Satellite random access method based on multi-ground station selection

Abstract

The invention relates to a satellite random access method based on multi-ground station selection. The satellite random access method comprises the following steps: step S1, designing telemetering quantity; s2, determining the number of ground stations which pass random access; s3, selecting an access ground station; step S4, carrying out access application on the ground station selected in the step S3; step S5, judging whether the satellite ID in the uplink control packet is the satellite ID, and if yes, determining access; if not, executing the step S6; and S6, judging whether to re-execute the step S3 or not based on the access frame sending time and the access frame sending times. According to the invention, the satellite can be automatically and flexibly accessed to the random ground stations without being limited by the number of the random ground stations, and the availability is high.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite random access, and in particular to a satellite random access method based on multi-ground station selection. Background Art

[0002] With the development of my country's aerospace industry, the number of satellites in orbit is increasing day by day, and the contradiction between limited ground measurement and control resources and the increasing measurement and control needs is prominent. In order to solve the problem of insufficient ground measurement and control resources, experts have proposed a random access measurement and control technology. The process of random access measurement and control in the existing technology is usually:

[0003] 1) The satellite enters the measurement and control range of the ground-based measurement and control network, and the satellite access system receives the forward access broadcast signal sent by the ground station.

[0004] 2) After the satellite access system completes locking, demodulation and verification, it sends a return access request signal.

[0005] 3) After receiving the satellite return signal, the ground station verifies and judges the signal content. If it fails, the signal is discarded. If it passes, the access request is approved.

[0006] 4) After receiving the request, the TT&C station sends a query request to the ground-based TT&C network control center to verify the satellite identity and confirm its TT&C demand level. After verification and confirmation, if the station has TT&C resources, it will directly agree to the access request and continue the random access process; if the station channel is full, it will choose to interrupt the current non-priority service or reject the request depending on the demand level.

[0007] 5) After the current circle measurement and control service is completed, the satellite access system initiates the disconnection procedure and completes the random access process.

[0008] The above random access measurement and control process only designs the process of satellite access to a single ground station, and does not design the access process when the satellite receives random access broadcasts sent by multiple ground stations at the same time. How a satellite that can access multiple ground stations at the same time chooses a ground station to access is the main problem that the current satellite random access system needs to solve.

[0009] Therefore, designing a satellite random access method based on multi-ground station selection is an urgent problem to be solved. Summary of the invention

[0010] In order to solve the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a satellite random access method based on multi-ground station selection, which can effectively solve the problem of how to select a ground station to access when a satellite can access multiple ground stations at the same time.

[0011] To achieve the above-mentioned object of the invention, the present invention provides a satellite random access method based on multi-ground station selection, comprising the following steps:

[0012] Step S1, design telemetry;

[0013] Step S2, determining the number of ground stations that are accessed by random access;

[0014] Step S3, selecting an access ground station;

[0015] Step S4, applying for access to the ground station selected in step S3;

[0016] Step S5, judging whether the satellite ID in the uplink control packet is the local satellite ID, if so, determining access; if not, executing step S6;

[0017] Step S6: Based on the access frame sending time and the access frame sending times, determine whether to re-execute step S3.

[0018] According to a technical solution of the present invention, before designing the telemetry, the number N of random ground stations is determined;

[0019] Design telemetry "Suiyu ground station 1 broadcast frame synchronization lock state", "Suiyu ground station 2 broadcast frame synchronization lock state", ..., "Suiyu ground station N broadcast frame synchronization lock state" inside the Suiyu transponder, and divide the Suiyu access ground station broadcast frame synchronization lock state into two states: locked and unlocked;

[0020] Telemetry measurements of "Suiyu ground station 1 broadcast verification status", "Suiyu access ground station 2 broadcast verification status", ..., "Suiyu ground station N broadcast verification status" are designed inside the Suiyu transponder and the Suiyu access ground station broadcast verification status is divided into two states: verification success and verification failure.

[0021] According to a technical solution of the present invention, step S2 includes:

[0022] Step S21, setting the access pass criterion: checking whether the broadcast frame synchronization lock of each ground station is locked, and whether the verification status is successful;

[0023] Step S22: Calculate the number M of ground stations that have been accessed, in the range of [0, N].

