Satellite communication system user capacity test method based on semi-physical digital simulation

Abstract

The invention discloses a satellite communication system user capacity testing method based on semi-physical digital simulation, and relates to the field of satellite communication. The system comprises a test management subsystem, a multi-user digital simulation subsystem, a multi-user terminal subsystem or a protocol adaptation subsystem. A test scene and beam parameters are configured through the test management subsystem, the multi-user digital simulation subsystem generates simulated user control plane data and behaviors, the simulated user control plane data and behaviors are forwarded to the satellite load through the multi-user terminal subsystem or the protocol adaptation subsystem, the satellite load responds, and the data and behaviors are displayed through one-time or multi-time interaction. And the user control plane data and the interaction result information are stored by the test management subsystem, and a corresponding test report is generated, so that the satellite communication system user capacity test based on semi-physical digital simulation is realized. The method is closer to real satellite channel equipment, and meets the requirement of saturation or supersaturation test of the user capacity of a satellite communication system.

Description

Technical Field

[0001] The invention relates to the field of satellite communication, in particular to a method for testing user capacity of a satellite communication system based on semi-physical digital simulation. Background Art

[0002] The user capacity of a satellite communication system refers to the number of users supported by a satellite payload. In theoretical analysis, a satellite payload supports thousands or even tens of thousands of users on the network at the same time. Actual measurement requires tens of thousands of satellite channel devices, which results in a very high cost and low efficiency for measuring the user capacity of a satellite communication system. In addition, in the test phase before the satellite is launched, it is necessary to simulate the control plane data and behaviors of large-scale satellite channel devices such as network entry and exit and service access under laboratory conditions in order to test the system performance of the satellite payload. Therefore, it is necessary to build a user capacity test platform to simulate large-scale satellite channel devices.

[0003] The main technical directions of current user capacity testing are: hardware simulation based on actual satellite channel equipment and software simulation based on large-capacity virtual users. The former is based on physical satellite channel equipment and uses multi-carrier technology to simulate the behavior of multiple satellite channel devices. However, the number of satellite channel devices that can be simulated is limited, and it is impossible to simulate the statistical characteristics of user behavior, nor can it meet the requirements of saturated or oversaturated user capacity testing. The latter simulates the behavior of satellite channel equipment through terminal simulation software and tests user capacity by software-to-software interaction. This method cannot simulate the characteristics of real satellite channel equipment and cannot verify the impact of satellite channels on user capacity. Summary of the invention

[0004] In view of this, the present invention proposes a method for testing user capacity of a satellite communication system based on semi-physical digital simulation. The method is closer to real satellite channel equipment and meets the requirements of saturation or oversaturation testing of user capacity of a satellite communication system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The user capacity test method of the satellite communication system based on semi-physical digital simulation is implemented based on a test management subsystem, a multi-user digital simulation subsystem and a multi-user terminal subsystem; the test management subsystem is used to configure the test scene and beam parameters, and generate a test report in word form; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; the multi-user terminal subsystem includes a physical satellite channel device, which is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload;

[0007] Specifically include the following steps:

[0008] Step 1: Connect the test management subsystem, the multi-user digital simulation subsystem and the multi-user terminal subsystem through a switching network, and connect the satellite payload and the physical satellite channel equipment in the multi-user terminal subsystem through an intermediate frequency cable, thereby building a test environment;

[0009] Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required;

[0010] Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem and the multi-user terminal subsystem respectively through the test management subsystem;

[0011] Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem;

[0012] Step 5, the multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the physical satellite channel device in the multi-user terminal subsystem according to the control instruction;

[0013] Step 6, the physical satellite channel equipment in the multi-user terminal subsystem adopts multi-carrier parallel modulation technology to forward the user control plane data generated by the multi-user digital simulation subsystem to the satellite payload;

[0014] Step 7, the physical satellite channel device in the multi-user terminal subsystem receives the information data responded by the satellite payload;

[0015] Step 8: The physical satellite channel device in the multi-user terminal subsystem forwards the response information data to the multi-user digital simulation subsystem. The multi-user digital simulation subsystem completes one or more rounds of interaction with the satellite payload based on the simulated user control surface behavior and the response information data. The data interaction process is observed on the multi-user digital simulation subsystem interface, and the user communication status change is simulated through the test management subsystem.

