An online calibration method for multi-antenna navigation anechoic chamber link delay

Abstract

The application discloses a kind of online calibration methods of multi-antenna navigation darkroom link delay, belong to satellite navigation user equipment test field.The application includes: by metrology / testing, the receiving zero value of calibration receiver at each frequency point is obtained;Navigation signal link delay calibration environment is constructed in multi-antenna navigation darkroom;Single star multi-output navigation signal simulator transmits single star single frequency point test signal;The current channel link delay is obtained by calibration receiver;Change single star multi-output navigation signal simulator output signal frequency point and obtain other frequency point link delay;Change signal output channel and obtain the link delay of each frequency point of other channel.The application can realize the automation online calibration of multi-antenna navigation darkroom link delay, can effectively shorten system calibration time, reduce the advantages of link delay calibration complexity.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation user equipment testing technology, and in particular to an online calibration method for link delay in a multi-antenna navigation anechoic chamber. Background Technology

[0002] A multi-antenna navigation anechoic chamber (also known as a starry sky anechoic chamber) is used to simulate the navigation signal receiving environment of a navigation terminal under laboratory conditions. Multiple navigation antennas are deployed inside the microwave anechoic chamber to simulate an actual navigation satellite constellation.

[0003] Currently, the calibration method for the link delay of test signals in multi-antenna navigation anechoic chambers generally involves periodic calibration using a vector network analyzer after the system is built. However, due to the large number of navigation antennas deployed in multi-antenna navigation anechoic chambers and the actual testing requirement to test the link delay of multiple navigation frequencies, the calibration cycle is long and the calibration process is cumbersome. Summary of the Invention

[0004] In view of this, the present invention proposes an online calibration method for link delay in a multi-antenna navigation test anechoic chamber, which can automatically calibrate the link delay of multiple navigation test signals arriving at the antenna port of the navigation terminal, effectively shortening the calibration time and reducing the complexity of link delay calibration.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] An online calibration method for link delay in a multi-antenna navigation anechoic chamber includes the following steps:

[0007] Step 1: Obtain the receiving and processing delay of the calibration receiver through testing in the navigation anechoic chamber, that is, the zero value of the receiving and processing of the calibration receiver at each frequency point;

[0008] Step 2: Set up a multi-antenna navigation anechoic chamber, a single-satellite multi-output navigation signal simulator, a time and frequency reference, and a calibration receiver, wherein the calibration receiver includes a zero-phase center antenna;

[0009] Step 3: Fix the zero-phase center antenna of the calibration receiver on the test turntable. The phase center of the zero-phase center antenna should be consistent with the phase center of the test turntable. The 10MHz time-frequency reference and the 1pps system reference signal are connected to the calibration receiver as reference clocks.

[0010] Step 4: The single-satellite multi-output navigation signal simulator broadcasts a navigation signal with a fixed satellite number and fixed pseudorange. The signal level is the maximum output value of the simulator. The delay value of the current link at the current frequency is obtained by calibrating the observations output by the receiver.

[0011] Step 5, the single-star multi-output navigation signal simulator changes the output frequency point of the single-star signal, calibrates the acquisition of the link delay observation of the receiver, and completes the link delay calibration of other navigation frequency points of the signal output channel;

[0012] Step 6, the single-star multi-output navigation signal simulator changes the single-star signal output channel and the corresponding navigation antenna, and completes the link delay calibration of all navigation frequency points of the remaining output channels.

[0013] Further, the specific manner of step 4 is:

[0014] (401) The single-star multi-output navigation signal simulator outputs a single channel navigation signal, broadcasts a navigation signal with a fixed satellite number and a zero pseudo-range, and the output signal power is maximum;

[0015] (402) The calibration receiver is set to work in a fixed channel mode, that is, the receiving channel does not change in the entire calibration process;

[0016] (403) The calibration receiver receives the navigation signal broadcast by the single-star navigation signal simulator, and obtains the observation T of the link delay 观测量i1 , wherein i represents the corresponding navigation frequency point, and 1 represents the current link channel;

[0017] (404) The current link delay observation T 观测量i1 is deducted from the zero value T 校准零i calibrated by the calibration receiver, to obtain the current measured link delay value T 链路时延i1 .

[0018] The present application has the following beneficial effects:

[0019] 1. The present application uses the characteristic that the zero value change of the zero phase center antenna when receiving navigation signals in different directions can be ignored, controls the single-star multi-output navigation signal simulator to output a navigation signal with a fixed satellite number and a zero pseudo-range, and realizes online automatic calibration of the link delay of the multi-antenna navigation darkroom by using the fixed receiving channel of the calibration receiver, so that the link delay measurement process is more simple and efficient.

[0020] 2. The present application can automatically calibrate the test signal link delay of the navigation signal simulator to the navigation terminal antenna port, effectively solving the problem that the process of using the traditional vector network analyzer for link delay test in the multi-antenna navigation darkroom is relatively cumbersome. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the zero value calibration principle of the calibration receiver.

