Unmanned aerial vehicle-based phased array channel phase high-precision measurement method and system

Abstract

The invention relates to a phased array channel phase high-precision measurement method and system based on an unmanned aerial vehicle, and belongs to the field of radio, and the measurement method comprises the steps: a certain transmitting channel of a large-scale phased array antenna array actively transmits a test signal to the unmanned aerial vehicle, receives a return signal of the unmanned aerial vehicle, and records the phase information # imgabs0 # of the received signal; the unmanned aerial vehicle actively transmits a test signal to the large phased-array antenna array on the ground, and the large phased-array antenna array records the phase information # imgabs1 # of the signal at the moment after receiving the signal; according to the obtained phase information # imgabs2 # and # imgabs3 #, the inherent phase of the transmitting channel of the large phased-array antenna array is obtained; and switching the next transmitting channel to transmit the test signal, and carrying out the operation until each transmitting channel is measured. By comparing the phase differences in the two modes, the influence of the distance change between the unmanned aerial vehicle and the large-scale phased array on the measurement result is effectively eliminated, and the measurement precision of the phase of the large-scale phased array transmitting channel is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of radio, and in particular to a method and system for high-precision measurement of the phase of a phased array channel based on an unmanned aerial vehicle (UAV). Background Art

[0002] A large phased array achieves fast beam scanning and shaping by precisely controlling the phase of signals in each transmitting channel. Therefore, it is necessary to accurately test the phased array. The traditional measurement method is to perform phase testing in a darkroom environment. However, large phased arrays usually need to be actually deployed in the field again, and the phase usually changes after disassembly and reassembly. Therefore, it is necessary to perform phase testing in situ. In in-situ testing, the high tower testing method is easily affected by the ground multipath effect. Therefore, it is best to keep the antenna at a high elevation angle or a lying angle, and use a UAV directly above the antenna for phase testing. However, the position distance accuracy of the UAV will vary from more than ten centimeters to dozens of centimeters, which can lead to a phase testing error in the range of several wavelengths, seriously affecting the measurement accuracy and phase consistency calibration. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art, and provides a method and system for high-precision measurement of the phase of a phased array channel based on a UAV, solving the deficiencies existing in the prior art.

[0004] The purpose of the present invention is achieved through the following technical solutions: A method for high-precision measurement of the phase of a phased array channel based on a UAV, the measurement method comprising: Step 1: A certain transmitting channel of a large phased array antenna array on the ground actively transmits a test signal to the UAV, and records the phase information of the signal received by the large phased array antenna array at this time after receiving the UAV's feedback signal ; Step 2: The UAV actively transmits a test signal to the large phased array antenna array on the ground, and the large phased array antenna array records the phase information of the signal at this time after receiving the signal ; Step 3: Through the phase information obtained in Step 1 and Step 2 and , eliminate the distance phase error related to the distance R between the UAV and the large phased array antenna array, and obtain the inherent phase of this transmitting channel of the large phased array antenna array; Step 4: Switch to the next transmitting channel to transmit the test signal, and repeat the operations in Step 1 to Step 3 until each transmitting channel has been measured.

[0005] The specific content of Step 1 includes the following: Deploy a drone equipped with a DRFM module above the large phased array antenna to be measured, and keep the drone stable. The DRFM module represents a digital radio frequency memory module; A certain transmitting channel of the large phased array antenna to be measured emits a test signal in the direction of the drone. After the DRFM module on the drone receives the signal through the antenna, it performs digital storage and processing, and then immediately re - transmits the processed signal back to the large phased array antenna on the ground through the antenna; The large phased array antenna to be measured receives the signal re - transmitted by the drone and records the phase information of the signal received by the large phased array antenna at this time 。

[0006] The specific content of the second step is as follows: Within a microsecond - level time interval after the end of the first step, the DRFM module on the drone switches to the active transmission mode, or another signal source actively emits a test signal to the large phased array antenna on the ground through the antenna; The large phased array antenna to be measured receives the signal actively transmitted by the drone and records the phase information of the signal received by the large phased array antenna at this time 。

[0007] The specific content of the third step is as follows: Phase information contains the distance information of 2R, as well as the inherent phase of this transmitting channel of the large phased array antenna , the fixed - delay phase introduced by the DRFM module , that is , where R is the distance between the drone and the large phased array antenna, and c is the transmission speed of electromagnetic waves in the air; Phase information contains the distance information of R, as well as the inherent phase of the drone signal source , that is ; By calculating to eliminate the distance - phase error related to R and obtain the inherent phase of this transmitting channel of the large phased array antenna , where π represents the constant of pi, and f is the carrier frequency.

