied to various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality (VR), augmented reality (AR), industrial control, automatic driving, remote medical treatment, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal can be a mobile phone (such as 120a and 120b in FIG. 1), a tablet computer (such as 120c in FIG. 1), a printer with wireless transceiving function (such as 120d in FIG. 1), a wearable device, a vehicle, a charging pile, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. Embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal.

[0076] By way of example and not limitation, in embodiments of the present application, a wearable device can also be referred to as a wearable smart device, which is a general term for devices that can be worn on the body, such as glasses, gloves, watches, clothing, and shoes, etc. The wearable device is a portable device that can be directly worn on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a device that can realize powerful functions through software support and data interaction and cloud interaction. Broadly, a wearable smart device includes an electronic device with full functionality, large size, and the ability to realize complete or partial functions without relying on a smart phone, such as a smart watch or smart glasses, or an electronic device that focuses on a certain application function and needs to be used in conjunction with other devices such as a smart phone, such as various smart wristbands and smart jewelry for measuring vital signs.

[0077] By way of example and not limitation, in embodiments of the present application, a vehicle can be a smart car or an intelligent car, a digital car, an unmanned car or driverless car or pilotless car or automobile, a self-driving car or autonomous car, or an electric vehicle (EV), where the EV can be a pure EV or battery EV, a hybrid electric vehicle (HEV), a range extended EV (REEV), a plug-in HEV (PHEV), or a new energy vehicle. The various terminals introduced above, if located on a vehicle (e.g., placed inside or installed inside a vehicle), can be considered as a vehicle-mounted terminal, which can also be referred to as a vehicle-mounted module, a vehicle-mounted chip, or an on-board unit (OBU).

[0078] The base stations and terminals can be fixed in position or mobile. The base stations and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can be deployed on water; can also be deployed on airplanes, balloons, and artificial satellites. Embodiments of the present application do not limit the application scenarios of the base stations and terminals.

[0079] The roles of the base stations and terminals can be relative, for example, 110d (which can be a helicopter or a drone) in FIG. 1 can be configured as a mobile base station, and for those terminals accessing the wireless access network 100 through 110d, 110d is a base station; but for 110a, 110d is a terminal, that is, 110a and 110d communicate with each other through a wireless air interface protocol. Of course, 110a and 110d can also communicate through an interface protocol between base stations and base stations, at this time, relative to 110a, 110d is also a base station. Therefore, the base stations and terminals can be collectively referred to as communication devices, 110a-110e in FIG. 1 can be referred to as communication devices with base station functions, and 120a-120d in FIG. 1 can be referred to as communication devices with terminal functions.

[0080] The base station and the terminal, the base station and the base station, the terminal and the terminal can communicate through the licensed spectrum, or through the unlicensed spectrum, or through the licensed spectrum and the unlicensed spectrum at the same time; can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6 GHz, or through the spectrum below 6 GHz and the spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used by wireless communication.

[0081] In the embodiments of the present application, the functions of the base station can also be performed by a module (such as a chip) in the base station, or by a control subsystem containing the functions of the base station. The control subsystem containing the functions of the base station herein can be a control center in the above-mentioned application scenarios such as smart grid, industrial control, intelligent transportation, and smart city. The functions of the terminal can also be performed by a module (such as a chip or a modem) in the terminal, or by a device containing the functions of the terminal.

[0082] In the embodiments of the present application, the base station sends downlink information to the terminal, the downlink information is carried on the downlink channel, and the downlink information can also be referred to as a downlink signal; the terminal sends uplink information to the base station, the uplink information is carried on the uplink channel, and the uplink information can also be referred to as an uplink signal.

[0083] In order to facilitate understanding of the embodiments of the present application, the technologies involved in the embodiments of the present application are briefly introduced as follows.

[0084] 1, NTN.

[0085] The network that realizes communication with the help of non-terrestrial network equipment can be referred to as NTN. The NTN can include satellite, HAPS or UAS and other aerial network equipment, has the advantages of wide coverage, long communication distance, high reliability, great flexibility, high throughput, etc., is not affected by geographical environment, climate conditions and natural disasters, etc., and has been widely used in various fields. For example, the NTN can provide communication services for areas that are difficult to cover by ground networks (such as oceans, forests, deserts or remote areas); on the other hand, the NTN can enhance the reliability of mobile communication, such as providing more stable communication services for users in high-speed mobile scenarios such as trains and airplanes; in addition, the NTN can also provide more data transmission resources to support a larger number of terminal devices to be connected. The NTN containing a satellite is taken as an example for description.

[0086] Generally speaking, the higher the orbit of a satellite, the larger the coverage area, but the longer the communication delay. According to the orbit height, satellites can be divided into geostationary earth orbit (GEO) satellites, medium earth orbit (MEO) satellites and low earth orbit (LEO).

[0087] The orbit height of a GEO satellite is about 35000 km. The GEO satellite is stationary relative to the ground and can provide a large coverage area. However, the GEO satellite is too far from the ground, requiring a large-diameter antenna for communication. The large distance also results in a large transmission delay of the GEO satellite, which cannot meet the needs of real-time services. In addition, the tight synchronous orbit resources, high launch cost and inability to cover the polar regions are all factors that restrict the development of GEO satellites.

[0088] The orbit height of a MEO satellite is about 2000 km to 35000 km. The orbit height of a MEO satellite is lower than that of a GEO satellite but higher than that of a LEO satellite. A small number of MEO satellites can achieve global coverage. At present, MEO satellites are mainly used for positioning and navigation.

[0089] The orbit height of a LEO satellite is about 300 km to 2000 km. The orbit height of a LEO satellite is relatively low, and the transmission delay and launch cost are lower than those of a GEO satellite and a MEO satellite. Therefore, communication systems based on LEO satellites have made great progress in recent years.

[0090] According to the working mode, the working mode of a satellite can generally be divided into two categories, namely, transparent mode and regenerative mode.

[0091] The main difference between the transparent mode and the regenerative mode is the processing method of the signal. A satellite working in the transparent mode performs radio frequency processing on the uplink signal before transmitting it downward, but does not perform baseband demodulation, decoding and other processing. For example, a satellite working in the transparent mode can change the carrier frequency of the uplink signal and perform filtering and amplification processing. For a satellite working in the regenerative mode, in addition to performing radio frequency processing on the uplink signal before transmitting it downward, it can also perform demodulation, decoding, re-encoding and re-modulation processing on the uplink signal, which is equivalent to integrating part or all of the functions of the base station on the satellite. In addition, a satellite working in the regenerative mode usually has an inter-satellite link (ISL), which can work in the radio frequency (RF) band or the optical band. A satellite working in the transparent mode does not necessarily have an ISL.

[0092] The NTN architecture involved in the present application is described below taking the transparent mode as an example.

[0093] FIG. 3 is a schematic diagram of an NTN architecture including a transparent mode satellite. In the transparent mode, the main role of the satellite is layer (L) 1 relay, for example, performing processing such as radio frequency filtering, frequency conversion, and amplification on physical layer signals, without the function of higher protocol layers. The terminal connects with a ground network device through the satellite, and the ground network device includes a gateway and a base station shown in FIG. 3, wherein the gateway can also be referred to as a “gateway station”. In the transparent mode, the satellite and the gateway can be regarded as RRUs, and the satellite, the gateway, and the base station collectively implement the function of the RAN. Alternatively, the gateway can also be integrated with the base station.

