Scheduling cycle updating method, earth master station and satellite communication system

Abstract

The present invention provides a scheduling cycle updating method, a geo-master station and a satellite communication system, and relates to the field of satellite communication. The geo-master station includes a network control center and a gateway, and the gateway includes a processor and a forward modulation board. The method is: when the network control center completes the time slot scheduling each time, it will dynamically adjust the scheduling cycle based on the change trend sequence of the time parameters maintained by the gateway in the most recent M time periods to obtain a target scheduling cycle, and the target scheduling cycle is the waiting time for the next time slot scheduling. Therefore, the present invention dynamically adjusts the scheduling cycle in real time based on the change trend of the time parameter, so that when the gateway suspends the transmission of the data baseband data packet, the transmission queue will not accumulate a large number of baseband data packets carrying TBTP signaling due to the fixed scheduling cycle, thereby avoiding the time slot expiration in the TBTP signaling received by the subsequent terminal station.

Description

Technical Field

[0001] The present invention relates to the field of satellite communications, and in particular to a scheduling period updating method, a ground master station and a satellite communication system. Background Art

[0002] In the MF-TDMA (Multi-Frequency Time Division Multiple Access) satellite communication system, the business requirements of the terminal station (RCST) are constantly changing, and it is necessary to send bandwidth requests to the Network Control Center (NCC) in real time. According to the bandwidth requests sent by each RCST, the NCC allocates the reverse channel (uplink between the satellite and the RCST) bandwidth to the RCST according to the resource allocation rules, and broadcasts the TBTP (Terminal Burst Time Plan) to the RCST through the forward channel (downlink between the satellite and the RCST).

[0003] In the existing MF-TDMA satellite communication system, the NCC uses a fixed time slot scheduling cycle when scheduling time slots. For example, it schedules time slots every 50ms and then sends TBTP signaling to the gateway processor. The TBTP signaling is transmitted between the gateway processor and the forward modulation board as forward baseband data. The TBTP signaling is finally sent by the forward modulation board and broadcast to each RCST via satellite. However, in the actual transmission process, there are the following problems:

[0004] After the gateway processor establishes a link with the forward transmission channel, the baseband data in the transmission queue needs to be sent to the receiving unit of the forward modulation board. When sending data, the rate of sending data needs to match the rate of receiving data. If the rate of sending data is greater than the rate of receiving data, data back pressure will be caused, causing the sender to suspend sending;

[0005] During the time when the transmitter suspends transmission, the baseband data packets containing TBTP signaling will be cached and accumulated in the transmission queue. When the transmitter resumes transmission, a certain amount of time has passed, which will cause the time slot data included in the TBTP signaling received by RCST to be likely to have expired, so that RCST cannot use the time slot allocated in the TBTP signaling to send business data. Summary of the invention

[0006] The purpose of the present invention is to provide a scheduling period updating method, a ground master station and a satellite communication system to improve the problems existing in the prior art.

[0007] The embodiments of the present invention can be implemented as follows:

[0008] In a first aspect, the present invention provides a scheduling cycle updating method, which is applied to a geostationary master station, wherein the geostationary master station includes a network control center and a gateway, wherein the gateway includes a processor and a forward modulation board; the network control center, the processor, and the forward modulation board are sequentially connected in communication; the forward modulation board is connected in communication with at least one terminal station via a satellite, and the processor maintains a sending queue; the method includes:

[0009] The network control center sends the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and dynamically adjusts the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain a target scheduling period; the target scheduling period is the waiting time for the next time slot scheduling;

[0010] The processor encapsulates the received TBTP signaling to obtain a baseband data packet and adds it to the sending queue. After taking the baseband data packet out of the sending queue and sending it to the forward modulation board, the processor subtracts the sending waiting time carried by the baseband data packet from the time parameter to characterize the sending rate of the processor. When the reduced time parameter is less than or equal to the time lower limit threshold, the sending of the baseband data packet is stopped.

[0011] The forward modulation board modulates the received baseband data packet and sends it to all terminal stations via the satellite, and returns the sending waiting time carried by the sent baseband data packet to the processor when the sending is completed;

[0012] The processor increases the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and continues to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

[0013] Optionally, before the step of obtaining the target scheduling period, the method further includes:

[0014] The network control center samples the time parameter maintained by the processor according to a set sampling period to obtain an observed value of the time parameter;

[0015] The network control center calculates the observed mean of the time parameter in the current time period every preset time period based on the observed values ​​of N sampling periods in the current time period; wherein the change trend sequence is determined based on the observed mean in the most recent M time periods.

[0016] Optionally, the step of the network control center dynamically adjusting the scheduling period based on the change trend sequence of the time parameter maintained by the processor in the most recent M time periods to obtain the target scheduling period includes:

[0017] Obtaining an observation mean sequence of the time parameter in the most recent M time periods;

[0018] Based on the observed mean value sequence, determining a change trend sequence of the time parameter;

[0019] Based on the change trend sequence and the prior probability sequence of the preset duration sequence, a target scheduling period is selected from a plurality of scheduling durations in the preset duration sequence using a Bayesian algorithm.

