Resource dynamic allocation method and system for uplink communication of multi-beam low-orbit satellite

Abstract

The invention discloses a resource dynamic allocation method and system for uplink communication of a multi-beam low-orbit satellite, and the method comprises the steps: a user management unit senses that a user accesses a satellite communication network, and transmits a resource request to an uplink resource allocation unit; after receiving the resource request, the uplink resource allocation unit allocates uplink wave beams, time slots and channel resources for the user and respectively sends a resource allocation result to the user management unit and the on-satellite transmission unit, and the user management unit sends the received resource allocation result to the user; and the on-satellite transmission unit schedules a specified beam to receive uplink data of the user in a specified channel and a specified time slot according to a resource allocation result. The method has a high resource utilization rate, and supports multi-user on-demand dynamic scheduling of satellite uplink beam resources.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method and system for dynamically allocating resources for multi-beam low-orbit satellite uplink communication. Background Art

[0002] In a multi-beam satellite communication system, each satellite carries multiple beams, covering different areas on the ground. These beams work together to complete the ground visible area coverage of a single satellite. Figure 1 This is a typical schematic diagram of a multi-beam low-orbit satellite communication system, which is mainly composed of three parts: ground gateway station, low-orbit satellite constellation, and users. As the control and management center of the satellite communication system, the ground gateway station manages and controls the entire satellite network and communicates with the satellite through a feeder link; the low-orbit satellite constellation is composed of several low-orbit satellites distributed in different orbits connected by inter-satellite links, and has wide-area coverage capabilities; users are satellite terminals that use satellite resources to communicate with each other. Users exchange information through satellite-to-ground links and inter-satellite links. Users send data to the satellite system through uplinks, and the satellite system accurately and efficiently forwards the user data to the destination user through downlinks. Low-orbit satellites move at high speed relative to the ground according to their own preset orbits. Multi-beam antennas are configured on the satellite. The coverage area corresponding to a single beam is called a wave position. The ground area that can be covered by the satellite is called the sub-satellite coverage area, which is composed of several wave positions. Satellites can flexibly dispatch multi-beam resources as needed so that each beam covers a specified wave position. Each beam is relatively independent and has certain bandwidth resources. Each beam can only point to one wave position at the same time, but multiple beams can cover different wave positions or the same wave position. During the mobile process, the high-speed movement of low-orbit satellites can easily cause dynamic changes in the coverage area. Wave position switching and satellite switching are required to ensure the full communication of the service. The user's data transmission capacity is proportional to the antenna aperture and power amplifier configured with it. The larger the power amplifier and antenna aperture, the higher the transmission rate that can be supported. The maximum supported transmission rate is called the uplink rate limit.

[0003] The satellite uplink communication resource structure based on MF-TDMA (MultiFrequency Time-Division Multiple Access) is as follows: Figure 2As shown in the figure, all frequency resources are divided into multiple orthogonal channels in the frequency domain, and divided into multiple time slots in the time domain with the time frame as the cyclic structure. Each two-dimensional grid of time and frequency is the basic unit of channel resources. The dynamic allocation of resources for multi-beam low-orbit satellite uplink communication mainly faces two technical challenges. On the one hand, compared with the traditional MF-TDMA, multi-beam low-orbit satellite uplink communication introduces beam resources on the basis of its two-dimensional resource structure. The system has more schedulable resources, and the two-dimensional resource allocation problem of frequency and time slot is elevated to the three-dimensional resource optimization scheduling problem of beam, frequency and time slot. Beam resources and time-frequency resources constrain each other, and the complexity of resource allocation with the goal of improving resource utilization is significantly increased. On the other hand, the low-orbit satellite communication system itself is highly dynamic, including frequent switching of wave positions caused by the high-speed movement of users relative to the satellite, and the random access and exit of many users, which all require a high dynamic response capability and flexible adaptability for the allocation of uplink communication resources. Therefore, for mobile users who need to initiate business communications at any time, how the satellite system can efficiently and reasonably allocate reasonable uplink channel resources to them from the three-dimensional resources of beam, frequency and time slot has become a key issue that needs to be solved.

[0004] The existing technical solutions mainly include:

[0005] Fixed allocation method based on pre-planning: The satellite's ground system allocates designated beams, frequencies and time slot resources to users in a pre-planned manner according to the user's activity area and application mode, and uploads the resource allocation results to the satellite through feed and inter-satellite links. The satellite schedules uplink channel resources for users according to the uploaded resource allocation results. This method is simple to allocate and easy to implement on-board equipment. However, since the movement trajectory and actual bandwidth requirements of each user cannot be accurately predicted during the planning stage, this method is mainly used to protect a very small number of important fixed users. It lacks flexibility and dynamic adaptability, has low resource utilization, and cannot provide matching uplink resources for mobile users who access at will.

[0006] Polling allocation method based on beam partitioning: The satellite system divides the sub-satellite coverage area into multiple sub-areas according to the number of available beams, and each beam is responsible for serving multiple wave positions in a single sub-area. During the service communication process, the satellite dispatches the corresponding beam resources for each sub-area, and polls all the wave positions in the sub-area in turn in a specific order. Only the users who are asked can send data on the specified uplink beam resources. This allocation method is simple to operate and is suitable for satellite communication systems with a large number of users and a relatively uniform geographical distribution. This method has the following two main disadvantages. First, in most cases, users are unevenly distributed in geographical space, the communication traffic between each sub-area and each wave position varies greatly, and the channel resource requirements are different. In particular, some wave positions have no users using resources, and users of other wave positions cannot use the resources, which is easy to cause a large waste of resources and congestion in some wave positions. Secondly, when the number of wave positions is large, this method is easy to cause a large uplink service delay, and it cannot guarantee that users who access at will can quickly enjoy satellite resources.

[0007] The existing technical solutions all have their own limitations. The fixed allocation based on pre-planning has problems such as low resource utilization and inability to support random access by users. The polling allocation method based on beam partitioning has inherent defects such as uneven resource allocation and large latency. Therefore, the existing technical solutions cannot meet the needs of efficient uplink resource allocation for multiple random access mobile users. Summary of the invention

[0008] In view of this, the present invention provides a method and system for dynamic resource allocation for multi-beam low-orbit satellite uplink communications. Based on real-time acquisition of user information such as the user's wave position, uplink bandwidth requirements and uplink rate limit, the method and system distinguish user levels, have high resource utilization, support users to access and exit at any time, support flexible networking of multiple users, and are suitable for dynamic resource allocation for multi-beam low-orbit satellite uplink communications.