[0024] According to a technical solution of the present invention, the step S21 specifically includes:

[0025] A satellite random access pass criterion is designed inside the random transponder; the criterion is expressed as: random ground station 1 access pass or random ground station 2 access pass or ... or random ground station N access pass;

[0026] The access pass criteria of the random ground station are that "random ground station broadcast frame synchronization lock" is locked and "random ground station broadcast verification status" is verification success.

[0027] According to a technical solution of the present invention, the step S22 specifically includes:

[0028] The variable M of the ground stations through which the satellite accesses is designed inside the transponder, and the value range of M is [0, N];

[0029] Random ground station number P1, ..., PN;

[0030] The serial number Pi of the random ground station that the satellite is going to access, i ranges from [1, N];

[0031] The number of times the return access frame is sent is COUNT;

[0032] Return access frame sending time T;

[0033] In the same access process, the inaccessible ground station number Pq, q range is [0, N].

[0034] According to a technical solution of the present invention, step S3 specifically includes:

[0035] Step S31: read the inaccessible ground station number Pq. If q is equal to 0, directly execute step S32. If q is greater than 0, update the value of M to M-1, and then execute step S32. The ground station numbers that the satellite randomly accesses are P1, ..., P N P is not included q ;

[0036] Step S32: The number M of ground stations accessed by the call is determined inside the call transponder. If M is greater than or equal to 0, step S4 is executed. If M is equal to 0, step S32 is repeated.

[0037] According to a technical solution of the present invention, the step S4 specifically includes:

[0038] Step S41, the number M of ground stations accessed by the call is determined in the call transponder, if M is equal to 1, step S43 is executed, if M is greater than 1, step S42 is executed;

[0039] Step S42: The SNR of the broadcast signals of the M ground stations is determined in the transponder, and the ground station P with the largest SNR is selected. i Access is performed and step S43 is executed;

[0040] Step S43: Generate a fill ground station P at random transponder iThe return access frame is sent to the ground station P after authentication. i , COUNT counts up by 1, T=0.

[0041] According to a technical solution of the present invention, in step S5, after completing the ground station access, the random transponder sets the return access frame sending time T to increase by 1s, and judges the uplink control packet in the random access broadcast sent by the ground station. If the satellite ID in the uplink control packet is the local satellite ID, the satellite completes the access, and the satellite carries out related work according to the preset logic or uplink instruction of the corresponding ground station; if the satellite ID in the uplink control packet is not the local satellite ID, step S6 is executed.

[0042] According to a technical solution of the present invention, step S6 specifically includes:

[0043] Step S61, the transponder determines whether the return access frame transmission time T is greater than or equal to 5s, if not, execute step S5; if yes, execute step S62;

[0044] Step S62: The answering machine determines whether COUNT is greater than or equal to 4. If not, execute step S5; if so, q=i, and execute step S3.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention proposes a satellite random access method based on multi-ground station selection, which can be applied to a satellite measurement and control system with random access function. The satellite application scenario is not limited by the number of random ground stations, and can realize the automatic and flexible access of the satellite to a random ground station, with strong availability.

[0047] Moreover, the satellite application scenario of the present invention will only access one random ground station at the same time, and will not interfere with the reception of other ground stations by sending return access frames of other random ground stations;

[0048] The present invention can enhance the anti-interference capability of the satellite transponder and can switch an inaccessible ground station to another ground station. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1A flowchart schematically showing a satellite random access method based on multi-ground station selection according to an embodiment of the present invention;

[0051] Figure 2 The flowchart schematically shows a satellite random access method based on multi-ground station selection according to another embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] like Figure 1 As shown, a satellite random access method based on multi-ground station selection of the present invention comprises the following steps:

[0054] Step S1, design telemetry;

[0055] Before designing telemetry, determine the number of random ground stations N;

[0056] Design telemetry "Suiyu ground station 1 broadcast frame synchronization lock state", "Suiyu ground station 2 broadcast frame synchronization lock state", ..., "Suiyu ground station N broadcast frame synchronization lock state" inside the Suiyu transponder, and divide the Suiyu access ground station broadcast frame synchronization lock state into two states: locked and unlocked;

[0057] Telemetry measurements of "Suiyu ground station 1 broadcast verification status", "Suiyu access ground station 2 broadcast verification status", ..., "Suiyu ground station N broadcast verification status" are designed inside the Suiyu transponder and the Suiyu access ground station broadcast verification status is divided into two states: verification success and verification failure.