[0094] For example, for uplink, the terminal sends an uplink signal (carrying the uplink data of the terminal) through a Uu interface, the satellite receives the uplink signal and forwards the uplink signal to the gateway (the satellite can perform frequency conversion on the signal), and the gateway forwards the uplink signal to the base station. After the base station receives the uplink signal, it performs relevant processing to obtain the data that the terminal needs to send to the core network, and can send the data to the core network through an interface (such as an NG interface) between the base station and the core network. The core network can send the data to the Internet through an N6 interface. For downlink, the Internet can send downlink data to the core network through an N6 interface, and the core network sends the downlink data to the base station through an interface between the base station and the core network. After the base station receives the downlink data, it performs relevant processing to generate a downlink signal (carrying the downlink data) and can send the downlink signal to the gateway through a Uu interface. The gateway sends the downlink signal to the satellite, and the satellite forwards the downlink signal to the terminal (the satellite can perform frequency conversion on the signal).

[0095] It should be noted that in the description of various places in the present application, the name of the interface is an example and not a limitation. As technology develops, other interfaces with the same or similar functions can appear, and these new interfaces are also applicable to the present application. The present application does not limit the interface through which data is transmitted between devices.

[0096] 2. Initial access in NTN.

[0097] Initial access is also referred to as initial channel access, including cell search and random access, and the present application mainly relates to cell search.

[0098] A cell can be regarded as a wireless signal coverage area identified by a cell global identifier (CGI) or a physical cell identifier (PCI). The signal coverage area of each base station can be divided into one or more cells.

[0099] The above description about the cell is an example and is not limited, and as the technology develops, concepts similar or identical to the functions of the cell can appear, and these concepts are also applicable to the embodiments of the present application.

[0100] Cell search can be considered as a process of finding a new cell and completing time synchronization and frequency synchronization with the new cell. The terminal can perform cell search before performing cell handover or when turning on and searching for a network.

[0101] The terminal can perform cell search based on a synchronization signal and a physical broadcast channel block (SSB). The synchronization signal and the physical broadcast channel block can also be referred to as a synchronization signal block. As shown in FIG. 4, the SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcasting channel (PBCH), occupies 4 orthogonal frequency division multiplexing (OFDM) symbols in the time domain, and occupies 240 subcarriers in the frequency domain, wherein the PSS and the SSS each occupy 127 subcarriers.

[0102] As a network device, the satellite can send different SSBs to different areas and distinguish them by the index of the SSB. Different SSB indexes represent areas covered by SSBs in different beam directions.

[0103] After receiving the SSB, the terminal decodes the SSB and performs corresponding operations according to the decoded information. As shown in FIG. 5, by detecting the PSS, the terminal can complete time synchronization and frequency synchronization with the new cell and determine the transmission time of the SSS; by detecting the PSS and the SSS, the terminal can determine the PCI of the new cell. The PBCH carries the main information block (MIB), and the terminal decodes the PBCH to obtain the MIB and obtain the information related to random access in the MIB, such as the time-frequency resource information of the physical downlink control channel (PDCCH); the terminal can detect the PDCCH according to the time-frequency resource information of the PDCCH to obtain the downlink control information, which indicates or configures the time-frequency resource of the SIB1, and the terminal receives the SIB1 on the time-frequency resource of the SIB1 and decodes the SIB1 to obtain the cell system information. In the NTN containing satellites, the SIB1 can also indicate or configure the time-frequency resource of the SIB19, and the terminal receives the SIB19 on the time-frequency resource of the SIB19 and decodes the SIB19 to obtain the satellite ephemeris information.

[0104] After obtaining the cell system information and the ephemeris information, the terminal can send a random access preamble on the uplink resource corresponding to the SSB index to start random access. For the network device, the area where the terminal is located can be determined by the received random access preamble and the corresponding uplink resource, and a connection with the terminal can be established.

[0105] 3. Transmission link of the NTN.

[0106] FIG. 6 is a schematic diagram of a transmission link of an NTN provided by an embodiment of the present application. In the NTN, according to the communication object, the link between the terminal and the satellite can be referred to as a service link, and the link between the satellite and the gateway can be referred to as a feeder link. In addition, according to the data flow direction, the link in the gateway→satellite→terminal direction can be referred to as a forward link (i.e., a downlink), and the link in the terminal→satellite→gateway direction can be referred to as a reverse link (i.e., an uplink). Therefore, the transmission delay of the NTN includes the transmission delay on the service link and the transmission delay on the feeder link.

[0107] As shown in FIG. 6, in the NTN, the distance between the terminal and the satellite is far, which causes a large path loss of the service link. If the terminal still receives the downlink control information according to the search space-based downlink control information receiving mode in the terrestrial network, the probability of decoding failure of the downlink control information will increase, and therefore the search space-based downlink control information receiving mode cannot be applied to the NTN.

[0108] The communication method provided by an embodiment of the present application will be described below.

[0109] As shown in FIG. 7, the method 700 is respectively performed by a base station and a terminal, or the method 700 is respectively performed by a chip applied to the base station and a chip applied to the terminal. The following is described by taking the base station and the terminal as examples. The method 700 comprises:

[0110] S710, the base station determines a repetition number M and a first time domain position in a time slot n0 used to carry first downlink control information, the first downlink control information is used to indicate (or configure) a time-frequency resource of a broadcast message, and M is an integer greater than 1.

[0111] M is the repetition number of the first downlink control information, and the base station can determine a specific value of M according to an internal algorithm and a current communication environment. For example, the satellite is currently located at an apogee, resulting in poor link budget of a service link, and the base station can determine M as a larger value to improve the decoding performance of the first downlink control information. For another example, the satellite is currently located at a perigee, and the link budget of the service link is good, and the base station can determine M as a smaller value to reduce the resource overhead of the first downlink control information.

[0112] The starting position of the first time domain position can be located at the first symbol of the time slot n0, or can be located at a symbol other than the first symbol of the time slot n0. When the starting position of the first time domain position is located at the first symbol of the time slot n0, the terminal can receive the first downlink control information as soon as possible, and accelerate the rate of cell search.

[0113] The number of symbols occupied by the first time domain position is related to the information amount of the first downlink control information. For example, in the case of unchanged frequency domain resource, when the information amount of the first downlink control information is large, the first time domain position occupies more symbols; when the information amount of the first downlink control information is small, the first time domain position occupies fewer symbols. Alternatively, the first downlink control information can occupy 1, 2 or 3 symbols.

[0114] Alternatively, M and the first time domain position can be information in a first predefined table, wherein the indexes corresponding to M and the first time domain position in the first table are first indexes, and the time slot n0 can be determined according to other parameters indicated by M and the first indexes. The base station can send the first indexes to the terminal through the MIB, so as to facilitate the terminal to determine M, the first time domain position and the time slot n0, wherein the time slot n0 can be a time slot adjacent to a time slot where the SSB is located.

[0115] Alternatively, M, the first time domain position and the time slot n0 can also be dynamically indicated by the base station, and are no longer associated with the first predefined table. For example, the base station sends the value of M, the index of the first time domain position and the index of the time slot n0 through the MIB.

[0116] Taking the base station sending the first index as an example, the base station can perform the following steps.

[0117] S720, the base station sends an SSB to the terminal, and the MIB in the SSB carries the first index.

[0118] Correspondingly, the terminal receives the SSB from the base station and obtains the first index therefrom.

