Downlink data transmission method, device, equipment and storage medium

Abstract

The invention relates to a downlink data transmission method and device, equipment and a storage medium. According to the invention, the base station sends the first indication information to the terminal to indicate whether the terminal performs coverage enhancement. And under the condition that coverage enhancement needs to be carried out, sending second indication information to the terminal, and sending downlink data to the terminal according to the second indication information. According to the embodiment of the invention, the terminal receives the downlink data from the corresponding time slot on the basis of the repetition times of the downlink data indicated in the second indication information and / or the time slot number for transmitting the downlink data, and the same downlink data is transmitted in multiple time slots, so that the demodulation performance is improved by reducing the code rate. Besides, the terminal merges the repeated downlink data received on different time slots, so that the success rate of receiving the downlink data by the terminal is improved, the transmission delay caused by retransmission is avoided, and the downlink data transmission efficiency of the satellite communication system is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a downlink data transmission method, device, equipment and storage medium. Background Art

[0002] With the development of 5G wireless mobile communication technology, various fields have begun to use 5G wireless mobile communication technology. For example, taking satellite communication as an example, the combination of satellite communication and 5G wireless mobile communication technology may be a future development trend.

[0003] Since the link budget of satellite communication system is poor, the probability of transmission failure is high. For example, the probability of the terminal successfully receiving downlink data is low. The distance between the base station and the terminal is far, and the transmission delay is large. If the terminal fails to receive the downlink data and retransmits it, the transmission efficiency will be seriously reduced. Summary of the invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a downlink data transmission method, device, equipment and storage medium to improve the downlink data transmission efficiency of a satellite communication system.

[0005] In a first aspect, an embodiment of the present disclosure provides a downlink data transmission method, including:

[0006] Sending first indication information to the terminal, where the first indication information is used to indicate whether coverage enhancement is required;

[0007] In the case where the coverage enhancement is required, generating second indication information, where the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, where the number of time slots is greater than or equal to 2;

[0008] sending the second indication information to the terminal;

[0009] The downlink data is sent to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0010] In a second aspect, an embodiment of the present disclosure provides a downlink data transmission method, the method comprising:

[0011] receiving first indication information sent by a base station in a satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required;

[0012] In the case where the coverage enhancement is required, receiving second indication information sent by the base station, where the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2;

[0013] The downlink data is received according to the second indication information.

[0014] In a third aspect, an embodiment of the present disclosure provides a downlink data transmission device, including:

[0015] A first sending module, used to send first indication information to the terminal, where the first indication information is used to indicate whether coverage enhancement is required;

[0016] A generating module, configured to generate second indication information when the coverage enhancement is required, wherein the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2;

[0017] A second sending module, used to send the second indication information to the terminal;

[0018] The third sending module is used to send the downlink data to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0019] In a fourth aspect, an embodiment of the present disclosure provides a downlink data transmission device, including:

[0020] A first receiving module is used to receive first indication information sent by a base station in the satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required;

[0021] A second receiving module is used to receive second indication information sent by the base station when the coverage enhancement is needed, where the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2;

[0022] A third receiving module is used to receive the downlink data according to the second indication information.

[0023] In a fifth aspect, an embodiment of the present disclosure provides a base station, including:

[0024] Memory;

[0025] Processor; and

[0026] Computer programs;

[0027] The computer program is stored in the memory and is configured to be executed by the processor to implement the method as described in the first aspect.

[0028] In a sixth aspect, an embodiment of the present disclosure provides a terminal, including:

[0029] Memory;

[0030] Processor; and

[0031] Computer programs;

[0032] The computer program is stored in the memory and is configured to be executed by the processor to implement the method as described in the second aspect.

[0033] In a seventh aspect, an embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the method described in the first aspect or the second aspect.

[0034] The downlink data transmission method, apparatus, device and storage medium provided by the embodiments of the present disclosure send first indication information to the terminal through the base station to indicate whether the terminal performs coverage enhancement. In the case where coverage enhancement is required, the base station generates second indication information to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2, wherein the number of repetitions of the downlink data allows the base station to repeatedly transmit the downlink data multiple times, and the number of time slots used to transmit the downlink data allows the same downlink data to be transmitted in multiple time slots. Further, the base station sends the second indication information to the terminal, and according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, sends the downlink data to the terminal, so that the downlink data is repeated multiple times and / or the same downlink data is transmitted in multiple time slots. When the terminal determines that there is coverage enhancement according to the first indication information, based on the number of repetitions of the downlink data indicated in the second indication information and / or the number of time slots used to transmit the downlink data, the terminal receives downlink data from the corresponding time slot. Since the same downlink data is transmitted in multiple time slots, that is, different parts of the downlink data are transmitted in different time slots, the demodulation performance of the terminal for downlink data is improved by reducing the code rate, thereby helping to improve the transmission efficiency of downlink data. In addition, the base station repeatedly transmits the downlink data multiple times, so that the terminal combines the multiple repeated downlink data received in different time slots, thereby improving the success rate of the terminal receiving downlink data, avoiding the transmission delay caused by retransmission, and improving the downlink data transmission efficiency of the satellite communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 A flow chart of a downlink data transmission method provided in an embodiment of the present disclosure;

[0038] Figure 2 A schematic diagram of an application scenario provided by an embodiment of the present disclosure;

[0039] Figure 3 The corresponding relationship between the transmission block and the time slot provided in the embodiment of the present disclosure;

[0040] Figure 4 A bit diagram provided for an embodiment of the present disclosure;

[0041] Figure 5 A flow chart of a downlink data transmission method provided in an embodiment of the present disclosure;

[0042] Figure 6 A flow chart of a downlink data transmission method provided in an embodiment of the present disclosure;

[0043] Figure 7 It is a schematic diagram of the monitoring window corresponding to SSB in the prior art;

[0044] Figure 8 A flow chart of a downlink data transmission method provided in an embodiment of the present disclosure;

[0045] Fig. 9 A schematic diagram of the structure of a downlink data transmission device provided in an embodiment of the present disclosure;

[0046] Fig.10 A schematic diagram of the structure of a downlink data transmission device provided in an embodiment of the present disclosure;

[0047] Fig.11 A schematic diagram of the structure of a terminal provided in an embodiment of the present disclosure;

[0048] Fig.12 A schematic diagram of the structure of a base station provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0051] With the development of 5G wireless mobile communication technology, various fields have begun to use 5G wireless mobile communication technology. For example, taking satellite communication as an example, the combination of satellite communication and 5G wireless mobile communication technology may be a future development trend. Due to the poor link budget of the satellite communication system, the probability of transmission failure is high. For example, the probability of the terminal successfully receiving downlink data is low. The distance between the base station and the terminal is far, and the transmission delay is large. If the terminal retransmits when it fails to successfully receive the downlink data, the transmission efficiency will be seriously reduced.

[0052] To address this problem, an embodiment of the present disclosure provides a downlink data transmission method, which is described below in conjunction with a specific embodiment.

[0053] Figure 1 The flowchart of the downlink data transmission method provided by the embodiment of the present disclosure is as follows. Figure 2 The application scenario shown includes a terminal 21 and a base station 22, and the base station 22 is specifically a base station in a satellite communication system. For example, the base station 22 can be mounted on a satellite. Or in other embodiments, the satellite communication system includes a terminal, a satellite, and a gateway station (i.e., a base station), wherein the gateway station performs data processing, and the satellite can transparently forward data or information transmitted between the terminal and the gateway station. The terminal 21 and the base station 22 can constitute a satellite communication system. It can be understood that the satellite communication system is not limited to including terminals and base stations, but can also include other network elements, such as transfer stations, relay stations and other equipment. In addition, this embodiment does not specifically limit the number of terminals and base stations that can be included in the satellite communication system. The method described in this embodiment can be executed by the base station 22. The following is combined with Figure 2 This method is described in detail. Figure 1 As shown, the specific steps of this method are as follows:

[0054] S101. Send first indication information to a terminal, where the first indication information is used to indicate whether coverage enhancement is required.

