Low-orbit satellite mobile communication resource scheduling method

Abstract

The invention discloses a low earth orbit satellite mobile communication resource scheduling method, and belongs to the technical field of low earth orbit satellite mobile communication. The method comprises the following steps: firstly, setting a time slot number n, scheduling the data volume of n time slots in one scheduling process, mapping the data to continuous n time slots, and sending out the data; the terminal judges whether the scheduling is one-time multi-time-slot scheduling or not according to the time slot number n; and if multi-time-slot scheduling is carried out, the terminal continuously receives signals of n time slots and carries out merging processing on the continuously received signals of the n time slots to obtain the sizes of transmission blocks of the n time slots. The invention provides a new continuous scheduling method based on a media access layer scheduling process, which is applied to the 120KHz subcarrier scheduling process of a low-orbit satellite mobile communication system, and can effectively reduce the load processing load, improve the system processing efficiency and improve the system stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-orbit satellite mobile communications, and in particular relates to a low-orbit satellite mobile communications resource scheduling method. Background Art

[0002] In the low-orbit satellite mobile communication system, the satellite payload equipment is responsible for the wireless access protocol processing function. In the case of 120KHz subcarrier, the length of a time slot is 0.125 milliseconds. Since the satellite payload equipment is different from the ground mobile protocol processing equipment, the payload equipment processing capacity is limited. A time slot as a scheduling cycle has high requirements for equipment performance, which poses a huge challenge to the design and implementation of the payload equipment.

[0003] Therefore, how to process subcarriers under the existing payload equipment processing capability has become an urgent problem to be solved in the prior art. Summary of the invention

[0004] In view of this, the present invention proposes a method for scheduling low-orbit satellite mobile communication resources. The present invention effectively alleviates the problem of excessive satellite payload system overhead caused by too frequent scheduling, reduces the difficulty of payload system implementation, and improves system stability.

[0005] The object of the present invention is achieved in that:

[0006] A method for scheduling low-orbit satellite mobile communication resources, comprising the following steps:

[0007] (1) The network side of the low-orbit satellite mobile communication system adjusts the scheduling mode of the next scheduling cycle according to the CPU occupancy rate fed back by the load balancing module of the satellite payload equipment in each scheduling cycle: if the CPU occupancy rate of the satellite payload equipment is between 25% and 50%, the number of time slots n is set to 1; if the CPU occupancy rate of the satellite payload equipment is between 50% and 70%, the number of time slots n is set to 2; if the CPU occupancy rate of the satellite payload equipment is between 70% and 80%, the number of time slots n is set to 4; if the CPU occupancy rate of the satellite payload equipment exceeds 80%, the number of time slots n is set to 8;

[0008] (2) In a scheduling process, the network side of the low-orbit satellite mobile communication system schedules the amount of data in n time slots. After coding and modulation, in the resource mapping stage, the data is mapped to n consecutive time slots and sent out. The information bits at each position of the data are different, but the transmission format is the same and belongs to the same HARQ process. In addition, the network side of the low-orbit satellite mobile communication system uses the time slot number n as a time slot identifier and sends it to the terminal through the PDCCH channel.

[0009] (3) The terminal receives the PDCCH channel signal and determines whether this scheduling is a multi-slot scheduling according to the number of time slots n;

[0010] (4) If n is greater than 1, it indicates that this is a multi-slot scheduling. The terminal continuously receives signals of n time slots and combines the signals of the n time slots continuously received to obtain a transmission block size of n time slots.

[0011] If n=1, scheduling is performed in a single time slot manner.

[0012] Furthermore, in step (4), the signals of the n time slots received continuously are combined to obtain the transmission block size of the n time slots, specifically in the following manner:

[0013] By demodulating and decoding, the following formula is implemented to obtain the number of bits N in n time slots: info :

[0014] N info =n*N RE *R*Q m *v

[0015] in,

[0016] N RE =min(156,N' RE )*n PRB

[0017]

[0018] Where N RE is the number of available resource units for the data channel in a time slot, R and Q m are the code rate and modulation order determined according to the modulation and coding strategy, v is the number of layers, N′ RE is the number of available resource units in a physical resource block, n PRB is the number of physical resource blocks, min() is the minimum value, is the number of subcarriers in a resource block, is the number of symbols occupied by the data channel in a time slot, is the number of resource units occupied by the demodulation reference signal in a physical resource block, Overhead configured for high-level layers;

[0019] Number of bits N info Quantize and obtain the transmission block size TBS:

[0020]

[0021] in, Indicates rounding up.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention proposes a new low-orbit satellite mobile communication resource scheduling method for onboard processing equipment, which can effectively alleviate the problem of excessive satellite payload system overhead caused by too frequent scheduling.

[0024] 2. The present invention can reduce the difficulty of implementing the load system and improve the stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of an application scenario of a low-orbit satellite mobile communication system in an embodiment of the present invention.

[0026] Figure 2 It is a flow chart of a method for scheduling low-orbit satellite mobile communication resources in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] A low-orbit satellite mobile communication resource scheduling method is applied to Figure 1 The application scenario of the low-orbit satellite mobile communication system shown in the figure. This scenario includes satellite mobile terminals, satellite payloads and ground stations. The low-orbit satellite payload equipment is responsible for processing the wireless access network protocol, the core network equipment is located in the ground station, and the terminal accesses the satellite mobile communication network through the onboard access network.