[0119] Optionally, the first index can be indicated in an explicit manner, for example, the first index can be represented by two bits, when the two bits are 00, it represents index 0; when the two bits are 01, it represents index 1. Optionally, the first index can also be indicated in an implicit manner, for example, the first index can be indicated by the encoding manner of a certain information in the MIB, when the information adopts a first encoding manner, the MIB indicates index 0; when the information adopts a second encoding manner, the MIB indicates index 1. The embodiments of the present application do not limit the indication manner of the first index.

[0120] Subsequently, the terminal can perform the following steps.

[0121] S730, the terminal determines the repetition number M and the first time domain position in the time slot n0 used to carry the first downlink control information, the first downlink control information being used to indicate (or configure) the time-frequency resource of the broadcast message, M being an integer greater than 1.

[0122] The terminal can determine M, the time slot n0 and the first time domain position through the MIB. The following takes the MIB carrying the first index as an example to introduce the process of the terminal determining M, the time slot n0 and the first time domain position. Table 1 is an example of the first table.

[0123] Table 1

[0124] In Table 1, the index value in the first column is an example of the first index; M is the repetition number of the first downlink control information; the index of the first symbol represents the index of the starting symbol of the first time domain position, and optionally, the index of the first symbol can also be 1 or 2; O is a parameter used to configure the starting time slot of the PDCCH, that is, a parameter used to calculate the time slot n0, and optionally, the value of O can also be 5 or 7.

[0125] For example, when the MIB carries the index 0, the base station determines the value of M as 1 according to the index 0 querying the table 1, and thus determines the repetition number of the first downlink control information as 1, i.e., the base station transmits 1 first downlink control information; when the MIB carries the index 1, the base station determines the value of M as 2 according to the index 1 querying the table 1, and thus determines the repetition number of the first downlink control information as 2, i.e., the base station transmits 2 first downlink control information; when the MIB carries the index 2, the base station determines the value of M as 1 according to the index 2 querying the table 1, and thus determines the repetition number of the first downlink control information as 1, i.e., the base station transmits 1 first downlink control information; when the MIB carries the index 3, the base station determines the value of M as 4 according to the index 3 querying the table 1, and thus determines the repetition number of the first downlink control information as 4, i.e., the base station transmits 4 first downlink control information.

[0126] The terminal can calculate n0 according to the following formula:

[0127] Wherein, O and M are the values in the table 1, i represents the index of the SSB, μ represents a calculation coefficient corresponding to the NR subcarrier spacing, for example, for the subcarrier spacing configuration Δf, Δf = 2 μ · 15 [kHz], when the value of Δf is 15, μ is equal to 0, represents the floor operation, mod represents the modulo operation, represents the number of slots included in a system frame.

[0128] The first index is combined with the pre-defined table to indicate M, the first time domain position and the slot n0, and the base station only needs to transmit a small amount of transmission resource to transmit the first index, thereby reducing the information overhead of the transmission resource indicating the first downlink control information.

[0129] It should be noted that the table 1 is an example and is not limited, and the table 1 can also include more or less information. For example, the index of the first symbol can also be protocol-defined or pre-configured, and the table 1 does not need to reserve the column where the index of the first symbol is located. For another example, the table 1 can increase the index of the slot n0, so that the terminal does not need to calculate the index of n0 again, thereby reducing the calculation resource overhead of the terminal.

[0130] After the base station transmits the first index, the following steps can be performed.

[0131] S740, the base station transmits the first downlink control information at the first time domain position, and transmits M-1 retransmitted first downlink control information at the same time domain position in the consecutive M-1 slots after the slot n0. That is, the base station transmits M first downlink information.

[0132] Correspondingly, the terminal receives the first downlink control information at the first time domain position, and receives the M-1 retransmitted first downlink control information at the same time domain position in the M-1 continuous time slots after the time slot n0.

[0133] In the transparent scene, the base station is located on the ground, and the base station can send the M first downlink information to the terminal through the satellite or other aircraft. In the renewable scene, the base station is a satellite or other aircraft, and the base station can directly send the M first downlink information to the terminal.

[0134] The above-mentioned M-1 continuous time slots can be M-1 time slots adjacent to the time slot n0, that is, there is no other time slot between the M-1 continuous time slots and the time slot n0, so that the base station does not need to additionally indicate the position of the M-1 continuous time slots, and the terminal can receive the M-1 retransmitted first downlink control information in the M-1 continuous time slots after the time slot n0 according to the default rule.

[0135] It should be pointed out that in various embodiments of the present application, the retransmission can be a concept related to the redundancy version, or a concept related to the redundancy version.

[0136] In addition, the encoding mode of the M first downlink control information can be the same or different, and the embodiments of the present application do not limit the retransmission mode of the M first downlink control information.

[0137] Optionally, the first downlink control information in the time slot n0+j is used to indicate the time-frequency resource of the broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}. The broadcast message can be SIB1.

[0138] The time domain positions of the M first downlink control information and the M broadcast messages are shown in FIG. 8.

[0139] In FIG. 8, the base station sends two SSBs in the time slot 0 and the time slot 1 respectively, wherein the SSB in the symbol 2-symbol 5 of the time slot 0 is used to schedule the PDCCH in the time slot 2, and the PDCCH in the time slot 2 is repeatedly transmitted at the same time domain position in the time slot 3-time slot 5; the SSB in the symbol 8-symbol 11 of the time slot 0 is used to schedule the PDCCH in the time slot 6, and the PDCCH in the time slot 6 is repeatedly transmitted at the same time domain position in the time slot 7-time slot 9. The PDCCH in each time slot is used to carry the downlink control information, and the downlink control information in each time slot is used to schedule the broadcast message in the respective time slot.

[0140] For example, when M is equal to 4, the downlink control information in time slot 2, time slot 3, time slot 4 and time slot 5 are all first downlink control information, and time slot 2 is an example of time slot n0, and the first symbol in time slot 2 is an example of the first time domain position. Among them, the downlink control information in time slot 2 is used to schedule the broadcast message in time slot 2, the downlink control information in time slot 3 is used to schedule the broadcast message in time slot 3, the downlink control information in time slot 4 is used to schedule the broadcast message in time slot 4, and the downlink control information in time slot 5 is used to schedule the broadcast message in time slot 5.

[0141] In FIG. 8, the number of repetitions of the broadcast message is the same as the number of repetitions of the downlink control information. For example, when M is equal to 4, the broadcast messages in time slot 2, time slot 3, time slot 4 and time slot 5 are all first broadcast messages.

[0142] The above broadcast message carries information for terminal access, and the terminal can combine and decode the broadcast messages received multiple times to improve the decoding success rate, thereby improving the transmission reliability of access information in the NTN.

[0143] Optionally, the above broadcast message can be SIB1, or a combination of SIB1 and SIB19.

[0144] In the NTN, some access information is carried in SIB19, and if SIB1 or SIB19 is sent alone, SIB19 also needs to be repeated multiple times to improve transmission reliability. In the embodiment, the network device in the NTN can compress SIB1 and SIB19 and send them as one broadcast message repeatedly, so that the terminal does not need to wait for the scheduling of SIB1 to receive SIB19, thereby improving the access rate of the terminal.

