Directional data link two-stage beam alignment method

Abstract

The invention belongs to the technical field of directional data link communication, and discloses a directional data link two-stage beam alignment method, which utilizes first-stage information-free coarse alignment and second-stage information fine alignment, does not need to carry out omnidirectional transmission and omnidirectional receiving at both transmitting and receiving ends, and only needs to carry out omnidirectional transmission on a single user side twice. The subsequent beam alignment is directional narrow beam sending and directional narrow beam receiving; two-stage beam alignment: the first stage does not send valid data for fast beam coarse alignment, and the second stage sends valid data for beam fine alignment. Human interference can be effectively resisted, gain matching of directional antennas at the two ends of a user is guaranteed, and the network link performance is improved; and the beam alignment speed and the data reliability are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of directional data link communication and relates to a two-stage beam alignment method of a directional data link. Background Art

[0002] The use of high-gain directional links to achieve multi-user networking has attracted strong attention. It has many advantages: (1) Using directional antennas at both the receiving and transmitting ends can provide longer transmission distances and higher data rates; (2) By limiting the emission and detection of energy to a specified direction, signal interference in useless directions can be greatly reduced, improving anti-interference capabilities; (3) Since the links between multiple nodes can be scheduled for simultaneous directional transmission, the transmission efficiency can be doubled through space division multiplexing. Therefore, mobile self-organizing networks using directional transmission can achieve significant performance improvements in network service quality, throughput, anti-interference and detection.

[0003] At present, the difficulty of directional data link application lies in how to quickly achieve beam alignment between different users to ensure the reliability of user communication. The common method is to use omnidirectional transmission and omnidirectional reception in the initial stage. The transmitter sends the message carrying its own location information to the receiver through omnidirectional radiation. The receiver also uses omnidirectional reception. After receiving the message from the transmitter, it parses the location information, obtains the location of the transmitter, and uses its own location information to adjust the antenna beam direction to achieve beam alignment. However, omnidirectional transmission and omnidirectional reception are very vulnerable to human interference, and the gain of omnidirectional antennas and directional antennas do not match, which greatly affects the improvement of network performance. Summary of the invention

[0004] (I) Purpose of the invention

[0005] The purpose of the present invention is to propose a two-stage beam alignment method for a directional data link in view of the defects of poor anti-interference ability and low antenna gain in a traditional directional link beam alignment method.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides a directional data link two-stage beam alignment method, comprising the following steps:

[0008] Step 1: After the network user receives the network establishment message, user A sends a continuous T signal in omnidirectional radiation mode. trans The length of the network access sequence;

[0009] Step 2: User B performs the first-level beam alignment, and the antenna scans in a narrow beam according to N b The user A's message is received by each wave position, and the position of user A is obtained by matching it with the network access sequence; Nb The number of narrow beam scanning wave bits at the receiving end;

[0010] Step 3: User A sends a reference message in an omnidirectional antenna radiation mode;

[0011] Step 4: User B calculates the starting position of the reference message sent by user A based on the first-level beam alignment result, receives the reference message sent by user A from this starting position, and parses the reference message;

[0012] Step 5: User B performs the second-level beam alignment, and calculates the accurate beam pointing based on the reference message parsed in step 4 and its own inertial navigation information;

[0013] Step 6: User B selects the antenna beam aimed at user A based on the accurate beam direction calculated in step 5 and sends a continuous T signal in a directional manner. trans The length of the network access sequence;

[0014] Step 7: User A performs the first-level beam alignment to obtain the position of user B;

[0015] Step 8: User B sends a reference message in a directional radiation mode of the antenna;

[0016] Step 9: User A calculates the starting position of the reference message sent by user B based on the first-level beam alignment result, starts receiving the reference message sent by user B from the starting position, and parses the reference message;

[0017] Step 10: User A performs the second-level beam alignment, calculates the accurate beam pointing based on the position information of user B analyzed in step 9 and its own inertial navigation information.

[0018] (III) Beneficial effects

[0019] The directional data link two-stage beam alignment method provided by the above technical solution has the following beneficial effects compared with the traditional directional data link beam alignment method:

[0020] (1) There is no need to perform omnidirectional transmission and omnidirectional reception at both the transmitting and receiving ends. Only two omnidirectional transmissions are required on the single user side. Subsequent beam alignments are directional narrow beam transmission and directional narrow beam reception. This can effectively resist artificial interference and ensure that the gains of the directional antennas at both ends of the user are matched, thereby improving network link performance.

[0021] (2) Through two-stage beam alignment, the first stage does not send valid data for fast coarse beam alignment, and the second stage sends valid data for fine beam alignment, thus ensuring beam alignment speed and data reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a network access sequence structure diagram of the present invention's "a two-stage beam alignment method for a directional data link";

[0023] Figure 2 This is the working flow chart of “a two-stage beam alignment method for a directional data link” of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0025] In order to solve the problems existing in the traditional directional data link beam alignment process, the present invention proposes a two-stage beam alignment method, which uses the first stage of coarse alignment without information and the second stage of fine alignment with information to ensure the transmission efficiency and reliability of the system based on fast beam alignment.