[0009] The present invention discloses a method for dynamically allocating resources for multi-beam low-orbit satellite uplink communication, which comprises:

[0010] The user management unit senses that the user has accessed the satellite communication network and sends a resource request to the uplink resource allocation unit; after receiving the resource request, the uplink resource allocation unit allocates uplink beams, time slots and channel resources to the user, and sends the resource allocation results to the user management unit and the on-board transmission unit respectively, and the user management unit sends the received resource allocation results to the user; the on-board transmission unit schedules the specified beam to receive the user's uplink data in the specified channel and specified time slot according to the resource allocation results.

[0011] Furthermore, it also includes:

[0012] When the user management unit senses that the user has joined the satellite communication network, it sends a resource allocation request to the uplink resource allocation unit, which carries the user's level, wave position, uplink bandwidth requirement and uplink rate limit information; after receiving the request, the uplink resource allocation unit allocates uplink beam, time slot and channel resources to the user, and sends the resource allocation result to the user management unit, which sends the uplink resource allocation result to the user through the downlink after receiving the request;

[0013] The user management unit senses that the user has switched the wave position during network operation, and sends a resource reallocation request to the uplink resource allocation unit, carrying the new wave position information of the user. After receiving the request, the uplink resource allocation unit clears the original uplink resources of the user, and reallocates the uplink resources to the user, and sends the resource allocation result to the user management unit. After receiving the request, the user management unit sends the uplink resource allocation result to the user via the downlink.

[0014] The user management unit senses that the user has exited the satellite communication network, and sends a resource release request to the uplink resource allocation unit. After receiving the request, the uplink resource allocation unit clears the original uplink resources of the user.

[0015] Furthermore, the uplink resource allocation unit allocates an uplink beam to the user, including:

[0016] Step 11: The uplink resource allocation unit extracts the user level and the wave position C of the user u information;

[0017] Step 12: The uplink resource allocation unit calculates the available beam set P of the user;

[0018] Step 13: The uplink resource allocation unit determines whether the available beam set P is not empty. If it is not empty, it proceeds to step 14, otherwise it terminates the allocation;

[0019] Step 14: The uplink resource allocation unit calculates a cost value representing the load state of each beam in the available beam set P according to the number of currently covered beam positions of the beam and the number of equivalent users;

[0020] Step 15: The uplink resource allocation unit determines the level of the user. If the user is an important user, the process proceeds to step 16; if the user is an ordinary user, the process proceeds to step 17;

[0021] Step 16: The uplink resource allocation unit determines whether there is an idle reserved beam in the available beam set P. If yes, it proceeds to step 12; otherwise, it proceeds to step 17;

[0022] Step 17: The uplink resource allocation unit determines whether there are one or more beams in the available beam set P that cover the same beam position C. u If yes, go to step 18, otherwise go to step 19;

[0023] Step 18: The uplink resource allocation unit covers the same beam position C from the available beam set P u Select the beam with the smallest cost value from one or more beams and allocate it to the user, then go to step 113 to update the beam resource allocation table;

[0024] Step 19: The uplink resource allocation unit determines whether there is an idle non-reserved beam in the available beam set P. If yes, the process proceeds to step 110; otherwise, the process proceeds to step 111;

[0025] Step 110: The uplink resource allocation unit selects the beam with the smallest beam number from all idle non-reserved beams in the available beam set P and allocates it to the user, and then proceeds to step 113 to update the beam resource allocation table;

[0026] Step 111: the uplink resource allocation unit selects a beam with the smallest cost value from the available beam set P and allocates it to the user, and then proceeds to step 113 to update the beam resource allocation table;

[0027] Step 112: The uplink resource allocation unit selects the beam with the smallest beam number from all idle reserved beams in the available beam set P and allocates it to the user, and then proceeds to step 113 to update the beam resource allocation table;

[0028] Step 113: The uplink resource allocation unit updates the relevant table entries of the allocated beam in the resource allocation table.

[0029] Furthermore, the step 2 comprises:

[0030] Initialize the available beam set P to be empty, and traverse all uplink beams b1~b according to the user level. B , add the qualified beams to the set P; if the user is an important user, if a beam satisfies both the number of covered wavelets less than Nc and the number of equivalent users less than Nu, then the beam is added to the set P; if the user is an ordinary user, if a beam satisfies both the number of covered wavelets less than Nc, the number of equivalent users less than Nu and the beam is a non-reserved beam, then the beam is added to the set P; where Nc and Nu are the upper limits of the number of covered wavelets and the number of equivalent users preset by the system, respectively.

[0031] Furthermore, the system presets different upper limits for reserved beams and non-reserved beams respectively. The upper limit of the number of covered wavelets of reserved beams is preset to Nc1, the upper limit of the number of equivalent users of reserved beams is preset to Nu1, the upper limit of the number of covered wavelets of non-reserved beams is preset to Nc2, and the upper limit of the number of equivalent users of non-reserved beams is preset to Nu2. The values ​​of Nc and Nu depend on the number of carriers and time slots of the uplink beam resources, satisfying Nu2>Nc2≥Nu1>Nc1.

[0032] Further, after the uplink resource allocation unit completes the beam allocation for the user, it extracts the user's uplink bandwidth requirement, uplink rate limit, wave position, and beam allocation result information, and initiates the time-frequency resource allocation process for the user.

[0033] Further, the time-frequency resource allocation process for the user includes:

[0034] Step 21: Calculate the number of slot requirements Si, calculate the available slot set of the same wave position and count the number of slots Sp included in the available slot set of the same wave position, calculate the available slots of the empty wave position and count the number of slots Sw included in the available slot set of the empty wave position;

[0035] Step 22: The uplink resource allocation unit determines whether Si ≤ Sp holds. If so, it proceeds to Step 23; otherwise, it proceeds to Step 24;

[0036] Step 23: The uplink resource allocation unit selects Si slots for the user from the available slot set of the same wave position according to the principle of uniformity, such that the variance of the differences in slot numbers of all selected adjacent slots is minimized; then it proceeds to Step 33;

[0037] Step 24: The uplink resource allocation unit determines whether 0 < Sp < Si holds. If so, it proceeds to Step 25; otherwise, it proceeds to Step 29;

[0038] Step 25: The uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to Step 26 to determine whether Sw ≥ Si - Sp holds; otherwise, it proceeds to Step 23;

[0039] Step 26: The uplink resource allocation unit determines whether Sw ≥ Si - Sp holds. If so, it proceeds to Step 27; otherwise, it proceeds to Step 28;

[0040] Step 27: The uplink resource allocation unit selects a total of Si slots for the user, where it selects all Sp slots from the available slot set of the same wave position and then selects Si - Sp slots from the available slot set of the empty wave position according to the principle of uniformity, such that the variance of the differences in slot numbers of all selected adjacent slots is minimized; then it proceeds to Step 33;

