A satellite beam-hopping timeslot allocation method based on dynamic programming

Abstract

The present invention relates to a satellite beam-hopping time slot allocation method based on dynamic programming, and belongs to the field of beam-hopping time slot allocation. It includes: receiving communication service applications and caching, estimating service rates, and submitting user terminal service requirements to satellites; satellites receive user terminal service requirements and summarize them to obtain satellite service requirements; satellite service requirements are decomposed into time slot allocation problems of multiple service sets, and dynamic programming algorithms are modeled and solved to calculate time slot resource plans; the time slot resource plans are broadcast to all user terminals, and the user terminals determine the transmission rate according to the time slot resource plans; the user terminals send service data at the transmission rate, re-estimate the service rate and queue the cache amount, calculate the transmission requirements and send them to the satellite. The present invention can effectively reduce the cache queue length of each user terminal in the satellite phased array beam-hopping uplink, thereby reducing communication delays and improving network throughput.

Description

Technical Field

[0001] The present invention relates to the technical field of beam hopping time slot allocation in satellite communications, and in particular to a satellite beam hopping time slot allocation method based on dynamic programming, which is suitable for terminal time slot allocation scenarios in satellite beam hopping. Background Art

[0002] With the development of the integrated information network between the earth and the sky, current communication satellites are generally equipped with phased array antennas and use beam hopping control. The control process of phased array beam hopping is to first divide the earth's surface into multiple cells. The range of each cell matches the irradiation range of the phased array beam. There is a certain overlap between adjacent cells to ensure seamless coverage of the ground. Then, during the communication process, the phased array beam is flexibly switched between different cells. Each time it irradiates a cell, it stays in the cell for a period of time. During this period, the satellite terminals in the cell can communicate. Through the space division multiplexing method of beam hopping, the coverage capability of the phased array beam can reach the effect of the regional beam while ensuring that the link transmission capacity is equivalent to that of the mechanical point beam, achieving a win-win situation of transmission and coverage. In addition, unlike the coplanar design of the traditional parabolic antenna, the receiving and transmitting beams of the phased array antenna can be independently controlled, and cooperate with the on-board processing and forwarding. Through a reasonable time slot resource allocation method, the waste of uplink and downlink link resources caused by unbalanced transmission and reception in a certain area can be avoided, thereby maximizing the throughput capacity of the beam.

[0003] Phased array beam hopping has stricter requirements on the management and optimization methods of time slot resources. An unreasonable time slot allocation method will cause the loss of underutilization of data bursts, resulting in waste of on-board resources. In current research and practical applications, rule-based time slot allocation methods cannot maximize the use of time slot resources, and machine learning-based methods cannot meet the requirements of real-time reasoning for on-board deployment. Therefore, a method is needed that can meet on-board processing capabilities and maximize the use of time slot resources. Summary of the invention

[0004] To solve the above problems, the present invention proposes a satellite beam-hopping time slot allocation method based on dynamic programming. The present invention can effectively reduce the buffer queue length of each user terminal in the satellite phased array beam-hopping uplink, thereby reducing communication delay and improving network throughput.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A satellite beam hopping time slot allocation method based on dynamic programming comprises the following steps:

[0007] Step 1: The user terminal receives the communication service application and caches it in the service queue. According to the service queue, the service rate is periodically estimated and updated, and the user terminal service requirements are periodically submitted to the satellite.

[0008] Step 2: The satellite receives the user terminal service demand in a hopping cycle, and summarizes the collected user terminal service demands in the next cycle to obtain the satellite service demand;

[0009] Step 3: The satellite processes the satellite service requirements collected in the previous cycle in a centralized manner, decomposes them into time slot allocation problems for multiple service sets, and models and solves them using a dynamic programming algorithm to calculate the time slot resource plan for each service set within the cycle.