[0020] Optionally, the observed mean sequence includes M observed means;

[0021] The step of determining the change trend sequence of the time parameter based on the observed mean sequence includes:

[0022] Starting from the first observed mean of the observed mean sequence, for the mth observed mean, based on the preset increase threshold and the comparison formula, determine the characteristic value of the change trend from the mth observed mean to the m+1th observed mean; m= ;

[0023] Based on the obtained M-1 change trend characteristic values, the change trend sequence is obtained.

[0024] Optionally, the preset duration sequence includes M-1 scheduling durations;

[0025] The step of selecting a target scheduling period from a plurality of scheduling durations in the preset duration sequence using a Bayesian algorithm based on the prior probability sequence of the change trend sequence and the preset duration sequence comprises:

[0026] Obtaining a posterior probability sequence of the preset duration sequence obtained in the process of determining the target scheduling period last time, and using it as the a priori probability sequence when determining the target scheduling period this time;

[0027] Based on the preset weights, the probability distribution matrix and the prior probability sequence, the Bayesian algorithm is used to calculate the total value of the posterior probability of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence, and the target posterior probability sequence of the preset duration sequence is obtained;

[0028] The maximum target posterior probability total value in the target posterior probability sequence is found, and the scheduling duration corresponding to the target posterior probability total value is used as the target scheduling period.

[0029] Optionally, the change trend sequence includes M-1 change trend characteristic values, and the prior probability sequence includes M-1 prior probability total values;

[0030] The step of calculating the total value of the posterior probability of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence by using the Bayesian algorithm based on the preset weight, the probability distribution matrix and the prior probability sequence to obtain the target posterior probability sequence of the preset duration sequence includes:

[0031] For any of the scheduling durations in the preset duration sequence, based on the preset weight, the probability distribution matrix and the total prior probability value corresponding to the scheduling duration in the prior probability sequence, a posterior probability value of the scheduling duration is calculated using a Bayesian algorithm when the change trend of the time parameter meets each of the change trend characteristic values;

[0032] Performing a sum operation on all the posterior probability values ​​corresponding to the scheduling duration to obtain a total posterior probability value of the scheduling duration when the change trend of the time parameter conforms to the change trend sequence;

[0033] Each of the scheduling durations in the preset duration sequence is traversed to obtain a target posterior probability sequence of the preset duration sequence.

[0034] Optionally, the comparison formula is:

[0035]

[0036] In the formula, is the mth change trend characteristic value, adding a threshold to said preset, is the mth observation mean in the observation mean sequence, is the m+1th observation mean in the observation mean sequence.

[0037] Optionally, the calculation formula for the total value of the posterior probability is:

[0038]

[0039] In the formula, Represents that the change trend of the parameter at the time conforms to the change trend sequence In the case of preset duration sequence The mth scheduling duration The corresponding total value of the posterior probability; Represents that the change trend of the parameter at the time conforms to the change trend sequence The i-th change trend characteristic value in In the case of preset duration sequence The mth scheduling duration The corresponding posterior probability value;

[0040] The calculation formula of the posterior probability value is:

[0041]

[0042] In the formula, Represents a preset duration sequence The mth scheduling duration The variation trend of the time parameter conforms to the variation trend sequence The i-th change trend characteristic value in The likelihood probability when ; Represents the total value of the mth prior probability in the prior probability sequence; Represents a trend sequence The i-th change trend characteristic value in Evidence factor of distribution;

[0043]

[0044]

[0045]

[0046] In the formula, is the preset weight, , Preset weights of Second power, Power; is the probability distribution matrix An element in represents the first scheduling duration The characteristic value of the changing trend is The probability of presentation when is the probability distribution matrix An element in represents the mth scheduling duration The characteristic value of the changing trend is The probability of presentation when Represents the first scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the mth scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Respectively represent the second scheduling duration In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the M-1th scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively;

[0047]

[0048]

[0049] In the formula, Represents the first change trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence, Representative The trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence.

[0050] In a second aspect, the present invention provides a ground master station, comprising a network control center and a gateway, the gateway comprising a processor and a forward modulation board, the network control center, the processor, and the forward modulation board are sequentially connected in communication; the forward modulation board is connected in communication with at least one terminal station via a satellite, and the processor maintains a sending queue;

[0051] The network control center is used to send the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and at the same time dynamically adjust the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain a target scheduling period; the target scheduling period is the waiting time for the next time slot scheduling;

[0052] The processor is used to encapsulate the received TBTP signaling to obtain a baseband data packet and add it to the sending queue, and after taking the baseband data packet out of the sending queue and sending it to the forward modulation board, subtract the sending waiting time carried by the baseband data packet from the time parameter to characterize the sending rate of the processor, and stop sending the baseband data packet when the reduced time parameter is less than or equal to the time lower limit threshold;

[0053] The forward modulation board is used to modulate the received baseband data packets and then send them to all terminal stations via the satellite, and return the sending waiting time carried by the sent baseband data packets to the processor when the sending is completed;

[0054] The processor is also used to increase the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and continue to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

[0055] In a third aspect, the present invention provides a satellite communication system, comprising the earth master station as described in the second aspect, a satellite and at least one terminal station.