[0145] For example, for low-altitude flying vehicles such as unmanned aerial vehicles, the terminal does not need ephemeris information to access the network of such low-altitude flying vehicles, so the broadcast message can be SIB1; for high-altitude flying vehicles such as GEO satellites, ephemeris information is necessary for random access, so the above broadcast message can be a combination of SIB1 and SIB19, wherein the base station can compress SIB1 and SIB19 and combine them into one SIB that can be scheduled in one time slot.

[0146] As shown in FIG. 9, one time slot can carry two PDCCHs and two broadcast messages, the two PDCCHs can be adjacent or not adjacent, each PDCCH schedules one broadcast message, that is, indicates the time-frequency resources of one broadcast message. The two broadcast messages can be compressed SIB1 and compressed SIB19, or the two broadcast messages can be part of the information in SIB1 (information for access) and part of the information in SIB19 (information for access), and the remaining information in SIB1 and SIB19 can be transmitted in subsequent system messages supporting repetition.

[0147] To sum up, in the method 700, the first downlink control information can be sent by a network device (such as a satellite) in an NTN, and the terminal can combine and decode the first downlink control information received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, the time domain position of the first downlink control information is determined, and the terminal does not need to perform blind detection in the search space, which also improves the transmission reliability of the downlink control information.

[0148] The following describes a communication method provided by another embodiment of the application.

[0149] As shown in FIG. 10, the method 1000 is respectively performed by a base station and a terminal, or the method 1000 is respectively performed by a chip applied to the base station and a chip applied to the terminal. The following describes the base station and the terminal as examples. The method 1000 includes:

[0150] S1010, the base station determines a repetition number M1 and a time slot n0 for carrying first downlink control information, the first downlink control information is used to indicate (or configure) time-frequency resources of a broadcast message, and M1 is an integer greater than 1.

[0151] M1 is the repetition number of the first downlink control information, and the base station can determine the specific value of M1 according to an internal algorithm and the current communication environment. For example, the satellite is currently located at the apogee, resulting in poor link budget of the service link, and the base station can determine M1 as a larger value to improve the decoding performance of the first downlink control information. For another example, the satellite is currently located at the perigee, and the link budget of the service link is good, and the base station can determine M1 as a smaller value to reduce the resource overhead of the first downlink control information.

[0152] The time domain position where the first downlink control information among the M1 first downlink control information is transmitted first can be referred to as a first time domain position. The starting position of the first time domain position can be located at the first symbol of the time slot n0, or can be located at a symbol other than the first symbol in the time slot n0. When the starting position of the first time domain position is located at the first symbol of the time slot n0, the terminal can receive the first downlink control information as soon as possible, and accelerate the rate of cell search.

[0153] The number of symbols occupied by the first time domain position is related to the information amount of the first downlink control information. For example, in the case where the frequency domain resource is unchanged, when the information amount of the first downlink control information is large, the first time domain position occupies more symbols; when the information amount of the first downlink control information is small, the first time domain position occupies fewer symbols. Alternatively, the first downlink control information can occupy 1, 2 or 3 symbols.

[0154] Alternatively, M1 and the first time domain position can be information in a second predefined table, wherein the corresponding index of M1 and the first time domain position in the second table is a second index, and the time slot n0 can be determined according to other parameters indicated by M1 and the second index. The base station can send the second index to the terminal through the MIB, so as to facilitate the terminal to determine M1, the first time domain position and the time slot n0, wherein the time slot n0 can be a time slot adjacent to the time slot where the SSB is located.

[0155] Alternatively, M1, the first time domain position and the time slot n0 can also be dynamically indicated by the base station, and are no longer associated with the second predefined table. For example, the base station sends the value of M, the index of the first time domain position and the index of the time slot n0 through the MIB.

[0156] Taking the case where the base station sends the second index as an example, the base station can perform the following steps.

[0157] S1020, the base station sends an SSB to the terminal, and the MIB in the SSB carries the second index.

[0158] Correspondingly, the terminal receives the SSB from the base station, and obtains the second index therefrom.

[0159] Alternatively, the second index can be indicated in an explicit manner, for example, the second index can be represented by two bits, when the two bits are 00, it represents index 0; when the two bits are 01, it represents index 1. Alternatively, the second index can also be indicated in an implicit manner, for example, the second index can be indicated by the encoding manner of a certain information in the MIB, when the information adopts a first encoding manner, the MIB indicates index 0; when the information adopts a second encoding manner, the MIB indicates index 1. The embodiments of the present application do not limit the indication manner of the second index.

[0160] Subsequently, the terminal can perform the following steps.

[0161] S1030, the terminal determines a repetition number M1 and a time slot n0 used to carry the first downlink control information, the first downlink control information being used to indicate a time-frequency resource of a broadcast message, M1 being an integer greater than 1.

[0162] The terminal can determine M1, the time slot n0 and the first time domain position through the MIB. The following takes an example of the MIB carrying a second index to introduce the process of the terminal determining M1, the time slot n0 and the first time domain position. Table 2 is an example of a second table.

[0163] Table 2

[0164] In Table 2, the index value in the first column is an example of the second index; M1 is the repetition number of the first downlink control information; the index of the first symbol represents the index of the starting symbol of the first time domain position, and optionally, the index of the first symbol can also be 1 or 2; O is a parameter for configuring the starting time slot of the PDCCH, that is, a parameter for calculating the time slot n0, and optionally, the value of O can also be 5 or 7.

[0165] For example, when the MIB carries the index 0, the base station determines the value of M1 as 1 according to the index 0 querying Table 2, so as to determine that the repetition number of the first downlink control information is 1, that is, the base station will send 1 first downlink control information; when the MIB carries the index 1, the base station determines the value of M1 as 2 according to the index 1 querying Table 2, so as to determine that the repetition number of the first downlink control information is 2, that is, the base station will send 2 first downlink control information; when the MIB carries the index 2, the base station determines the value of M1 as 1 according to the index 2 querying Table 2, so as to determine that the repetition number of the first downlink control information is 1, that is, the base station will send 1 first downlink control information; when the MIB carries the index 3, the base station determines the value of M1 as 4 according to the index 3 querying Table 2, so as to determine that the repetition number of the first downlink control information is 4, that is, the base station will send 4 first downlink control information.

[0166] The terminal can calculate n0 according to the following formula:

[0167] Wherein, O and M1 are the values in Table 2, i represents the index of the SSB, and μ represents a calculation coefficient corresponding to the NR subcarrier spacing, for example, for the subcarrier spacing configuration Δf, Δf = 2 μ 15 [kHz], when the value of Δf is 15, μ is equal to 0, represents the floor operation, and mod represents the modulo operation. represents the number of time slots included in a system frame.

[0168] The M1, the first time domain position and the time slot n0 are indicated by the second index in combination with the predefined table, and the base station only needs a small amount of transmission resources to transmit the second index, thereby reducing the information overhead of the transmission resources for indicating the first downlink control information.

[0169] It should be noted that Table 2 is an example and is not limited, and Table 2 can also include more or less information. For example, the index of the first symbol can also be protocol-defined or pre-configured, and Table 2 does not need to reserve the column where the index of the first symbol is located. For another example, Table 2 can add the index of the time slot n0, so that the terminal does not need to calculate the index of n0 again, thereby reducing the calculation resource overhead of the terminal.

[0170] Returning to S1010, after the base station performs S1010, the following steps can be performed.