[0058] Step S2, determining the number of ground stations that are accessed randomly, including:

[0059] Step S21, setting the access pass criterion: checking whether the broadcast frame synchronization lock of each ground station is locked, and whether the verification status is successful, specifically including:

[0060] A satellite random access pass criterion is designed inside the random transponder; the criterion is expressed as: random ground station 1 access pass or random ground station 2 access pass or ... or random ground station N access pass;

[0061] The access pass criteria of the random ground station are that "random ground station broadcast frame synchronization lock" is locked and "random ground station broadcast verification status" is verification success.

[0062] Step S22: Calculate the number of ground stations M that have been accessed, in the range of [0, N], specifically including:

[0063] The variable M of the ground stations through which the satellite accesses is designed inside the transponder, and the value range of M is [0, N];

[0064] Random ground station number P1, ..., PN;

[0065] The serial number Pi of the random ground station that the satellite is going to access, i ranges from [1, N];

[0066] The number of times the return access frame is sent is COUNT;

[0067] Return access frame sending time T;

[0068] In the same access process, the inaccessible ground station number Pq, q range is [0, N].

[0069] Step S3: Selecting an access ground station, specifically including:

[0070] Step S31: read the inaccessible ground station number Pq. If q is equal to 0, directly execute step S32. If q is greater than 0, update the value of M to M-1, and then execute step S32. The ground station numbers that the satellite randomly accesses are P1, ..., P N P is not included q ;

[0071] Step S32: The number M of ground stations accessed by the call is determined inside the call transponder. If M is greater than or equal to 0, step S4 is executed. If M is equal to 0, step S32 is repeated.

[0072] Step S4, applying for access to the ground station selected in step S3, specifically comprising:

[0073] Step S41, the number M of ground stations accessed by the call is determined in the call transponder, if M is equal to 1, step S43 is executed, if M is greater than 1, step S42 is executed;

[0074] Step S42: The SNR (signal-to-noise ratio) of the broadcast signals of the M ground stations is judged inside the transponder, and the ground station P with the largest SNR is selected. i Access is performed and step S43 is executed;

[0075] Step S43: Generate a fill ground station P at random transponder iThe return access frame is sent to the ground station P after authentication. i , COUNT counts up by 1, T=0.

[0076] Step S5, judging whether the satellite ID in the uplink control packet is the local satellite ID, if so, determining access; if not, executing step S6;

[0077] After completing the ground station access, the random transponder sets the return access frame sending time T to increase by 1s, and judges the uplink control packet in the random access broadcast sent by the ground station. If the satellite ID in the uplink control packet is the local satellite ID, the satellite completes the access, and the satellite carries out related work according to the preset logic or uplink instruction of the corresponding ground station; if the satellite ID in the uplink control packet is not the local satellite ID, execute step S6.

[0078] Step S6, based on the access frame sending time and the access frame sending times, determining whether to re-execute step S3, specifically includes:

[0079] Step S61, the transponder determines whether the return access frame transmission time T is greater than or equal to 5s, if not, execute step S5; if yes, execute step S62;

[0080] Step S62: The answering machine determines whether COUNT is greater than or equal to 4. If not, execute step S5; if so, q=i, and execute step S3.

[0081] Example

[0082] like Figure 2 As shown, a satellite random access method based on multi-ground station selection of the present invention, taking a random transponder as an example, the steps are as follows:

[0083] (1) The number of random ground stations is N.

[0084] (2) Design telemetry "Suiyu ground station 1 broadcast frame synchronization lock status", "Suiyu ground station 2 broadcast frame synchronization lock status", ..., "Suiyu ground station N broadcast frame synchronization lock status" inside the Suiyu transponder; the Suiyu access ground station broadcast frame synchronization lock status is divided into two states: locked and unlocked.

[0085] (3) Design telemetry "Suiyu ground station 1 broadcast verification status", "Suiyu access ground station 2 broadcast verification status", ..., "Suiyu ground station N broadcast verification status" inside the Suiyu transponder; the Suiyu access ground station broadcast verification status is divided into two states: verification success and verification failure.

