Method and system for estimating uplink signal emission time of high-speed aircraft platform satellite system

Abstract

The invention discloses a high-speed aircraft platform satellite system uplink signal emission moment estimation method and system, and belongs to the field of satellite communication, and the method comprises the following steps: a satellite user terminal obtains own position coordinates in a first time range at fixed time; the position prediction of a plurality of moments in a subsequent first time range at intervals of a second time range is completed through a polynomial fitting mode; and the transmission delay of the satellite user terminal transmitting signal to the satellite communication load is estimated through an approximation method, so that the accurate calculation of the uplink signal transmitting time of the satellite user terminal is realized. The method can ensure that uplink signals of a plurality of satellite user terminals reach the satellite communication load on time, realizes accurate control of the arrival time of the uplink signals of the satellite system, and is suitable for a satellite communication system based on TDMA channel multiplexing.

Description

Technical Field

[0001] The present invention relates to the field of satellite communications, and more specifically, to a method and system for estimating the transmission time of an uplink signal of a high-speed aircraft platform satellite system. Background Art

[0002] With the construction of my country's national satellite Internet system, high-orbit and low-orbit satellites and ground systems are used as network nodes, and integrated networking and interconnection are realized through inter-satellite and satellite-to-ground links to serve users in various fields of military and civilian sectors, forming a global network system including space segment, ground segment and application segment. The satellite system has the advantages of full coverage without blind spots, good real-time performance and strong anti-interference ability. Using satellite systems to complete measurement, security control, remote control, telemetry and other functions during the launch of launch vehicles and missiles is the inevitable direction of the development of range measurement and control.

[0003] At present, the uplink of my country's national satellite Internet satellite system generally adopts a TDMA-based channel multiplexing method, which requires the arrival time of multi-user terminal transmission signals to be accurate to the microsecond level. For high-speed aircraft, high maneuverability leads to drastic fluctuations in signal space transmission delay. In order to achieve time synchronization and meet the time synchronization requirements for uplink signal access, it is necessary to accurately estimate the transmission time of the satellite user terminal uplink signal to ensure that the time when the uplink signal arrives at the satellite meets the satellite system design requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method and system for estimating the transmission time of uplink signals of a high-speed aircraft platform satellite system, which solves the problem that the uplink signal transmission delay of the satellite system fluctuates violently in the use scenario of a high-dynamic platform, resulting in difficulty in time synchronization of the uplink signal of the satellite user terminal, and ensures that the time when the uplink signal arrives at the satellite meets the design requirements of the satellite system.

[0005] The object of the present invention is achieved through the following solutions:

[0006] A method for estimating the transmission time of an uplink signal of a high-speed aircraft platform satellite system comprises the following steps:

[0007] The satellite user terminal obtains its own position coordinates within the first time range, and completes the position prediction of multiple moments within the first time range and the second time range through polynomial fitting. Then, the transmission delay of the satellite user terminal's transmission signal to the satellite communication payload is estimated through the approximation method, so as to realize the accurate calculation of the satellite user terminal uplink signal transmission time.

[0008] Furthermore, the satellite user terminal acquires its own position coordinates within a first time range on a regular basis, and completes position predictions of multiple times within the first time range and within a second time range through a polynomial fitting method; and then estimates the transmission delay of the satellite user terminal transmitting signal to the satellite communication payload through an approximation method, so as to achieve accurate calculation of the satellite user terminal uplink signal transmission time, which specifically includes the following sub-steps:

[0009] Step 1), the satellite user terminal obtains its own position coordinates regularly according to the first time range, and completes the subsequent position prediction within the first time range by polynomial fitting;

[0010] Step 2), the satellite communication payload requires the signal to arrive at The satellite user terminal obtains its own position coordinates at the current time t0, and the satellite user terminal calculates the current position and satellite communication payload The spatial transmission delay of the signal at the moment is τ0;

[0011] Step 3), if Then enter the signal transmission preparation process, otherwise enter the 2) state;

[0012] Step 4), during the signal transmission preparation process, the satellite user terminal predicts the position of the satellite user terminal at each second time range after time t0 by polynomial fitting, and the prediction time length is the first time range, and calculates the position of each predicted time t m Satellite User Terminal and Satellite Communication Payload The spatial transmission delay of the signal at the moment τ m , select Minimum space transmission delay Satellite user terminals Turn on signal transmission.

[0013] Furthermore, the first time range is 1 ms.

[0014] Furthermore, the second time range is 0.1 ms.