[0056] Compared with the prior art, the embodiment of the present invention provides a scheduling cycle updating method, a geo-master station and a satellite communication system. The geo-master station includes a network control center and a gateway. The gateway includes a processor and a forward modulation board. The method is as follows: the network control center sends the TBTP signaling obtained by the time slot scheduling to the gateway each time the time slot scheduling is completed, and at the same time, the scheduling cycle is dynamically adjusted based on the change trend sequence of the time parameters maintained by the gateway in the most recent M time periods to obtain a target scheduling cycle; the target scheduling cycle is the waiting time for the next time slot scheduling; the gateway encapsulates the received TBTP signaling to obtain a baseband data packet and then adds it to the sending The invention provides a sending queue, and after taking the baseband data packet out of the sending queue and sending it to the forward modulation board, the time parameter is subtracted from the sending waiting time carried by the baseband data packet to characterize the sending rate of the gateway, and when the reduced time parameter is less than or equal to the time lower limit threshold, the sending of the baseband data packet is stopped; the forward modulation board modulates the received baseband data packet and sends it to the satellite, and when the sending is completed, the sending waiting time carried by the sent baseband data packet is returned to the gateway; the gateway increases the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and when the increased time parameter is greater than the time lower limit threshold, the baseband data packet is continued to be sent. The present invention dynamically adjusts the scheduling cycle in real time based on the changing trend of the time parameter, so that when the gateway suspends the sending of the data baseband data packet, the sending queue will not accumulate a large number of baseband data packets carrying TBTP signaling due to the fixed scheduling cycle, thereby avoiding the expiration of the time slot in the TBTP signaling received by the subsequent terminal station. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0058] Figure 1 A schematic diagram of an application scenario provided by an embodiment of the present invention.

[0059] Figure 2 One of the flow charts of a scheduling period updating method provided in an embodiment of the present invention.

[0060] Figure 3 An example diagram of a scheduling period distribution provided in an embodiment of the present invention.

[0061] Figure 4 The second flowchart of a scheduling period updating method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0063] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0065] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0066] Here, the application scenarios of the present invention are first introduced.

[0067] See also Figure 1 , Figure 1A schematic diagram of an application scenario provided by an embodiment of the present invention. A satellite communication system includes a satellite, a main earth station connected to the satellite communication, and at least one terminal station. Figure 1 The earth master station includes a network control center (abbreviated as NCC) and a gateway. The gateway includes a processor and a forward modulation board. The network control center, the processor, and the forward modulation board are communicatively connected in sequence; the forward modulation board is communicatively connected with at least one terminal station (terminal station 1~N) via a satellite.

[0068] Among them, NCC is the control and management center of the satellite communication system, responsible for the configuration, monitoring, maintenance and troubleshooting of the entire network. In the process of time slot scheduling, NCC generates a TBTP signaling each time the time slot scheduling is completed. The TBTP signaling is used to indicate the uplink time slot resources available to each terminal station, that is, to inform each terminal station when it can send signals and which time slots it can occupy;

[0069] The processor of the gateway is the core computing unit inside the gateway. It is responsible for executing the instructions of the NCC, processing data, and controlling various hardware components inside the gateway, including the forward modulation board. The processor maintains a sending queue, which is used to store various signaling data to be sent from the NCC;

[0070] The forward modulation card is a hardware component in the gateway that is responsible for converting digital signals into RF signals and performing the necessary modulation, amplification and filtering for transmission to the satellite via the uplink.

[0071] Please refer to Figure 2 , Figure 2 A flowchart of a scheduling period updating method provided by an embodiment of the present invention is provided. The execution subject of the method is the earth master station introduced above. The scheduling period updating method may include the following steps S300-S600:

[0072] S300. Each time the network control center completes the time slot scheduling, it sends the TBTP signaling obtained by the time slot scheduling to the processor, and at the same time dynamically adjusts the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain the target scheduling period.

[0073] In this embodiment, the target scheduling period is the waiting time for the next time slot scheduling after completing one time slot scheduling. Figure 1 The size of the time parameter maintained by the processor can reflect the size relationship between the sending rate of the sending unit of the processor and the receiving rate of the receiving unit of the forward modulation board.

[0074] That is, each time the network control center completes a time slot scheduling, it updates the target scheduling period based on the change trend sequence of the time parameters in the most recent M time periods, and waits for the target scheduling period before starting the next time slot scheduling.

[0075] For example, please combine Figure 3 , NCC in t 1 The first time slot scheduling is performed at time t, and after completion, the scheduling period is dynamically adjusted to obtain the target scheduling period T 1 ; from t 1 Always waiting for T 1 After that, at t 2 The second time slot scheduling starts at time t, and after completion, the scheduling period is dynamically adjusted to obtain the target scheduling period T 2 ; from t 2 Always waiting for T 2 After that, at t 3 The second time slot scheduling starts at the moment, and so on. In this way, the scheduling period of the time slot scheduling interval performed by the NCC is completely updated and changed in real time, rather than being a fixed value. This example is only an example and is not limited here.

[0076] S400, the processor encapsulates the received TBTP signaling to obtain a baseband data packet and adds it to the sending queue. After taking the baseband data packet out of the sending queue and sending it to the forward modulation board, the time parameter is subtracted from the sending waiting time carried by the baseband data packet to characterize the sending rate of the processor. When the reduced time parameter is less than or equal to the lower time limit threshold, the sending of the baseband data packet is stopped.

