Data link system receiving sensitivity test system and application method thereof

Abstract

The present invention discloses a receiving sensitivity test system for a data link system and an application method thereof, comprising a receiver and a corresponding signal input device, further comprising: a corresponding power splitter is provided between the signal input device and the receiver, and the power splitter is also connected to a spectrum analyzer for testing; wherein a corresponding adjustable attenuator is provided between the power splitter and the signal input device; the receiver, the spectrum analyzer, the power splitter, the signal input device, and the adjustable attenuator are respectively connected by a plurality of corresponding first radio frequency cables to obtain a corresponding test environment. The present invention provides a receiving sensitivity test system for a data link system and an application method thereof, providing a software configuration function for transmitting attenuation of airborne equipment and ground equipment, namely, a function for calculating the receiving sensitivity of the receiver by using an adjustable attenuator in combination with the detection of the receiving state by a host computer during measurement, so that it is coordinated with the test process and the test effect meets the requirements.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and more particularly to a receiving sensitivity testing system for a data link system and an application method thereof. Background Art

[0002] Sensitivity is an important indicator for measuring a receiver's ability to receive weak signals. This indicator is related to the system's signal-to-noise ratio, noise, bandwidth and other parameters. A signal source is often used to test a receiver's sensitivity. However, when a standard signal source cannot be used as the input signal, or when there is no signal source due to limited conditions, how to test the receiver's sensitivity becomes a common problem.

[0003] However, in the existing technology, there is currently no method for testing the receiving sensitivity of the data link system. Without testing, it is uncertain whether the designed or produced products meet the sensitivity requirements. Therefore, in actual application, the receiving sensitivity does not meet the predetermined requirements, resulting in a shorter communication distance and failing to meet the predetermined communication distance requirements. As a result, business data cannot be transmitted within the specified communication distance or bit errors occur, affecting the normal data transmission of the data link system. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] To achieve these objectives and other advantages of the present invention, a receiving sensitivity test system for a data link system is provided, comprising a receiver and a corresponding signal input device, and further comprising:

[0006] A matching power splitter is provided between the signal input device and the receiver, and the power splitter is also connected to a spectrum analyzer for testing;

[0007] Wherein, a matching adjustable attenuator is provided between the power divider and the signal input device;

[0008] The receiver, the spectrum analyzer, the power splitter, the signal input device, and the adjustable attenuator are connected to each other through a plurality of matching first radio frequency cables to obtain a corresponding test environment.

[0009] Preferably, a first fixed attenuator is provided between the power splitter and the receiver, and a second fixed attenuator is provided between the adjustable attenuator and the signal input device;

[0010] The first fixed attenuator and the power divider, and the second fixed attenuator and the signal input device are connected respectively via matching second RF cables;

[0011] The adjustable attenuator is configured to have a first adjusting knob with a 10-fold step and a second adjusting knob with a 1-fold step.

[0012] A method for applying a receiving sensitivity test system uses a test environment to perform a one-way or two-way test on the receiving sensitivity of an uplink and / or downlink of a data link system.

[0013] Preferably, the test process of the test system is configured to include:

[0014] Step 1: Measure the loss of each accessory in the test environment;

[0015] Step 2: Set the transmission attenuation of the ground equipment and the aerial equipment through the host computer, and measure the transmission power of the signal input device through the spectrum analyzer;

[0016] Step 3: Obtain an initial value Pc of the power sent by the signal input device to the receiver RF port by measurement or calculation;

[0017] Step 4: Connect all accessories in the test environment, adjust the adjustable attenuator, and calculate the receiver sensitivity based on the following formula:

[0018] Receiving sensitivity Kf = initial power value Pc - final attenuation value Kf of the adjustable attenuator.

[0019] Preferably, in step 1, the loss measurement is obtained by performing a calibration test on a vector analyzer.