[0086] (4) A satellite access pass criterion is designed inside the satellite transponder; the criterion is that the satellite ground station 1 access is passed or the satellite ground station 2 access is passed or ... or the satellite ground station N access is passed; the satellite ground station access pass criterion is that "the satellite ground station broadcast frame synchronization lock" is locked and "the satellite ground station broadcast verification status" is verification success.

[0087] (5) Design a variable in the transponder to indicate the number of ground stations M through which the satellite can access randomly, where the value of M ranges from [0, N]; and the serial numbers of the random ground stations P1, ..., P N ; The number of the random ground station that the satellite is ready to access P i , the value range of i is [1, N]; the number of times the return access frame is sent COUNT; the time T for sending the return access frame; the sequence number P of the ground station that cannot be accessed during this access process q , the value range of q is [0, N]; when the answering machine is powered on, M=0, COUNT=0, T=0, q=0 by default;

[0088] (6) The q in step (5) is read inside the transponder. If q is greater than or equal to 0, then M = M-1, and the ground stations through which the satellite accesses are numbered P1, ..., P N (No P q ), and execute step (7); if q is equal to 0, execute step (7);

[0089] (7) The M in step (4) is read inside the transponder. If M is greater than or equal to 0, step (8) is executed. If M is equal to 0, step (7) is repeated.

[0090] (8) The M in step (4) is read inside the answering machine. If M is greater than 1, step (9) is executed. If M is equal to 1, step (10) is executed.

[0091] (9) The SNR of the broadcast signals of the M ground stations is judged inside the transponder, and the ground station P with the largest SNR is selected. i Access and execute step (10);

[0092] (10) Generate a random transponder to fill in the ground station P i The return access frame is sent to the ground station P after authentication. i , COUNT counts up by 1, T=0;

[0093] (11) The random transponder sets the return access frame transmission time T count plus 1 (i.e., the return access frame transmission time T is increased by 1 second), and judges the uplink control packet in the random access broadcast sent by the ground station. If the satellite ID in the uplink control packet is the local satellite ID, the satellite completes the access and can carry out related work according to the preset logic or uplink instruction; if the satellite ID in the uplink control packet is not the local satellite ID, execute step (12);

[0094] (12) The random transponder determines whether the return access frame transmission time T count is greater than or equal to 5 (determines whether the return access frame transmission time T is greater than or equal to 5s). If not, execute step (11); if yes, execute step (13);

[0095] (13) The answering machine determines whether COUNT is greater than or equal to 4. If not, it executes step (11); if so, q=i, and executes step (6).

[0096] In summary, the satellite random access method based on multi-ground station selection of the present invention includes the following internal design parameters of the random transponder: random ground station broadcast frame synchronization lock state, random ground station broadcast verification state, satellite random access pass criterion, random ground station number N, satellite random access pass ground station number M; random ground station sequence number P1, ..., PN; random ground station sequence number Pi that the satellite is ready to access; return access frame transmission count COUNT; return access frame transmission time T; ground station sequence number Pq that cannot be accessed during this access process;

[0097] First, the satellite random access pass criteria are read. If not, the reading continues; if passed, random access is performed. The random transponder reads the number of ground stations that have passed the satellite random access. If it is 1, the ground station is accessed; if it is greater than 1, the ground station with the largest broadcast signal SNR is selected for access. The random transponder reads the number of return access request frames sent before the access is completed. If it does not exceed 4 times, the return access request frame is sent repeatedly; if it exceeds 4 times, the ground station is eliminated and other ground stations are reselected for access.

[0098] The random access method of the random transponder of the present invention is applicable to satellites in the integrated space-ground measurement and control network, and is applicable to the satellite automatically and flexibly selecting multiple or single random ground stations for access; it has anti-interference capability and can switch the inaccessible ground stations to other ground stations.

[0099] In the present invention, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device including the element.

[0100] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for those skilled in the art, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A satellite random access method based on multi-ground station selection, characterized in that: The following steps are involved: Step S1, design telemetry; Step S2, determining the number of ground stations that are accessed by random access; Step S3, selecting an access ground station; Step S4, applying for access to the ground station selected in step S3; Step S5, judging whether the satellite ID in the uplink control packet is the local satellite ID, if so, determining access; if not, executing step S6; Step S6: Based on the access frame sending time and the access frame sending times, determine whether to re-execute step S3.