[0055] In this embodiment, the base station 22 may determine whether coverage enhancement is required for the downlink data before sending the downlink data to the terminal 21. If coverage enhancement is required, the base station 22 sends first indication information to the terminal 21, thereby indicating whether coverage enhancement is required through the first indication information.

[0056] Specifically, the communication network to which the method described in the embodiments of the present application is applicable may support terminals with multiple capabilities, where the capabilities may specifically include but are not limited to communication capabilities, computing capabilities, processing capabilities, etc. For example, the communication network supports three types of terminals, namely, the terminal with the worst capability, the terminal with relatively poor capability, and the terminal with relatively strong capability, wherein the relatively poor capability and the relatively strong capability can be measured by a pre-set threshold, for example, a capability greater than the threshold indicates a relatively strong capability; a capability less than the threshold indicates a relatively poor capability; the worst capability can be determined by sorting, for example, the capabilities of the various terminals in the communication network are sorted in order from large to small, and the terminal at the end indicates the worst capability.

[0057] In this embodiment, the base station may determine whether coverage enhancement is required based on the capabilities of the terminals in the communication network. For example, coverage enhancement is required for the terminals with the worst capabilities and relatively poor capabilities, while coverage enhancement is not required for the terminals with relatively strong capabilities.

[0058] It is understandable that the capability of the terminal is a factor for the base station to determine whether coverage enhancement is needed. In other embodiments, when the base station determines coverage enhancement, there are other influencing factors, such as the orbital height of the satellite, the link status, the G / T value, etc. Among them, G represents the antenna gain, T represents the antenna noise temperature, and the G / T value is the main difference between different terminals.

[0059] S102. When the coverage enhancement is required, generate second indication information, where the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2.

[0060] In this embodiment, coverage enhancement includes TB processing over multi-slot (TBoMS) and / or repetition. Multi-slot processing of transmission blocks can be referred to as multi-slot transmission. The so-called multi-slot transmission refers to the transmission of the same transmission block (TB) in multiple time slots. The multiple time slots here can be greater than or equal to 2 time slots. Taking the transmission of the same transmission block in 2 time slots as an example, the transmission block can be divided into two parts, assuming that it is divided into a first part and a second part. The first part is transmitted in the first time slot, and the second part is transmitted in the second time slot. The first time slot and the second time slot are two adjacent time slots. In addition, the number and position of orthogonal frequency division multiplexing (OFDM) symbols occupied by the first part in the first time slot are respectively the same as the number and position of OFDM symbols occupied by the second part in the second time slot. TBoMS can reduce the code rate of satellite communication systems in limited coverage or narrow transmission bandwidth. For example, the code rate of using two time slots to transmit a transmission block is half that of using one time slot to transmit a transmission block. This allows data transmission at a lower code rate without changing the existing Modulation and Coding Scheme (MCS) table.

[0061] Assume that the transport block includes downlink data and the transport block is carried on the physical downlink shared channel (PDSCH). Assume that the number of resource elements (RE) in a physical resource block (PRB) allocated by the base station to the terminal for receiving PDSCH is denoted as N′ RE , the total number of PRBs allocated by the base station to the terminal is n PRB If TBoMS is not used, the terminal needs to use N as shown in the following formula (1): RE REs are used to receive the transport blocks carried on the PDSCH.

[0062] N RE =min(156,N′ RE )*n PRB (1)

[0063] If TBoMS is used, the terminal needs to use N as shown in the following formula (2): RE REs are used to receive the transport blocks carried on the PDSCH.

[0064] N RE =N*min(156,N′ RE )*n PRB (2)

[0065] Here, N represents that the same transport block is transmitted in N time slots, that is, N represents the number of time slots used to transmit one transport block.

[0066] In this embodiment, RE is the smallest resource unit in physical resources, occupies 1 OFDM Symbol in the time domain and is 1 subcarrier in the frequency domain.

[0067] The so-called repetition refers to the repeated transmission of a transmission block for multiple times. For example, the same transmission block is transmitted in L time slots, L is greater than or equal to 1. Taking L=1 as an example, time slot 1 can be used to transmit the transmission block, and time slot 2 can be used to transmit the transmission block again, so that the same transmission block is repeated twice, that is, a transmission block is repeatedly transmitted in multiple time slots, so that the terminal can merge the data repeatedly transmitted in the multiple time slots, thereby obtaining a repetition transmission gain. Theoretically, a repetition transmission gain of 3dB can be obtained by repeating the transmission twice. Assuming that one transmission block is transmitted in one time slot without considering multi-time slot transmission, if one transmission block needs to be repeatedly transmitted multiple times, one transmission block can be repeatedly transmitted in multiple time slots, that is, the transmission block is transmitted once in each time slot of the multiple time slots. Optionally, the multiple time slots are continuous.

[0068] It is understandable that the multi-slot transmission and repeated transmission described above can be applied in a superimposed manner or can be applied separately. In the case of superimposed application, assuming that the number of time slots required for multi-slot transmission is recorded as N, and the number of repeated transmissions is recorded as H, then one transmission block needs to occupy N*H time slots. The N*H time slots can be a plurality of continuous time slots. In addition, the number and position of OFDM symbols corresponding to the transmission block in the N*H time slots are the same. In addition, N*H does not exceed the maximum number of repetitions supported by the terminal.

[0069] When the base station determines that it is necessary to perform coverage enhancement of downlink data, a second indication information may be generated, and the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2. The number of repetitions of the downlink data corresponds to the repeated transmission included in the coverage enhancement as described above, that is, the downlink data is repeatedly transmitted multiple times, so that the downlink data appears repeatedly once in each of the multiple consecutive time slots. For example, the base station sends the downlink data to the terminal once in time slot 1, and sends the downlink data to the terminal again in time slot 2, so that the terminal can receive the downlink data once in time slot 1 and receive the downlink data again in time slot 2, ensuring that the terminal has multiple opportunities to receive the downlink data. It can be understood that if the downlink data does not need to be repeated, the base station does not need to repeatedly send the downlink data in consecutive time slots. If the downlink data needs to be repeated, the base station needs to at least send the downlink data twice in two consecutive time slots. Therefore, the "repeat" in the number of repetitions itself has the meaning of at least 2 times. The number of time slots used to transmit the downlink data corresponds to the multi-slot transmission included in the coverage enhancement as described above, that is, the downlink data can be split into multiple parts, and different parts are transmitted in different time slots, so that multiple time slots are used to transmit the same downlink data, that is, the same downlink data occupies multiple time slots, for example, the downlink data is divided into a first part and a second part, the first part is transmitted in a first time slot, and the second part is transmitted in a second time slot, and the first time slot and the second time slot are two adjacent time slots. In addition, since the multi-slot transmission and repeated transmission included in the coverage enhancement can be applied in a superimposed manner or can be applied separately, the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2. In this embodiment, the base station can decide to use multi-slot transmission and / or repeated transmission to enhance the coverage of the downlink data. Therefore, the base station needs to inform the terminal through the second indication information as to which specific method is used to enhance the coverage.

[0070] S103: Send the second indication information to the terminal.

[0071] For example, after the base station generates the second indication information, it sends the second indication information to the terminal. Specifically, the base station can send the second indication information to the terminal through downlink control information (Downlink Control Information, DCI), or the base station can send the second indication information to the terminal through radio resource control (Radio Resource Control, RRC) parameters, or the base station can send the second indication information to the terminal through a combined DCI and RRC method. In other words, the second indication information can be carried in DCI and / or RRC parameters. It can be understood that DCI and / or RRC parameters are not only used to carry the second indication information, but on the basis of maintaining their respective existing functions, they additionally carry the second indication information. The specific carrying method will be described in detail in subsequent embodiments.

[0072] Since the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, the terminal can determine the time slots on which to receive the downlink data according to the second indication information, and thus receive the downlink data in the corresponding time slots.