[0008] A high - precision phase measurement system for phased array channels based on a drone. The system includes a main - transmitting and re - transmitting module, a drone main - transmitting module, a phase - difference calculation module, and a multi - channel measurement module; The main transmitting and forwarding module: It is configured to actively transmit a test signal from a certain transmitting channel of the large ground phased array antenna array to the UAV, and record the phase information of the signal received by the large phased array antenna array at this time after receiving the feedback signal from the UAV. ; The UAV main transmitting module: It is configured to actively transmit a test signal from the UAV to the large ground phased array antenna array, and record the phase information of the signal at this time after the large phased array antenna array receives the signal. ; The phase difference calculation module: It is configured to obtain the phase information and , eliminate the range phase error related to the distance R between the UAV and the large phased array antenna array, and obtain the inherent phase of this transmitting channel of the large phased array antenna array. The multi-channel measurement module: It is configured to switch to the next transmitting channel to transmit a test signal, and repeat the operations in steps one to three until each transmitting channel has been measured.

[0009] The main transmitting and forwarding module is used to implement the following functions: Deploy the UAV equipped with the DRFM module (where DRFM module represents the digital radio frequency memory module) above the large phased array antenna array to be measured, and keep the UAV stable. A certain transmitting channel of the large phased array antenna array to be measured transmits a test signal in the direction of the UAV. After the DRFM module on the UAV receives the signal through the antenna, it performs digital storage and processing, and then immediately re-forwards the processed signal back to the large phased array antenna array to be measured on the ground through the antenna. The large phased array antenna array to be measured receives the signal re-forwarded by the UAV, and records the phase information of the signal received by the large phased array antenna array at this time. .

[0010] The UAV main transmitting module is used to implement the following functions: Within the microsecond time interval after the main transmitting and forwarding module ends, the DRFM module on the UAV switches to the active transmitting mode, or another signal source actively transmits a test signal to the large phased array antenna array to be measured on the ground through the antenna. The large phased array antenna array to be measured receives the signal actively transmitted by the UAV, and records the phase information of the signal received by the large phased array antenna array at this time. .

[0011] The phase difference calculation module is used to implement the following functions: Phase information It contains the distance information of 2R, as well as the inherent phase of the transmitting channel of the large phased array antenna , and the fixed delay phase introduced by the DRFM module , that is , where R is the distance between the UAV and the large phased array antenna, and c is the transmission speed of electromagnetic waves in the air; Phase information contains the distance information of R, as well as the inherent phase of the UAV signal source , that is ; By calculating to eliminate the distance phase error related to R, the inherent phase of the transmitting channel of the large phased array antenna is obtained , where π represents the constant of pi, and f is the carrier frequency.

[0012] The present invention has the following advantages: 1. High-precision measurement: By comparing the phase differences in two modes, the influence of the distance change between the UAV and the large phased array on the measurement result is effectively eliminated, and the measurement accuracy of the phase of the large phased array transmitting channel is significantly improved.

[0013] 2. Elimination of multipath effects: The UAV is located above the antenna for measurement, which can effectively avoid the interference of ground multipath effects.

[0014] 3. Fast and efficient: The entire measurement process can be completed within hundreds of milliseconds, realizing fast measurement of all transmitting channels and phase consistency evaluation. Description of the Drawings

[0015] Figure 1 is a schematic flow chart of the method of the present invention. Detailed Embodiments

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application usually described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the protection scope of the present application required to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application. The present invention will be further described below in conjunction with the drawings.

[0017] The present invention specifically relates to a method for high-precision measurement of the phase of a phased array channel based on an unmanned aerial vehicle, aiming to solve the problems of insufficient measurement accuracy of the phase of a large phased array channel and susceptibility to distance changes and multipath effects in the prior art. By using two modes, namely, the echo simulation signal of the DRFM module carried by the unmanned aerial vehicle and the signal actively transmitted by the unmanned aerial vehicle, and comparing their phase differences, the influence of distance changes is eliminated, and the accurate measurement of the phase of the large phased array channel is realized.