2. The satellite random access method based on multi-ground station selection according to claim 1, characterized in that: Before designing telemetry, determine the number of random ground stations N; Design telemetry "Suiyu ground station 1 broadcast frame synchronization lock state", "Suiyu ground station 2 broadcast frame synchronization lock state", ..., "Suiyu ground station N broadcast frame synchronization lock state" inside the Suiyu transponder, and divide the Suiyu access ground station broadcast frame synchronization lock state into two states: locked and unlocked; Telemetry "Suiyu ground station 1 broadcast verification status", "Suiyu access ground station 2 broadcast verification status", ..., "Suiyu ground station N broadcast verification status" are designed inside the Suiyu transponder and the Suiyu access ground station broadcast verification status is divided into two states: verification success and verification failure.

3. The satellite random access method based on multi-ground station selection according to claim 2, characterized in that: The step S2 includes: Step S21, setting the access pass criterion: checking whether the broadcast frame synchronization lock of each ground station is locked, and whether the verification status is successful; Step S22: Calculate the number M of ground stations that have been accessed, in the range of [0, N].

4. The satellite random access method based on multi-ground station selection according to claim 3, characterized in that: The step S21 specifically includes: A satellite random access pass criterion is designed inside the random transponder; the criterion is expressed as: random ground station 1 access pass or random ground station 2 access pass or ... or random ground station N access pass; The access pass criteria of the random ground station are that "random ground station broadcast frame synchronization lock" is locked and "random ground station broadcast verification status" is verified successfully.

5. The satellite random access method based on multi-ground station selection according to claim 3, characterized in that: The step S22 specifically includes: The variable M of the ground stations through which the satellite accesses is designed inside the transponder, and the value range of M is [0, N]; Random ground station number P1, ..., PN; The serial number Pi of the random ground station that the satellite is going to access, i ranges from [1, N]; The number of times the return access frame is sent is COUNT; Return access frame sending time T; In the same access process, the inaccessible ground station number Pq, q range is [0, N].

6. The satellite random access method based on multi-ground station selection according to claim 5, characterized in that: The step S3 specifically includes: Step S31: read the inaccessible ground station number Pq. If q is equal to 0, directly execute step S32. If q is greater than 0, update the value of M to M-1, and then execute step S32. The ground station numbers that the satellite randomly accesses are P1, ..., P N P is not included q ; Step S32: The number M of ground stations accessed by the call is determined inside the call transponder. If M is greater than or equal to 0, step S4 is executed. If M is equal to 0, step S32 is repeated.

7. The satellite random access method based on multi-ground station selection according to claim 6, characterized in that: The step S4 specifically includes: Step S41, the number M of ground stations accessed by the call is determined in the call transponder, if M is equal to 1, step S43 is executed, if M is greater than 1, step S42 is executed; Step S42: The SNR of the broadcast signals of the M ground stations is determined in the transponder, and the ground station P with the largest SNR is selected. i Access is performed and step S43 is executed; Step S43: Generate a fill ground station P at random transponder i The return access frame is sent to the ground station P after authentication. i , COUNT counts up by 1, T=0.

8. The satellite random access method based on multi-ground station selection according to claim 6, characterized in that: In step S5, after completing the ground station access, the random transponder sets the return access frame sending time T to increase by 1s, and judges the uplink control packet in the random access broadcast sent by the ground station. If the satellite ID in the uplink control packet is the local satellite ID, the satellite completes the access, and the satellite performs related work according to the preset logic or uplink instruction of the corresponding ground station; If the satellite ID in the uplink control packet is not the local satellite ID, execute step S6.

9. The satellite random access method based on multi-ground station selection according to claim 8, characterized in that: The step S6 specifically includes: Step S61, the transponder determines whether the return access frame transmission time T is greater than or equal to 5s, if not, execute step S5; if yes, execute step S62; Step S62: The answering machine determines whether COUNT is greater than or equal to 4. If not, execute step S5; if so, q=i, and execute step S3.

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