[0041] Step 28: The uplink resource allocation unit selects a total of Sp + Sw slots for the user, where it first selects all Sp slots from the available slot set of the same wave position and then selects all Sw slots from the available slot set of the empty wave position; then it proceeds to Step 33;

[0042] Step 29: The uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to Step 30; otherwise, it proceeds to Step 36 to terminate the allocation;

[0043] Step 30: The uplink resource allocation unit determines whether Sw≥Si is established. If so, it proceeds to step 31, otherwise it proceeds to step 32;

[0044] Step 31: The uplink resource allocation unit selects Si time slots from the set of available time slots with empty wavelengths for the user according to the uniformity principle, so that the variance of the time slot number differences of all the selected adjacent time slots is minimized, and then proceeds to step 33;

[0045] Step 32: The uplink resource allocation unit selects all Sw time slots from the set of available time slots with empty wavelengths for the user, and then proceeds to step 33;

[0046] Step 33: The uplink resource allocation unit allocates channels for each time slot selected for the user according to the principle that the channel number starts from the smallest one, that is, selects beam b u The idle channel with the smallest sequence number in the time slot is allocated to the user, and then the process goes to step 34;

[0047] Step 34: The uplink resource allocation unit updates the time-frequency resource allocation table for beam b according to the time slot and channel resources selected for the user. u The relevant information includes the wave position and the user, and then proceeds to step 35;

[0048] Step 35: The uplink resource allocation unit outputs a resource allocation result, which includes information about the beam number, time slot number, and channel number allocated to the user, and sends the resource allocation result to the user management unit and the onboard transmission unit;

[0049] Step 36: The uplink resource allocation unit terminates the resource allocation process for the user, and feeds back to the user management unit the allocation result that insufficient resources make allocation impossible.

[0050] Furthermore, the number of time slots Si required by the user in the time frame is calculated by the following formula:

[0051]

[0052] Wherein, Tf is the time frame length, Ts is the time slot length, Rq is the uplink bandwidth requirement of the user, Rm is the uplink rate limit of the user, and ceil is rounded up.

[0053] Further, the calculating of the same-wavelength available time slot set includes:

[0054] The uplink resource allocation unit maintains the time-frequency resource allocation table and the user's beam allocation result b u and the user's wave position C u , calculate beam b u The set of available time slots with the same wavelength:

[0055] Q1 is initialized to empty and traverses beam bu In each time slot t within the allocation period j , 1≤j≤T, T is the time frame, if the following three conditions are met at the same time, then the time slot t j Join the same-wavelength available time slot set Q1; condition 1 is beam b u In time slot t j Covering wave C u , that is, wave position C(b u ,t j )=C u ; Condition 2 is beam b u The time slot t j There is an idle channel on the network, that is, there is at least one channel U(b u ,f k, t j ) is empty, 1≤k≤F; Condition 3 is beam b u The time slot t j Not allocated to the user, that is, there is no channel U(b u ,f k, t j )=u,1≤k≤F;F is beam b u The total number of corresponding channels.

[0056] Further, the calculating the number of available time slots of empty wave positions includes:

[0057] The uplink resource allocation unit maintains the time-frequency resource allocation table and the user's beam allocation result b u , calculate beam b u The set of available time slots with empty wavelengths is:

[0058] The available time slot set of empty beam positions is initialized to empty, and beam b is traversed. u In each time slot t within the allocation period j , 1≤j≤T, T is the time frame, if the following two conditions are met at the same time, then the time slot t j Add the empty beam position available time slot set; condition 1 is beam b u In time slot t j No wave position is covered, that is, wave position C(b u ,t j ) is empty; condition 2 is beam b u The time slot t j There is an idle channel on the network, that is, there is at least one channel U(b u ,f k, t j ) is empty, 1≤k≤F; F is beam b u The total number of corresponding channels.

[0059] The present invention also discloses an uplink resource allocation and scheduling system applicable to a multi-beam low-orbit satellite communication system, which comprises:

[0060] The user management unit is used to obtain user information of each user in real time, the user information includes the user's level, the wave position of each user, the uplink bandwidth requirement of each user, and the uplink rate limit of each user, and when the user randomly accesses the satellite communication network or re-accesses the satellite communication network after wave position switching, it sends a resource allocation request to the uplink resource allocation unit, carrying the user's level, wave position, uplink bandwidth requirement and uplink rate limit information; the user's level includes important users and ordinary users;

[0061] The uplink resource allocation unit is used to calculate the user's available beam set and the cost value representing the load state of each available beam according to the user's level and wave position information, using the beam resource allocation table maintained in real time, allocate uplink beams to the user, update the beam resource allocation table, calculate the number of time slots required by the user in the time frame according to the user's uplink bandwidth requirement and uplink rate limit information, and calculate the user's co-wave position available time slot set and empty wave position available time slot set in sequence according to the maintained time-frequency resource allocation table, allocate uplink time slots to the user on the allocated beam in the order that co-wave position time slots take precedence over empty wave position time slots, allocate idle channels to each allocated uplink time slot, and update the time-frequency resource allocation table; after completing the uplink resource allocation for the user, send the resource allocation result to the user management unit and the on-board transmission unit;

[0062] The user management unit is used to send the received resource allocation result to the user; the on-board transmission unit schedules the designated beam to receive the user's uplink data in the designated channel and designated time slot according to the resource allocation result.

[0063] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0064] 1. It has a high resource utilization rate and supports dynamic scheduling of satellite uplink beam resources on demand by multiple users. When scheduling uplink beam resources, the present invention dynamically allocates uplink beams and time-frequency resources according to user information such as the number of users accessing the satellite communication network, user wave positions, uplink bandwidth requirements, and uplink rate limits. On the one hand, when allocating beams, for ordinary users, the wave position aggregation principle is followed, and new access users are allocated to the allocated beams with the same wave position as much as possible to meet the limitation that the beam can only cover one wave position at the same time, and the multi-channel resources in the same beam are better reused to avoid the problem of beam resource waste caused by allocating multiple users with the same wave position to different beams. At the same time, when there are multiple beams with the same wave position, the beam with light load is preferentially selected, which is conducive to the balanced allocation of beam resources; on the other hand, when allocating time-frequency resources, the time-frequency resource blocks are allocated strictly according to the user's uplink bandwidth requirements and uplink rate limits, accurately matching the user's needs and capabilities to avoid resource waste. In addition, when selecting time-frequency resources for users, the principle of giving priority to time slots with the same wavelength over time slots with empty wavelengths is followed, and multiple users are allowed to reuse the same time slot resources through frequency division as much as possible to further improve resource utilization efficiency. Finally, when allocating channel resources to users, the principle of starting with small numbers is followed, and the allocated frequencies are concentrated in the lower segments as much as possible to avoid fragmentation of frequency resources. Therefore, compared with the existing technology, the resource utilization rate can be greatly improved, and the resource utilization rate can be increased by at least 1 / 3 under the same network configuration conditions.