[0016] Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem;

[0017] Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

[0018] Furthermore, the specific method of step 2 is:

[0019] Step 201, the multi-user digital simulation subsystem generates a random number M in a pseudo-random binary sequence, M = 0, 1, 2, 3, ..., 216 -1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user;

[0020] Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution;

[0021] Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior;

[0022] Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

[0023] Furthermore, the satellite channel equipment in the multi-user terminal subsystem includes a protocol processing unit and a modulator, and the specific method of step 6 is:

[0024] Step 601, the satellite channel equipment in the multi-user terminal subsystem receives the user control plane data sent by the multi-user digital simulation subsystem;

[0025] Step 602, the satellite channel device in the multi-user terminal subsystem diverts the user control plane data to 64 independent buffers through the QoS buffer queue;

[0026] Step 603, the satellite channel device protocol processing unit in the multi-user terminal subsystem generates a time slot control frame according to the resource allocation situation;

[0027] Step 604: The satellite channel device modulator in the multi-user terminal subsystem triggers 64 channels to send user control plane data in parallel according to the time slot control frame.

[0028] The user capacity test method of the satellite communication system based on semi-physical digital simulation is implemented based on a test management subsystem, a multi-user digital simulation subsystem and a protocol adaptation subsystem; the test management subsystem is used to configure the test scene and beam parameters, and generate a test report in word format; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; the protocol adaptation subsystem is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload;

[0029] Specifically include the following steps:

[0030] Step 1, connecting the test management subsystem, the multi-user digital simulation subsystem and the protocol adaptation subsystem through a switching network, and connecting the satellite payload and the protocol adaptation subsystem through an LVDS interface, thereby building a test environment;

[0031] Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required;

[0032] Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem through the test management subsystem;

[0033] Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem;

[0034] Step 5: The multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the protocol adaptation subsystem according to the control instruction;

[0035] Step 6, the protocol adaptation subsystem forwards the user control surface data generated by the multi-user digital simulation subsystem to the satellite payload;

[0036] Step 7, the protocol adaptation subsystem receives information data responded by the satellite payload;

[0037] Step 8: The protocol adaptation subsystem forwards the response information data to the multi-user digital simulation subsystem. The multi-user digital simulation subsystem completes one or more rounds of interaction with the satellite payload based on the simulated user control surface behavior and the response information data, observes the data interaction process on the multi-user digital simulation subsystem interface, and simulates the user communication status change through the test management subsystem.

[0038] Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem;

[0039] Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

[0040] Furthermore, the specific method of step 2 is:

[0041] Step 201: The multi-user digital simulation subsystem generates a random number M in a pseudo-random sequence, where M = 0, 1, 2, 3, ..., 2 16-1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user;

[0042] Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution;

[0043] Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior;

[0044] Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

[0045] Due to the adoption of the above technical solution, the beneficial effects of the present invention compared with the prior art are:

[0046] 1. The user capacity test system designed by the present invention has simple structure and debugging, stable performance and strong scalability.

[0047] 2. The satellite channel equipment simulated by the test method designed by the present invention is closer to the real satellite communication networking state. The generated simulated user information data is sent and received through the satellite channel equipment and the real physical channel, which is closer to the real satellite communication networking state.

[0048] 3. The test method designed by the present invention verifies the signal processing capability of the satellite payload while testing the user capacity of the satellite communication system.

[0049] 4. The test method designed by the present invention can access different satellite beams and test the user capacity of the satellite payload under different beams.

[0050] 5. The test method of the present invention includes two application scenarios connected with satellite payloads, which confirm and complement each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of the composition of a user capacity test simulation platform in an embodiment of the present invention.