[0010] Step 4: After a satellite-to-ground delay, the satellite broadcasts the time slot resource plan to all user terminals, and the user terminals determine the transmission rate based on the time slot resource plan;

[0011] Step 5: After waiting for a period of time, the user terminal sends the service data at the sending rate, re-estimates the service rate and counts the buffer volume of the current queue, calculates the sending demand and sends it to the satellite along with the service data;

[0012] Step 6: The user terminal determines whether the service queue is 0. If so, the process ends; otherwise, the user terminal continues to send data and user terminal service needs at the sending rate indicated by the time slot resource plan of the previous cycle, and repeats the above steps 1 to 5 until the process ends.

[0013] Furthermore, in step 3, the dynamic programming algorithm is modeled and solved, specifically in the following manner:

[0014] Step S31, define each time slot allocation of a user terminal as a stage of the dynamic programming algorithm, for the time slot allocation problem of the service set , a total of stage, Representative of the community With carrier group The number of user terminals under

[0015] Step S32, perform state modeling on the time slot allocation problem of the service set, define the stage The number of time slots remaining in the grid at the beginning is the phase Status , define the initial state of the service set time slot allocation problem ,in, Represents satellite beam hopping at The number of time slots that a cell resides in, Represents carrier group The time slot factor, Represents carrier group Number of subcarriers;

[0016] Step S33, a dynamic programming algorithm is used to make a decision model for the time slot allocation problem of the service set, and the time slot allocation problem of the service set is obtained. Decision space under ,in, represents the number of time slots allocated to the user terminal, Represents carrier group The carrier rate, Indicates that the terminal meets the transmission requirements at the specified carrier rate The number of time slots required, min() means taking the minimum value;

[0017] Step S34, calculate the state transition equation of the dynamic programming algorithm for the time slot allocation problem of the service set, using the state transition equation of the dynamic programming algorithm from the stage To stage The problem is solved by the reverse method, and the optimal value function is solved step by step according to the state transfer equation and the indicator function. , until the optimal value of the first stage is obtained , The time slot allocation result representing the service set;

[0018] The state transfer equation is specifically:

[0019]

[0020] The indicator function is used to measure the quality of the decision made at a certain stage based on a specific state, specifically:

[0021]

[0022] The optimal value function is the indicator function The optimal value of is expressed as follows:

[0023]

[0024] Among them, max is the maximum value function, is the indicator function, The number of time slots allocated to the user terminal;

[0025] Step S35: Execute the process from step S31 to step S35 for each service set to obtain the time slot allocation result and form a time slot resource plan. .

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Aiming at the characteristics of satellite beam hopping cycle agility and satellite-to-ground time delay, the present invention realizes a phased array beam hopping time slot allocation method based on a dynamic programming method. Under the premise of considering the satellite-to-ground time delay and the hopping reception cycle, a modeling and dynamic programming calculation method for the time slot allocation problem in a specific scenario is given.

[0028] 2. In practical applications, the present invention improves the time slot allocation efficiency and the network throughput while meeting the real-time requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flowchart of a satellite beam hopping time slot allocation method based on dynamic programming in an embodiment of the present invention.

[0030] Figure 2 The present invention is a schematic diagram of a service cycle of a satellite beam hopping time slot allocation method based on dynamic programming in an embodiment of the present invention.

[0031] Figure 3 The present invention provides a flow chart of dynamic programming modeling and solution of a satellite beam hopping time slot allocation method based on dynamic programming in an embodiment of the present invention.

[0032] Figure 4 The present invention is a schematic diagram of a dynamic programming representation of a satellite beam hopping time slot allocation method based on dynamic programming in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] A satellite beam-hopping time slot allocation method based on dynamic programming, such as Figure 1 As shown, the following steps are included:

[0035] Step S1: The user terminal receives the communication service application and caches it in the service queue, periodically estimates and updates the service rate based on the service queue cache, and periodically submits the user terminal service requirements to the satellite;

[0036] Step S2: The satellite receives user terminal service demands in a hopping cycle, and summarizes the collected user terminal service demands in the next cycle to obtain satellite service demands;

[0037] Step S3: The satellite processes the satellite service requirements collected in the previous cycle in a centralized manner, decomposes them into time slot allocation problems for multiple service sets, and performs modeling and solving of dynamic programming algorithms, and calculates the time slot resource plan for each service set in the cycle;

[0038] Step S4: The satellite transmits the time slot resource plan after a satellite-to-ground time delay and broadcasts it to all user terminals. The user terminals determine the transmission rate according to the time slot resource plan.