[0065] 2. It has good dynamic adaptability. The uplink resource allocation method proposed in the present invention dynamically allocates resources according to the user changes perceived in real time by the user management unit. On the one hand, it can immediately respond to the resource allocation needs of users who access at will, and dynamically allocate reasonable beam and time-frequency resources to them according to the current allocation status of uplink resources, without the need to statically plan resources for them. On the other hand, it can immediately respond to the resource reallocation needs caused by the wave position switching caused by the relative movement of the user, and can reallocate beam resources to them according to the new wave position, effectively adapting to the relative topology changes of the highly dynamic low-orbit satellite network. In addition, it can also recover resources in time when the user exits the network at any time, which can be used for the resource allocation of other subsequent access users, and has good allocation flexibility. Therefore, compared with the prior art, it has better dynamic resource allocation capabilities and can adapt to various dynamic changes of low-orbit satellite network users.

[0066] 3. It has good user-level resource guarantee capability. When allocating beams to users, the present invention differentiates the users by level, reserves some beam resources for important users, and ordinary users cannot use reserved beams. Important users give priority to using idle reserved beams. When reserved beam resources are insufficient, they can share non-reserved beams with ordinary users, and set different coverage wave-bit numbers and equivalent user upper limits for reserved beams and non-reserved beams. The upper limit of reserved beams is smaller than that of non-reserved beams, thereby guaranteeing the continuous and stable resource needs of important users to the greatest extent.

[0067] 4. It has lower uplink service delay and delay jitter. When allocating time slots to users, the present invention selects the allocated time slots from the available time slot set according to the uniformity principle, so that the variance of the time slot number difference of all selected adjacent time slots is minimized. Therefore, when the user uses the time slot to send uplink data, the interval between adjacent time slots is as stable as possible, and the uplink service delay and delay jitter are lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0069] Figure 1 This is a schematic diagram of a typical multi-beam low-orbit satellite communication system;

[0070] Figure 2 This is a schematic diagram of the satellite uplink communication resource structure based on MF-TDMA;

[0071] Figure 3 A block diagram of a resource dynamic allocation system for multi-beam low-orbit satellite uplink communications;

[0072] Figure 4 This is a schematic diagram of the resource composition of uplink communication of a multi-beam low-orbit satellite communication system;

[0073] Figure 5 A block diagram of a resource dynamic allocation system for uplink communication of a multi-beam low-orbit satellite is provided;

[0074] Figure 6 A schematic diagram of the interaction process between the user management unit and the uplink resource allocation unit;

[0075] Figure 7 A process flow chart for uplink resource allocation unit beam allocation;

[0076] Figure 8 A processing flow chart of time-frequency resource allocation for an uplink resource allocation unit;

[0077] Fig. 9 A diagram of the composition of the beam resource allocation table maintained by the uplink resource allocation unit;

[0078] Fig.10 A diagram showing the composition of the time-frequency resource allocation table maintained by the uplink resource allocation unit. DETAILED DESCRIPTION

[0079] The present invention is further described in conjunction with the accompanying drawings and embodiments, and the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present invention.

[0080] See also Figure 3 The satellite uplink communication function is mainly composed of an on-board protocol processing unit and an on-board transmission unit. The on-board transmission unit includes multiple beam receiving units such as beam 1, beam 2, ... beam B, which are used to receive uplink data sent by users in the coverage area of ​​each beam. The on-board protocol processing unit mainly includes a user management unit and an uplink resource allocation unit. Among them, the user management unit uses the user management protocol to manage the user's access to the network, exit from the network, and wave position switching, and obtains user information such as the level, wave position, uplink bandwidth requirement, and uplink rate limit of each user in real time. During the network operation process, the uplink resource allocation unit responds to the resource allocation or release request input by the user management unit, dynamically allocates or releases beam, channel and time slot resources for the user according to the user information, and sends the resource allocation result information to the on-board transmission unit and the user management unit.

[0081] See also Figure 4 The figure shows the resource composition of the uplink communication of the multi-beam low-orbit satellite communication system. The uplink resource allocation unit allocates the B uplink beams b1 to b B The uplink resource allocation unit allocates each beam b to two groups, one of which is reserved beams and is specially allocated to important users; the other is non-reserved beams and can be used by both important users and ordinary users. i The total bandwidth is divided into F mutually orthogonal channels f i1 ~f iF , in the time domain, the time frame is divided into T time slots t1~t T Each grid on the beam is called a resource block RB, which is the smallest resource unit that can be allocated by the system.

[0082] See also Figure 5 The user management unit uses the general user management protocol to obtain the level of each user (important user or ordinary user) in real time among users u1, u2, ..., and the wave position C of each user. u1 , C u2, ..., each user's uplink bandwidth requirement Rq u1 , Rq u2 , ..., and the uplink rate limit Rm for each user u1 , Rm u2 , ..., and sends a resource allocation request to the uplink resource allocation unit during the management process of user u's random access to the satellite communication network or wave position switching, carrying the level, wave position, uplink bandwidth requirement and uplink rate limit information of user u. The uplink resource allocation unit first calculates the available beam set of user u and the cost value representing the load state of each available beam according to the level and wave position information of user u, using the beam resource allocation table maintained in real time, and allocates a unique uplink beam to user u according to the allocation principles of giving priority to idle reserved beams for important users, giving priority to beams with the same wave position for important users and ordinary users when there are no idle beams, and giving priority to beams with light loads under the same conditions, and updates the beam resource allocation table. Then, the uplink resource allocation unit calculates the number of time slots required by user u in the time frame according to the uplink bandwidth requirement and uplink rate limit information of user u, and calculates the available time slot set and empty time slot set of user u in sequence according to the maintained time-frequency resource allocation table. In the order of time slots at the same wavelength taking precedence over time slots at empty wavelengths, the uplink time slots that match the bandwidth requirement as much as possible and are distributed as evenly as possible are allocated to user u on the allocated beam, and then an idle channel is allocated to each allocated time slot according to the principle of starting with the smallest sequence number, and the time-frequency resource allocation table is updated. After completing the uplink resource allocation for user u, the uplink resource allocation unit sends the resource allocation result to the user management unit and the onboard transmission unit. According to the resource allocation result, the onboard transmission unit schedules the specified beam to receive the uplink data of user u in the specified channel and specified time slot.