[0015] Furthermore, the method of completing the position prediction of multiple moments within the subsequent first time range and separated by the second time range by polynomial fitting specifically includes the following sub-steps:

[0016] Considering the limited power of the aircraft, the speed and acceleration change slowly in a short time of seconds, which can be expressed by a polynomial approximation as follows:

[0017] s(t-t0)=s(t)-s(t0)=g1*(t-t0)+g2*(t-t0) 2 +g3*(t-t0) 3 ;

[0018] Wherein, s(t-t0) represents the moving distance of the user terminal in the time period t-t0, s(t) represents the position of the user terminal at time t, s(t0) represents the position of the user terminal at the starting time t0, g1, g2 and g3 represent the coefficients of the first-order term, the second-order term and the third-order term of the polynomial respectively;

[0019] Combine the most recent N observations s(t-t0), t s For the observation sampling time, construct a linear equation system about g1, g2, and g3:

[0020]

[0021] Where n is the observation error; the solution of the equation system is obtained according to the least squares criterion:

[0022]

[0023]

[0024] Get the corrected formula for position estimation

[0025]

[0026] in, and Respectively represent the estimated values ​​of the coefficients of the linear, quadratic and cubic terms of the polynomial;

[0027] The above algorithm is used to complete the satellite user terminal position prediction.

[0028] A satellite communication system includes a satellite user terminal, which is installed on a high-speed aircraft platform. The satellite user terminal and the satellite communication payload use a unified time system and have completed synchronization. The satellite user terminal regularly obtains its own position coordinates and has the ability to calculate satellite orbits, and is used to execute the high-speed aircraft platform satellite system uplink signal transmission time estimation method as described in any of the above items.

[0029] The beneficial effects of the present invention include:

[0030] The present invention solves the problem of satellite system uplink signal transmission delay fluctuations under high-dynamic platform usage scenarios, which leads to difficulty in uplink signal time synchronization of satellite user terminals, and ensures that the time when the uplink signal reaches the satellite meets the satellite system design requirements. The time when the uplink transmission signal reaches the satellite communication payload can be accurately controlled with an accuracy of up to 0.1us. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 The figure is a flowchart of the steps of the method according to the embodiment of the present invention. DETAILED DESCRIPTION

[0033] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0034] The present invention particularly relates to a method for estimating the transmission time of uplink signals of a high-speed aircraft platform satellite system. In the specific inventive concept, the satellite user terminal signal transmission time is calculated by an approximation method to solve the problem of large satellite communication link transmission delay and drastic fluctuation of signal space transmission delay caused by high-speed aircraft high maneuverability, realize the time synchronization of multi-user terminal transmission signals arriving at satellite communication payloads, and meet the signal arrival time accuracy requirements of satellite communication systems based on TDMA channel multiplexing.

[0035] More specifically, if Figure 1 As shown, the present invention proposes a method for estimating the transmission time of uplink signals of a satellite system applicable to a high-speed aircraft platform, which aims to provide a method for estimating the transmission time of uplink signals of satellite user terminals by an approximation method, ensuring that uplink signals of multiple satellite user terminals arrive at the satellite communication payload on time, and realizing accurate control of the arrival time of uplink signals of the satellite system, and is applicable to a satellite communication system based on TDMA channel multiplexing. The uplink signal of the satellite system applicable to the present invention is generated and transmitted by a satellite user terminal, and the satellite user terminal is installed on a high-speed aircraft platform. The satellite user terminal and the satellite communication payload use a unified time system and have completed synchronization. The satellite user terminal can obtain its own position coordinates regularly and has the ability to calculate satellite orbits.

[0036] According to the present invention, the satellite user terminal can obtain its own position coordinates from the external timing in the system design, and has the position prediction capability formed by polynomial fitting. Based on the above premise, the following process is executed:

[0037] 1) The satellite user terminal obtains its own position coordinates at 1ms intervals and completes the subsequent position prediction within 1ms through polynomial fitting;

[0038] 2) Satellite communication payload requires the signal arrival time to be The satellite user terminal obtains its own position coordinates at the current time t0, and the satellite user terminal calculates the current position and satellite communication payload The spatial transmission delay of the signal at the moment is τ0;

[0039] 3) If Then enter the signal transmission preparation process, otherwise enter the 2) state;

[0040] 4) During the signal transmission preparation process, the satellite user terminal predicts the position of the satellite user terminal every 0.1ms after time t0 by polynomial fitting. The prediction time length is 1ms. The predicted time t m Satellite User Terminal and Satellite Communication Payload The spatial transmission delay of the signal at the moment τ m , select Minimum space transmission delay Satellite user terminals Turn on signal transmission.

[0041] In other implementations of the present invention, based on the above embodiment, the position prediction of multiple moments within the subsequent first time range and the interval between the second time range is completed by polynomial fitting, which specifically includes the following sub-steps:

[0042] Considering the limited power of the aircraft, the speed and acceleration change slowly in a short time of seconds, which can be expressed by a polynomial approximation as follows:

[0043] s(t-t0)=s(t)-s(t0)=g1*(t-t0)+g2*(t-t0) 2 +g3*(t-t0) 3 ;

[0044] Wherein, s(t-t0) represents the moving distance of the user terminal in the time period t-t0, s(t) represents the position of the user terminal at time t, s(t0) represents the position of the user terminal at the starting time t0, g1, g2 and g3 represent the coefficients of the first-order term, the second-order term and the third-order term of the polynomial respectively;

[0045] Combine the most recent N observations s(t-t0), t s For the observation sampling time, construct a linear equation system about g1, g2, and g3:

[0046]

[0047] Where n is the observation error; the solution of the equation system is obtained according to the least squares criterion:

[0048]

[0049] Get the corrected formula for position estimation

[0050]

[0051] in, and Respectively represent the estimated values ​​of the coefficients of the linear, quadratic and cubic terms of the polynomial;

[0052] The above algorithm is used to complete the satellite user terminal position prediction.