[0073] S104: Send the downlink data to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0074] For example, the base station uses a combination of multi-slot transmission and repeated transmission to enhance coverage. The number of time slots required for multi-slot transmission is N, and the number of repeated transmissions is H. Therefore, the second indication information is used to indicate the number of repetitions of downlink data and the number of time slots used to transmit the downlink data. The number of repetitions of downlink data is H, and the number of time slots used to transmit the downlink data is N. At this time, the base station needs to send downlink data on N*H time slots. Assuming that the downlink data is carried in a transmission block, the base station needs to send the transmission block on N consecutive time slots, and the transmission block is repeatedly transmitted H times. Taking N=2 and H=3 as an example, Figure 3 As shown, a transmission block is transmitted in two time slots, which is repeated three times. Then, the base station sends the first part of the transmission block in time slot 0, sends the second part of the transmission block in time slot 1, sends the first part again in time slot 2, sends the second part again in time slot 3, sends the first part again in time slot 4, and sends the second part again in time slot 5.

[0075] In the embodiment of the present disclosure, the base station sends first indication information to the terminal to indicate whether the terminal performs coverage enhancement. In the case where coverage enhancement is required, the base station generates second indication information to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, which number of time slots is greater than or equal to 2, wherein the number of repetitions of downlink data allows the base station to repeatedly transmit the downlink data multiple times, and the number of time slots used to transmit the downlink data allows the same downlink data to be transmitted in multiple time slots. Further, the base station sends the second indication information to the terminal, and according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, sends the downlink data to the terminal, so that the downlink data is repeated multiple times and / or the same downlink data is transmitted in multiple time slots. When the terminal determines that there is coverage enhancement according to the first indication information, based on the number of repetitions of the downlink data indicated in the second indication information and / or the number of time slots used to transmit the downlink data, the downlink data is received from the corresponding time slot. Since the same downlink data is transmitted in multiple time slots, that is, different parts of the downlink data are transmitted in different time slots, the demodulation performance of the terminal for the downlink data is improved by reducing the code rate, thereby helping to improve the transmission efficiency of the downlink data. In addition, the base station transmits the downlink data repeatedly for multiple times, so that the terminal can combine the multiple repeated downlink data received in different time slots, thereby improving the terminal's success rate in receiving downlink data, avoiding the transmission delay caused by retransmission, and improving the downlink data transmission efficiency of the satellite communication system.

[0076] In addition, in the scenario where the satellite payload is limited, this embodiment transmits the same transmission block in multiple time slots. This can reduce the data transmission code rate through coverage enhancement design without modifying the MCS table, thereby improving the efficiency of data transmission.

[0077] In this embodiment, the first indication information may be sent to the terminal in a variety of ways.

[0078] In a feasible implementation manner, sending first indication information to a terminal includes: sending a synchronization signal block to the terminal, wherein a master information block or a physical broadcast channel in the synchronization signal block is used to carry the first indication information.

[0079] Specifically, the base station 22 can send a synchronization signal block (Synchronization Signaling Block, SSB) to the terminal 21, and the SSB includes a primary synchronization signal (Primary Synchronization Signal, PSS), a secondary synchronization signal (Secondary Synchronization Signal, SSS), and a physical broadcast channel (Physical Broadcast Channel, PBCH). Among them, PBCH can be used to carry a master information block (Master Information Block, MIB) message. The base station 22 can carry the first indication information in the MIB or the PBCH. For example, the first indication information is carried by a reserved bit in the MIB or PBCH to notify the terminal whether downlink coverage enhancement is required. Accordingly, when the terminal 21 receives the information carried in the MIB or PBCH, it obtains the first indication information according to the reserved bit to determine whether there is coverage enhancement.

[0080] For example, the base station can carry the first indication information through one bit reserved in the MIB, or the base station can add one bit in the MIB to carry the first indication information. For example, when the value of the bit is 1, it indicates that coverage enhancement is required, and when the value of the bit is 0, it indicates that coverage enhancement is not required.

[0081] For another example, the base station can carry the first indication information through one bit reserved in the PBCH, or the base station can add one bit in the PBCH to carry the first indication information. For example, when the value of the bit is 1, it indicates that coverage enhancement is required, and when the value of the bit is 0, it indicates that coverage enhancement is not required.

[0082] In another feasible implementation manner, sending the first indication information to the terminal includes: sending a first system information block to the terminal, where the first system information block is used to carry the first indication information.

[0083] Specifically, the base station 22 may send a first system information block to the terminal 21, and the first system information block may specifically be a system information block 1 (System Information Block 1, SIB1), and the base station 22 carries the first indication information through the cell barred non-terrestrial network (cell Barred Non-Terrestrial Network, cellBarredNTN) in SIB1. For example, if celtBarredNTN in SIB1 is configured as allowed, it indicates that coverage enhancement is required, otherwise it indicates that coverage enhancement is not required.

[0084] In another feasible implementation, sending the first indication information to the terminal includes: sending the first indication information to the terminal, the first indication information is determined by whether to send the second system information block to the terminal, and if the second system information block is sent to the terminal, it indicates that coverage enhancement is required. Specifically, the base station 22 can send the second system information block to the terminal 21, and the second system information block can specifically be system information block 19 (System Information Block 19, SIB19), and the first indication information is determined by whether the base station 22 sends SIB19 to the terminal 21. For example, when the base station 22 sends SIB19 to the terminal 21, it indicates that downlink coverage enhancement is required. When the base station 22 does not send SIB19 to the terminal 21, it indicates that downlink coverage enhancement is not required. That is, when the base station 22 sends SIB19 to the terminal 21, the first system information block can indicate that coverage enhancement is required. When the base station 22 does not send SIB19 to the terminal 21, the first system information block can indicate that coverage enhancement is not required. Correspondingly, the terminal 21 can determine whether there is coverage enhancement by whether SIB19 is received. For example, if the terminal 21 receives SIB19, it is determined that there is coverage enhancement. If the terminal 21 does not receive SIB19, it is determined that there is no coverage enhancement.

[0085] Optionally, generating the second indication information includes multiple implementation methods, and several feasible implementation methods are introduced below.

[0086] In a feasible implementation manner, generating the second indication information includes: adding the second indication information to the downlink control information.

[0087] For example, the base station may add second indication information in downlink control information (Downlink Control Information, DCI).

[0088] Optionally, adding the second indication information to the downlink control information includes: indicating the second indication information through reserved bits of the downlink control information; or indicating the second indication information through newly added bits of the downlink control information; or indicating the second indication information by multiplexing existing bits of the downlink control information.

[0089] For example, the base station may indicate the second indication information through a reserved bit in the DCI, or the base station may add a new bit in the DCI and then indicate the second indication information through the new bit. Alternatively, the base station may reuse an existing bit in the DCI to indicate the second indication information. For example, there are 4 reserved bits in the DCI, and the 4 reserved bits correspond to 16 different values, each value corresponds to a meaning, and the 16 different values ​​can indicate 16 different meanings.

[0090] For example, the base station indicates the number of repetitions (repetition number) of downlink data by 2, 3 or 4 reserved bits or newly added bits in the DCI. Specifically, the method of indicating the repetition number by 2 bits may be the corresponding relationship shown in Table 1 or Table 2 below, the method of indicating the repetition number by 3 bits may be the corresponding relationship shown in Table 3 below, and the method of indicating the repetition number by 4 bits may be the corresponding relationship shown in Table 4 below.

[0091] Table 1

[0092] Repeat times indication Repetitions 00 1 01 2 10 3 11 4

[0093] Table 2

[0094] Repeat times indication Repetitions 00 1 01 2 10 4 11 8

[0095] Table 3

[0096] Repeat times indication Repetitions 000 1 001 2 010 3 011 4 100 7 101 8 110 12 111 16

[0097] Table 4

[0098]

[0099]

[0100] In addition, the base station can also indicate the number of time slots used to transmit the downlink data (recorded as the number of time slots of TBoMS) by 2, 3 or 4 reserved bits or newly added bits in the DCI. The specific representation method can refer to Tables 1 to 4 as described above, which will not be repeated here. It can be understood that the bits used to indicate the number of repetitions of downlink data and the bits used to indicate the number of time slots of TBoMS in the DCI are independent of each other. In addition, the number of bits used to indicate the number of repetitions of downlink data and the number of bits used to indicate the number of time slots of TBoMS in the DCI may be the same or different. For example, the number of bits used to indicate the number of repetitions of downlink data is 2 bits, and the number of bits used to indicate the number of time slots of TBoMS is 3 bits.