[0018] As Figure 1 shown, it specifically includes the following content: Step 1: The large phased array antenna array and the unmanned aerial vehicle transmit signals to each other; 1. Deployment of the unmanned aerial vehicle: The unmanned aerial vehicle equipped with a DRFM (Digital Radio Frequency Memory) digital frequency storage module is deployed above the large phased array antenna array to be measured. The unmanned aerial vehicle should be kept as relatively stable as possible, but small displacements within an acceptable range are allowed.

[0019] 2. Transmission by the large phased array antenna array and reception by the unmanned aerial vehicle: A test signal (for example, a pulse or a continuous wave) is transmitted from a certain transmitting channel of the large phased array antenna array to be measured in the direction of the unmanned aerial vehicle. The DRFM module on the unmanned aerial vehicle receives the transmitted waveform through the antenna.

[0020] 3. Processing and forwarding by the DRFM module: The DRFM module digitally stores and processes the received waveform (for example, performs a fixed and known delay processing), and then immediately re-forwards (transmits) the processed signal back to the large phased array antenna array on the ground through the antenna.

[0021] 4. Reception by the large phased array antenna array and data recording: The large phased array antenna array to be measured receives the signal forwarded by the unmanned aerial vehicle, and records the phase information of the signal received by the large phased array antenna array at this time. .

[0022] In this mode, the electromagnetic wave is emitted from the transmitting end of the large phased array, propagates to the unmanned aerial vehicle, and then is re-transmitted by the unmanned aerial vehicle and propagates back to the receiving end of the large phased array. Its propagation distance is 2R (where R is the instantaneous distance from the large phased array to the unmanned aerial vehicle). Therefore, the phase of the received signal contains the distance information of 2R, as well as the inherent phase ϕradar of this transmitting channel of the large phased array antenna array and the fixed delay phase ϕdrfm introduced by the DRFM module.

[0023] Step 2: The unmanned aerial vehicle actively transmits a signal to the large phased array antenna array; 1. UAV signal source startup: After the adjacent large phased array transmitting - UAV relaying mode ends (usually within a time interval of microseconds, so it can be ensured that the distance R between the UAV and the large phased array can be regarded as having no significant change within this extremely short time), another signal source on the UAV (or the DRFM module switches to the active transmitting mode) actively transmits a test signal to the large phased array antenna array to be measured on the ground through the antenna.

[0024] 2. Large phased array antenna array reception and data recording: The large phased array antenna array to be measured receives the signal actively transmitted by the UAV and records the phase information of the signal received by the large phased array antenna array at this time. 。

[0025] In this mode, the electromagnetic wave is emitted from the active transmitting end of the UAV and propagates to the receiving end of the large phased array antenna array. Its propagation distance is R. Therefore, the phase of the received signal contains the distance information of R and the inherent phase of the UAV signal source. 。

[0026] Step 3. Phase difference calculation and acquisition of channel inherent phase; By pre - calibrating the fixed delay phase of the DRFM module and the inherent phase of the UAV signal source, the true phase value of the transmitting channel of the large phased array antenna array to be measured can be accurately calculated from the phase information; Since Step 1 and Step 2 are carried out within an extremely short time interval, the distance R between the UAV and the large phased array antenna array can be regarded as constant. Therefore, contains the distance phase contribution of 2R, contains the distance phase contribution of R. By calculating , the distance phase error related to R can be effectively eliminated.

[0027] Therefore, from , the inherent phase of the transmitting channel of the large phased array antenna array can be obtained . Among them, π is the constant of pi, and f is the carrier frequency.

[0028] Step 4. Sequential measurement of multiple channels and realization of phase consistency; 1. Channel switching: After completing the phase measurement of a single transmitting channel, the large phased array antenna array to be measured switches to the next transmitting channel.

[0029] 2. Repeated measurement: Repeat Steps 1 to 3 to measure each transmitting channel of the large phased array. The channel switching interval is usually at the millisecond (ms) level, and the entire measurement process can be completed within a few hundred milliseconds.

[0030] 3. Phase consistency analysis and calibration: Analyze the measurement results of all transmitting channels to obtain the accurate phase values of each channel. Based on these measurement results, the phase consistency of the entire large phased array antenna can be evaluated, and corresponding phase calibration can be performed to ensure that all channels have a consistent phase reference during transmission, thereby optimizing the beamforming and scanning performance of the large phased array antenna.