[0171] S1040, the base station determines to receive M1 first downlink control information in the continuous N time slots starting from the time slot n0 according to the first repetition number M1, the symbol number A of the first downlink control information and the maximum symbol number B in a time slot for carrying downlink control information, the M1 first downlink control information is the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

[0172] In the above steps, represents the floor operation, represents the ceiling operation, the value of N is equal to the value of In the case of a positive integer, each of the N time slots carries first downlink control information; in the case of a non-positive integer, first downlink control information, the Nth time slot in the N time slots carries the remaining first downlink control information, and

[0173] The design idea of the above steps is to place as much first downlink control information as possible in the time slot close to the SSB, so that the terminal can receive M1 first downlink control information as soon as possible. The following gives several examples of calculating N.

[0174] Example 1: The PDCCH carrying the first control information is repeated 4 times in total, each PDCCH occupies 1 symbol, and each time slot has a maximum of 3 symbols carrying PDCCH, then M1=4, A=1, B=3. The calculation process of the number N of time slots carrying PDCCH is as follows:​

[0175] indicates that each slot carries at most 3 PDCCHs;

[0176] that is, N = 2, indicates that 2 slots are needed to carry 4 PDCCHs.

[0177] Example 2: The PDCCH carrying the first control information is repeated a total of 4 times, each PDCCH occupies 2 symbols, and each slot carries at most 3 symbols of PDCCH, then M1 = 4, A = 2, and B = 3. The calculation process of the number of slots N carrying PDCCH is as follows:

[0178] indicates that each slot carries at most 1 PDCCH;

[0179] that is, N = 4, indicates that 4 slots are needed to carry 4 PDCCHs.

[0180] In Examples 1 and 2, A and B can be pre-set, such as values specified in the protocol. In Example 1, the base station can send 4 first control information on slot n0 and slot n1, where slot n0 is a slot adjacent to the SSB, and slot n1 is a slot adjacent to slot n0 after slot n0; in Example 2, the base station can send 4 first control information on slot n0, slot n1, slot n2, and slot n3, where slot n0 is a slot adjacent to the SSB, and slot n1, slot n2, and slot n3 are three consecutive slots adjacent to slot n0 after slot n0.

[0181] For the terminal, after the terminal determines M1, S1050 can be performed.

[0182] S1050, the terminal determines to receive M1 first downlink control information in the consecutive N slots starting from slot n0 according to the first repetition number M1, the symbol number A of the first downlink control information, and the maximum symbol number B for carrying downlink control information in a slot, the M1 first downlink control information is the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

[0183] The terminal determines N in the same way as the base station determines N, which will not be repeated here.

[0184] After the base station determines N, the following steps can be performed.

[0185] S1060, the base station sends M1 first downlink control information in N slots.

[0186] Accordingly, the terminal receives M1 first downlink control information in N time slots.

[0187] In the transparent transmission scenario, the base station is located on the ground, and the base station can transmit the M1 first downlink information to the terminal through a satellite or other aircraft. In the renewable scenario, the base station is a satellite or other aircraft, and the base station can directly transmit the M1 first downlink information to the terminal.

[0188] As described above, the first downlink control information indicates the time-frequency resource of the broadcast message. Optionally, the first downlink control information further indicates a second repetition number M2 of the broadcast message; the method 1000 further includes: receiving M2 broadcast messages in M2 time slots, the M2 broadcast messages are the same, and M2 is a positive integer greater than or equal to M1.

[0189] The above broadcast message carries information for terminal access, and the terminal can combine and decode multiple received broadcast messages to improve the decoding success rate, thereby improving the transmission reliability of access information in the NTN. Optionally, M2 can also be a positive integer less than M1, and the network device can flexibly indicate or configure the repetition number M2 of the broadcast message according to the actual situation.

[0190] The time domain positions of the M1 first downlink control information and the M2 broadcast messages are shown in FIG. 11 and FIG. 12.

[0191] In FIG. 11, the base station transmits two SSBs in time slot 0 and time slot 1, respectively, wherein the SSB in symbol 2-symbol 5 of time slot 0 is used to schedule the PDCCH in time slot 2, 1 PDCCH in time slot 2 occupies 1 symbol, and the maximum number of symbols for carrying downlink control information in each time slot is 3, if M1 is equal to 4, the PDCCH occupies 3 symbols in time slot 2, and 1 symbol in time slot 3, the PDCCH in the 4 symbols is used to schedule the broadcast messages in time slot 2-time slot 5, that is, to indicate the time-frequency resources of the broadcast messages. The SSB in symbol 8-symbol 11 of time slot 0 is used to schedule the PDCCH in time slot 6, the PDCCH in time slot 6 occupies 1 symbol, and the maximum number of symbols for carrying downlink control information in each time slot is 3, if M1 is equal to 4, the PDCCH occupies 3 symbols in time slot 6, and 1 symbol in time slot 7, the PDCCH in the 4 symbols is used to schedule the broadcast messages in time slot 6-time slot 9, that is, to indicate the time-frequency resources of the broadcast messages.

[0192] For example, when M is equal to 4, the downlink control information in slots 2 and 3 are all first downlink control information, slot 2 being an example of slot n0, the first symbol in slot 2 being an example of the first time domain position. Each of the first downlink control information indicates the time-frequency resource of the broadcast message in slot 2, and the terminal receives the repeated broadcast message in the same time domain position in slots 3-5 according to the repetition number M2.

[0193] In FIG. 12, the base station transmits two SSBs in slots 0 and 1 respectively, wherein the SSB in symbols 2-5 of slot 0 is used to schedule the PDCCH in slot 2, the PDCCH in slot 2 occupies 2 symbols, the maximum number of symbols for carrying downlink control information in each slot is 3, if M1 is equal to 4, the PDCCH occupies 2 symbols in slot 2, and 2 symbols in slots 3-5 respectively, the PDCCH in the 8 symbols is used to schedule the broadcast message in slots 2-5, i.e., indicates the time-frequency resource of the broadcast message. The SSB in symbols 8-11 of slot 0 is used to schedule the PDCCH in slot 6, the PDCCH in slot 6 occupies 2 symbols, the maximum number of symbols for carrying downlink control information in each slot is 3, if M1 is equal to 4, the PDCCH occupies 2 symbols in slot 6, and 2 symbols in slots 6-9 respectively, the PDCCH in the 8 symbols is used to schedule the broadcast message in slots 6-9, i.e., indicates the time-frequency resource of the broadcast message.

[0194] For example, when M is equal to 4, the downlink control information in slots 2-5 are all first downlink control information, slot 2 being an example of slot n0, the first symbol in slot 2 being an example of the first time domain position. Each of the first downlink control information indicates the time-frequency resource of the broadcast message in slot 2, and the terminal receives the repeated broadcast message in the same time domain position in slots 3-5 according to the repetition number M2.

[0195] In FIGS. 11 and 12, the repetition number M2 of the broadcast message is the same as the repetition number M1 of the downlink control information. Alternatively, M2 and M1 can also be different.

[0196] The above broadcast message carries information for terminal access, and the terminal can combine and decode multiple received broadcast messages to improve the decoding success rate by receiving multiple repeated broadcast messages, thereby improving the transmission reliability of access information in NTN.

[0197] Alternatively, the above broadcast message can be: SIB1, or a combination of SIB1 and SIB19.

[0198] In the NTN, some access information is carried in SIB19. If SIB1 or SIB19 is sent alone, SIB19 also needs to be repeated multiple times to improve transmission reliability. In this embodiment, the network device in the NTN can compress SIB1 and SIB19 and send them repeatedly as one broadcast message. The terminal does not need to wait for the scheduling of SIB1 to receive SIB19, thereby improving the access rate of the terminal.