[0020] Preferably, in step 3, the measurement of the initial power value is obtained by directly connecting the spectrum analyzer, the second fixed attenuator, and the signal input device for testing;

[0021] The calculation of the initial power value is obtained by the following formula:

[0022] The initial power value Pc = the transmit power Pf of the input device - the total loss of each RF cable - the total attenuation value of each fixed attenuator - the power divider loss Gf - the initial attenuation value Kc of the adjustable attenuator.

[0023] Preferably, in step 4, the method for obtaining the final attenuation value of the adjustable attenuator is configured to include:

[0024] S40, performing initial stepping by the first adjustment knob, and when the receiver host computer cannot communicate with the air unit, calling back one step to complete the coarse adjustment;

[0025] S41, performing a second stepping by using the second adjustment knob, and when the receiver loses synchronization with the signal input device, calling back one step at a time until the receiver is synchronized with the signal input device and fine adjustment is completed when no error frames increase;

[0026] S42, the final attenuation value Kf of the adjustable attenuator = the first adjustment knob value + the second adjustment knob value.

[0027] Preferably, when performing a one-way test of the receiving sensitivity of the aerial device in the uplink, the aerial device is used as a receiver and the ground device is used as a signal input device;

[0028] In step 2, when testing the receiving sensitivity of the aerial device, the transmit attenuation of the split ground system is set to 17dB by default.

[0029] Preferably, when performing a one-way test of the receiving sensitivity of the ground equipment in the downlink of the data link system, the ground equipment is used as the receiver and the airborne equipment is used as the signal input device;

[0030] In step 2, when performing the receive sensitivity test on the split ground system, the transmit attenuation of the aerial device is set to 4dB by default.

[0031] Preferably, when performing a bidirectional test of the receiving sensitivity of the aerial device in the uplink and the split ground system in the downlink, it is also necessary to set the attenuation value of the host computer of the ground device, and the attenuation value = the transmission power of the high-power transmitting device - the transmission power of the low-power transmitting device + the transmission attenuation default setting value of the split ground system.

[0032] The present invention includes at least the following beneficial effects: the present invention provides a test system that can be extended to other data link systems and can also be applied to the receiving sensitivity test of other communication systems, and provides a transmission attenuation software configuration function for aerial equipment and ground equipment, that is, the function of using an adjustable attenuator in combination with the detection of the receiving state by the upper computer to calculate the receiving sensitivity of the receiver during the measurement, so that it can be coordinated with the test process and the test effect meets the needs.

[0033] The present invention provides an application method of a test system, which provides a one-way single-device receiving sensitivity test, an uplink aerial device receiving sensitivity test, and a downlink ground device receiving sensitivity test.

[0034] The present invention further realizes a function of simultaneous bidirectional receiving sensitivity testing through a receiving sensitivity testing method for devices at both ends with asymmetric transmitting power.

[0035] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the connection of the test system of the present invention when performing a one-way test of receiving sensitivity;

[0037] Figure 2 A schematic diagram of the connection of the test system of the present invention when measuring transmission power;

[0038] Figure 3 A schematic diagram of the connection of the test system of the present invention when testing the receiving sensitivity of an aerial device;

[0039] Figure 4 A schematic diagram of the connection of the test system of the present invention when testing the receiving sensitivity of ground equipment;

[0040] Figure 5 This is a schematic diagram of the connection of the test system of the present invention when performing a bidirectional test of receiving sensitivity. DETAILED DESCRIPTION

[0041] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0042] It should be understood that terms such as “having,” “including,” and “comprising” used herein do not prescribe the existence or addition of one or more other elements or combinations thereof.

[0043] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "mounted / connected," and "connected" should be understood in a broad sense. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can also be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance.

[0044] To solve the above problem, since sensitivity indicates the ability to receive weak signals, the simplest way is to input a very weak signal to the receiver. The input signal can be generated by aerial equipment or ground equipment. The receiver is tested to see if it can receive the input signal. If so, the input signal power is continuously reduced until it can no longer receive the signal. The signal power input to the receiver's RF port at this time is the receiver's receiving sensitivity.