[0083] See also Figure 6 The figure shows the interaction between the user management unit and the uplink resource allocation unit. It mainly includes three resource dynamic allocation interaction scenarios.

[0084] Scenario 1: The user management unit senses that user u has joined the satellite communication network, and sends a resource allocation request to the uplink resource allocation unit, carrying the level, wave position, uplink bandwidth requirement and uplink rate limit information of user u. After receiving the request, the uplink resource allocation unit allocates uplink beam, time slot and channel resources to user u, and sends the resource allocation result to the user management unit. After receiving the request, the user management unit sends the uplink resource allocation result to user u via the downlink.

[0085] Scenario 2: The user management unit senses that user u has switched wave positions during network operation, and sends a resource reallocation request to the uplink resource allocation unit, carrying the new wave position information of the user. After receiving the request, the uplink resource allocation unit clears the original uplink resources of user u, reallocates uplink resources for user u, and sends the resource allocation result to the user management unit. After receiving the result, the user management unit sends the uplink resource allocation result to user u through the downlink.

[0086] Scenario 3: The user management unit senses that user u has exited the satellite communication network, and sends a resource release request to the uplink resource allocation unit. After receiving the request, the uplink resource allocation unit clears the original uplink resources of user u.

[0087] See Figure 7 , where the beam allocation processing flow of the uplink resource allocation unit is given in the figure.

[0088] Step 100, the uplink resource allocation unit extracts the user level of user u and the wave position C u information, starts the beam allocation process for user u, and transfers to step 101 to calculate the available beam set;

[0089] Step 101, the uplink resource allocation unit calculates the available beam set P of user u. The calculation method is as follows, and then transfers to step 102 to determine whether P is non-empty;

[0090] The method for calculating the available beam set P of user u is: first initialize the available beam set P to be empty, and then traverse all uplink beams b1~b B according to the user level of user u, and add the eligible beams to the set P. If u is an important user, if a certain beam satisfies both the conditions of the number of covered wave positions < Nc and the number of equivalent users < Nu at the same time, then add this beam to the set P; if u is an ordinary user, if a certain beam satisfies the three conditions of the number of covered wave positions < Nc, the number of equivalent users < Nu, and the beam is a non-reserved beam at the same time, then add this beam to the set P. Among them, Nc and Nu are the upper limits of the number of covered wave positions and the upper limits of the number of equivalent users preset by the system respectively. The system presets different number limits for reserved beams and non-reserved beams. The upper limit of the number of covered wave positions of reserved beams is preset as Nc1, the upper limit of the number of equivalent users of reserved beams is preset as Nu1, the upper limit of the number of covered wave positions of non-reserved beams is preset as Nc2, and the upper limit of the number of equivalent users of non-reserved beams is preset as Nu2. The specific values of Nc and Nu depend on the number of carriers and time slots of the uplink beam resources, and satisfy Nu2 > Nc2 ≥ Nu1 > Nc1.

[0091] Step 102, the uplink resource allocation unit determines whether the available beam set P is non-empty. If it is non-empty, it transfers to step 103 to calculate the cost value of each beam, otherwise it transfers to step 113 to terminate the allocation;

[0092] Step 103: The uplink resource allocation unit calculates the cost value representing the load state of each beam in the available beam set P according to the number of currently covered beam positions and the number of equivalent users. The smaller the cost value, the lighter the load of the beam. Wherein, nc is the number of wave positions currently covered by the beam, nu is the current number of equivalent users of the beam, Nc is the upper limit of the number of wave positions covered by the beam, Nu is the upper limit of the number of equivalent users of the beam, F is the number of channels of the beam, and α is the proportional factor preset by the system, 0<α<1. Then proceed to step 104 to determine the user level;

[0093] Step 104: The uplink resource allocation unit determines the level of user u. If u is an important user, the process proceeds to step 105 to determine whether there is an idle reserved beam in P. If u is an ordinary user, the process proceeds to step 106 to determine whether there is an existing beam in P that covers the same wavelength position C. u ;

[0094] Step 105: The uplink resource allocation unit determines whether there is an idle reserved beam in the available beam set P. If so, the process proceeds to step 111 to select an idle reserved beam to allocate to user u. Otherwise, the process proceeds to step 106 to determine whether there is an existing beam in P that covers the same beam position C. u ;

[0095] Step 106: The uplink resource allocation unit determines whether there are one or more beams in the available beam set P that cover the same beam position C. u If yes, proceed to step 107 to select the one with the smallest cost value to allocate to user u, otherwise proceed to step 108 to determine whether there is an idle non-reserved beam in P;

[0096] Step 107: The uplink resource allocation unit covers the same beam position C from the available beam set P. u Select the beam with the smallest cost value from one or more beams and assign it to user u, then go to step 112 to update the beam resource allocation table;

[0097] Step 108: the uplink resource allocation unit determines whether there is an idle non-reserved beam in the available beam set P. If yes, the process proceeds to step 109 to select an idle non-reserved beam to allocate to user u. Otherwise, the process proceeds to step 110 to select a beam with the smallest cost value from P to allocate to user u.

[0098] Step 109: the uplink resource allocation unit selects the beam with the smallest beam number from all idle non-reserved beams in the available beam set P and allocates it to user u, and then proceeds to step 112 to update the beam resource allocation table;

[0099] Step 110, the uplink resource allocation unit selects the beam with the smallest cost value from the available beam set P and allocates it to the user u, and then proceeds to step 112 to update the beam resource allocation table;

[0100] Step 111, the uplink resource allocation unit selects the beam with the smallest beam number from all idle reserved beams in the available beam set P and allocates it to user u, and then proceeds to step 112 to update the beam resource allocation table;

[0101] Step 112: The uplink resource allocation unit updates the relevant entries of the allocated beam in the resource allocation table: Let U = U∪{u}, C = C∪{C u}, Z is a system preset parameter, and its value is an integer greater than 1.

[0102] Step 113: The uplink resource allocation unit terminates the resource allocation process for user u, and feeds back to the user management unit an allocation result indicating that insufficient resources make allocation impossible.

[0103] See also Figure 8 , the figure shows the time-frequency resource allocation processing flow of the uplink resource allocation unit.