[0039] Step S5: After waiting for a period of time, the user terminal sends the service data at the sending rate, re-estimates the service rate and counts the buffer volume of the current service queue, calculates the sending demand and sends it to the satellite along with the service data;

[0040] Step S6: Determine whether the service queue buffer is 0. If so, the process ends; otherwise, the user terminal continues to send data and user terminal service requirements at the sending rate indicated by the time slot resource plan of the previous cycle, and repeats the above steps 1 to 5 until the process ends.

[0041] Here is a more specific example:

[0042] A satellite beam-hopping time slot allocation method based on dynamic programming Figure 1 , the specific process is as follows:

[0043] Step S1, such as Figure 2 As shown, the user terminal Receive communication service applications and cache them in the service queue. Periodically estimate and update service rates , and periodically submit user terminal service requirements to the satellite , after a satellite-to-ground link transmission delay, User terminal service requirements at a certain moment in the cycle Reaching the satellite;

[0044] Step S2: The satellite uses a phased array beam hopping cycle The time slot allocation is performed in units, and the satellite Periodically receive user terminal service requirements Then, store the satellite service requirements , in the cycle The starting time of the cycle Summarize the user terminal business requirements collected within the system;

[0045] Step S3, in the cycle At the beginning of the cycle, the satellite receives the satellite service requirements collected in the previous cycle. Centralized processing based on the cell to which the user terminal belongs With the carrier group The problem is decomposed into the time slot allocation problem of multiple business sets. , the time slot allocation problem of each service set is solved by dynamic programming algorithm, including the stages, states, decisions, state transition equations, indicator functions and optimization functions of dynamic programming. Then, based on the dynamic programming algorithm, the period Each service set in the time slot is allocated to obtain the time slot resource plan .

[0046] Among them, the time slot allocation problem of each service set is modeled and solved by a dynamic programming algorithm. Figure 3 As shown, the specific steps include:

[0047] Step S31: define the time slot allocation of each user terminal as a stage of the dynamic programming algorithm. , a total of stage, Representative community With carrier group The number of user terminals under

[0048] Step S32: Perform state modeling on the time slot allocation problem of the service set and define the phase The number of time slots remaining in the grid at the beginning is the phase Status . Define the initial state of the service set time slot allocation problem ,in Represents satellite beam hopping at The number of time slots that a cell resides in, Represents carrier group The time slot factor, Represents carrier group Number of subcarriers;

[0049] Step S33: Perform dynamic programming algorithm decision modeling on the time slot allocation problem of the service set to obtain the time slot allocation problem in the stage Decision space under , represents the number of time slots allocated to the user terminal, Represents carrier group The carrier rate; Indicates that the terminal meets the transmission requirements at the specified carrier rate The number of time slots required;

[0050] Step S34: Calculate the state transition equation of the dynamic programming algorithm for the time slot allocation problem of the service set, using the state transition equation of the dynamic programming algorithm from the stage To stage The problem is solved by the reverse method, and the optimal value function is solved step by step according to the state transfer equation and the indicator function. , until the optimal value of the first stage is obtained The time slot allocation result representing the service set;

[0051] The state transfer equation is specifically:

[0052]

[0053] The indicator function is used to measure the quality of the decision made at a certain stage based on a specific state, specifically:

[0054]

[0055] Optimal value function is the indicator function The optimal value of is expressed as follows:

[0056]

[0057] Step S35: Each service set executes the process from step S31 to step S35 to obtain the time slot allocation result, such as Figure 4 As shown, and constitute the time slot resource plan .

[0058] Step S4: The satellite plans the time slot resources After a delay between the satellite and the ground, the data is broadcast to all user terminals. according to , determine the The sending rate of the cycle is ,in Represents the transition period experienced by a satellite-to-ground link transmission delay The number of .