[0101] In a feasible implementation manner, generating the second indication information includes: adding the second indication information to a radio resource control parameter.

[0102] For example, the base station may add the second indication information in a Radio Resource Control (RRC) parameter. Specifically, the base station may define a new RRC parameter to indicate the second indication information, or may extend the value of an existing RRC parameter to indicate the second indication information.

[0103] In another feasible implementation, generating the second indication information includes: adding the second indication information to the downlink control information and the wireless resource control parameter; the wireless resource control parameter includes multiple first values ​​and / or multiple second values, the downlink control information includes a first index value and / or a second index value, the first value corresponding to the first index value in the multiple first values ​​represents the number of repetitions, and the second value corresponding to the second index value in the multiple second values ​​represents the number of time slots.

[0104] For example, the base station may combine DCI and RRC parameters to represent the second indication information. Since the second indication information includes the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, several bits corresponding to the number of repetitions of downlink data may be selected from the reserved bits of DCI, and other several bits corresponding to the number of time slots used to transmit the downlink data may be selected. Figure 4 As shown, the DCI includes 4 reserved bits, bit 0 and bit 1 together correspond to the number of repetitions of downlink data, and bit 2 and bit 3 together correspond to the number of time slots used to transmit the downlink data.

[0105] by Figure 4 Taking bit 0 and bit 1 as an example, there are 4 different values ​​for bit 0 and bit 1, namely 00, 01, 10, and 11, and each value can be recorded as a first index value. Correspondingly, the RRC parameter includes 4 values, such as 2, 4, 6, and 8, and each value is recorded as a first value. Multiple first index values ​​correspond to multiple first values ​​one by one, and the corresponding relationship is shown in Table 5 below:

[0106] Table 5

[0107] First index value First value 00 2 01 4 10 6 11 8

[0108] Specifically, in this embodiment, the first index value may be used to indicate which first value in the RRC parameter is used to represent the number of repetitions of the downlink data. For example, the first index value 00 points to the first value 2 in the RRC parameter, indicating that the number of repetitions of the downlink data is 2. The first index value 01 points to the first value 4 in the RRC parameter, indicating that the number of repetitions of the downlink data is 4, and so on.

[0109] Similarly Figure 4 Taking bit 2 and bit 3 as an example, there are 4 different values ​​for bit 2 and bit 3, namely 00, 01, 10, and 11, and each value can be recorded as a second index value. Correspondingly, the RRC parameter includes 4 values, such as 2, 3, 4, and 5, and each value is recorded as a second value. Multiple second index values ​​correspond to multiple second values ​​one by one, and the corresponding relationship is shown in Table 6 below:

[0110] Table 6

[0111] Second index value Second value 00 2 01 3 10 4 11 5

[0112] Specifically, in this embodiment, the second index value may be used to indicate which second value in the RRC parameter is used to represent the number of time slots used to transmit the downlink data. For example, the second index value 00 points to the second value 2 in the RRC parameter, indicating that the same downlink data is transmitted using 2 time slots. The second index value 01 points to the second value 3 in the RRC parameter, indicating that the same downlink data is transmitted using 3 time slots, and so on.

[0113] In actual application scenarios, the downlink data sent by the base station to the terminal may be different types of data, such as SIB1, other system messages, paging messages, message 2 (Msg2), message 4 (Msg4), and downlink data after the terminal accesses the base station. These types of downlink data are carried in PDSCH. The scheduling information of PDSCH is carried on the Physical Downlink Control Channel (PDCCH). Therefore, the terminal needs to monitor PDCCH, obtain the scheduling information of PDSCH carried by PDCCH, and then monitor PDSCH according to the scheduling information of PDSCH, so as to obtain the downlink data carried on PDSCH. Since the number of bits of paging messages and Msg2 is small, the link budget is sufficient and coverage enhancement is not required. Therefore, this embodiment specifically introduces the coverage enhancement of other downlink data except paging messages and Msg2.

[0114] For SIB1, the base station can carry the first indication information through the reserved bits in the MIB or PBCH to notify the terminal whether coverage enhancement is required. If coverage enhancement is required, the base station further generates a second indication information, and the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots of the TBoMS. Specifically, the base station can configure the number of repetitions and the number of time slots of the TBoMS on the reserved bits of the DCI. The DCI may be the DCI carried in the PDCCH corresponding to the PDSCH carrying SIB1. The DCI is scrambled using the System Information Radio Network Temporary Identity (SI-RNTI), and the DCI format is DCI format 1_0. For example, the DCI has 4 reserved bits, of which 2 reserved bits are configured as the number of repetitions and the remaining 2 bits are configured as the number of time slots of the TBoMS. When the terminal operates in an unlicensed spectrum in the frequency range (FR) 1 or in FR2, the DCI domain reserved bits are 17 bits, otherwise the reserved bits are 15 bits. After using the coverage enhancement shown in this embodiment, the reserved bits in the DCI domain will be reduced, and the number of reserved bits after modification = the current number of reserved bits - the number of bits used for the repetition indication - the number of time slots used by the TBoMS.

[0115] For other system messages, the base station may carry the first indication information through the reserved bits in the MIB or PBCH to notify the terminal whether coverage enhancement is required. Alternatively, the base station carries the first indication information through the cellBarredNTN in SIB1 to notify the terminal whether coverage enhancement is required. If coverage enhancement is required, the base station further generates second indication information, and the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots of the TBoMS. Specifically, the base station may configure the number of repetitions and the number of time slots of the TBoMS on the reserved bits of the DCI. The DCI may be the DCI carried in the PDCCH corresponding to the PDSCH carrying SIB1. The DCI is scrambled with the System Information Radio Network Temporary Identity (SI-RNTI), and the DCI format is DCI format 10. For example, the DCI has 4 reserved bits, of which 2 reserved bits are configured as the number of repetitions and the remaining 2 bits are configured as the number of time slots of the TBoMS. Figure 5As shown, the base station can notify the terminal whether coverage enhancement is required through the reserved bits in MIB or PBCH. Specifically, the base station can determine whether coverage enhancement is indicated through the reserved bits in MIB or PBCH. If so, the coverage enhancement of SIB1 or other system messages is configured, that is, the number of repetitions and the number of time slots of TBoMS are configured. Otherwise, the coverage enhancement of SIB1 or other system messages is not configured. Or Figure 6 As shown, the base station can notify the terminal whether coverage enhancement is required through cellBarredNTN in SIB1. Specifically, the base station can determine whether cellBarredNTN in SIB1 is configured as 'allowed'. If so, the coverage enhancement of other system messages is configured, that is, the number of repetitions and the number of time slots of TBoMS are configured. Otherwise, the coverage enhancement of other system messages is not configured.

[0116] For Msg4, the base station can carry the second indication information through RRC parameters and / or DCI according to the repetition request sent by the terminal. For example, the base station can configure the number of repetitions and the number of time slots of TBoMS through RRC parameters and / or DCI. The specific configuration method can refer to the method shown in the above embodiment, which will not be repeated here. For example, the base station can indicate the number of repetitions and the number of time slots of TBoMS by reserving bits, adding bits or reusing existing bits in DCI. The DCI can be the DCI carried in the PDCCH corresponding to the PDSCH carrying Msg4, and the DCI is encrypted with a temporary cell radio network temporary identifier (Temporary Cell Radio Network Temporary Identity, TC-RNTI), and the DCI format is DCI format 1_0. For another example, the base station can combine RRC parameters and DCI to indicate the number of repetitions and the number of time slots of TBoMS. The specific joint method can refer to the method described in the above embodiment, which will not be repeated here. For another example, the base station can directly use RRC parameters to indicate the number of repetitions and the number of time slots of TBoMS.