[0199] For example, for low-altitude aircraft such as drones, the terminal does not need ephemeris information to access the network of such low-altitude aircraft, and the broadcast message can be SIB1. For high-altitude aircraft such as GEO satellites, ephemeris information is necessary for random access. The above broadcast message can be a combination of SIB1 and SIB19, wherein the base station can compress SIB1 and SIB19 and combine them into one SIB that can be scheduled in one time slot. The design of SIB1 and SIB19 can refer to FIG. 9, and will not be described again.

[0200] In summary, in the method 1000, the first downlink control information can be sent by the network device (such as a satellite) in the NTN. The terminal can combine and decode the first downlink control information received multiple times to improve the decoding success rate, thereby improving the transmission reliability of the downlink control information in the NTN. In addition, the time domain position of the first downlink control information is determined, and the terminal does not need to perform blind detection in the search space, which also improves the transmission reliability of the downlink control information. In addition, in the case where B is greater than or equal to 2A, the multiple first downlink control information can be located in one time slot, and the terminal can decode the first downlink control information as soon as possible to improve the access efficiency.

[0201] Optionally, in the method 700 and the method 1000, the time slot can also be replaced by a time unit with a shorter time length such as a micro time slot, or the time slot can also be replaced by a time unit with a longer time length.

[0202] The above describes the method examples provided by the embodiments of the present application in detail. It can be understood that the corresponding device contains the corresponding hardware structure and / or software module to implement the functions. Those skilled in the art should easily realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed in the present text can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is driven by hardware or computer software to drive hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0203] FIG. 13 and FIG. 14 are structural diagrams of two communication apparatuses provided by embodiments of the present application, which can be used to implement the functions of the terminal or the base station in the above-mentioned method embodiments, and therefore have the beneficial effects of the above-mentioned method embodiments. In embodiments of the present application, the apparatuses can be the terminal shown in FIG. 1, can be the base station shown in FIG. 1, or can be a module (e.g., a chip) applied to the terminal or the base station.

[0204] As shown in FIG. 13, the apparatus 1300 includes a processing unit 1310 and a transceiver unit 1320. The transceiver unit 1320 performs the receiving step and / or the transmitting step under the control of the processing unit 1310, wherein the transceiver unit 1320 is a transmitting unit when performing the transmitting step, and the transceiver unit 1320 is a receiving unit when performing the receiving step. The apparatus 1300 is used to implement the functions of the terminal or the base station in the above-mentioned method embodiments of FIG. 7 or FIG. 10.

[0205] When the apparatus 1300 is used to implement the functions of the terminal in the method embodiments of FIG. 7, the processing unit 1310 is configured to: determine a repetition number M and a first time domain position in a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate (or configure) time-frequency resources of a broadcast message, and M being an integer greater than 1; and the transceiver unit 1320 is configured to: receive the first downlink control information at the first time domain position, and receive M-1 retransmitted first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

[0206] Optionally, the first downlink control information in the time slot n0+j is used to indicate the time-frequency resources of the broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; and the transceiver unit 1320 is further configured to: receive M broadcast messages in the M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

[0207] Optionally, the transceiver unit 1320 is further configured to: receive a synchronization signal block, the synchronization signal block including a first index, the first index being an index in a predefined first table; and the processing unit 1310 is specifically configured to: determine the repetition number M and the first time domain position in the first table according to the first index, and determine the time slot n0 according to part parameters corresponding to the first index in the first table.

[0208] Optionally, the broadcast message is: an SIB1, or a combination of an SIB1 and an SIB19.

[0209] When the apparatus 1300 is configured to implement the functions of the base station in the method embodiment described in FIG. 7, the processing unit 1310 is configured to: determine a repetition number M and a first time domain position in a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate (or configure) time-frequency resources of a broadcast message, M being an integer greater than 1; and the transceiver 1320 is configured to: transmit the first downlink control information at the first time domain position, and transmit M-1 first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

[0210] Optionally, the first downlink control information in the time slot n0+j is used to indicate the time-frequency resources of the broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; and the transceiver 1320 is further configured to: transmit M broadcast messages in the M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

[0211] Optionally, the transceiver 1320 is further configured to: transmit a synchronization signal block, the synchronization signal block including a first index, the first index being an index in a predefined first table, parameters corresponding to the first index in the first table including the repetition number M and the first time domain position, and part of the parameters corresponding to the first index in the first table being used to determine the time slot n0.

[0212] Optionally, the broadcast message is: SIB1, or a combination of SIB1 and SIB19.

[0213] When the apparatus 1300 is configured to implement the functions of the terminal in the method embodiment described in FIG. 10, the processing unit 1310 is configured to: determine a repetition number M1 and a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate (or configure) time-frequency resources of a broadcast message, M1 being an integer greater than 1; and determine, according to the first repetition number M1, a number of symbols A of the first downlink control information, and a maximum number of symbols B used to carry downlink control information in one time slot, that M1 first downlink control information is received by the transceiver 1320 in N consecutive time slots starting from the time slot n0, the M1 first downlink control information being the same, A being a positive integer, B being a positive integer greater than or equal to A, and N being a positive integer less than or equal to M1; and wherein N, M1, A, and B satisfy:

[0214] Optionally, the first downlink control information further indicates a second repetition number M2 of the broadcast message; and the transceiver 1320 is further configured to: receive M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, M2 being a positive integer greater than or equal to M1.

[0215] Optionally, the transceiver 1320 is further configured to receive a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table; and the processing unit 1310 is specifically configured to determine the repetition number M1 in the second table according to the second index, and determine the time slot n0 according to the partial parameters corresponding to the second index in the second table.

[0216] Optionally, the broadcast message is SIB1, or a combination of SIB1 and SIB19.

[0217] When the apparatus 1300 is configured to implement the functions of the base station in the method embodiment described in FIG. 10, the processing unit 1310 is configured to determine the repetition number M1 and the time slot n0 for carrying the first downlink control information, the first downlink control information being used to indicate the time-frequency resource of the broadcast message, M1 being an integer greater than 1; determine that M1 first downlink control information is transmitted in the continuous N time slots starting from the time slot n0 by the transceiver 1320 according to the first repetition number M1, the number of symbols A of the first downlink control information, and the maximum number of symbols B for carrying downlink control information in one time slot, the M1 first downlink control information being the same, A being a positive integer, B being a positive integer greater than or equal to A, and N being a positive integer less than or equal to M1; and wherein N, M1, A, and B satisfy:

[0218] Optionally, the first downlink control information further indicates a second repetition number M2 of the broadcast message; and the transceiver 1320 is further configured to transmit M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, and M2 being a positive integer greater than or equal to M1.

[0219] Optionally, the transceiver 1320 is further configured to transmit a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table, parameters corresponding to the second index in the second table comprising the repetition number M1, and the partial parameters corresponding to the second index in the second table being used to determine the time slot n0.

[0220] Optionally, the broadcast message is SIB1, or a combination of SIB1 and SIB19.

[0221] The apparatus 1300 can be a terminal or a base station. The processing unit 1310 can be implemented by hardware or by software. When implemented by hardware, the processing unit 1310 is a logic circuit, an integrated circuit, or the like. When implemented by software, the processing unit 1310 can be a general-purpose processor, which reads software code stored in a storage unit to implement the processing unit 1310. The storage unit can be integrated in the processing unit 1310 or exist independently.