[0104] Step 200, after the uplink resource allocation unit completes the beam allocation for user u, it extracts the uplink bandwidth requirement, uplink rate limit, beam position, and beam allocation result information of user u, starts the time-frequency resource allocation process for user u, and proceeds to step 201 to calculate the time slot requirement;

[0105] Step 201: The uplink resource allocation unit calculates the number of time slots required by user u in the time frame according to the uplink bandwidth requirement and uplink rate limit of user u. Tf is the time frame length (s), Ts is the time slot length (s), Rq is the uplink bandwidth requirement (bps), Rm is the uplink rate limit (bps), and ceil is rounded up. Then go to step 202 to calculate the available time slot set of the same wavelength;

[0106] Step 202: The uplink resource allocation unit allocates the resource according to the maintained time-frequency resource allocation table and the beam allocation result b of user u. u and user u's wave position C u , calculate beam b u The method is as follows: the available time slot set Q1 of the same wavelength is obtained, and the number of time slots Sp contained in Q1 is counted. Then, the process goes to step 203 to calculate the number of available time slots of the empty wavelength;

[0107] Q1 is initialized to empty and traverses beam b u In each time slot t within the allocation period j , 1≤j≤T, if the following three conditions are met at the same time, then time slot t jAdd the available time slots in the same wave position to the set Q1. The first condition is that beam b u in time slot t j covers wave position C u , that is, C(b u , t j ) = C u ; The second condition is that there is an idle channel in time slot t u in beam b j , that is, there is at least 1 U(b u , f k , t j ) is empty, 1 ≤ k ≤ F; The third condition is that time slot t u in beam b j is not allocated to user u, that is, there does not exist any U(b u , f k , t j ) = u, 1 ≤ k ≤ F;

[0108] Step 203, the uplink resource allocation unit calculates the available time slots of the empty wave positions in set Q2 for beam b u according to the maintained time-frequency resource allocation table and the beam allocation result b u of user u, as follows, and counts the number Sw of time slots included in Q2. Then go to step 204 to judge whether Si ≤ Sp holds;

[0109] Initialize Q2 to be empty, and traverse each time slot t u in beam b j during the allocation period, 1 ≤ j ≤ T. If the following two conditions are met simultaneously, then add time slot t j to the available time slots of the empty wave positions in set Q2. The first condition is that beam b u does not cover any wave positions in time slot t j , that is, C(b u , t j ) = empty; The second condition is that there is an idle channel in time slot t u in beam b j , that is, there is at least 1 U(b u , f k , t j ) is empty, 1 ≤ k ≤ F;

[0110] Step 204, the uplink resource allocation unit judges whether Si ≤ Sp holds. If so, go to step 205 to uniformly select Si time slots from Q1, otherwise go to step 206 to judge whether 0 < Sp < Si holds;

[0111] Step 205, the uplink resource allocation unit selects Si time slots for user u from Q1 according to the principle of uniformity, such that the variance of the differences in the time slot numbers of all the selected adjacent time slots is minimized. Then it proceeds to step 215 to allocate channel numbers;

[0112] Step 206, the uplink resource allocation unit determines whether 0 < Sp < Si holds. If so, it proceeds to step 207 to determine whether Sw > 0 holds; otherwise, it proceeds to step 211 to determine whether Sw > 0 holds;

[0113] Step 207, the uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to step 208 to determine whether Sw ≥ Si - Sp holds; otherwise, it proceeds to step 205 to uniformly select Si time slots from Q1;

[0114] Step 208, the uplink resource allocation unit determines whether Sw ≥ Si - Sp holds. If so, it proceeds to step 209 to select all Sp time slots from Q1 and then uniformly select Si - Sp time slots from Q2; otherwise, it proceeds to step 210 to select all Sp time slots from Q1 and then select all Sw time slots from Q2;

[0115] Step 209, the uplink resource allocation unit selects a total of Si time slots for user u, where it selects all Sp time slots from Q1 and then selects Si - Sp time slots from Q2 according to the principle of uniformity, such that the variance of the differences in the time slot numbers of all the selected adjacent time slots is minimized. Then it proceeds to step 215 to allocate channel numbers;

[0116] Step 210, the uplink resource allocation unit selects a total of Sp + Sw time slots for user u, where it first selects all Sp time slots from Q1 and then selects all Sw time slots from Q2. Then it proceeds to step 215 to allocate channel numbers;

[0117] Step 211, the uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to step 212 to determine whether Sw ≥ Si holds; otherwise, it proceeds to step 218 to terminate the allocation;

[0118] Step 212, the uplink resource allocation unit determines whether Sw ≥ Si holds. If so, it proceeds to step 213 to uniformly select Si time slots from Q2; otherwise, it proceeds to step 214 to select all Sw time slots from Q2;

[0119] Step 213, the uplink resource allocation unit selects Si time slots for user u from Q2 according to the principle of uniformity, such that the variance of the differences in the time slot numbers of all the selected adjacent time slots is minimized. Then it proceeds to step 215 to allocate channel numbers;

[0120] Step 214, the uplink resource allocation unit selects all Sw time slots from Q2 for user u. Then the process goes to step 215 to allocate channel numbers;

[0121] Step 215: The uplink resource allocation unit allocates channels for each time slot selected for user u according to the principle that the channel number starts from the smallest. That is, it selects beam b. u The idle channel with the smallest sequence number in the time slot is allocated to user u. Then the process goes to step 216 to update the time-frequency resource allocation table;

[0122] Step 216: The uplink resource allocation unit updates the time-frequency resource allocation table for beam b according to the time slot and channel resources selected for user u. u Then, the process goes to step 217 to output the resource allocation result;

[0123] Step 217: The uplink resource allocation unit outputs a resource allocation result, which includes information on the beam number, time slot number and channel number allocated to user u, and sends the resource allocation result to the user management unit and the on-board transmission unit.

[0124] Step 218: The uplink resource allocation unit terminates the resource allocation process for user u, and feeds back to the user management unit the allocation result that insufficient resources make allocation impossible.

[0125] See also Fig. 9 . The figure shows the composition of the beam resource allocation table. The uplink resource allocation unit maintains the beam resource allocation table in real time. The table records the allocation identifier, coverage wave position, and allocated user status information of each beam for the beam allocation process. Among them, the beam allocation identifier indicates whether the current beam is idle. It is idle initially. Once the allocated user set is not empty, the beam allocation identifier is set to occupied. The beam reservation identifier indicates whether the current beam is a reserved beam or a non-reserved beam. This attribute is preset by the system and remains unchanged during the resource allocation process. The allocated user set U indicates which users the current beam is allocated to. It is an empty set initially. Once the beam is allocated to user u, user u is added to the allocated user set. If user u exits the network and causes resource release or the wave position switching causes beam reallocation, user u needs to be removed from the allocated user set of the current beam. The covered wave position set C indicates which wave positions are covered by the current beam. This set is equal to the union of the wave positions of all users in the allocated user set. The equivalent user number nu represents the equivalent user number allocated to the current beam, which is initially 0. Once the beam is allocated to user u or the original resources of u are cleared, the equivalent user number needs to be updated according to the level of user u.