[0022] Figure 2 is a schematic diagram of the signal link delay calibration principle of the multi-antenna navigation darkroom. DETAILED DESCRIPTION

[0023] The application will be further described in connection with specific embodiments and drawings.

[0024] An online calibration method of multi-antenna navigation anechoic chamber link delay, comprising the following steps:

[0025] (1) Obtain the receiving processing delay of the calibration receiver by metering or in the navigation anechoic chamber test, i.e. the zero value of the calibration receiver receiving processing at each frequency point;

[0026] (2) Prepare the multi-antenna navigation anechoic chamber and the supporting test equipment, including: multi-antenna navigation anechoic chamber, single-star multi-output navigation signal simulator, time-frequency reference, calibration receiver (including zero phase center antenna);

[0027] (3) Fix the zero phase center antenna of the calibration receiver on the test turntable, and keep the phase center of the zero phase center antenna consistent with the phase center of the test turntable; connect the 10MHz of the time-frequency reference and the system reference 1pps signal to the calibration receiver as the reference clock;

[0028] (4) The single-star multi-output navigation signal simulator broadcasts the navigation signal of a fixed satellite number and fixed pseudo-range, and the signal level is the maximum value of the simulator output; obtain the delay value of the current frequency point and the current link through the observation value output by the calibration receiver;

[0029] (5) Change the output frequency point of the single-star signal of the single-star multi-output navigation signal simulator, and complete the acquisition of the link delay observation value of the calibration receiver, and complete the link delay calibration of the other navigation frequency points of the signal output channel;

[0030] (6) Change the single-star signal output channel and the corresponding navigation antenna of the single-star multi-output navigation signal simulator, and complete the link delay calibration of all navigation frequency points of the remaining output channels.

[0031] In the step (4), the following steps are included:

[0032] (401) The single-star multi-output navigation signal simulator outputs a single channel navigation signal, broadcasts the navigation signal of fixed satellite number and zero pseudo-range, and the output signal power is the maximum;

[0033] (402) Set the calibration receiver to work in the fixed channel mode, i.e. the receiving channel does not change in the whole calibration process;

[0034] (403) The calibration receiver receives the signal broadcasted by the single-star navigation signal simulator, and obtains the observation value T of the link delay 观测量i1 , wherein i represents the corresponding navigation frequency point, and 1 indicates the current link channel;

[0035] (404)Since the calibration receiver uses a zero-phase center antenna to receive the navigation signal, the zero value change can be ignored when receiving navigation signals in different directions, so the current link delay observation T 观测量i1 Subtract the zero value T 校准零i of the calibration receiver from the current measured link delay value T 链路时延i1 .

[0036] The following is a more specific example:

[0037] An online calibration method for multi-antenna navigation anechoic chamber link delay includes the following steps:

[0038] (1) Obtain the receive processing delay of the calibration receiver by measurement or in the navigation anechoic chamber test, that is, the zero value of the calibration receiver receiving processing at each frequency point;

[0039] As shown in Figure 1 , the receive processing zero value calibration method of the calibration receiver at each frequency point is as follows:

[0040] a) Fix the standard gain antenna on the test turntable, and connect the standard gain antenna to the high-speed oscilloscope through the low-noise amplifier and the radio frequency test cable. The 10MHz of the time-frequency reference is connected to the reference clock input of the high-speed oscilloscope as the reference clock, and the system reference 1pps signal measurement trigger signal is connected to the measurement channel of the high-speed oscilloscope;

[0041] b) The navigation signal simulator broadcasts a single-star fixed pseudo-range signal, and the signal level is the maximum output of the simulator. The high-speed oscilloscope is used to measure the link delay at this time, and the link delay true value T 真值1 of the navigation antenna broadcasting navigation signal is obtained by calculating and deducting the standard gain antenna, low-noise amplifier and radio frequency test cable delay;

[0042] c) Fix the zero-phase center antenna of the calibration receiver on the test turntable, and the phase center of the zero-phase center antenna is consistent with the phase center of the test turntable. The 10MHz of the time-frequency reference and the system reference 1pps signal are connected to the calibration as the reference clock;

[0043] d) Obtain the current link delay measurement value T 测量 according to the observation value output by the current calibration receiver, and obtain the receive processing zero value T 真值1 of the current calibration receiver by comparing with the link delay true value T 校准零 .

[0044] (2) Prepare the multi-antenna navigation anechoic chamber and the supporting test equipment, including: multi-antenna navigation anechoic chamber, single-star multi-output navigation signal simulator, time-frequency reference, calibration receiver (including zero-phase center antenna);

[0045] Multi-antenna navigation anechoic chamber: also known as a full-sky anechoic chamber, used to simulate the navigation signal receiving environment in which the navigation terminal is located under laboratory conditions. A plurality of navigation antennas are arranged inside the microwave anechoic chamber to simulate the actual navigation satellite constellation.