[0117] For the downlink data after the terminal accesses the base station, the base station can carry the second indication information through RRC parameters and / or DCI. For example, the base station can configure the number of repetitions and the number of time slots of TBoMS through RRC parameters and / or DCI. The specific configuration method can refer to the method shown in the above embodiment and will not be repeated here.

[0118] It is understandable that the base station first sends the information carried by PDCCH to the terminal. The information carried by PDCCH includes the scheduling information of PDSCH, and PDSCH carries SIB1. Therefore, in order to successfully receive SIB1, the terminal needs to monitor PDCCH according to the monitoring time or monitoring window indicated by the base station, and then obtain the scheduling information of PDSCH from the information carried by PDCCH. Further, according to the scheduling information of PDSCH, monitor PDSCH to obtain SIB1 carried by PDSCH. In addition, different SSBs correspond to different SIB1s, and the monitoring times or monitoring windows corresponding to different SSBs may not overlap or may partially overlap. Since the case introduces the number of repetitions of downlink data and / or the number of time slots of TBoMS, resource collisions may occur in SIB1s corresponding to different SSBs. The following introduces the degree of overlap of monitoring windows corresponding to different SSBs in the prior art, and how to avoid resource collisions in SIB1s corresponding to different SSBs after introducing the number of repetitions of downlink data and / or the number of time slots of TBoMS in this case.

[0119] The current PDSCH is divided into PDSCH before access and PDSCH after access. PDSCH before access does not support repeated transmission, and the base station transmits the information carried by PDSCH in one time slot. PDSCH after access supports repeated transmission. The number of repeated transmissions can be configured through RRC parameters, and a maximum of 8 repetitions can be supported. A cell supports time-sharing transmission of multiple SSBs. The PDCCH corresponding to SIB1 is mapped in the type 0-PDCCH common space. The specific time-frequency resource allocation is determined by PDCCH-ConfigSIB1IE, which contains the configuration of CORESET#0 and search space#0, each with 4 bits, indicating the row index of the table used. Among them, the configuration of CORESET#0 includes the multiplexing mode of CORESET0 and SS / PBCH Block, the number of consecutive resource blocks occupied by CORESET0, the number of consecutive OFDM symbols of CORESET0, and the deviation of the lower boundary of the CORESET frequency band from the lower boundary of the SSB frequency band (in RB units). The configuration of search space#0 includes the values ​​of parameters O and M (mode 1), the index of the first OFDM symbol in the search space, and the number of search spaces in each slot (mode 1).

[0120] The new radio (NR) supports three multiplexing modes of CORESET0 and SS / PBCH Block.

[0121] Mode 1 can be used when the carrier frequency is less than 6 GHz and greater than 6 GHz (and less than 52.6 GHz), and modes 2 and 3 can be used when the carrier frequency is greater than 6 GHz. For mode 1 (unless otherwise specified in this article, only this mode is used), the Type0-PDCCH CSS of an SSB is within a monitoring window containing 2 time slots. The mapping relationship between the index i of the SSB and the first time slot n0 of the corresponding monitoring window is as follows:

[0122]

[0123] Where n0 is the index of the first time slot of the monitoring window in a wireless frame. When the SFN is mapped to the first radio frame of 20ms, c mod2=0(SFN c The parameter M in Table 7 below indicates the degree of overlap of the monitoring windows corresponding to SSB i and SSB i+1.

[0124] Table 7: PDCCH monitoring timing parameters for mode 1 in FR1

[0125]

[0126] like Figure 7 As shown, when M=2, the monitoring window corresponding to SSB0 does not overlap with the monitoring window corresponding to SSB1 at all. When M=1, the monitoring window corresponding to SSB0 overlaps with the monitoring window corresponding to SSB1 by 1 time slot. When M=1 / 2, the monitoring window corresponding to SSB0 completely overlaps with the monitoring window corresponding to SSB1. The design of overlapping monitoring windows can reduce the resource overhead of beam scanning to a certain extent. For the index i of SSB, when μ=0, 1, 2, 3, the two time slots of the monitoring window refer to time slots n0 and n0+1; when μ=4, the two time slots of the monitoring window refer to time slots n0 and n0+4; when μ=5, it refers to time slots n0 and n0+8. This embodiment involves the case where μ=0, 1, 2, 3.

[0127] Assuming a subcarrier spacing of 30 kHz, taking row indexes 0, 1, and 8 in Table 1 as an example, the time slots where the monitoring window corresponding to each SSB is located are shown in Tables 8, 9, and 10 respectively.

[0128] Table 8: The time slot of the monitoring window corresponding to SSB (row index 0)

[0129] SSB Index 0 1 2 3 4 5 6 7 The time slot index where the monitoring window is located 0，1 1，2 2，3 3，4 4，5 5，6 6，7 7，8

[0130] Table 9: The time slot of the monitoring window corresponding to SSB (row index 1)

[0131] SSB Index 0 1 2 3 4 5 6 7 The time slot index where the monitoring window is located 0，1 0，1 1，2 1，2 2，3 2，3 3，4 3，4

[0132] Table 10: The time slot of the monitoring window corresponding to SSB (row index 8)

[0133] SSB Index 0 1 2 3 4 5 6 7 The time slot index where the monitoring window is located 0，1 2，3 4，5 6，7 8，9 10，11 12，13 14，15

[0134] The time domain resource allocation table configured by RRC for the PDSCH of SIB1 is shown in Table 11 below, where Type A represents time slot-based PDSCH mapping, Type B represents non-time slot-based PDSCH mapping, K0 represents the downlink allocation timing (PDCCH and PDSCH interval, in time slots, 0 represents PDCCH and PDSCH in the same time slot), S represents the starting OFDM symbol index of PDSCH, and L represents the number of OFDM symbols that PDSCH continues.

[0135] Table 11: SIB1 PDSCH time domain resource allocation

[0136]

[0137] As shown in Tables 8 to 10 above, the PDCCH of SIB1 corresponding to two adjacent SSBs may be sent in the same time slot or adjacent time slots, and the K0 value in Table 11 determines that the PDCCH and its corresponding PDSCH are in the same time slot. If the coverage enhancement of SIB1 is performed according to the coverage enhancement described in this embodiment, resource collision may occur in SIB1 corresponding to different SSBs.

[0138] For example, Figure 7 Taking M=2 as an example, since the base station sends a transport block in one time slot, the base station can send SIB1 corresponding to SSB0 in time slot 0 or time slot 1, and the terminal monitors the PDCCH corresponding to SSB0 in time slot 0 or time slot 1. Similarly, the base station can send SIB1 corresponding to SSB1 in time slot 2 or time slot 3, and the terminal monitors the PDCCH corresponding to SSB1 in time slot 2 or time slot 3. It can be understood that Figure 7In , taking M=2 as an example, although the monitoring window corresponding to SSB0 includes time slot 0 and time slot 1, the monitoring window indicates that the terminal can monitor the PDCCH corresponding to SSB0 in a range of two time slots. If the base station sends SIB1 corresponding to SSB0 in time slot 0, the terminal monitors the PDCCH corresponding to SSB0 in time slot 0. If the base station sends SIB1 corresponding to SSB0 in time slot 1, the terminal monitors the PDCCH corresponding to SSB0 in time slot 1. Specifically, the base station may send a notification message to the terminal in advance, and the notification message is used to indicate the time slot corresponding to the SIB1. Alternatively, the base station and the terminal may pre-agree on the time slot corresponding to the SIB1. Alternatively, the base station may send the row number of a row in Table 7 to the terminal. The row number is usually in the MIB, so that the terminal uses the row number as an index and searches for the index in Table 7 to determine the PDCCH monitoring timing corresponding to the row number. The PDCCH monitoring timing is the time slot corresponding to the SIB1. Similarly, if Figure 7 As shown, taking M=2 as an example, although the monitoring window corresponding to SSB1 includes time slot 2 and time slot 3, the monitoring window indicates that the terminal can monitor the PDCCH corresponding to SSB1 in a range of two time slots.