[0222] As shown in FIG. 14, the apparatus 1400 includes a processor 1410 and an interface circuit 1420. The processor 1410 and the interface circuit 1420 are coupled to each other. It can be understood that the interface circuit 1420 can be a transceiver or an input / output interface. Optionally, the apparatus 1400 can further include a memory 1430 for storing instructions executed by the processor 1410 or storing input data required by the processor 1410 to execute instructions or storing data generated after the processor 1410 executes instructions.

[0223] When the apparatus 1400 is used to implement the method shown in FIG. 7 or FIG. 10, the processor 1410 is configured to implement the functions of the processing unit 1310 described above, and the interface circuit 1420 is configured to implement the functions of the transceiving unit 1320 described above.

[0224] When the apparatus 1400 is a terminal chip (i.e., a chip applied to a terminal), the terminal chip implements the functions of the terminal in the method embodiments described above. The terminal chip receives information from a base station, which can be understood as that the information is first received by other modules (such as a radio frequency module or an antenna) in the terminal and then transmitted to the terminal chip by the modules. The terminal chip transmits information to the base station, which can be understood as that the information is first transmitted to other modules (such as a radio frequency module or an antenna) in the terminal and then transmitted to the base station by the modules.

[0225] When the apparatus 1400 is a base station chip (i.e., a chip applied to a base station), the base station chip implements the functions of the base station in the method embodiments described above. The base station chip receives information from a terminal, which can be understood as that the information is first received by other modules (such as a radio frequency module or an antenna) in the base station and then transmitted to the base station chip by the modules. The base station chip transmits information to the terminal, which can be understood as that the information is first transmitted to other modules (such as a radio frequency module or an antenna) in the base station and then transmitted to the terminal by the modules.

[0226] In this application, when entity A transmits information to entity B, it can be that A directly transmits to B, or A indirectly transmits to B through other entities. Similarly, when entity B receives information from entity A, it can be that entity B directly receives the information transmitted by entity A, or entity B indirectly receives the information transmitted by entity A through other entities. Here, entity A and B can be RAN nodes or modules inside the RAN nodes. The transmission and reception of information can be the information interaction between RAN nodes, for example, the information interaction between a base station and a terminal; the transmission and reception of information can also be the information interaction between different modules inside an apparatus, for example, the information interaction between a terminal chip and other modules in the terminal, or the information interaction between a base station chip and other modules in the base station.

[0227] It is appreciated that a processor in the embodiments of the present application can be a CPU, and can also be other general-purpose processors, a digital signal processor (DSP), an ASIC, an FPGA or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, or can be any conventional processor.

[0228] The method steps in the embodiments of the present application can be implemented in hardware, or can be implemented in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a compact disc read-only memory (CD-ROM), or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from, and write information to, the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also exist as discrete components in the base station or the terminal.

[0229] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments are performed. The computer can be a general purpose computer, a special purpose computer, a computer network, a network device, a user equipment or other programmable apparatus. The computer programs or instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transferred from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; or an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid state disk. The computer readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0230] Finally, regarding the embodiments of the present application, the following points are explained:

[0231] First, in the embodiments of the present application, the first, second and various numerical numbers are only distinguished for convenience of description, and do not limit the scope of the embodiments of the present application. For example, the first information and the second information represent two information, which can be two different information, or can be the same information.

[0232] Second, in the embodiments of the present application, "indication" can include direct indication and indirect indication, and can also include explicit indication and implicit indication. The information indicated by a certain information is called to be indicated information, and there are many ways to indicate the to-be-indicated information in the specific implementation process, for example, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or the index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, wherein the other information and the to-be-indicated information have an association relationship. The to-be-indicated information can also be indicated only by a part, and the other part of the to-be-indicated information is known or agreed in advance, for example, whether a certain information element exists can be used to indicate the to-be-indicated information by means of pre-agreement (for example, agreement), thereby reducing the indication overhead to a certain extent.

[0233] Thirdly, the "protocol" involved in the embodiments of the present application can refer to a standard protocol in the communication field, which can include a long term evolution (LTE) protocol, an NR protocol, and a related protocol in a future communication system, and the present application does not make any limitation thereon.

[0234] Fourthly, the "predefined" or "preconfigured" can be implemented by pre-storing a corresponding code, table or other information indicating related information in a device (for example, a terminal or a base station), and the present application does not make any limitation on the specific implementation manner. Wherein, the "storing" can refer to storing in one or more memories, which can be separately arranged or integrated in a processor or a communication device; the one or more memories can be partially separately arranged and partially integrated in the processor or the communication device. The type of the memory can be any form of storage medium, and the present application does not make any limitation thereon.

[0235] Fifthly, "at least one" refers to one or more, and "multiple" refers to two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time, wherein A and B can be a single object or multiple objects. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b and c can represent: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c. Wherein a, b and c can be a single object or multiple objects.

[0236] Sixthly, in the embodiments of the present application, the descriptions such as "when", "in the case of", "if" and "if" all refer to the objective situation that the device (for example, a terminal or a base station) will make corresponding processing, which is not limited by time, and does not require the device to have a judgment action when implemented, nor means that there are other limitations.

[0237] Seventhly, in various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be mutually referenced if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

Claims

1. A communication method characterized by comprising: The method comprises: determining a repetition number M and a first time domain position in a time slot n0 carrying first downlink control information, the first downlink control information being used for indicating time-frequency resources of a broadcast message, M being an integer greater than 1; receiving the first downlink control information at the first time domain position and M-1 repeated first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

2. The method of claim 1, wherein, The first downlink control information in the time slot n0+j is used for indicating time-frequency resources of a broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; the method further comprises: receiving M broadcast messages in M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

3. The method according to claim 1 or 2, characterized in that, The determining the repetition number M and the first time domain position in the time slot n0 carrying the first downlink control information comprises: receiving a synchronization signal block, the synchronization signal block comprising a first index, the first index being an index in a predefined first table; determining the repetition number M and the first time domain position in the first table according to the first index, and determining the time slot n0 according to part parameters corresponding to the first index in the first table.

4. The method according to any one of claims 1 to 3, characterized in that, The broadcast message is: a system information block SIB1, or a combination of SIB1 and SIB19.

5. A communication method characterized by comprising: The method comprises: determining a repetition number M and a first time domain position in a time slot n0 carrying first downlink control information, the first downlink control information being used for indicating time-frequency resources of a broadcast message, M being an integer greater than 1; sending the first downlink control information at the first time domain position and M-1 repeated first downlink control information at the same time domain position in M-1 time slots after the time slot n0.

6. The method of claim 5, wherein, The first downlink control information in the time slot n0+j is used for indicating time-frequency resources of a broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; the method further comprises: sending M broadcast messages in M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

7. The method according to claim 5 or 6, characterized in that, The method further comprises: sending a synchronization signal block, the synchronization signal block comprising a first index, the first index being an index in a predefined first table, parameters corresponding to the first index in the first table comprising the repetition number M and the first time domain position, and part parameters corresponding to the first index in the first table being used for determining the time slot n0.

8. The method according to any one of claims 5 to 7, characterized in that, The broadcast message is: a system information block SIB1, or a combination of SIB1 and SIB19.