[0031] Another embodiment of the present invention relates to a high-precision measurement system for the phase of phased array channels based on an unmanned aerial vehicle (UAV), which includes a main transmitting and forwarding module, a UAV main transmitting module, a phase difference calculation module, and a multi-channel measurement module; Among them, the main transmitting and forwarding module: is configured to actively transmit a test signal from a certain transmitting channel of the large phased array antenna on the ground to the UAV, and record the phase information of the signal received by the large phased array antenna at this time after receiving the feedback signal from the UAV ; The UAV main transmitting module: is configured to actively transmit a test signal from the UAV to the large phased array antenna on the ground, and the large phased array antenna records the phase information of the signal at this time after receiving the signal ; The phase difference calculation module: is configured to obtain the phase information obtained by the main transmitting and forwarding module and the UAV main transmitting module and , eliminate the range phase error related to the distance R between the UAV and the large phased array antenna, and obtain the inherent phase of this transmitting channel of the large phased array antenna; The multi-channel measurement module: is configured to switch to the next transmitting channel to transmit the test signal, and repeat the operations in steps one to three until each transmitting channel is measured.

[0032] Furthermore, the main transmitting and forwarding module is used to implement the following functions: Deploy a UAV equipped with a DRFM module (where DRFM represents a digital radio frequency memory module) above the large phased array antenna to be measured, and keep the UAV stable; A certain transmitting channel of the large phased array antenna to be measured transmits a test signal in the direction of the UAV. After receiving the signal through the antenna, the DRFM module on the UAV performs digital storage and processing, and then immediately re-transmits the processed signal back to the large phased array antenna to be measured on the ground through the antenna; The large phased array antenna to be measured receives the signal re-transmitted by the UAV, and records the phase information of the signal received by the large phased array antenna at this time .

[0033] Further, the main transmission module of the drone is used to implement the following functions: Within the microsecond time interval after the main transmission and relay module ends, the DRFM module on the drone switches to the active transmission mode, or another signal source actively transmits a test signal to the large phased array antenna array to be measured on the ground through the antenna; The large phased array antenna array to be measured receives the signal actively transmitted by the drone and records the phase information of the signal received by the large phased array antenna array at this time .

[0034] Further, the phase difference calculation module is used to implement the following functions: The phase information contains the distance information of 2R, as well as the inherent phase of the transmitting channel of the large phased array antenna array , the fixed delay phase introduced by the DRFM module , that is , where R is the distance between the drone and the large phased array antenna array, and c is the transmission speed of electromagnetic waves in the air; The phase information contains the distance information of R, as well as the inherent phase of the drone signal source , that is ; By calculating to eliminate the distance phase error related to R and obtain the inherent phase of the transmitting channel of the large phased array antenna array , where π represents the constant of pi, and f is the carrier frequency.

[0035] The above is only the preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and improvements, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And the changes and alterations made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A method for high-precision measurement of the phase of a phased array channel based on an unmanned aerial vehicle, characterized in that: The measurement method includes: Step 1: A certain transmitting channel of the large phased array antenna array on the ground actively transmits a test signal to the UAV, and after receiving the signal returned by the UAV, records the phase information of the signal received by the large phased array antenna array at this time ; Step 2: The UAV actively transmits a test signal to the large phased array antenna array on the ground. After receiving the signal, the large phased array antenna array records the phase information of the signal at this time ; Step 3: The phase information obtained through Step 1 and Step 2 and , eliminate the range phase error related to the distance R between the UAV and the large phased array antenna array, and obtain the inherent phase of the transmitting channel of the large phased array antenna array Step Four: Switch to the next transmitting channel to transmit a test signal, and repeat the operations of Step One to Step Three until each transmitting channel has been measured.