[0026] like Figure 2 As shown, the directional data link two-stage beam alignment method of this embodiment includes the following steps:

[0027] Step 1: After the network user receives the network establishment message, user A sends a continuous T signal in omnidirectional radiation mode. trans Duration of the network access sequence.

[0028] The network access sequence does not contain data information, but only contains the PN sequence and UW sequence used for time synchronization and beam alignment. Its structure is as shown in the attached manual. Figure 1 shown.

[0029] Among them, the PN sequence has a repetition period of L pn symbols, retransmit N pn A pseudo-random sequence of times, where N pn ≥N b +1, N b The number of narrow beam scanning bits at the receiving end.

[0030] The UW sequence is of length L uw A pseudo-random sequence of symbols.

[0031] Step 2: User B performs the first-level beam alignment, and the antenna scans in a narrow beam according to N b The message of user A is received wave bit by wave bit, and the location of user A is obtained by matching it with the network access sequence.

[0032] Step 2.1 User B stays L in each wave position pn symbols, and perform sliding correlation matching with the PN sequence of user A. After obtaining the correlation result, the correlation peak is compared with the measurement threshold A. th_pn If the correlation peak exceeds the measurement threshold, the wave position scanning is stopped and stays at the current wave position n. b_AWait for the UW sequence; if the correlation peak does not exceed the measurement threshold, continue scanning the next wave position until the correlation peak of a certain wave position exceeds the measurement threshold;

[0033] Step 2.2 Perform sliding correlation matching between the UW sequences of user B and user A. After obtaining the correlation results, compare the correlation peak with the measurement threshold A. th_uw If the correlation peak exceeds the measurement threshold, the correlation peak position L is recorded. p_A , used to calculate the starting position of user A sending the reference message; if the correlation peak does not exceed the measurement threshold, it means that the current wave position receiving signal is a false alarm, and continue to return to step 2.1 to scan the wave position;

[0034] Step 3: User A sends a reference message using omnidirectional antenna radiation, which contains user A's location information, time information, etc.

[0035] Step 4: User B adjusts the receiving beam position to the nth beam position according to the first-level beam alignment result. b_A wave positions, and according to the correlation peak position L obtained in step 2.2 p_A , calculate the starting position where user A sends the benchmark message, start receiving the benchmark message from this position, and parse the user A location information and time information contained in the benchmark message.

[0036] Step 5: User B performs the second-level beam alignment, calculates the accurate beam pointing based on the position information of user A analyzed in step 4 and its own inertial navigation information.

[0037] Step 6: User B selects the antenna beam aimed at user A based on the accurate beam direction calculated in step 5 and sends a continuous T signal in a directional manner. trans Duration of the network access sequence.

[0038] Step 7: User A performs the first-level beam alignment, and the antenna scans in a narrow beam according to N b The signal of user B is received wave bit by wave bit, and the position of user B is obtained by matching it with the network access sequence.

[0039] Step 7.1 User A stays L in each wave position pn symbols, and perform sliding correlation matching with the PN sequence of user B. After obtaining the correlation result, compare the correlation peak with the measurement threshold A. th_pn If the correlation peak exceeds the measurement threshold, the wave position scanning is stopped and stays at the current wave position n. b_B Wait for the UW sequence; if the correlation peak does not exceed the measurement threshold, continue scanning the next wave position until the correlation peak of a certain wave position exceeds the measurement threshold;

[0040] Step 7.2 Perform sliding correlation matching on the UW sequences of user A and user B. After obtaining the correlation results, compare the correlation peak with the measurement threshold A. th_uw If the correlation peak exceeds the measurement threshold, the correlation peak position L is recorded. p_B , used to calculate the starting position of user B sending the reference message; if the correlation peak does not exceed the measurement threshold, it means that the current wave position receiving signal is a false alarm, and continue to return to step 7.1 to scan the wave position;

[0041] Step 8: User B sends a reference message using antenna directional radiation, which contains user B's location information, time information, etc.

[0042] Step 9: User A adjusts the receiving beam position to the nth beam position according to the first-level beam alignment result. b_B wave positions, and according to the correlation peak position L obtained in step 7.2 p_B , calculate the starting position where user B sends the benchmark message, start receiving the benchmark message from this position, and parse the user B location information and time information contained in the benchmark message.

[0043] Step 10: User A performs the second-level beam alignment, calculates the accurate beam pointing based on the position information of user B analyzed in step 9 and its own inertial navigation information.