[0126] See also Fig.10The figure shows the composition of the time-frequency resource allocation table. The uplink channel allocation unit maintains the time-frequency resource allocation table in real time. The table records the time-frequency resource allocation status on each beam and is used in the time-frequency allocation process. i ,t j ) represents beam b i In time slot t j Each beam can only cover one beam position in the same time slot, but can cover the same or different beam positions in different time slots. i ,f ik, t j ) indicates obtaining a resource block RB(b i ,f ik, t j ) users, different channels in the same time slot on each beam can be allocated to different users, but cannot be allocated to the same user. i ,t j ) and U(b i ,f ik, t j ) are initially empty. Once RB(b i ,f ik, t j ) is assigned to a user u, then let U(b i ,f ik, t j )=u,C(b i ,t j )=u's wave position C u , 1≤i≤B, 1≤j≤T, 1≤k≤F. If resources are released due to user u leaving the network or resources are reallocated due to wave switching during network operation, the uplink channel allocation unit needs to allocate all U(b i ,f ik, t j ) is cleared, only when beam b i In time slot t j C(b) is cleared only when all channels on the i ,t j ).

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for dynamic resource allocation for multi-beam low-orbit satellite uplink communication, characterized in that: include: The user management unit senses that the user has accessed the satellite communication network and sends a resource request to the uplink resource allocation unit; After receiving the resource request, the uplink resource allocation unit allocates uplink beams, time slots and channel resources to the user, and sends the resource allocation results to the user management unit and the on-board transmission unit respectively. The user management unit sends the received resource allocation results to the user; the on-board transmission unit schedules the specified beam to receive the user's uplink data in the specified channel and specified time slot according to the resource allocation results.

2. The method according to claim 1, characterized in that: Also includes: When the user management unit senses that the user has joined the satellite communication network, it sends a resource allocation request to the uplink resource allocation unit, which carries the user's level, wave position, uplink bandwidth requirement and uplink rate limit information; after receiving the request, the uplink resource allocation unit allocates uplink beam, time slot and channel resources to the user, and sends the resource allocation result to the user management unit, which sends the uplink resource allocation result to the user through the downlink after receiving the request; The user management unit senses that the user has switched the wave position during network operation, and sends a resource reallocation request to the uplink resource allocation unit, carrying the new wave position information of the user. After receiving the request, the uplink resource allocation unit clears the original uplink resources of the user, and reallocates the uplink resources to the user, and sends the resource allocation result to the user management unit. After receiving the request, the user management unit sends the uplink resource allocation result to the user via the downlink. The user management unit senses that the user has exited the satellite communication network, and sends a resource release request to the uplink resource allocation unit. After receiving the request, the uplink resource allocation unit clears the original uplink resources of the user.

3. The method according to claim 1, characterized in that: The uplink resource allocation unit allocates uplink beams to users, including: Step 11: The uplink resource allocation unit extracts the user level and the wave position C of the user u information; Step 12: The uplink resource allocation unit calculates the available beam set P of the user; Step 13: The uplink resource allocation unit determines whether the available beam set P is not empty. If it is not empty, it proceeds to step 14, otherwise it terminates the allocation; Step 14: The uplink resource allocation unit calculates a cost value representing the load state of each beam in the available beam set P according to the number of currently covered beam positions of the beam and the number of equivalent users; Step 15: The uplink resource allocation unit determines the level of the user. If the user is an important user, the process proceeds to step 16; if the user is an ordinary user, the process proceeds to step 17; Step 16: The uplink resource allocation unit determines whether there is an idle reserved beam in the available beam set P. If yes, it proceeds to step 12; otherwise, it proceeds to step 17; Step 17: The uplink resource allocation unit determines whether there are one or more beams in the available beam set P that cover the same beam position C. u If yes, go to step 18, otherwise go to step 19; Step 18: The uplink resource allocation unit covers the same beam position C from the available beam set P u Select the beam with the smallest cost value from one or more beams and allocate it to the user, then go to step 113 to update the beam resource allocation table; Step 19: The uplink resource allocation unit determines whether there is an idle non-reserved beam in the available beam set P. If yes, the process proceeds to step 110; otherwise, the process proceeds to step 111; Step 110: The uplink resource allocation unit selects the beam with the smallest beam number from all idle non-reserved beams in the available beam set P and allocates it to the user, and then proceeds to step 113 to update the beam resource allocation table; Step 111: the uplink resource allocation unit selects a beam with the smallest cost value from the available beam set P and allocates it to the user, and then proceeds to step 113 to update the beam resource allocation table; Step 112: The uplink resource allocation unit selects the beam with the smallest beam number from all the idle reserved beams in the available beam set P and allocates it to the user, and then proceeds to Step 113 to update the beam resource allocation table; Step 113: The uplink resource allocation unit updates the relevant entries of the beam allocated in the resource allocation table.

4. The method according to claim 3, characterized in that The said Step 2 includes: Initialize the available beam set P to be empty, and traverse all uplink beams b1~b according to the user level. B , add the qualified beams to the set P; if the user is an important user, if a beam satisfies both the number of covered wavelets less than Nc and the number of equivalent users less than Nu, then the beam is added to the set P; if the user is an ordinary user, if a beam satisfies both the number of covered wavelets less than Nc, the number of equivalent users less than Nu and the beam is a non-reserved beam, then the beam is added to the set P; where Nc and Nu are the upper limits of the number of covered wavelets and the number of equivalent users preset by the system, respectively.

5. The method according to claim 4, characterized in that The system pre-sets different upper limits for the reserved beams and non-reserved beams respectively. The upper limit of the coverage wave positions of the reserved beams is pre-set to Nc1, the upper limit of the equivalent number of users of the reserved beams is pre-set to Nu1, the upper limit of the coverage wave positions of the non-reserved beams is pre-set to Nc2, and the upper limit of the equivalent number of users of the non-reserved beams is pre-set to Nu2. The values of Nc and Nu depend on the number of carriers and time slots of the uplink beam resources, and satisfy Nu2 > Nc2 ≥ Nu1 > Nc1.

6. The method according to claim 1, characterized in that After the uplink resource allocation unit completes the beam allocation for the user, it extracts the uplink bandwidth requirement, uplink rate limit, wave position, and beam allocation result information of the user, and initiates the time-frequency resource allocation process for the user.