[0052] Figure 2 The figure is a connection diagram of a user capacity test environment of a satellite communication system in an embodiment of the present invention.

[0053] Figure 3 It is a schematic diagram of using a multi-user terminal subsystem to perform user capacity testing in an embodiment of the present invention.

[0054] Figure 4 It is a schematic diagram of using the protocol adaptation subsystem to perform user capacity testing in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0056] The user capacity test method of the satellite communication system based on semi-physical digital simulation is implemented based on a test management subsystem, a multi-user digital simulation subsystem and a multi-user terminal subsystem; the test management subsystem is used to configure the test scene and beam parameters, and generate a test report in word form; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; the multi-user terminal subsystem includes a physical satellite channel device, which is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload;

[0057] Specifically, Figure 1 The user capacity test simulation platform in this embodiment is shown. The test management subsystem in the user capacity test simulation platform includes a server, a switching device and a test management software installed; the multi-user digital simulation subsystem includes a server and a test management software installed; Figure 2 As shown, the satellite payload includes an onboard network control and switching processor and a satellite signal processor, and the physical satellite channel equipment in the multi-user terminal subsystem interacts with the satellite payload through a splitter and combiner;

[0058] like Figure 3 As shown, the specific steps include:

[0059] Step 1: Connect the test management subsystem, the multi-user digital simulation subsystem and the multi-user terminal subsystem through a switching network, and connect the satellite payload and the physical satellite channel equipment in the multi-user terminal subsystem through an intermediate frequency cable, thereby building a test environment;

[0060] Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required;

[0061] Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem and the multi-user terminal subsystem respectively through the test management subsystem;

[0062] Specifically, it includes satellite number, beam, and operating parameters;

[0063] Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem;

[0064] Step 5, the multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the physical satellite channel device in the multi-user terminal subsystem according to the control instruction;

[0065] Step 6, the physical satellite channel equipment in the multi-user terminal subsystem adopts multi-carrier parallel modulation technology to forward the user control plane data generated by the multi-user digital simulation subsystem to the satellite payload;

[0066] Step 7, the physical satellite channel device in the multi-user terminal subsystem receives the information data responded by the satellite payload;

[0067] Step 8, the physical satellite channel device in the multi-user terminal subsystem forwards the response information data to the multi-user digital simulation subsystem, and the multi-user digital simulation subsystem repeats steps 5, 6, 7, and 8 according to the simulated user control surface behavior and the response information data, completing one or more rounds of interaction with the satellite payload, observing the data interaction process on the multi-user digital simulation subsystem interface, and simulating the user communication state change through the test management subsystem;

[0068] Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem;

[0069] Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

[0070] Furthermore, the specific method of step 2 is:

[0071] Step 201, the multi-user digital simulation subsystem generates a random number M in a pseudo-random binary sequence, M = 0, 1, 2, 3, ..., 2 16 -1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user;

[0072] Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution;

[0073] Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior;

[0074] Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

[0075] Furthermore, the satellite channel equipment in the multi-user terminal subsystem includes a protocol processing unit and a modulator, and the specific method of step 6 is:

[0076] Step 601, the satellite channel equipment in the multi-user terminal subsystem receives the user control plane data sent by the multi-user digital simulation subsystem;

[0077] Step 602, the satellite channel device in the multi-user terminal subsystem diverts the user control plane data to 64 independent buffers through the QoS buffer queue;

[0078] Step 603, the satellite channel device protocol processing unit in the multi-user terminal subsystem generates a time slot control frame according to the resource allocation situation;

[0079] Step 604: The satellite channel device modulator in the multi-user terminal subsystem triggers 64 channels to send user control plane data in parallel according to the time slot control frame.