[0044] So far, the two-stage beam alignment of the directional data link of this embodiment is completed from step one to step ten.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A two-stage beam alignment method for a directional data link, characterized in that: The following steps are involved: Step 1: After the network user receives the network establishment message, user A sends a continuous T signal in omnidirectional radiation mode. trans The length of the network access sequence; Step 2: User B performs the first-level beam alignment, and the antenna scans in a narrow beam according to N b The user A's message is received by each wave position, and the position of user A is obtained by matching it with the network access sequence; N b The number of narrow beam scanning wave bits at the receiving end; Step 3: User A sends a reference message in an omnidirectional antenna radiation mode; Step 4: User B calculates the starting position of the reference message sent by user A based on the first-level beam alignment result, receives the reference message sent by user A from this starting position, and parses the reference message; Step 5: User B performs the second-level beam alignment, and calculates the accurate beam pointing based on the reference message parsed in step 4 and its own inertial navigation information; Step 6: User B selects the antenna beam aimed at user A based on the accurate beam direction calculated in step 5 and sends a continuous T signal in a directional manner. trans The length of the network access sequence; Step 7: User A performs the first-level beam alignment to obtain the position of user B; Step 8: User B sends a reference message in a directional radiation mode of the antenna; Step 9: User A calculates the starting position of the reference message sent by user B based on the first-level beam alignment result, starts receiving the reference message sent by user B from the starting position, and parses the reference message; Step 10: User A performs the second-level beam alignment, calculates the accurate beam pointing based on the position information of user B analyzed in step 9 and its own inertial navigation information.

2. The directional data link two-stage beam alignment method according to claim 1, characterized in that: In step 1, the network access sequence does not contain data information, but only contains the PN sequence and UW sequence used for time synchronization and beam alignment.

3. The directional data link two-stage beam alignment method as claimed in claim 2, characterized in that: The PN sequence has a repetition period of L pn symbols, retransmit N pn A pseudo-random sequence of times, where N pn ≥N b +1.

4. The directional data link two-stage beam alignment method as claimed in claim 3, characterized in that: The UW sequence is of length L uw A pseudo-random sequence of symbols.

5. The directional data link two-stage beam alignment method as claimed in claim 4, characterized in that: Step 2 includes the following sub-steps: Step 2.1 User B stays L in each wave position pn symbols, and perform sliding correlation matching with the PN sequence of user A. After obtaining the correlation matching result, the correlation peak is compared with the measurement threshold A. th_pn If the correlation peak exceeds the measurement threshold, the wave position scanning is stopped and stays at the current wave position n. b_A Wait for the UW sequence; if the correlation peak does not exceed the measurement threshold, continue scanning the next wave position until the correlation peak of a certain wave position exceeds the measurement threshold; Step 2.2 Perform sliding correlation matching on the UW sequences of user B and user A. After obtaining the correlation matching result, compare the correlation peak with the measurement threshold A. th_uw If the correlation peak exceeds the measurement threshold, the correlation peak position L is recorded. p_A , which is used to calculate the starting position of user A sending the reference message; if the correlation peak does not exceed the measurement threshold, it means that the current wave position receiving signal is a false alarm, and continue to return to step 2.1 to perform wave position scanning.

6. The directional data link two-stage beam alignment method as claimed in claim 5, characterized in that: In step 3, the reference message sent by user A includes user A's location information and time information.

7. The directional data link two-stage beam alignment method as claimed in claim 6, characterized in that: In step 4, user B adjusts the receiving beam position to the nth beam position according to the first-level beam alignment result. b_A wave positions, and according to the correlation peak position L obtained in step 2.2 p_A , calculate the starting position where user A sends the benchmark message.

8. The directional data link two-stage beam alignment method as claimed in claim 7, characterized in that: In step 7, user A uses a narrow beam scanning method, and the antenna uses N b The signal of user B is received wave bit by wave bit, and the position of user B is obtained by matching it with the network access sequence.

9. The directional data link two-stage beam alignment method as claimed in claim 8, characterized in that: Step seven includes the following sub-steps: Step 7.1 User A stays L in each wave position pn symbols, and perform sliding correlation matching with the PN sequence of user B. After obtaining the correlation result, compare the correlation peak with the measurement threshold A. th_pn If the correlation peak exceeds the measurement threshold, the wave position scanning is stopped and stays at the current wave position n. b_B Wait for the UW sequence; if the correlation peak does not exceed the measurement threshold, continue scanning the next wave position until the correlation peak of a certain wave position exceeds the measurement threshold; Step 7.2 Perform sliding correlation matching on the UW sequences of user A and user B. After obtaining the correlation results, compare the correlation peak with the measurement threshold A. th_uw If the correlation peak exceeds the measurement threshold, the correlation peak position L is recorded. p_B , which is used to calculate the starting position of user B sending the reference message; if the correlation peak does not exceed the measurement threshold, it means that the current wave position receiving signal is a false alarm, and continue to return to step 7.1 to perform wave position scanning.

10. The directional data link two-stage beam alignment method according to claim 9, characterized in that: In step 8, the reference information sent by user B includes user B's location information and time information; in step 9, user A adjusts the receiving beam position to the nth beam position according to the first-level beam alignment result. b_B wave positions, and according to the correlation peak position L obtained in step 7.2 p_B , calculate the starting position where user B sends the benchmark message.

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