7. The method according to claim 6, characterized in that The said time-frequency resource allocation process for the user includes: Step 21: Calculate the number of required time slots Si, calculate the available time slot set of the same wave position and count the number of time slots Sp included in the available time slot set of the same wave position, calculate the available time slots of the empty wave positions and count the number of time slots Sw included in the available time slot set of the empty wave positions; Step 22: The uplink resource allocation unit determines whether Si ≤ Sp holds. If so, it proceeds to Step 23; otherwise, it proceeds to Step 24; Step 23: The uplink resource allocation unit selects Si time slots for the user from the available time slot set of the same wave position according to the uniformity principle, so that the variance of the differences in the time slot numbers of all the selected adjacent time slots is the smallest; then it proceeds to Step 33; Step 24: The uplink resource allocation unit determines whether 0 < Sp < Si holds. If so, it proceeds to Step 25; otherwise, it proceeds to Step 29; Step 25: The uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to Step 26 to determine whether Sw ≥ Si - Sp holds; otherwise, it proceeds to Step 23; Step 26: The uplink resource allocation unit determines whether Sw ≥ Si - Sp holds. If so, it proceeds to Step 27; otherwise, it proceeds to Step 28; Step 27: The uplink resource allocation unit selects a total of Si time slots for the user, where all Sp time slots are selected from the available time slot set of the same wave position, and then Si - Sp time slots are selected from the available time slot set of the empty wave positions according to the uniformity principle, so that the variance of the differences in the time slot numbers of all the selected adjacent time slots is the smallest; then it proceeds to Step 33; Step 28: The uplink resource allocation unit selects a total of Sp + Sw time slots for the user, where all Sp time slots are first selected from the available time slot set of the same wave position, and then all Sw time slots are selected from the available time slot set of the empty wave positions; then it proceeds to Step 33; Step 29: The uplink resource allocation unit determines whether Sw > 0 holds. If so, it proceeds to Step 30; otherwise, it proceeds to Step 36 to terminate the allocation; Step 30: The uplink resource allocation unit determines whether Sw ≥ Si holds. If so, it proceeds to Step 31; otherwise, it proceeds to Step 32; Step 31: The uplink resource allocation unit selects Si time slots from the set of available time slots with empty wavelengths for the user according to the uniformity principle, so that the variance of the time slot number differences of all the selected adjacent time slots is minimized, and then proceeds to step 33; Step 32: The uplink resource allocation unit selects all Sw time slots from the set of available time slots with empty wavelengths for the user, and then proceeds to step 33; Step 33: The uplink resource allocation unit allocates channels for each time slot selected for the user according to the principle that the channel number starts from the smallest one, that is, selects beam b u The idle channel with the smallest sequence number in the time slot is allocated to the user, and then the process goes to step 34; Step 34: The uplink resource allocation unit updates the time-frequency resource allocation table for beam b according to the time slot and channel resources selected for the user. u The relevant information includes the wave position and the user, and then proceeds to step 35; Step 35: The uplink resource allocation unit outputs a resource allocation result, which includes information about the beam number, time slot number, and channel number allocated to the user, and sends the resource allocation result to the user management unit and the onboard transmission unit; Step 36: The uplink resource allocation unit terminates the resource allocation process for the user, and feeds back to the user management unit the allocation result that insufficient resources make allocation impossible.

8. The method according to claim 7, characterized in that The number of time slots Si required by the user in the time frame is calculated by the following formula: Wherein, Tf is the time frame length, Ts is the time slot length, Rq is the uplink bandwidth requirement of the user, Rm is the uplink rate limit of the user, and ceil is rounded up.

9. The method according to claim 7, characterized in that: The calculating of the available time slot set of the same wavelength position comprises: The uplink resource allocation unit maintains the time-frequency resource allocation table and the user's beam allocation result b u and the user's wave position C u , calculate beam b u The set of available time slots with the same wavelength: The set of available time slots in the same beam position is initialized to empty, and the beam b is traversed. u In each time slot t within the allocation period j , 1≤j≤T, T is the time frame, if the following three conditions are met at the same time, then the time slot t j Join the same-wavelength available time slot set; condition 1 is beam b u In time slot t j Covering wave C u , that is, wave position C(b u ,t j )=C u ; Condition 2 is beam b u The time slot t j There is an idle channel on the network, that is, there is at least one channel U(b u ,f k ,t j ) is empty, 1≤k≤F; Condition 3 is beam b u The time slot t j Not allocated to the user, that is, there is no channel U(b u ,f k ,t j )=u,1≤k≤F;f k is beam b u The corresponding kth channel, F is the beam b u The total number of corresponding channels.

10. The method according to claim 7, characterized in that The step of calculating the number of available time slots of empty wave positions comprises: The uplink resource allocation unit maintains the time-frequency resource allocation table and the user's beam allocation result b u , calculate beam b u The set of available time slots with empty wavelengths is: The available time slot set of empty beam positions is initialized to empty, and beam b is traversed. u In each time slot t within the allocation period j , 1≤j≤T, T is the time frame, if the following two conditions are met at the same time, then the time slot t j Add the empty beam position available time slot set; condition 1 is beam b u In time slot t j No wave position is covered, that is, wave position C(b u ,t j ) is empty; condition 2 is beam b u The time slot t j There is an idle channel on the network, that is, there is at least one channel U(b u ,f k ,t j ) is empty, 1≤k≤F; f k is beam b u The corresponding kth channel, F is the beam b u The total number of corresponding channels.

11. A resource dynamic allocation system for multi-beam low-orbit satellite uplink communication, characterized in that: include: The user management unit is used to obtain user information of each user in real time, the user information includes the user's level, the wave position of each user, the uplink bandwidth requirement of each user, and the uplink rate limit of each user, and when the user randomly accesses the satellite communication network or re-accesses the satellite communication network after wave position switching, it sends a resource allocation request to the uplink resource allocation unit, carrying the user's level, wave position, uplink bandwidth requirement and uplink rate limit information; the user's level includes important users and ordinary users; The uplink resource allocation unit is used to calculate the user's available beam set and the cost value representing the load state of each available beam according to the user's level and wave position information, using the beam resource allocation table maintained in real time, allocate uplink beams to the user, update the beam resource allocation table, calculate the number of time slots required by the user in the time frame according to the user's uplink bandwidth requirement and uplink rate limit information, and calculate the user's co-wave position available time slot set and empty wave position available time slot set in sequence according to the maintained time-frequency resource allocation table, allocate uplink time slots to the user on the allocated beam in the order that co-wave position time slots take precedence over empty wave position time slots, allocate idle channels to each allocated uplink time slot, and update the time-frequency resource allocation table; after completing the uplink resource allocation for the user, send the resource allocation result to the user management unit and the on-board transmission unit; The user management unit is used to send the received resource allocation result to the user; The onboard transmission unit schedules the designated beam to receive the user's uplink data in the designated channel and time slot according to the resource allocation result.

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