[0139] Since the case introduces the number of repetitions of downlink data and / or the number of time slots for transmitting the downlink data, and the number of time slots is greater than or equal to 2, when the downlink data is SIB1, SIB1 may occupy multiple time slots. For example, taking the number of repetitions of SIB1 as 4 and the same SIB1 occupying 1 time slot as an example, the base station needs to send SIB1 in 4 time slots, such as Figure 7 As shown, the base station sends the SIB1 corresponding to SSB0 in time slot 0, time slot 1, time slot 2, and time slot 3, and repeats the SIB1 corresponding to SSB0 once in one time slot, which is equivalent to the base station sending the SIB1 corresponding to SSB0 four times in a row. Therefore, the monitoring window corresponding to SSB0 includes time slot 0, time slot 1, time slot 2, and time slot 3. Similarly, when the base station sends the SIB1 corresponding to SSB1 to the terminal, it also needs to occupy similar four time slots. If the four time slots overlap with the four time slots of time slot 0, time slot 1, time slot 2, and time slot 3 mentioned above, it may cause resource collisions between the SIB1 corresponding to SSB0 and SSB1. Therefore, in order to avoid such resource collisions, the method described in this embodiment also includes: the base station sends the monitoring timing of the physical downlink control channel to the terminal, and the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data. For example, the base station can send the monitoring timing of the PDCCH corresponding to different SSBs to the terminal in advance, such as Figure 7As shown, for M=2, if coverage enhancement is required, it can be changed to M=4, that is, the base station can send the monitoring time of the PDCCH corresponding to SSB0 to the terminal in advance starting from time slot 0, and / or send the monitoring time of the PDCCH corresponding to SSB1 to the terminal in advance starting from time slot 4, so as to avoid resource collision of SIB1 corresponding to SSB0 and SSB1. It can be understood that for Figure 7 In the case where M=1 or M=1 / 2, when coverage enhancement is required, a similar method can be used to avoid resource collision between SIB1s corresponding to different SSBs.

[0140] It is understandable that before the base station sends the monitoring opportunity of the PDCCH corresponding to different SSBs to the terminal, the base station knows that the monitoring opportunity is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, for example Figure 7 In the case of M=4, according to the number of repetitions of the downlink data, for example 4, and the number of time slots used to transmit the downlink data, for example 1, it can be known that the starting time slots of the PDCCH monitoring opportunities corresponding to different SSBs need to be at least 4 time slots apart. Therefore, the PDCCH monitoring opportunity corresponding to SSB0 starts from time slot 0, and the PDCCH monitoring opportunity corresponding to SSB1 starts from time slot 4. Specifically, in the case where coverage enhancement is required, one achievable way for the base station to send the PDCCH monitoring opportunities corresponding to different SSBs to the terminal is that the base station sends the row number of a row in the following Table 12 to the terminal, so that the terminal uses the row number as an index and searches in Table 12 with the index to determine the PDCCH monitoring opportunity corresponding to the row number. In other words, when the terminal obtains a row number from the MIB, it is necessary to first determine whether coverage enhancement is required. If coverage enhancement is not required, the terminal searches for the PDCCH monitoring opportunity from Table 7 according to the row number. If coverage enhancement is required, the terminal searches for the PDCCH monitoring opportunity from Table 12 according to the row number. That is to say, the following Table 12 is a reference table of PDCCH monitoring opportunities set in this embodiment for coverage enhancement, and the reference table is known to both the base station and the terminal.

[0141] Table 12: PDCCH monitoring timing parameters for mode 1 in FR1

[0142] Index O The number of search space sets contained in each time slot M Starting symbol index 0 0 1 4 0 1 0 1 8 0 2 0 1 4 1 3 0 1 8 1 4 2 1 4 0 5 2 1 8 0 6 2 1 4 1 7 2 1 8 1 8 5 1 4 0 9 5 1 8 0 10 7 1 4 0 11 7 1 8 0 12 0 1 16 0 13 0 1 16 0 14 2 1 32 0 15 2 1 32 0

[0143] Figure 8 A flowchart of a downlink data transmission method provided by another embodiment of the present disclosure. The method described in this embodiment may be executed by a terminal. In this embodiment, the method comprises the following specific steps:

[0144] S801. Receive first indication information sent by a base station in a satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required.

[0145] For example, the terminal may receive first indication information sent by the base station, where the first indication information is used to indicate whether coverage enhancement is required. The specific indication method may be implemented with reference to the method described in the above embodiment, which will not be described in detail here.

[0146] S802. When the coverage enhancement is required, receive second indication information sent by the base station, where the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2.

[0147] In the case where the coverage enhancement is required, the base station will further generate second indication information and send the second indication information to the terminal. Correspondingly, the terminal receives the second indication information, and the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data. The specific indication method can be implemented with reference to the method described in the above embodiment, which will not be repeated here. It can be understood that in the case where coverage enhancement is not required, the terminal does not need to execute S802 as described above and S803 as follows. At this time, the terminal uses the row number of a row in Table 7 sent by the base station as an index and searches in Table 7 with the index to determine the PDCCH monitoring time corresponding to the row number, and monitors the PDCCH at the monitoring time to obtain the scheduling information of the PDSCH carried by the PDCCH. Further, according to the scheduling information of the PDSCH, the PDSCH is monitored to obtain the downlink data carried by the PDSCH.

[0148] S803. Receive the downlink data according to the second indication information.

[0149] After generating the second indication information, the base station will send the downlink data to the terminal according to the number of repetitions of the downlink data and / or the number of time slots for transmitting the downlink data included in the second indication information. Therefore, when the terminal receives the second indication information, it can receive the downlink data according to the second indication information.

[0150] Optionally, receiving the downlink data according to the second indication information includes: determining a plurality of time slots corresponding to the downlink data according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data; and receiving the downlink data in the plurality of time slots. Optionally, the time slots used to repeatedly transmit the downlink data are continuous.

[0151] For example, the number of time slots required for multi-slot transmission is N, and the number of repeated transmissions is H. Therefore, the base station needs to send downlink data in N*H time slots. Assuming that the downlink data is carried in a transmission block, the base station needs to send the transmission block in N consecutive time slots, and the transmission block is repeatedly transmitted H times. Take N=2, H=3 as an example. Figure 3 As shown, a transport block is transmitted in two time slots, and this is repeated three times. Then the base station sends the first part of the transport block in time slot 0, sends the second part of the transport block in time slot 1, sends the first part again in time slot 2, sends the second part again in time slot 3, sends the first part again in time slot 4, and sends the second part again in time slot 5. Accordingly, the terminal needs to receive the first part of the transport block in time slot 0, receive the second part of the transport block in time slot 1, receive the first part of the transport block again in time slot 2, receive the second part of the transport block again in time slot 3, receive the first part of the transport block again in time slot 4, and receive the second part of the transport block again in time slot 5.

[0152] For example, when the downlink data is SIB1, the base station will send the row number of a row in Table 12 to the terminal, so that the terminal can query the row corresponding to the row number according to Table 12 as described above to determine the PDCCH monitoring time, monitor the PDCCH at the PDCCH monitoring time, and obtain the number of repeated transmissions and / or the number of TBoMS time slots from the DCI carried by the PDCCH. Further, according to the number of repeated transmissions and / or the number of TBoMS time slots, multiple time slots are determined, and SIB1 is received in the multiple time slots. If SIB1 is not covered, the terminal receives SIB1 only in one time slot.

[0153] For other system messages, if the terminal determines that coverage enhancement is required through cellBarredNTN in SIB1, the number of repeated transmissions and / or the number of TBoMS time slots are further obtained from the DCI carried by PDCCH, and further, multiple time slots are determined according to the number of repeated transmissions and / or the number of TBoMS time slots, and other system messages are received on the multiple time slots. If coverage enhancement is not performed on other system messages, the terminal receives other system messages only on one time slot.