[0080] The user capacity test method of the satellite communication system based on semi-physical digital simulation is implemented based on a test management subsystem, a multi-user digital simulation subsystem and a protocol adaptation subsystem; the test management subsystem is used to configure the test scene and beam parameters, and generate a test report in word format; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; the protocol adaptation subsystem is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload;

[0081] Specifically, Figure 1 The user capacity test simulation platform in this embodiment is shown, and the protocol adaptation subsystem in the user capacity test simulation platform includes a satellite protocol adaptation device;

[0082] like Figure 4 As shown, the specific steps include:

[0083] Step 1, connecting the test management subsystem, the multi-user digital simulation subsystem and the protocol adaptation subsystem through a switching network, and connecting the satellite payload and the protocol adaptation subsystem through an LVDS interface, thereby building a test environment;

[0084] Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required;

[0085] Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem through the test management subsystem;

[0086] Specifically, it includes satellite number, beam, and operating parameters;

[0087] Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem;

[0088] Step 5: The multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the protocol adaptation subsystem according to the control instruction;

[0089] Step 6, the protocol adaptation subsystem forwards the user control surface data generated by the multi-user digital simulation subsystem to the satellite payload;

[0090] Step 7, the protocol adaptation subsystem receives information data responded by the satellite payload;

[0091] Step 8, the protocol adaptation subsystem forwards the response information data to the multi-user digital simulation subsystem, and the multi-user digital simulation subsystem repeats steps 5, 6, 7, and 8 according to the simulated user control surface behavior and the response information data, completing one or more rounds of interaction with the satellite payload, observing the data interaction process on the multi-user digital simulation subsystem interface, and simulating the user communication status change through the test management subsystem;

[0092] Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem;

[0093] Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

[0094] Furthermore, the specific method of step 2 is:

[0095] Step 201: The multi-user digital simulation subsystem generates a random number M in a pseudo-random sequence, where M = 0, 1, 2, 3, ..., 2 16-1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user;

[0096] Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution;

[0097] Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior;

[0098] Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

[0099] In summary, the present invention is closer to the actual satellite channel equipment and meets the saturation or oversaturation test of the user capacity of the satellite communication system.

[0100] Those skilled in the art will appreciate that the embodiments described are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to the embodiments described. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for testing user capacity of a satellite communication system based on semi-physical digital simulation, characterized in that: It is implemented based on a test management subsystem, a multi-user digital simulation subsystem and a multi-user terminal subsystem; the test management subsystem is used to configure test scenarios and beam parameters, and generate a test report in word format; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; the multi-user terminal subsystem includes a physical satellite channel device, which is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload; Specifically include the following steps: Step 1: Connect the test management subsystem, the multi-user digital simulation subsystem and the multi-user terminal subsystem through a switching network, and connect the satellite payload and the physical satellite channel equipment in the multi-user terminal subsystem through an intermediate frequency cable, so as to build a test environment; Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required; Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem and the multi-user terminal subsystem respectively through the test management subsystem; Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem; Step 5, the multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the physical satellite channel device in the multi-user terminal subsystem according to the control instruction; Step 6, the physical satellite channel equipment in the multi-user terminal subsystem adopts multi-carrier parallel modulation technology to forward the user control plane data generated by the multi-user digital simulation subsystem to the satellite payload; Step 7, the physical satellite channel device in the multi-user terminal subsystem receives the information data responded by the satellite payload; Step 8: The physical satellite channel device in the multi-user terminal subsystem forwards the response information data to the multi-user digital simulation subsystem. The multi-user digital simulation subsystem completes one or more rounds of interaction with the satellite payload based on the simulated user control surface behavior and the response information data. The data interaction process is observed on the multi-user digital simulation subsystem interface, and the user communication status change is simulated through the test management subsystem. Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem; Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

2. The method for testing user capacity of a satellite communication system based on semi-physical digital simulation according to claim 1, characterized in that: Step 2: Step 201, the multi-user digital simulation subsystem generates a random number M in a pseudo-random binary sequence, M = 0, 1, 2, 3, ..., 2 16 -1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user; Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution; Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior; Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