2. The high-precision phase measurement method for phased array channels based on an unmanned aerial vehicle according to claim 1, wherein: The specific content of Step One includes the following: Deploy a drone equipped with a DRFM module above the large phased array antenna to be measured, and keep the drone stable. The DRFM module represents a digital radio frequency memory module; A certain transmitting channel of the large phased array antenna to be measured transmits a test signal in the direction of the drone. After the DRFM module on the drone receives the signal through the antenna, it performs digital storage and processing, and then immediately re-transmits the processed signal back to the large phased array antenna to be measured on the ground through the antenna; The large phased array antenna array to be measured receives the signal relayed back by the UAV and records the phase information of the signal received by the large phased array antenna array at this time 。 3. A high-precision measurement method for the phase of a phased array channel based on an unmanned aerial vehicle according to claim 1, characterized in that: The specific content of Step Two includes the following: Within a microsecond time interval after the end of Step One, the DRFM module on the drone switches to the active transmission mode or another signal source actively transmits a test signal to the large phased array antenna to be measured on the ground through the antenna; The large phased array antenna array to be measured receives the signal actively transmitted by the UAV, and records the phase information of the signal received by the large phased array antenna array at this time 。 4. A high-precision measurement method for the phase of a phased array channel based on an unmanned aerial vehicle according to claim 1, characterized in that: The specific content of Step Three includes the following: Phase information includes the distance information of 2R and the inherent phase of the transmitting channel of the large phased array antenna array , the fixed delay phase introduced by the DRFM module , that is , where R is the distance between the UAV and the large phased array antenna array, and c is the transmission speed of electromagnetic waves in the air; Phase information includes the distance information of R and the inherent phase of the UAV signal source , that is ; By calculation to eliminate the range phase error related to R and obtain the inherent phase of the transmit channel of the large phased array antenna array , where π represents the constant of the circumference ratio and f is the carrier frequency.

5. A high-precision measurement system for the phase of a phased array channel based on an unmanned aerial vehicle, characterized in that: The system includes a main transmitting and re-transmitting module, a drone main transmitting module, a phase difference calculation module, and a multi-channel measurement module; The main transmitting and forwarding module: It is configured to actively transmit a test signal from a certain transmitting channel of the large ground phased array antenna array to the UAV, and record the phase information of the signal received by the large phased array antenna array at this time after receiving the signal returned by the UAV. ; The main transmitting module of the UAV: It is configured to actively transmit a test signal from the UAV to the large ground phased array antenna array. After receiving the signal, the large phased array antenna array records the phase information of the signal at this time ; The phase difference calculation module: configured to obtain the phase information obtained by the main transmission and relay module and the UAV main transmission module and , eliminate the range phase error related to the distance R between the UAV and the large phased array antenna array, and obtain the inherent phase of the large phased array antenna array for this transmission channel; The multi-channel measurement module: is configured to switch to the next transmitting channel to transmit a test signal, and repeat the operations of Step One to Step Three until each transmitting channel has been measured.

6. The high-precision phase measurement system for phased array channels based on an unmanned aerial vehicle according to claim 5, characterized in that: The main transmitting and re-transmitting module is used to implement the following functions: Deploy a drone equipped with a DRFM module above the large phased array antenna to be measured, and keep the drone stable. The DRFM module represents a digital radio frequency memory module; A certain transmitting channel of the large phased array antenna to be measured transmits a test signal in the direction of the drone. After the DRFM module on the drone receives the signal through the antenna, it performs digital storage and processing, and then immediately re-transmits the processed signal back to the large phased array antenna to be measured on the ground through the antenna; The large phased array antenna array to be measured receives the signal relayed back by the UAV and records the phase information of the signal received by the large phased array antenna array at this time 。 7. A high-precision phase measurement system for phased array channels based on an unmanned aerial vehicle according to claim 5, characterized in that: The drone main transmitting module is used to implement the following functions: Within a microsecond time interval after the end of the main transmitting and re-transmitting module, the DRFM module on the drone switches to the active transmission mode or another signal source actively transmits a test signal to the large phased array antenna to be measured on the ground through the antenna; The large phased array antenna array to be measured receives the signal actively transmitted by the UAV and records the phase information of the signal received by the large phased array antenna array at this time 。 8. A phased array channel phase high-precision measurement system based on an unmanned aerial vehicle according to claim 5, characterized in that: The phase difference calculation module is used to implement the following functions: Phase information contains the distance information of 2R, as well as the inherent phase of the transmitting channel of the large phased array antenna array , and the fixed delay phase introduced by the DRFM module , that is , where R is the distance between the UAV and the large phased array antenna array, and c is the transmission speed of electromagnetic waves in the air; Phase information contains the distance information of R and the inherent phase of the UAV signal source , that is ; By calculation to eliminate the range phase error related to R and obtain the inherent phase of the transmitting channel of the large phased array antenna , where π represents the constant of pi and f is the carrier frequency.

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