[0045] The present invention provides a method for testing the receiving sensitivity of a data link system. The method mainly adopts a line-feed test method. Based on the sensitivity, which is determined by the weak signal receiving capability, an input signal device is replaced by an aerial device or a ground device instead of a standard signal source, and a receiver is correspondingly replaced by a ground device or an aerial device. A fixed attenuator is used to provide high-power protection for the aerial device and the ground device, ensuring that the signals input to the spectrum analyzer, the aerial device, and the ground device are not too strong, thereby avoiding damage to the instruments and equipment. Transmitting attenuation is configured by software or an FPGA in the ground device so that the output powers of the aerial device and the ground device are equal. The value of the adjustable attenuator is adjusted to achieve simultaneous testing of the receiving sensitivity in both directions. The software configuration is implemented by installing corresponding software on a monitoring host computer of the ground device. The software mainly implements configuration functions, link status monitoring functions, online upgrade functions, bit error testing functions, and real-time display functions of downlink data. The software configuration of transmitting attenuation is a configuration function in the ground device software. It is actually the underlying configuration of the baseband AD9361 or AD9363. The configuration is performed on the host computer, facilitating visual configuration without the need to re-burn code for each adjustment, which is both convenient and practical.

[0046] Example 1:

[0047] One-way receiving sensitivity test method

[0048] When performing a one-way receiving sensitivity test, you must first determine whether to test the receiving sensitivity of the aerial device or the ground device. When testing the receiving sensitivity of the ground device, the ground device acts as a receiver and the aerial device acts as an input signal device; when testing the receiving sensitivity of the aerial device, the aerial device acts as a receiver and the ground device acts as an input signal device. The test steps are as follows:

[0049] Step 1: Determine the accessories and measure the loss.

[0050] like Figure 1 The one-way test connection block diagram mainly includes a receiver 1 and a matching signal input device 2, and also includes:

[0051] A matching power splitter 3 is provided between the signal input device and the receiver, and the power splitter is also connected to a spectrum analyzer 4 for testing;

[0052] Wherein, a matching adjustable attenuator 5 is provided between the power divider and the signal input device, and the adjustable attenuator is configured to have a first adjustment knob with a 10-fold step and a second adjustment knob with a 1-fold step;

[0053] A first fixed attenuator G1 6 is provided between the power divider and the receiver, and a matching second fixed attenuator G2 7 is provided between the adjustable attenuator and the signal input device;

[0054] It was further determined that six RF cables were needed to connect the various components, namely, RF cable X1 between the power splitter and the first fixed attenuator, RF cable X2 between the receiver and the first fixed attenuator, RF cable X3 between the power splitter and the spectrum analyzer, RF cable X4 between the power splitter and the adjustable attenuator, RF cable X5 between the adjustable attenuator and the second fixed attenuator, and RF cable X6 between the signal input device and the second fixed attenuator. When applied, the power splitter uses two splitters, and the fixed attenuator is selected according to the transmission power of the input signal device 1 and the receiver 2. The rated power handling power of the fixed attenuator must be higher than the transmission power.

[0055] Use a vector analyzer to perform calibration tests on the determined test accessories, power splitters, attenuators, and RF cables, and record all loss values; the initial value of the adjustable attenuator is Kc.

[0056]

[0057] Step 2: Set the host computer transmission attenuation and measure the transmission power of the input signal device.

[0058] like Figure 2 Connect the input signal device and the spectrum analyzer, power on the input signal device, and use the host computer to set the transmit attenuation value. Forcibly pushing the transmit power of the ground device and the aerial device to saturation through software will cause waveform deformation. This will cause the receiver's FPGA to misjudge when capturing, resulting in communication abnormalities. The setting value varies depending on the product. Set the transmit attenuation of the aerial device to 4 and the ground device to 17. Use the spectrum analyzer to measure the transmit power of the aerial or ground device as Pf.