[0077] In this embodiment, the processor of the gateway will encapsulate the TBTP signaling sent by the NCC to obtain a baseband data packet and then add it to the sending queue to wait for sending. It can be understood that in addition to the TBTP signaling, the NCC will also send other signaling to the processor of the gateway, such as FAP (Frequency Assignment Plan) signaling, DVB-RCS MAP (DVB-RCS Message Authentication Protocol) signaling and MAHO (Mobile Assisted HandOver) signaling, etc. The processor of the gateway will also encapsulate other signaling to obtain a baseband data packet and then add it to the sending queue.

[0078] Therefore, the sending queue contains not only the baseband data packets of TBTP signaling, but also baseband data packets of various other signaling. In addition, each encapsulated baseband data packet carries a waiting time estimated by the processor.

[0079] The processor maintains a time parameter, and the initial value of the time parameter can be a default set time length (for example, 20ms or 30ms). When the processor takes out a baseband data packet from the sending queue and sends it to the forward modulation board, it will use the time parameter to subtract the sending waiting time carried by the sent baseband data packet to obtain the reduced time parameter. If it is determined that the reduced time parameter is less than or equal to the preset time lower limit threshold at this time, the sending of the baseband data packets in the sending queue will be suspended.

[0080] S500, the forward modulation board modulates the received baseband data packet and sends it to all terminal stations via satellite, and returns the sending waiting time carried by the sent baseband data packet to the processor when the sending is completed.

[0081] S600: The processor increases the time parameter by the received sending waiting time to represent the receiving rate of the forward modulation board, and continues to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

[0082] In this embodiment, the forward modulation board modulates each received baseband data packet and sends it to the satellite, which is responsible for sending it to the receiving terminal station. When the forward modulation board sends a baseband data packet, it returns the sending waiting time carried by the sent baseband data packet to the processor.

[0083] The processor will use the time parameter plus the waiting time returned by the forward modulation board to obtain the increased time parameter. If it is determined that the increased time parameter is greater than the preset time lower limit threshold, it will continue to send the baseband data packet of the sending queue.

[0084] It can be understood that once the processor suspends the transmission of the baseband data packet, the baseband data packets of various signals encapsulated by the processor during the suspension period will be backlogged in the transmission queue. Since the TBTP signaling has timeliness, once the suspension time is too long, the time slot allocated by the baseband data packet of the TBTP signaling will expire, resulting in the terminal station being unable to use it. However, in the present invention, the network control center will dynamically determine the target scheduling period to wait before each time slot scheduling based on the changing trend of the time parameter in M ​​consecutive time periods. In this way, if the time parameter gradually decreases, the target scheduling period determined by the network control center will be larger, and the time interval for generating the TBTP signaling will be longer, so that the number of baseband data packets obtained by the processor encapsulating the TBTP signaling during the suspension period will be greatly reduced, avoiding the expiration of the time slot in the TBTP signaling received by the subsequent terminal station. On the contrary, if the time parameter gradually increases and returns to the default setting time length, the target scheduling period determined by the network control center will be smaller, and the network control center will perform time slot scheduling normally.

[0085] The scheduling cycle updating method provided by the embodiment of the present invention, the earth master station includes a network control center and a gateway, the gateway includes a processor and a forward modulation board, and the method is: the network control center will dynamically adjust the scheduling cycle based on the change trend sequence of the time parameters maintained by the gateway in the most recent M time periods when completing the time slot scheduling each time, and obtain the target scheduling cycle, which is the waiting time for the next time slot scheduling. Therefore, the present invention dynamically adjusts the scheduling cycle in real time based on the change trend of the time parameter, so that when the gateway suspends the transmission of the data baseband data packet, the transmission queue will not accumulate a large number of baseband data packets carrying TBTP signaling due to the fixed scheduling cycle, thereby avoiding the time slot expiration in the TBTP signaling received by the subsequent terminal station.

[0086] In an optional implementation, since the time parameter is maintained by the processor of the gateway, the network control center needs to sample the time parameter regularly. Therefore, before step S300, the method may further include S100~S200:

[0087] S100, the network control center samples the time parameters maintained by the processor according to the set sampling period to obtain the observed value of the time parameter;

[0088] S200 . The network control center calculates the observed mean value of the time parameter in the current time period based on the observed values ​​of N sampling periods in the current time period at every preset time period.

[0089] In this embodiment, the observed mean of the time parameter within a time period K is for:

[0090]

[0091] in, It represents the i-th sampling period in the time period K. The trend sequence is determined based on the mean of observations in the most recent M time periods.

[0092] In an optional example, the sampling period may be 10ms or 5ms, and the preset time period may be 500ms or 400ms. This example is only an example, and the size of the sampling period and the preset time period may be flexibly set and is not limited here.

[0093] In an optional implementation, the network control center can use the Bayesian algorithm to determine the target scheduling period. Figure 2 Based on Figure 4In the above step S300, the network control center dynamically adjusts the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain the target scheduling period. The process may include the following sub-steps S310~S330, and the execution subjects of S310~S330 and their various sub-steps are all the network control center, and the execution subjects are omitted in the following steps and drawings.

[0094] S310, obtaining a sequence of observed mean values ​​of the time parameter in the most recent M time periods.

[0095] In this embodiment, the observation mean sequence may also be referred to as an SMA sequence, which includes M observation means.

[0096] S320. Determine a change trend sequence of a time parameter based on the observed mean sequence.