9. A communication method characterized by comprising: The method comprises: determining a repetition number M1 and a time slot n0 carrying first downlink control information, the first downlink control information being used for indicating time-frequency resources of a broadcast message, M1 being an integer greater than 1; According to the first repetition number M1, the symbol number A of the first downlink control information and the maximum symbol number B for carrying downlink control information in one time slot, it is determined to receive M1 first downlink control information in the continuous N time slots starting from the time slot n0, the M1 first downlink control information are the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

10. The method of claim 9, wherein, The first downlink control information further indicates a second repetition number M2 of the broadcast message; the method further comprises: receiving M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, M2 being a positive integer greater than or equal to M1.

11. The method according to claim 9 or 10, characterized in that, The determining comprises: receiving a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table, parameters corresponding to the second index in the second table comprising the repetition number M1, and part of parameters corresponding to the second index in the second table being used to determine the time slot n0. The determining comprises:

12. A communication method characterized by comprising: determining a repetition number M1 and a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate time-frequency resources of a broadcast message, M1 being an integer greater than 1; The first downlink control information further indicates a second repetition number M2 of the broadcast message; the method further comprises: According to the first repetition number M1, the symbol number A of the first downlink control information, and the maximum symbol number B for carrying downlink control information in one time slot, it is determined to send M1 first downlink control information in the next N time slots starting from the time slot n0, the M1 first downlink control information is the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

13. The method of claim 12, wherein, sending M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, M2 being a positive integer greater than or equal to M1. The method further comprises:

14. The method according to claim 12 or 13, characterized in that, sending a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table, parameters corresponding to the second index in the second table comprising the repetition number M1, and part of parameters corresponding to the second index in the second table being used to determine the time slot n0. comprising a processing unit and a receiving unit; 15. A communications device, characterized by The processing unit is configured to determine a repetition number M and a first time domain position in a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate time-frequency resources of a broadcast message, M being an integer greater than 1; The receiving unit is configured to receive the first downlink control information at the first time domain position, and receive M-1 retransmitted first downlink control information at the same time domain position in M-1 time slots after the time slot n0. The first downlink control information in the time slot n0+j is used to indicate time-frequency resources of a broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; the receiving unit is further configured to:

16. The apparatus of claim 15, wherein, receive M broadcast messages in M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

17. The apparatus of claim 15 or 16, wherein The receiving unit is further configured to receive a synchronization signal block, the synchronization signal block comprising a first index, the first index being an index in a predefined first table; The processing unit is specifically configured to determine the repetition number M and the first time domain position in the first time slot n0 in the first table according to the first index, and determine the time slot n0 according to part of parameters corresponding to the first index in the first table. The broadcast message is a system information block SIB1, or a combination of SIB1 and SIB19.

18. The apparatus of any one of claims 15-17, wherein, comprising a processing unit and a sending unit; 19. A communications device, characterized by The processing unit is configured to determine a repetition number M and a first time domain position in a time slot n0 used to carry first downlink control information, the first downlink control information being used to indicate time-frequency resources of a broadcast message, M being an integer greater than 1; ​ The sending unit is configured to send the first downlink control information at the first time domain position, and send M-1 first downlink control information at the same time domain position in the M-1 time slots after the time slot n0.

20. The apparatus of claim 19, wherein, The first downlink control information in the time slot n0+j is used to indicate time-frequency resources of a broadcast message in the time slot n0+j, where j={0, 1, 2, …, M-1}; the sending unit is further configured to: send M broadcast messages in the M time slots from the time slot n0 to the time slot n0+M-1, the M broadcast messages being the same.

21. The apparatus of claim 19 or 20, wherein, The sending unit is further configured to: send a synchronization signal block, the synchronization signal block comprising a first index, the first index being an index in a predefined first table, parameters corresponding to the first index in the first table comprising the repetition number M and the first time domain position, and part of the parameters corresponding to the first index in the first table being used to determine the time slot n0.

22. The apparatus of any one of claims 19-21, wherein, The broadcast message is a system information block SIB1, or a combination of SIB1 and SIB19.

23. A communications device, characterized by The device comprises a processing unit configured to: determine a repetition number M1 and a time slot n0 for carrying first downlink control information, the first downlink control information being used to indicate time-frequency resources of a broadcast message, M1 being an integer greater than 1; According to the first repetition number M1, the symbol number A of the first downlink control information, and the maximum symbol number B for carrying downlink control information in one time slot, it is determined to receive M1 first downlink control information in the continuous N time slots starting from the time slot n0, the M1 first downlink control information are the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

24. The apparatus of claim 23, wherein, The first downlink control information further indicates a second repetition number M2 of the broadcast message; the device further comprises a receiving unit configured to: receive M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, M2 being a positive integer greater than or equal to M1.

25. The apparatus of claim 23 or 24, wherein, The device further comprises a receiving unit; The receiving unit is configured to: receive a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table; The processing unit is specifically configured to: determine the repetition number M1 in the second table according to the second index, and determine the time slot n0 according to part of the parameters corresponding to the second index in the second table.

26. A communications device, characterized by The device comprises a processing unit configured to: determine a repetition number M1 and a time slot n0 for carrying first downlink control information, the first downlink control information being used to indicate time-frequency resources of a broadcast message, M1 being an integer greater than 1; According to the first repetition number M1, the symbol number A of the first downlink control information, and the maximum symbol number B for carrying downlink control information in one time slot, it is determined to send M1 first downlink control information in the next N time slots starting from the time slot n0, the M1 first downlink control information is the same, A is a positive integer, B is a positive integer greater than or equal to A, N is a positive integer less than or equal to M1; wherein N, M1, A and B satisfy:

27. The apparatus of claim 26, wherein, The first downlink control information further indicates a second repetition number M2 of the broadcast message; the device further comprises a sending unit configured to: send M2 broadcast messages in M2 time slots, the M2 broadcast messages being the same, M2 being a positive integer greater than or equal to M1.

28. The apparatus of claim 26 or 27, wherein, The device further comprises a sending unit configured to: send a synchronization signal block, the synchronization signal block comprising a second index, the second index being an index in a predefined second table, parameters corresponding to the second index in the second table comprising the repetition number M1, and part of the parameters corresponding to the second index in the second table being used to determine the time slot n0.

29. A communications device, characterized by The device comprises: A processor for implementing the method of any one of claims 1 to 4, or the method of any one of claims 5 to 8, or the method of any one of claims 9 to 11, or the method of any one of claims 12 to 14, by logic circuitry or executing code instructions. An interface circuit for receiving signals from other devices and transmitting signals to said processor or transmitting signals from said processor to other devices.

30. A communication system, characterized by Comprising: A communication device for implementing the method of any one of claims 1 to 4, and a communication device for implementing the method of any one of claims 5 to 8; or a communication device for implementing the method of any one of claims 9 to 11, and a communication device for implementing the method of any one of claims 12 to 14.

31. A computer readable storage medium, characterized in that, The computer readable storage medium stores a computer program or instructions which, when executed by a communication device, implement the method of any one of claims 1 to 4, or the method of any one of claims 5 to 8, or the method of any one of claims 9 to 11, or the method of any one of claims 12 to 14.

32. A computer program product, characterised in that, The computer program product comprises a computer program or instructions which, when executed by a communication device, implement the method of any one of claims 1 to 4, or the method of any one of claims 5 to 8, or the method of any one of claims 9 to 11, or the method of any one of claims 12 to 14.

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