[0059] Step 3: Measure or calculate the initial power value of the signal input to the receiver's RF port.

[0060] The initial power value input to the receiver's RF port can be obtained in two ways. One is direct calculation: calculate the initial power value input to the receiver's (airborne or ground-based) RF port and denote this power value as P1. Then P1 = input device's transmit power (Pf) - total cable loss (X1+X2+X4+X5+X6) - fixed attenuation value (G1+G2) - power splitter loss (Gf) - adjustable attenuation initial value (Kc).

[0061] Another way is to measure directly with a spectrum analyzer. Remove the end of cable 2 connected to the receiver's RF port, and remove the spectrum analyzer from the end of cable 3. Connect the spectrum analyzer to cable 2 and plug cable 3 with a load.

[0062] The initial power value Pc at this time is directly read from the spectrum analyzer. This power value is the initial power value input to the receiver's RF port. It is not difficult to find that Pc = P1.

[0063] Step 4: Connect the device and set up the test environment.

[0064] 1. Turn off the power of the input signal device;

[0065] 2. According to Figure 1 Check again to make sure the one-way receiving sensitivity test connection is correct;

[0066] 3. After the test environment is set up, power the input signal device and receiver to confirm whether the default parameters of the input signal device are effective;

[0067] 4. Open the host computer of the input signal device to check the transmission attenuation value. Check whether the transmission attenuation of the aerial device is 4 and the transmission attenuation of the ground device is 17. If the parameters are incorrect, reset them and they will take effect immediately.

[0068] Step 5: Adjust the adjustable attenuator and calculate the receiver sensitivity.

[0069] 1. Adjust the attenuation knob of the adjustable attenuator, the 10-fold step adjustment knob of the adjustable attenuator (from 10 to 80dB), the 1-fold step adjustment knob of the adjustable attenuator (from 1 to 9), and adjust the 10-fold step of the adjustable attenuator. When it is found on the receiver host computer that communication with the air unit cannot be achieved, reduce the step attenuation by 10 times so that the receiver can still receive the signal of the input signal device;

[0070] 2. Adjust the attenuation knob of the adjustable attenuator in steps of 1 until the receiver detects a state of loss of synchronization with the input signal device. Then reduce the attenuation by 1 dB until the receiver monitoring display is synchronized with the input signal device and no error frames are added.

[0071] 3. Record the final attenuation value (Kf) of the adjustable attenuator at this time = the sum of the 10x step adjustment knob value and the 1x step adjustment knob value;

[0072] 4. Calculate the receiver sensitivity = initial power input to the receiver RF port (Pc) - final attenuation value of the adjustable attenuator (Kf).

[0073] Example 2:

[0074] The air device receiving sensitivity test includes:

[0075] Step 1: Determine the accessories and measure the loss.

[0076] like Figure 3The receiver sensitivity test chart for the aerial device is shown below. The input signal device is the ground device, and the receiver is the aerial device. The power splitter used was determined to be the Tailai Microwave RS2W05180-S. The fixed attenuator used was the RA30A50, with a nominal 30dB attenuator rating of 50W. The six RF cables were calibrated and tested using a vector analyzer, with all loss values ​​recorded as shown in the table below. The initial attenuation value of the adjustable attenuator was set to 10dB.

[0077]

[0078] Step 2: Set the host computer transmission attenuation and measure the ground equipment transmission power.

[0079] according to Figure 2 Connect the ground equipment and the spectrum analyzer, power on the ground equipment, set the transmission attenuation value using the host computer, set the transmission attenuation of the ground equipment to 17, and use the spectrum analyzer to measure the transmission power of the ground equipment to be Pf = 43dBm;

[0080] Step 3: Measure or calculate the initial power value of the signal input to the RF port of the air device.