[0029] The specific process of this method includes the following steps:

[0030] (1) The network side of the low-orbit satellite mobile communication system adjusts the scheduling mode of the next scheduling cycle according to the CPU occupancy rate fed back by the load balancing module of the satellite payload equipment in each scheduling cycle: if the CPU occupancy rate of the satellite payload equipment is between 25% and 50%, the number of time slots n is set to 1; if the CPU occupancy rate of the satellite payload equipment is between 50% and 70%, the number of time slots n is set to 2; if the CPU occupancy rate of the satellite payload equipment is between 70% and 80%, the number of time slots n is set to 4; if the CPU occupancy rate of the satellite payload equipment exceeds 80%, the number of time slots n is set to 8;

[0031] In this example, the number of time slots n = 8;

[0032] If the number of time slots n=1, the conventional single time slot scheduling method can be directly adopted.

[0033] (2) Figure 2 As shown in the figure, in one scheduling process, the network side of the low-orbit satellite mobile communication system schedules the data volume of 8 time slots. After coding and modulation, in the resource mapping stage, the data is mapped to 8 consecutive time slots and sent out. The information bits on each time slot are different, the transmission format is the same, and they also belong to the same HARQ process.

[0034] (3) The network side of the low-orbit satellite mobile communication system indicates through the PDCCH channel that this is an 8-time slot scheduling;

[0035] (4) The terminal receives the PDCCH channel signal and determines, based on the indication therein, that this scheduling is a multi-slot scheduling;

[0036] (5) The terminal combines the signals of the eight consecutive time slots and obtains the number of intermediate information bits N. info :

[0037] N info =8*N RE *R*Q m *v

[0038] Among them, R and Q m is the code rate and modulation order determined by MCS, v is the number of layers, N RE is the number of available REs for the data channel in a time slot, calculated according to the following formula:

[0039] N RE =min(156,N' RE )*n PRB

[0040] Among them, N′ RE is the number of available REs in a PRB, n PRB is the number of PRBs. When calculating NRE, it is considered that a maximum of 156 REs in a PRB can be used for data transmission, that is, there is a minimum overhead of 12 REs. The number of available REs in a PRB is determined according to the following formula:

[0041]

[0042] in, is the number of subcarriers in one RB, fixed to 12, that is, is the number of symbols occupied by the data channel in one time slot; is the number of REs occupied by DMRS in a PRB, Overhead configured for the higher layer, the default value is 0;

[0043] Then, for N info Quantize and determine the final transmission block size TBS:

[0044]

[0045] in, Indicates rounding up.

[0046] In this method, PDSCH or PUSCH supports repeated transmission, that is, a PDSCH or PUSCH transmission scheduled by a PDCCH needs to be able to flexibly adjust the TBS according to the scheduling period. The TBS needs to meet byte alignment and be an integer multiple of the number of CBs.

[0047] In a low-orbit satellite mobile communication system with a subcarrier spacing of 120KHz, this method sends 8 time slots of data in each scheduling, extending the scheduling period from 1 time slot to 8 time slots, effectively alleviating the problem of excessive satellite payload system overhead caused by too frequent scheduling, reducing the difficulty of payload system implementation, and improving system efficiency and stability.

[0048] In summary, based on the media access layer scheduling process, the present invention proposes a new continuous scheduling method, which is applied to the 120KHz subcarrier scheduling process of the low-orbit satellite mobile communication system, and can effectively reduce the load processing load, improve the system processing efficiency, and enhance the system stability.

Claims

1. A method for scheduling low-orbit satellite mobile communication resources, characterized in that: The following steps are involved: (1) The network side of the low-orbit satellite mobile communication system adjusts the scheduling mode of the next scheduling cycle according to the CPU occupancy rate fed back by the load balancing module of the satellite payload equipment in each scheduling cycle: if the CPU occupancy rate of the satellite payload equipment is between 25% and 50%, the number of time slots n is set to 1; if the CPU occupancy rate of the satellite payload equipment is between 50% and 70%, the number of time slots n is set to 2; if the CPU occupancy rate of the satellite payload equipment is between 70% and 80%, the number of time slots n is set to 4; if the CPU occupancy rate of the satellite payload equipment exceeds 80%, the number of time slots n is set to 8; (2) In a scheduling process, the network side of the low-orbit satellite mobile communication system schedules the data volume of n time slots. After coding and modulation, in the resource mapping stage, the data is mapped to n consecutive time slots and sent out. The information bits on each time slot are different, but the transmission format is the same and they belong to the same HARQ process. In addition, the network side of the low-orbit satellite mobile communication system uses the time slot number n as a time slot identifier and sends it to the terminal through the PDCCH channel. (3) The terminal receives the PDCCH channel signal and determines whether this scheduling is a multi-slot scheduling according to the number of time slots n; (4) If n is greater than 1, it indicates that this is a multi-slot scheduling. The terminal continuously receives signals of n time slots and combines the signals of the n time slots continuously received to obtain a transmission block size of n time slots. If n=1, scheduling is performed in a single time slot manner.

2. A method for scheduling low-orbit satellite mobile communication resources according to claim 1, characterized in that: In step (4), the signals of n time slots received continuously are combined to obtain the transmission block size of n time slots, and the specific method is as follows: By demodulating and decoding, the following formula is implemented to obtain the number of bits N in n time slots: info : N info =n*N RE *R*Q m *v in, N RE =min(156,N' RE )*n PRB Where N RE is the number of available resource units for the data channel in a time slot, R and Q m are the code rate and modulation order determined according to the modulation and coding strategy, v is the number of layers, N' RE is the number of available resource units in a physical resource block, n PRB is the number of physical resource blocks, min() is the minimum value, is the number of subcarriers in a resource block, is the number of symbols occupied by the data channel in a time slot, is the number of resource units occupied by the demodulation reference signal in a physical resource block, Overhead for high-level configuration; Number of bits N info Quantize and obtain the transmission block size TBS: in, Indicates rounding up.

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