[0097] In this embodiment, the change trend sequence is determined by comparing two adjacent observation means in the observation mean sequence, so the sub-steps of step S320 may include:

[0098] S321, starting from the first observed mean of the observed mean sequence, for the mth observed mean, based on the preset increase threshold and comparison formula, determine the characteristic value of the change trend from the mth observed mean to the m+1th observed mean; m= ;

[0099] S322. Obtain a change trend sequence based on the obtained M-1 change trend characteristic values.

[0100] In this embodiment, the change trend sequence includes M-1 change trend characteristic values. The comparison formula is:

[0101] (1)

[0102] In the formula, is the mth change trend characteristic value, Add thresholds to presets, is the mth observed mean in the observed mean sequence, is the m+1th observed mean in the observed mean sequence.

[0103] In the optional example, if an SMA series includes 11 observed means, the SMA series = , assuming that =2, the change trend sequence T obtained by processing the SMA sequence based on step S321 includes 10 change trend characteristic values, namely This example is only an example and is not intended to be limiting.

[0104] S330 , based on the change trend sequence and the prior probability sequence of the preset duration sequence, a target scheduling period is selected from multiple scheduling durations in the preset duration sequence using a Bayesian algorithm.

[0105] In this embodiment, the preset duration sequence S may include M-1 scheduling durations from large to small or from small to large. The probability value of each scheduling duration in the preset duration sequence S can be calculated using the Bayesian algorithm, and the target scheduling period can be selected based on the probability value. Therefore, the sub-steps of step S330 may include S331~S333.

[0106] S331. Obtain a posterior probability sequence of a preset duration sequence obtained in the process of determining the target scheduling period last time, and use it as a priori probability sequence for determining the target scheduling period this time.

[0107] It can be understood that the characteristic of the Bayesian algorithm is to use the prior distribution as the starting point of inference. When the target scheduling period is determined for the first time, the prior probability sequence takes the initial value sequence, and when the target scheduling period is not determined for the first time, the posterior probability sequence of the preset time length sequence obtained in the process of determining the target scheduling period last time is used as the prior probability sequence when determining the target scheduling period this time. Among them, the prior probability sequence includes M-1 prior probability total values.

[0108] In the optional example, if M=11, the initial value sequence of the prior probability sequence can be: , this example is only an example and is not intended to be limiting.

[0109] S332. Based on the preset weights, probability distribution matrix and prior probability sequence, the Bayesian algorithm is used to calculate the total value of the posterior probability of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence, and the target posterior probability sequence of the preset duration sequence is obtained.

[0110] In this embodiment, for each scheduling duration in the preset duration sequence, it is necessary to use the Bayesian algorithm to calculate the total value of the posterior probability of the scheduling duration when the change trend of the time parameter conforms to the change trend sequence based on the preset weight, probability distribution matrix and prior probability sequence.

[0111] Therefore, the sub-steps of step S332 may include S3321~S3323.

[0112] S3321. For any scheduling duration in the preset duration sequence, based on the preset weight, probability distribution matrix and the total value of the prior probability corresponding to the scheduling duration in the prior probability sequence, the Bayesian algorithm is used to calculate the posterior probability value of the scheduling duration when the changing trend of the time parameter meets the characteristic value of each changing trend.

[0113] In this embodiment, the calculation formula of the posterior probability value is:

[0114] (2)

[0115] In formula (2), Indicates that the change trend of the time parameter conforms to the change trend sequence The i-th change trend characteristic value in In the case of preset duration sequence The mth scheduling duration The corresponding posterior probability value.

[0116] In formula (2), Represents a preset duration sequence The mth scheduling duration The changing trend of the time parameter conforms to the changing trend sequence The i-th change trend characteristic value in The likelihood probability when ; Represents the total value of the mth prior probability in the prior probability sequence; Represents a trend sequence The i-th change trend characteristic value in Evidence factor for distribution.

[0117] Among them, the likelihood probability is obtained based on the likelihood function. The likelihood function takes into account that the closer the time is, the greater the impact factor is, so the exponential weighting strategy is used to construct the likelihood function, and the probability distribution matrix is ​​also defined. The calculation formula of the likelihood function is:

[0118] (3)

[0119] (4)

[0120] (5)

[0121] In formulas (3), (4), and (5), is the preset weight, , Preset weights of Second power, Power; is the probability distribution matrix An element in represents the first scheduling duration The characteristic value of the changing trend is The probability of presentation when is the probability distribution matrix An element in represents the mth scheduling duration The characteristic value of the changing trend is The probability of presentation when .

[0122] In formula (5), Represents the first scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the mth scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Respectively represent the second scheduling duration In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the M-1th scheduling duration respectively In the changing trend characteristic value The probability of presentation when 1, 0, and -1 are respectively. That is, the probability distribution matrix Each column of is three presentation probabilities corresponding to a scheduling duration. For example, , represents the scheduling duration The probability of presentation when the characteristic value of the changing trend is 1, 0, or -1.

[0123] in, The calculation formula is:

[0124] (6)

[0125] (7)

[0126] In formula (6) and (7), , Preset weights of Second power, Power; Represents the first change trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence, Representative The trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence.