[0059] Step S5: User terminal After a period of time, press the sending rate Send business data to ensure that the data can be sent after a satellite-to-ground delay. At the same time, the user terminal t re-estimates the service rate , count the cache size of the current queue , and calculate the sending demand according to the following formula , sent to the satellite along with the business data:

[0060]

[0061] Step S6, determine the cache queue Is it 0? If so, the process ends; otherwise, the user terminal Continue to send data and user terminal service requirements at the sending rate indicated by the time slot resource plan of the previous cycle, and repeat the above steps 1 to 5 until the process ends.

[0062] Aiming at the characteristics of satellite beam hopping cycle agility and satellite-to-ground time delay, the present invention realizes a phased array beam hopping time slot allocation method based on a dynamic programming method. Under the premise of considering the satellite-to-ground time delay and the hopping reception cycle, a modeling and dynamic programming calculation method for the time slot allocation problem in a specific scenario is given. In practical applications, the time slot allocation efficiency is improved while meeting the real-time requirements, and the network throughput is increased.

[0063] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A satellite beam hopping time slot allocation method based on dynamic programming, characterized in that: The following steps are involved: Step 1: The user terminal receives the communication service application and caches it in the service queue. According to the service queue, the service rate is periodically estimated and updated, and the user terminal service requirements are periodically submitted to the satellite. Step 2: The satellite receives the user terminal service demand in a hopping cycle, and summarizes the collected user terminal service demand in the next cycle to obtain the satellite service demand; Step 3: The satellite centrally processes the satellite service requirements collected in the previous cycle, decomposes them into time slot allocation problems for multiple service sets, and performs modeling and solving of the dynamic programming algorithm, and calculates the time slot resource plan for each service set in the cycle; the specific method of modeling and solving the dynamic programming algorithm is as follows: Step S31, define each time slot allocation of a user terminal as a stage of the dynamic programming algorithm, for the time slot allocation problem of the service set , a total of stage, Representative of the community With carrier group The number of user terminals under Step S32, perform state modeling on the time slot allocation problem of the service set, define the stage The number of time slots remaining in the grid at the beginning is the phase Status , define the initial state of the service set time slot allocation problem ,in, Represents satellite beam hopping at The number of time slots that a cell resides in, Represents carrier group The time slot factor, Represents carrier group Number of subcarriers; Step S33, a dynamic programming algorithm is used to make a decision model for the time slot allocation problem of the service set, and the time slot allocation problem of the service set is obtained. Decision space under ,in, represents the number of time slots allocated to the user terminal, Represents carrier group The carrier rate, Indicates that the terminal meets the transmission requirements at the specified carrier rate The number of time slots required, min() means taking the minimum value; Step S34, calculate the state transition equation of the dynamic programming algorithm for the time slot allocation problem of the service set, using the state transition equation of the dynamic programming algorithm from the stage To stage The problem is solved by the reverse method, and the optimal value function is solved step by step according to the state transfer equation and the indicator function. , until the optimal value of the first stage is obtained , The time slot allocation result representing the service set; The state transfer equation is specifically: The indicator function is used to measure the quality of the decision made at a certain stage based on a specific state, specifically: The optimal value function is the indicator function The optimal value of is expressed as follows: Among them, max is the maximum value function, is the indicator function, The number of time slots allocated to the user terminal; Step S35: Execute the process from step S31 to step S35 for each service set to obtain the time slot allocation result and form a time slot resource plan. ; Step 4: After a satellite-to-ground delay, the satellite broadcasts the time slot resource plan to all user terminals, and the user terminals determine the transmission rate based on the time slot resource plan; Step 5: After waiting for a period of time, the user terminal sends the service data at the sending rate, re-estimates the service rate and counts the buffer volume of the current queue, calculates the sending demand and sends it to the satellite along with the service data; Step 6: The user terminal determines whether the service queue is 0. If so, the process ends; otherwise, the user terminal continues to send data and user terminal service needs at the sending rate indicated by the time slot resource plan of the previous cycle, and repeats the above steps 1 to 5 until the process ends.

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