[0081] The initial power value input to the RF port of the aerial device can be obtained in two ways. One is direct calculation: calculate the initial power value input to the RF port of the aerial device and denote this power value as P1. Then P1 = the transmission power of the ground device (Pf) - the total cable loss (X1+X2+X4+X5+X6) - the fixed attenuation value (G1+G2) - the power divider loss (Gf) - the initial adjustable attenuation value (Kc) = 43 - (2+1+2+2+2) - (30+30) - 3 - 10 = -39dBm.

[0082] Another method is to directly measure with a spectrum analyzer. Remove the end of cable 2 connected to the RF port of the aerial device, and remove the spectrum analyzer from the end of cable 3. Connect the spectrum analyzer to cable 2 and plug cable 3 with a load.

[0083] The initial power value Pc at this time is directly read from the spectrum analyzer as -39dBm, which is equal to the initial power value input to the RF port of the airborne device.

[0084] Step 4: Connect the device and set up the test environment.

[0085] 1. Turn off the power of the ground equipment;

[0086] 2. If Figure 3 Check again to make sure the receiving sensitivity test of the aerial device is connected correctly;

[0087] 3. After the test environment is set up, power the ground and aerial devices to confirm whether the default parameters (transmission attenuation) of the ground devices are effective.

[0088] 4. Open the host computer of the ground equipment to check the transmission attenuation value. Check whether the transmission attenuation of the ground equipment is 17. If the parameter is incorrect, reset it and it will take effect immediately.

[0089] Step 5: Adjust the adjustable attenuator and calculate the receiver sensitivity.

[0090] 1. Adjust the adjustable attenuator. The 10x step adjustment knob (from 10 to 80dB) and the 1x step adjustment knob (from 1 to 9) of the adjustable attenuator can be adjusted to 10x steps. If the aerial device host computer finds that communication with the ground device is impossible, reduce the step attenuation by 10x so that the aerial device can still receive the signal from the ground device.

[0091] 2. Adjust the attenuation knob of the adjustable attenuator in steps of 1 until the aerial device detects a loss of synchronization with the ground device. Then reduce the attenuation by 1 dB until the aerial device monitors and displays synchronization with the ground device and no error frames are added.

[0092] 3. Record the final attenuation value (Kf) of the adjustable attenuator at this time = the sum of the 10x step adjustment knob value and the 1x step adjustment knob value = 70 + 6 = 76;

[0093] 4. Calculate the receiving sensitivity of the aerial device = initial power value Pc - final attenuation value of the adjustable attenuator (Kf) = -39 - 76 = -115 dBm.

[0094] Example 3:

[0095] Ground equipment receiving sensitivity test includes:

[0096] Step 1: Determine the accessories and measure the loss.

[0097] like Figure 4 The ground equipment receiving sensitivity test chart is shown below. The aerial equipment serves as the input signal device, and the ground equipment serves as the receiver. The power splitter used was determined to be the Tailai Microwave RS2W05180-S. The fixed attenuator used was the RA30A50, with a nominal 30dB attenuator rating of 50W. The six RF cables were calibrated and tested using a vector analyzer, and all loss values ​​were recorded as shown in the table below. The initial attenuation value of the adjustable attenuator was set to 10dB.

[0098]

[0099] Step 2: Set the host computer's transmission attenuation and measure the transmission power of the aerial device.

[0100] according to Figure 2 Connect the aerial device and the spectrum analyzer, power on the aerial device, and use the host computer to set the transmit attenuation value. The aerial device is set to transmit attenuation 4, and the spectrum analyzer is used to measure the transmit power of the aerial device, which is Pf = 33dBm.

[0101] Step 3: Measure or calculate the initial power value of the signal input to the RF port of the ground equipment.

[0102] The initial power value input to the ground device's RF port can be obtained in two ways. One is direct calculation: Calculate the initial power value input to the ground device's RF port and denote this power value as P1. Then P1 = aerial device's transmit power (Pf) - total cable loss (X1+X2+X4+X5+X6) - fixed attenuation value (G1+G2) - power divider loss (Gf) - adjustable attenuation initial value (Kc) = 33 - (2+1+2+2+2) - (30+30) - 3 - 10 = -49dBm.