[0127] S3322. Sum all the posterior probability values ​​corresponding to the scheduling duration to obtain the total posterior probability value of the scheduling duration when the change trend of the time parameter conforms to the change trend sequence.

[0128] In this embodiment, the calculation formula for the total value of the posterior probability is:

[0129]

[0130] In the formula, Indicates that the change trend of the time parameter conforms to the change trend sequence In the case of preset duration sequence The mth scheduling duration The corresponding total posterior probability.

[0131] S3323. Traverse each scheduling duration in the preset duration sequence to obtain a target posterior probability sequence of the preset duration sequence.

[0132] In this embodiment, for each scheduling duration in the preset duration sequence, calculation is performed based on the above formulas (2) to (7), so as to obtain the target posterior probability sequence of the preset duration sequence.

[0133] S333: Find the maximum target posterior probability total value in the target posterior probability sequence, and use the scheduling duration corresponding to the target posterior probability total value as the target scheduling period.

[0134] In this embodiment, a target posterior probability total value in the target posterior probability sequence represents the probability of the corresponding scheduling duration being the target scheduling duration. Therefore, the scheduling duration corresponding to the largest posterior probability total value in the target posterior probability sequence is directly used as the target scheduling period.

[0135] For example, , if the target posterior probability sequence , the largest of which , for The corresponding total posterior probability value should be This example of the target scheduling period is only an example and is not intended to be limiting.

[0136] Therefore, in the present invention, each time slot scheduling is completed, based on the preset weight, probability distribution matrix and prior probability sequence, the Bayesian algorithm is used to calculate the total posterior probability of each scheduling duration in the preset duration sequence when the change trend of the time parameter conforms to the change trend sequence, and then the maximum total posterior probability is used as the target scheduling period, and the next time slot scheduling is performed after waiting for the target scheduling period. In this way, the target scheduling period is determined based on the recent change trend of the time parameter, so that during the period when the processor of the gateway suspends sending, each target scheduling period will be relatively large, so that the NCC time slot scheduling frequency is reduced, and the backlog of the baseband data packets of the TBTP signaling in the sending queue is reduced; similarly, even during the period when the processor of the gateway continues to send, each target scheduling period will be relatively small, so that the NCC time slot scheduling frequency is increased, and the baseband data packets of the TBTP signaling can be quickly sent out after being stored in the sending queue.

[0137] For example, in the preset duration sequence, the minimum scheduling duration is 50ms. Figure 3 , at t 2 to 5 During this period, the scheduling period is greater than 50ms, indicating that the time parameter is decreasing as a whole. It is possible that the gateway processor is in the period of suspending transmission. However, the scheduling period update method of the present invention is adopted. 2 to 5 During this period, NCC will only generate 3 TBTP signals. Figure 3 t in 2 to 5 During this period, the NCC will generate at least 5 TBTP signalings. It can be seen that the scheduling cycle update method provided by the present invention can effectively reduce the TBTP signaling generated by the NCC during the suspension of the transmission of the gateway processor, and avoid a large backlog of baseband data packets of TBTP signaling in the transmission queue.

[0138] The embodiment of the present invention further provides a geo-master station, which includes a network control center and a gateway, the gateway includes a processor and a forward modulation board, the network control center, the processor, and the forward modulation board are sequentially connected in communication; the forward modulation board is connected in communication with at least one terminal station via a satellite, and the processor maintains a sending queue;

[0139] The network control center is used to send the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and dynamically adjust the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the latest M time periods to obtain the target scheduling period; the target scheduling period is the waiting time for the next time slot scheduling;

[0140] The processor is used to encapsulate the received TBTP signaling to obtain a baseband data packet and add it to the sending queue. After taking the baseband data packet out of the sending queue and sending it to the forward modulation board, the time parameter is subtracted from the sending waiting time carried by the baseband data packet to characterize the sending rate of the processor. When the reduced time parameter is less than or equal to the time lower limit threshold, the sending of the baseband data packet is stopped.

[0141] The forward modulation board is used to modulate the received baseband data packets and then send them to all terminal stations via satellite, and return the sending waiting time carried by the sent baseband data packets to the processor when the sending is completed;

[0142] The processor is also used to increase the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and continue to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

[0143] Optionally, the network control center can also be used to: sample the time parameters maintained by the processor according to the set sampling period to obtain the observed values ​​of the time parameters; at every preset time period, based on the observed values ​​of N sampling periods in the current time period, calculate the observed mean of the time parameters in the current time period; wherein the change trend sequence is determined based on the observed mean within the most recent M time periods.

[0144] Optionally, when the network control center dynamically adjusts the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain the target scheduling period, it can be specifically used to: obtain the observed mean sequence of the time parameters in the most recent M time periods; based on the observed mean sequence, determine the change trend sequence of the time parameters; based on the change trend sequence and the prior probability sequence of the preset time length sequence, use the Bayesian algorithm to select the target scheduling period from multiple scheduling durations in the preset time length sequence.

[0145] Optionally, the observation mean sequence includes M observation means; when the network control center is used to determine the change trend sequence of the time parameter based on the observation mean sequence, it can be specifically used to: starting from the 1st observation mean of the observation mean sequence, for the mth observation mean, based on a preset increase threshold and a comparison formula, determine the change trend characteristic value from the mth observation mean to the m+1th observation mean; m= ; Based on the obtained M-1 change trend characteristic values, obtain the change trend sequence.