[0046] Single-satellite multi-output navigation signal simulator: used in conjunction with the multi-antenna navigation anechoic chamber, generally having no less than 12 individually output channels, each channel simulating the navigation signal output by a navigation satellite.

[0047] Time and frequency reference: provides a unified time and frequency reference for the system, wherein the navigation signal simulator outputs a zero pseudorange scenario corresponding to the system reference 1 pps.

[0048] Calibration receiver: a dedicated navigation receiver that can be configured to set the corresponding working mode to meet the calibration requirements. A zero-phase center antenna refers to an antenna whose phase center does not change when receiving navigation signals from different directions, i.e., the pseudorange after arriving at the zero-phase center antenna from different directions is constant.

[0049] (3) Fix the zero-phase center antenna of the calibration receiver on the test turntable, and ensure that the phase center of the zero-phase center antenna is consistent with the phase center of the test turntable. The 10 MHz of the time and frequency reference and the 1 pps signal of the system reference are input into the calibration receiver as reference clocks.

[0050] (4) The single-satellite multi-output navigation signal simulator broadcasts a navigation signal with a fixed satellite number and a fixed pseudorange. The signal level is the maximum output of the simulator. The time delay value of the current frequency point and the current link is obtained through the observation value output by the calibration receiver.

[0051] (401) The single-satellite multi-output navigation signal simulator outputs a single-channel navigation signal, broadcasts a navigation signal with a fixed satellite number and a zero pseudorange, and outputs a signal power at the maximum level.

[0052] (402) Set the calibration receiver to work in a fixed channel mode, i.e., the receiving channel does not change during the entire calibration process.

[0053] (403) The calibration receiver receives the signal broadcast by the single-satellite navigation signal simulator and obtains the observation value T 观测量i1 (i represents the corresponding navigation frequency point, and 1 indicates the current link channel).

[0054] (404) The current link time delay observation value T 观测量i1 Subtract the zero value T 校准零i from the calibration receiver, which is the current measured link time delay value T 链路时延i1 .

[0055] (5) The single-star multi-output navigation signal simulator changes the output frequency point of the single-star signal, calibrates the receiver to complete the acquisition of link time delay observation, and completes the link time delay calibration of other navigation frequency points of the signal output channel;

[0056] (6) The single-star multi-output navigation signal simulator changes the single-star signal output channel and the corresponding navigation antenna, and completes the link time delay calibration of all navigation frequency points of the remaining output channels. The principle of the whole multi-antenna navigation darkroom signal link time delay calibration process is shown in Figure 2

[0057] In summary, the application can realize the automatic online calibration of the multi-antenna navigation darkroom link time delay, effectively shorten the system calibration time, and reduce the complexity of the link time delay calibration.​

Claims

1. An online calibration method of multi-antenna navigation anechoic chamber link delay, characterized in that, The method comprises the following steps: Step 1, obtaining the receiving processing delay of the calibration receiver by testing in a navigation anechoic chamber, i.e. the receiving processing zero value of the calibration receiver at each frequency point; Step 2, setting a multi-antenna navigation anechoic chamber, a single-satellite multi-output navigation signal simulator, a time-frequency reference, and a calibration receiver, wherein the calibration receiver comprises a zero-phase center antenna; Step 3, fixing the zero-phase center antenna of the calibration receiver on a test turntable, keeping the phase center of the zero-phase center antenna consistent with the phase center of the test turntable, and connecting the 10MHz of the time-frequency reference and the system reference 1pps signal to the calibration receiver as a reference clock; Step 4, broadcasting a navigation signal with a fixed satellite number and a fixed pseudo-range by the single-satellite multi-output navigation signal simulator, the signal level being the maximum output of the simulator, and obtaining the time delay value of the current frequency point and the current link through the observation value output by the calibration receiver; Step 5, changing the output frequency point of the single-satellite signal by the single-satellite multi-output navigation signal simulator, and completing the acquisition of the link time delay observation by the calibration receiver, and completing the link time delay calibration of other navigation frequency points of the signal output channel; Step 6, changing the single-satellite signal output channel and the corresponding navigation antenna by the single-satellite multi-output navigation signal simulator, and completing the link time delay calibration of all navigation frequency points of the remaining output channels.

2. The online calibration method of multi-antenna navigation darkroom link delay according to claim 1, characterized in that, The specific manner of step 4 is as follows: (401) the single-satellite multi-output navigation signal simulator outputs a single-channel navigation signal, broadcasts a navigation signal with a fixed satellite number and a pseudo-range of zero, and the output signal power is maximum; (402) the calibration receiver is set to work in a fixed channel mode, i.e. the receiving channel does not change in the entire calibration process; (403)The calibration receiver receives the navigation signal broadcast by the single-star navigation signal simulator to obtain the observation T of the link delay 观测量i1 wherein i represents the corresponding navigation frequency point, and 1 represents the current link channel. (404)The current link latency observation T 观测量i1 Subtract the calibrated received null T 校准零i , to obtain the current measured link latency value T 链路时延i1 .

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