[0154] For Msg4, if the terminal has reported a repeat request to the base station, the terminal obtains the number of repeated transmissions and / or the number of TBoMS time slots from the DCI carried by the PDCCH, and further determines multiple time slots according to the number of repeated transmissions and / or the number of TBoMS time slots, and receives Msg4 in the multiple time slots. If the coverage of Msg4 is not enhanced, the terminal receives Msg4 only in one time slot.

[0155] For downlink data after the terminal accesses the base station, the terminal can obtain the number of repeated transmissions and / or the number of TBoMS time slots from the DCI carried by the PDCCH, and further determine multiple time slots according to the number of repeated transmissions and / or the number of TBoMS time slots, and receive this type of downlink data in the multiple time slots. If coverage enhancement is not performed on this type of downlink data, the terminal receives this type of downlink data only in one time slot.

[0156] In this embodiment, the base station sends first indication information to the terminal to indicate whether the terminal performs coverage enhancement. In the case where coverage enhancement is required, the base station generates second indication information to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, which number of time slots is greater than or equal to 2, wherein the number of repetitions of downlink data allows the base station to repeatedly transmit the downlink data multiple times, and the number of time slots used to transmit the downlink data allows the same downlink data to be transmitted in multiple time slots. Further, the base station sends the second indication information to the terminal, and according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, sends the downlink data to the terminal, so that the downlink data is repeated multiple times and / or the same downlink data is transmitted in multiple time slots. When the terminal determines that there is coverage enhancement according to the first indication information, based on the number of repetitions of the downlink data indicated in the second indication information and / or the number of time slots used to transmit the downlink data, the downlink data is received from the corresponding time slot. Since the same downlink data is transmitted in multiple time slots, that is, different parts of the downlink data are transmitted in different time slots, the demodulation performance of the terminal for the downlink data is improved by reducing the code rate, thereby helping to improve the transmission efficiency of the downlink data. In addition, the base station transmits the downlink data repeatedly for multiple times, so that the terminal can combine the multiple repeated downlink data received in different time slots, thereby improving the terminal's success rate in receiving downlink data, avoiding the transmission delay caused by retransmission, and improving the downlink data transmission efficiency of the satellite communication system.

[0157] Optionally, the method further includes: monitoring a physical downlink control channel according to a monitoring timing notified by the base station, wherein the monitoring timing is determined according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0158] For example, the base station first sends information carried by PDCCH to the terminal, and then sends information carried by PDSCH to the terminal, and PDSCH carries SIB. Before the base station sends information carried by PDCCH to the terminal, the base station needs to inform the terminal of the monitoring time of PDCCH, so that the terminal monitors PDCCH at the monitoring time. Specifically, if coverage enhancement is not required, the base station can send the row number of a row in Table 7 to the terminal, and the row number is usually in the MIB, so that the terminal uses the row number as an index and searches for the index in Table 7 to determine the PDCCH monitoring time corresponding to the row number. If coverage enhancement is required, the base station can send the row number of a row in Table 12 to the terminal, so that the terminal uses the row number as an index and searches for the index in Table 12 to determine the PDCCH monitoring time corresponding to the row number. That is to say, when the terminal obtains a row number from the MIB, it needs to first determine whether coverage enhancement is required. If coverage enhancement is not required, the terminal searches for the PDCCH monitoring opportunity from Table 7 according to the row number. If coverage enhancement is required, the terminal searches for the PDCCH monitoring opportunity from Table 12 according to the row number. This rule may be a rule agreed upon in advance by the terminal and the base station, or this rule is a rule pre-configured by the base station to the terminal. In addition, when the base station sends the row number for finding the PDCCH monitoring opportunity to the terminal, the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data need to be considered. However, the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data may not be considered. In theory, as long as the PDCCH monitoring opportunity corresponding to the row number sent by the base station to the terminal can avoid resource collisions between SIB1s corresponding to different SSBs, it can be sufficient.

[0159] Fig. 9 The structure diagram of the downlink data transmission device provided in the embodiment of the present disclosure is as follows. The downlink data transmission device provided in the embodiment of the present disclosure can execute the processing flow provided in the downlink data transmission method embodiment, such as Fig. 9 As shown, the downlink data transmission device 90 includes:

[0160] A first sending module 91 is used to send first indication information to the terminal, where the first indication information is used to indicate whether coverage enhancement is required;

[0161] A generating module 92, configured to generate second indication information when the coverage enhancement is required, wherein the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2;

[0162] A second sending module 93, configured to send the second indication information to the terminal;

[0163] The third sending module 94 is used to send the downlink data to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0164] Optionally, when the first sending module 91 sends the first indication information to the terminal, it is specifically used to:

[0165] sending a synchronization signal block to the terminal, where a master information block or a physical broadcast channel in the synchronization signal block is used to carry the first indication information; or

[0166] sending a first system information block to the terminal, where the first system information block is used to carry the first indication information; or

[0167] First indication information is sent to the terminal, where the first indication information is determined by whether a second system information block is sent to the terminal. If the second system information block is sent to the terminal, it indicates that coverage enhancement is required.

[0168] Optionally, when the generating module 92 generates the second indication information, it is specifically used to:

[0169] adding the second indication information to the downlink control information; or

[0170] The second indication information is added to the radio resource control parameter.

[0171] Optionally, when the generating module 92 adds the second indication information to the downlink control information, it is specifically used to:

[0172] Indicating the second indication information by using a reserved bit of the downlink control information; or

[0173] Indicating the second indication information by using a newly added bit of the downlink control information; or

[0174] The second indication information is represented by multiplexing existing bits of the downlink control information.

[0175] Optionally, when the generation module 92 generates the second indication information, it is specifically used to: add the second indication information to the downlink control information and the wireless resource control parameters; the wireless resource control parameters include multiple first values ​​and / or multiple second values, the downlink control information includes a first index value and / or a second index value, the first value corresponding to the first index value in the multiple first values ​​represents the number of repetitions, and the second value corresponding to the second index value in the multiple second values ​​represents the number of time slots.

[0176] Optionally, the downlink data transmission device 90 also includes: a fourth sending module 95, used to send a monitoring timing of a physical downlink control channel to the terminal, wherein the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0177] Fig. 9 The downlink data transmission device of the illustrated embodiment can be used to execute the technical solution of the above-mentioned method embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

[0178] Fig.10 The structure diagram of the downlink data transmission device provided in the embodiment of the present disclosure is as follows. The downlink data transmission device provided in the embodiment of the present disclosure can execute the processing flow provided in the downlink data transmission method embodiment, such as Fig.10 As shown, the downlink data transmission device 100 includes:

[0179] A first receiving module 101 is used to receive first indication information sent by a base station in a satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required;

[0180] A second receiving module 102 is used to receive second indication information sent by the base station when the coverage enhancement is required, where the second indication information is used to indicate the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2;

[0181] The third receiving module 103 is configured to receive the downlink data according to the second indication information.

[0182] Optionally, when the third receiving module 103 receives the downlink data according to the second indication information, it is specifically used to: determine a plurality of time slots corresponding to the downlink data according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data; and receive the downlink data in the plurality of time slots.

[0183] Optionally, the time slots used for repeatedly transmitting the downlink data are continuous.

[0184] Optionally, the downlink data transmission device 100 further includes a monitoring module 104, which is used to monitor the physical downlink control channel according to the monitoring timing notified by the base station, and the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

[0185] Fig.10 The downlink data transmission device of the illustrated embodiment can be used to execute the technical solution of the above-mentioned method embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

[0186] Fig.11 This is a schematic diagram of the structure of a terminal embodiment provided by the present disclosure. Fig.11 As shown, the terminal includes a processor 110, a communication component 111, a memory 112 and a user interface 113. The computer program is stored in the memory 112 and is configured so that the processor 110 executes the method steps on the terminal side as described above.

[0187] A communications component that receives and sends data under the control of the processor.