[0146] Optionally, the preset duration sequence includes M-1 scheduling durations. When the network control center uses the Bayesian algorithm to select the target scheduling period from multiple scheduling durations in the preset duration sequence based on the change trend sequence and the prior probability sequence of the preset duration sequence, it can be specifically used to: obtain the posterior probability sequence of the preset duration sequence obtained in the process of determining the target scheduling period last time, and use it as the prior probability sequence when determining the target scheduling period this time; based on the preset weights, probability distribution matrix and prior probability sequence, use the Bayesian algorithm to calculate the total posterior probability value of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence, and obtain the target posterior probability sequence of the preset duration sequence; find the largest target posterior probability total value in the target posterior probability sequence, and use the scheduling duration corresponding to the target posterior probability total value as the target scheduling period.

[0147] Optionally, the change trend sequence includes M-1 change trend characteristic values, and the prior probability sequence includes M-1 prior probability total values. When the network control center is used to calculate the total posterior probability value of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence based on the preset weights, probability distribution matrix and prior probability sequence, and obtain the target posterior probability sequence of the preset duration sequence, it can be specifically used to: for any scheduling duration in the preset duration sequence, based on the preset weights, probability distribution matrix and the total prior probability value corresponding to the scheduling duration in the prior probability sequence, calculate the posterior probability value of the scheduling duration when the change trend of the time parameter conforms to each change trend characteristic value using the Bayesian algorithm; sum all the posterior probability values ​​corresponding to the scheduling duration to obtain the total posterior probability value of the scheduling duration when the change trend of the time parameter conforms to the change trend sequence; traverse each scheduling duration in the preset duration sequence to obtain the target posterior probability sequence of the preset duration sequence.

[0148] An embodiment of the present invention further provides a satellite communication system, which includes the above-mentioned earth master station, a satellite and at least one terminal station.

[0149] In summary, the embodiment of the present invention provides a scheduling cycle update method, a geo-master station and a satellite communication system, wherein the geo-master station includes a network control center and a gateway, and the gateway includes a processor and a forward modulation board. The method is as follows: the network control center sends the TBTP signaling obtained by the time slot scheduling to the gateway each time the time slot scheduling is completed, and at the same time, dynamically adjusts the scheduling cycle based on the change trend sequence of the time parameters maintained by the gateway in the most recent M time periods to obtain a target scheduling cycle; the target scheduling cycle is the waiting time for the next time slot scheduling; the gateway encapsulates the received TBTP signaling to obtain a baseband data packet and then joins the sending queue The invention provides a method for adjusting the scheduling period in real time based on the changing trend of the time parameter, so that when the gateway suspends the sending of the data baseband data packet, the sending queue will not accumulate a large number of baseband data packets carrying TBTP signaling due to the fixed scheduling period, thereby avoiding the time slot expiration in the TBTP signaling received by the subsequent terminal station.

[0150] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A scheduling period updating method, characterized in that: Applied to a terrestrial master station, the terrestrial master station includes a network control center and a gateway, the gateway includes a processor and a forward modulation board; the network control center, the processor, and the forward modulation board are sequentially connected in communication; the forward modulation board is connected in communication with at least one terminal station via a satellite, and the processor maintains a sending queue; the method includes: The network control center sends the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and dynamically adjusts the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain a target scheduling period; the target scheduling period is the waiting time for the next time slot scheduling; The processor encapsulates the received TBTP signaling to obtain a baseband data packet and adds it to the sending queue. After taking the baseband data packet out of the sending queue and sending it to the forward modulation board, the processor deducts the sending waiting time carried by the baseband data packet from the time parameter to characterize the sending rate of the processor. When the reduced time parameter is less than or equal to the time lower limit threshold, the sending of the baseband data packet is stopped; wherein the sending waiting time carried by the baseband data packet is estimated by the processor; The forward modulation board modulates the received baseband data packet and sends it to all terminal stations via the satellite, and returns the sending waiting time carried by the sent baseband data packet to the processor when the sending is completed; The processor increases the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and continues to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

2. The method according to claim 1, characterized in that Before the step of the network control center sending the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and dynamically adjusting the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain the target scheduling period, the method further includes: The network control center samples the time parameter maintained by the processor according to a set sampling period to obtain an observed value of the time parameter; The network control center calculates the observed mean of the time parameter in the current time period every preset time period based on the observed values ​​of N sampling periods in the current time period; wherein the change trend sequence is determined based on the observed mean in the most recent M time periods.

3. The method according to claim 2, characterized in that The network control center dynamically adjusts the scheduling period based on the change trend sequence of the time parameter maintained by the processor in the most recent M time periods to obtain the target scheduling period, including: Obtaining an observed mean sequence of the time parameter in the most recent M time periods; Based on the observed mean value sequence, determining a change trend sequence of the time parameter; Based on the change trend sequence and the prior probability sequence of the preset duration sequence, a target scheduling period is selected from a plurality of scheduling durations in the preset duration sequence using a Bayesian algorithm.

4. The method according to claim 3, characterized in that The observed mean sequence includes M observed means; The step of determining the change trend sequence of the time parameter based on the observed mean sequence includes: Starting from the first observed mean of the observed mean sequence, for the mth observed mean, based on the preset increase threshold and the comparison formula, determine the characteristic value of the change trend from the mth observed mean to the m+1th observed mean; m= ; Based on the obtained M-1 change trend characteristic values, the change trend sequence is obtained.