3. The method for testing user capacity of a satellite communication system based on semi-physical digital simulation according to claim 1, characterized in that: The satellite channel equipment in the multi-user terminal subsystem includes a protocol processing unit and a modulator, and the specific method of step 6 is: Step 601, the satellite channel equipment in the multi-user terminal subsystem receives the user control plane data sent by the multi-user digital simulation subsystem; Step 602, the satellite channel device in the multi-user terminal subsystem diverts the user control plane data to 64 independent buffers through the QoS buffer queue; Step 603, the satellite channel device protocol processing unit in the multi-user terminal subsystem generates a time slot control frame according to the resource allocation situation; Step 604: The satellite channel device modulator in the multi-user terminal subsystem triggers 64 channels to send user control plane data in parallel according to the time slot control frame.

4. A method for testing user capacity of a satellite communication system based on semi-physical digital simulation, characterized in that: It is implemented based on the test management subsystem, multi-user digital simulation subsystem and protocol adaptation subsystem; the test management subsystem is used to configure the test scenario and beam parameters, and generate a test report in word format; the multi-user digital simulation subsystem is used to generate simulated user data and behavior according to test requirements; The protocol adaptation subsystem is used to realize the interaction between the multi-user digital simulation subsystem and the satellite payload; Specifically include the following steps: Step 1, connecting the test management subsystem, the multi-user digital simulation subsystem and the protocol adaptation subsystem through a switching network, and connecting the satellite payload and the protocol adaptation subsystem through an LVDS interface, thereby building a test environment; Step 2: The multi-user digital simulation subsystem generates corresponding simulated user control plane data and behavior according to the number of test users required; Step 3: configure the test scenario and beam parameters to the multi-user digital simulation subsystem through the test management subsystem; Step 4: The test management subsystem starts the control plane test and sends a control instruction to the multi-user digital simulation subsystem; Step 5: The multi-user digital simulation subsystem sends user control plane data of network entry and exit and service access to the protocol adaptation subsystem according to the control instruction; Step 6, the protocol adaptation subsystem forwards the user control surface data generated by the multi-user digital simulation subsystem to the satellite payload; Step 7, the protocol adaptation subsystem receives information data responded by the satellite payload; Step 8: The protocol adaptation subsystem forwards the response information data to the multi-user digital simulation subsystem. The multi-user digital simulation subsystem completes one or more rounds of interaction with the satellite payload based on the simulated user control surface behavior and the response information data, observes the data interaction process on the multi-user digital simulation subsystem interface, and simulates the user communication status change through the test management subsystem. Step 9, the multi-user digital simulation subsystem reports the user control surface data and satellite payload interaction result information to the test management subsystem; Step 10, the test management subsystem stores the user control surface data and satellite payload interaction result information in the specified format, then displays them graphically and generates a test report in word format, thus completing the user capacity test of the satellite communication system based on semi-physical digital simulation.

5. The method for testing user capacity of a satellite communication system based on semi-physical digital simulation according to claim 4 is characterized in that: The specific method of step 2 is: Step 201: The multi-user digital simulation subsystem generates a random number M in a pseudo-random sequence, where M = 0, 1, 2, 3, ..., 2 16 -1, the random number M is stored in 16 bits, and the decimal number corresponding to the lower 13 bits of the random number M is recorded as the user terminal address m corresponding to the current user; Step 202, 64 values ​​are randomly selected from 256 values ​​of 0 to 255 as sample values, and a timetable for storing user sending time intervals is set, wherein the timetable includes 8192 cells, and one sample value is written into each cell, so that the number of cells filled in corresponding to the 64 sample values ​​conforms to a negative exponential distribution; Step 203, set a timer, and according to the user end address m, record the sample value corresponding to the m+1th unit as the time interval cycle number B corresponding to the current user, wherein each cycle is 10 microseconds, and set the timer to B. After B cycles, the timer triggers the generation of a data packet, and the content of the data packet is generated according to the system signaling, including simulated user control plane data and behavior; Step 204 , determining whether the number of generated simulated user control plane data and behaviors reaches the required number of test users, if so, executing step 3 , otherwise continuing to execute step 201 .

Images