[0188] Among them, Fig.11 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by a processor and various circuits represented by a memory linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The communication component 111 may be a plurality of elements, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, including wireless channels, wired channels, optical cables, and other transmission media. For different user devices, the user interface may also be an interface capable of externally and internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

[0189] The processor 110 is responsible for managing the bus architecture and general processing, and the memory 112 can store data used by the processor 120 when performing operations.

[0190] Optionally, the processor 110 may be a CPU (central processing unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array) or a CPLD (Complex Programmable Logic Device), and the processor 110 may also adopt a multi-core architecture.

[0191] The processor 110 is used to execute any of the methods provided in the embodiments of the present application according to the obtained executable instructions by calling the program stored in the memory 112. The processor 110 and the memory 112 may also be arranged physically separately.

[0192] In addition, the present disclosure also provides a base station, such as Fig.12As shown, the base station includes a processor 120, a communication interface 121, and a memory 122. The memory 122 stores a computer program, and the computer program is configured to enable the processor 122 to execute the above-mentioned downlink data transmission method at the base station side.

[0193] The communication interface 121 is used to receive and send data under the control of the processor 120 .

[0194] Among them, Fig.12 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by a processor and a memory represented by a memory. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The communication interface 121 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, such as a wireless channel, a wired channel, an optical cable, and the like. The processor is responsible for managing the bus architecture and general processing, and the memory 122 may store data used by the processor 120 when performing operations.

[0195] The processor 120 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0196] In addition, an embodiment of the present disclosure further provides a computer-readable storage medium on which a computer program is stored. The computer program is executed by a processor to implement the downlink data transmission method described in the above embodiment.

[0197] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0198] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A downlink data transmission method, characterized in that: The method comprises: Sending first indication information to the terminal, where the first indication information is used to indicate whether coverage enhancement is required; In the case where the coverage enhancement is required, generating second indication information, where the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, where the number of time slots is greater than or equal to 2; sending the second indication information to the terminal; The downlink data is sent to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

2. The method according to claim 1, characterized in that Sending first indication information to a terminal includes: sending a synchronization signal block to the terminal, where a master information block or a physical broadcast channel in the synchronization signal block is used to carry the first indication information; or sending a first system information block to the terminal, where the first system information block is used to carry the first indication information; or First indication information is sent to the terminal, where the first indication information is determined by whether a second system information block is sent to the terminal. If the second system information block is sent to the terminal, it indicates that coverage enhancement is required.

3. The method according to claim 1, characterized in that Generating second indication information includes: adding the second indication information to the downlink control information; or The second indication information is added to the radio resource control parameter.

4. The method according to claim 3, characterized in that: Adding the second indication information to the downlink control information includes: Indicating the second indication information by using a reserved bit of the downlink control information; or Indicating the second indication information by using a newly added bit of the downlink control information; or The second indication information is represented by multiplexing existing bits of the downlink control information.

5. The method according to claim 1, characterized in that Generating second indication information includes: The second indication information is added to the downlink control information and the wireless resource control parameter; the wireless resource control parameter includes multiple first values ​​and / or multiple second values, the downlink control information includes a first index value and / or a second index value, a first value corresponding to the first index value in the multiple first values ​​represents the number of repetitions, and a second value corresponding to the second index value in the multiple second values ​​represents the number of time slots.

6. The method according to claim 1, characterized in that The method further comprises: A monitoring opportunity of a physical downlink control channel is sent to the terminal, where the monitoring opportunity is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

7. A downlink data transmission method, characterized in that: The method comprises: receiving first indication information sent by a base station in a satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required; In a case where the coverage enhancement is required, receiving second indication information sent by the base station, where the second indication information is used to indicate a number of repetitions of downlink data and / or a number of time slots used to transmit the downlink data, where the number of time slots is greater than or equal to 2; The downlink data is received according to the second indication information.

8. The method according to claim 7, characterized in that Receiving the downlink data according to the second indication information includes: Determine a plurality of time slots corresponding to the downlink data according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data; The downlink data is received in the multiple time slots.

9. The method according to claim 8, characterized in that The time slots used for repeatedly transmitting the downlink data are continuous.

10. The method according to claim 7, characterized in that The method further comprises: The physical downlink control channel is monitored according to the monitoring timing notified by the base station, wherein the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

11. A downlink data transmission device, characterized in that: include: A first sending module, used to send first indication information to the terminal, where the first indication information is used to indicate whether coverage enhancement is required; A generating module, configured to generate second indication information when the coverage enhancement is required, wherein the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2; A second sending module, used to send the second indication information to the terminal; The third sending module is used to send the downlink data to the terminal according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

12. A downlink data transmission device, characterized in that: include: A first receiving module is used to receive first indication information sent by a base station in the satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required; A second receiving module is used to receive second indication information sent by the base station when the coverage enhancement is required, where the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2; A third receiving module is used to receive the downlink data according to the second indication information.

13. A base station, characterized in that: include: Memory; processor; Computer programs; as well as Communication interface; The computer program is stored in the memory and is configured to execute the following steps by the processor: Sending first indication information to the terminal through the communication interface, where the first indication information is used to indicate whether coverage enhancement is required; In the case where the coverage enhancement is required, generating second indication information, where the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, where the number of time slots is greater than or equal to 2; sending the second indication information to the terminal through the communication interface; The downlink data is sent to the terminal through the communication interface according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

14. The base station according to claim 13, characterized in that: When the processor sends the first indication information to the terminal through the communication interface, it is specifically used to: Sending a synchronization signal block to the terminal through the communication interface, where a master information block or a physical broadcast channel in the synchronization signal block is used to carry the first indication information; or Sending a first system information block to the terminal through the communication interface, where the first system information block is used to carry the first indication information; or First indication information is sent to the terminal through the communication interface, and the first indication information is determined by whether a second system information block is sent to the terminal. If the second system information block is sent to the terminal, it indicates that coverage enhancement is required.

15. The base station according to claim 13, characterized in that: When the processor generates the second indication information, it is specifically used to: adding the second indication information to the downlink control information; or The second indication information is added to the radio resource control parameter.

16. The base station according to claim 15, characterized in that: When the processor adds the second indication information to the downlink control information, the processor is specifically configured to: Indicating the second indication information by using a reserved bit of the downlink control information; or Indicating the second indication information by using a newly added bit of the downlink control information; or The second indication information is represented by multiplexing existing bits of the downlink control information.

17. The base station according to claim 13, characterized in that: When the processor generates the second indication information, it is specifically used to: The second indication information is added to the downlink control information and the wireless resource control parameter; the wireless resource control parameter includes multiple first values ​​and / or multiple second values, the downlink control information includes a first index value and / or a second index value, a first value corresponding to the first index value in the multiple first values ​​represents the number of repetitions, and a second value corresponding to the second index value in the multiple second values ​​represents the number of time slots.

18. The base station according to claim 13, characterized in that: The processor is further configured to: The monitoring timing of the physical downlink control channel is sent to the terminal through the communication interface, and the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

19. A terminal, characterized in that: include: Memory; processor; Computer programs; as well as Communication components; The computer program is stored in the memory and is configured to execute the following steps by the processor: receiving, by the communication component, first indication information sent by a base station in a satellite communication system, where the first indication information is used to indicate whether coverage enhancement is required; In the case where the coverage enhancement is required, receiving, through the communication component, second indication information sent by the base station, where the second indication information is used to indicate the number of repetitions of downlink data and / or the number of time slots used to transmit the downlink data, and the number of time slots is greater than or equal to 2; According to the second indication information, the downlink data is received through the communication component.

20. The terminal according to claim 19, characterized in that When the processor receives the downlink data through the communication component according to the second indication information, the processor is specifically configured to: Determine a plurality of time slots corresponding to the downlink data according to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data; The downlink data is received in the plurality of time slots by the communication component.

21. The terminal according to claim 19, characterized in that The processor is further configured to: The physical downlink control channel is monitored according to the monitoring timing notified by the base station, wherein the monitoring timing is related to the number of repetitions of the downlink data and / or the number of time slots used to transmit the downlink data.

22. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

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