5. The method according to claim 3, characterized in that: The preset duration sequence includes M-1 scheduling durations; The step of selecting a target scheduling period from a plurality of scheduling durations in the preset duration sequence using a Bayesian algorithm based on the prior probability sequence of the change trend sequence and the preset duration sequence comprises: Obtaining a posterior probability sequence of the preset duration sequence obtained in the process of determining the target scheduling period last time, and using it as the a priori probability sequence when determining the target scheduling period this time; Based on the preset weights, the probability distribution matrix and the prior probability sequence, the Bayesian algorithm is used to calculate the total value of the posterior probability of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence, and the target posterior probability sequence of the preset duration sequence is obtained; The maximum target posterior probability total value in the target posterior probability sequence is found, and the scheduling duration corresponding to the target posterior probability total value is used as the target scheduling period.

6. The method according to claim 5, characterized in that The change trend sequence includes M-1 change trend characteristic values, and the prior probability sequence includes M-1 prior probability total values; The step of calculating the total value of the posterior probability of each scheduling duration when the change trend of the time parameter conforms to the change trend sequence by using the Bayesian algorithm based on the preset weight, the probability distribution matrix and the prior probability sequence to obtain the target posterior probability sequence of the preset duration sequence includes: For any of the scheduling durations in the preset duration sequence, based on the preset weight, the probability distribution matrix and the total prior probability value corresponding to the scheduling duration in the prior probability sequence, a posterior probability value of the scheduling duration is calculated using a Bayesian algorithm when the change trend of the time parameter meets each of the change trend characteristic values; Performing a sum operation on all the posterior probability values ​​corresponding to the scheduling duration to obtain a total posterior probability value of the scheduling duration when the change trend of the time parameter conforms to the change trend sequence; Each of the scheduling durations in the preset duration sequence is traversed to obtain a target posterior probability sequence of the preset duration sequence.

7. The method according to claim 4, characterized in that The comparison formula is: In the formula, is the mth change trend characteristic value, adding a threshold to said preset, is the mth observation mean in the observation mean sequence, is the m+1th observation mean in the observation mean sequence.

8. The method according to claim 6, characterized in that The calculation formula of the total value of the posterior probability is: In the formula, Represents that the change trend of the parameter at the time conforms to the change trend sequence In the case of preset duration sequence The mth scheduling duration The corresponding total value of the posterior probability; Represents that the change trend of the parameter at the time conforms to the change trend sequence The i-th change trend characteristic value in In the case of preset duration sequence The mth scheduling duration The corresponding posterior probability value; The calculation formula of the posterior probability value is: In the formula, Represents a preset duration sequence The mth scheduling duration The variation trend of the time parameter conforms to the variation trend sequence The i-th change trend characteristic value in The likelihood probability when ; Represents the total value of the mth prior probability in the prior probability sequence; Represents a trend sequence The i-th change trend characteristic value in Evidence factor of distribution; In the formula, is the preset weight, , Preset weights of Second power, Power; is the probability distribution matrix An element in represents the first scheduling duration The characteristic value of the changing trend is The probability of presentation when is the probability distribution matrix An element in represents the mth scheduling duration The characteristic value of the changing trend is The probability of presentation when Represents the mth scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Respectively represent the first scheduling duration In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the second scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; Represents the M-1th scheduling duration respectively In the changing trend characteristic value The presentation probabilities are 1, 0, and -1 respectively; In the formula, Represents the first change trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence, Representative The trend characteristic value Is it equal to the characteristic value of the change trend? The value of evidence.

9. A ground master station, characterized in that: It includes a network control center and a gateway, the gateway includes a processor and a forward modulation board, the network control center, the processor, and the forward modulation board are sequentially connected in communication; the forward modulation board is connected in communication with at least one terminal station via a satellite, and the processor maintains a sending queue; The network control center is used to send the TBTP signaling obtained by the time slot scheduling to the processor each time the time slot scheduling is completed, and at the same time dynamically adjust the scheduling period based on the change trend sequence of the time parameters maintained by the processor in the most recent M time periods to obtain a target scheduling period; the target scheduling period is the waiting time for the next time slot scheduling; The processor is used to encapsulate the received TBTP signaling to obtain a baseband data packet and then add it to the sending queue, and after taking the baseband data packet out of the sending queue and sending it to the forward modulation board, subtract the sending waiting time carried by the baseband data packet from the time parameter to characterize the sending rate of the processor, and stop sending the baseband data packet when the reduced time parameter is less than or equal to the time lower limit threshold; wherein the sending waiting time carried by the baseband data packet is estimated by the processor; The forward modulation board is used to modulate the received baseband data packets and then send them to all terminal stations via the satellite, and return the sending waiting time carried by the sent baseband data packets to the processor when the sending is completed; The processor is also used to increase the time parameter by the received sending waiting time to characterize the receiving rate of the forward modulation board, and continue to send the baseband data packet when the increased time parameter is greater than the time lower limit threshold.

10. A satellite communication system, characterized in that: It comprises the earth main station as claimed in claim 9, a satellite and at least one terminal station.

Images