[0053] In other embodiments of the present invention, a satellite communication system is provided, which includes a satellite user terminal and is installed on a high-speed aircraft platform. The satellite user terminal and the satellite communication payload use a unified time system and have completed synchronization. The satellite user terminal regularly obtains its own position coordinates and has the ability to calculate satellite orbits, and is used to execute the high-speed aircraft platform satellite system uplink signal transmission time estimation method described in the above embodiments.

[0054] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0055] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0056] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A method for estimating the transmission time of uplink signal of a high-speed aircraft platform satellite system, characterized in that: The following steps are involved: The satellite user terminal obtains its own position coordinates within a first time range on a regular basis, and completes position predictions for multiple moments within the first time range and within a second time range in a subsequent manner through polynomial fitting; Then, the transmission delay of the satellite user terminal transmission signal to the satellite communication payload is estimated through the approximation method, so as to achieve the accurate calculation of the satellite user terminal uplink signal transmission time.

2. The method for estimating the transmission time of uplink signal of a high-speed aircraft platform satellite system according to claim 1, characterized in that: The satellite user terminal acquires its own position coordinates within a first time range on a regular basis, and completes position predictions for multiple times within the first time range and within a second time range by means of polynomial fitting; and then estimates the transmission delay of the satellite user terminal transmitting signal to the satellite communication payload by means of an approximation method, so as to achieve accurate calculation of the satellite user terminal uplink signal transmission time, specifically including the following sub-steps: Step 1), the satellite user terminal obtains its own position coordinates regularly according to the first time range, and completes the subsequent position prediction within the first time range by polynomial fitting; Step 2), the satellite communication payload requires the signal to arrive at The satellite user terminal obtains its own position coordinates at the current time t0, and the satellite user terminal calculates the current position and satellite communication payload The spatial transmission delay of the signal at the moment is τ0; Step 3), if Then enter the signal transmission preparation process, otherwise enter the 2) state; Step 4), during the signal transmission preparation process, the satellite user terminal predicts the position of the satellite user terminal at each second time range after time t0 by polynomial fitting, and the prediction time length is the first time range, and calculates the position of each predicted time t m Satellite User Terminal and Satellite Communication Payload The spatial transmission delay of the signal at the moment τ m , select Minimum space transmission delay Satellite user terminals Turn on signal transmission.

3. The method for estimating the transmission time of uplink signal of a high-speed aircraft platform satellite system according to any one of claims 1 or 2, characterized in that: The first time range is 1 ms.

4. The method for estimating the transmission time of uplink signal of a high-speed aircraft platform satellite system according to any one of claims 1 or 2, characterized in that: The second time range is 0.1 ms.

5. The method for estimating the transmission time of uplink signal of a high-speed aircraft platform satellite system according to claim 2, characterized in that: The method of completing the position prediction of multiple moments within the first time range and the interval between the second time range by polynomial fitting specifically includes the following sub-steps: Considering the limited power of the aircraft, the speed and acceleration change slowly in a short time of seconds, which can be expressed by a polynomial approximation as follows: s(t-t0)=s(t)-s(t0)=g1*(t-t0)+g2*(t-t0) 2 +g3*(t-t0) 3 ; Wherein, s(t-t0) represents the moving distance of the user terminal in the time period t-t0, s(t) represents the position of the user terminal at time t, s(t0) represents the position of the user terminal at the starting time t0, g1, g2 and g3 represent the coefficients of the first-order term, the second-order term and the third-order term of the polynomial respectively; Combine the most recent N observations s(t-t0), t s For the observation sampling time, construct a linear equation system about g1, g2, and g3: Where n is the observation error; the solution of the equation system is obtained according to the least squares criterion: The corrected formula for position estimation is obtained: in, and Respectively represent the estimated values ​​of the coefficients of the linear, quadratic and cubic terms of the polynomial; The above algorithm is used to complete the satellite user terminal position prediction.

6. A satellite communication system, characterized in that: It includes a satellite user terminal and is installed on a high-speed aircraft platform. The satellite user terminal and the satellite communication payload use a unified time system and have completed synchronization. The satellite user terminal obtains its own position coordinates regularly and has the ability to calculate satellite orbits, and is used to execute the high-speed aircraft platform satellite system uplink signal transmission time estimation method described in any one of claims 1 or 2.

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