[0103] Another method is to measure directly with a spectrum analyzer. Remove the end of cable 2 connected to the RF port of the ground equipment, and remove the spectrum analyzer from the end of cable 3. Connect the spectrum analyzer to cable 2 and plug cable 3 with a load.

[0104] The initial power value Pc at this time is directly read from the spectrum analyzer as -49dBm, which is equal to the initial power value input to the RF port of the ground equipment.

[0105] Step 4: Connect the device and set up the test environment.

[0106] 1. Turn off the power of the aerial device;

[0107] 2. According to Figure 4 Check again to make sure the ground equipment receiving sensitivity test connection is correct;

[0108] 3. After the test environment is set up, power the ground and aerial devices and confirm whether the default parameters (transmission attenuation) of the aerial device are effective.

[0109] 4. Open the host computer of the aerial device to check the transmission attenuation value and check whether the transmission attenuation of the ground device is 4. If the parameter is incorrect, reset it and it will take effect immediately.

[0110] Step 5: Adjust the adjustable attenuator and calculate the receiver sensitivity.

[0111] 1. Adjust the adjustable attenuator. The attenuation knob of the adjustable attenuator 10x step adjustment knob (from 10 to 80dB) and the adjustable attenuator 1x step adjustment knob (from 1 to 9) can be adjusted to 10x steps of the adjustable attenuator. When the ground equipment host computer finds that communication with the aerial equipment cannot be achieved, reduce the step attenuation by 10x so that the ground equipment can still receive the signal from the aerial equipment.

[0112] 2. Adjust the attenuation knob of the adjustable attenuator in steps of 1 until the ground device detects a loss of synchronization with the aerial device. Then reduce the attenuation by 1 dB until the ground device monitors and displays synchronization with the aerial device, and no error frames are added.

[0113] 3. Record the final attenuation value (Kf) of the adjustable attenuator at this time = the sum of the 10x step adjustment knob value and the 1x step adjustment knob value = 60 + 5 = 65dB;

[0114] 4. Calculate the receiving sensitivity of the ground equipment = initial power value Pc - final attenuation value of the adjustable attenuator (Kf) = -49 - 65 = -114 dBm.

[0115] Example 4

[0116] Simultaneous testing of bidirectional receiving sensitivity: In the receiving sensitivity test process of Example 2-3, the receiving sensitivity of the unidirectional link device is tested. If the receiving sensitivity of the devices at both ends is to be tested at one time, the difference in transmission power between the aerial device and the ground device will result in the simultaneous testing of the receiving sensitivity using a line feed method. If the transmission power is not set, the transmission power of the aerial unit and the ground device will be equivalent. This will cause the aerial device to be synchronized with the ground device, with no error frames added and uplink communication normal; while the ground device has already lost synchronization with the aerial device and cannot achieve downlink communication.

[0117] In order to ensure that the uplink receiving sensitivity (air equipment) and downlink receiving sensitivity (ground equipment) tests can be carried out simultaneously, it is necessary to use the difference between the dBm of the high-power transmitting equipment and the dBm of the low-power transmitting equipment as the increase in the transmission attenuation value of the high-power equipment host computer to set it; from Example 2-3, it can be seen that the transmission power of the air equipment is 33dBm (2W), and the transmission power of the ground equipment is 43dBm (20W). The transmission attenuation of the ground equipment defaults to 17, and the transmission attenuation increase value of the ground equipment = 43-33 = 10, so the attenuation value needs to be set to 27 on the ground equipment host computer.

[0118] So you can press Figure 5By referring to the one-way receiving sensitivity test method, the receiving sensitivity test of the aerial equipment and the ground equipment can be realized. The receiving sensitivity of the two-way receiver (ground equipment or aerial equipment) can be measured at one time = the initial value Pc of the power input to the receiver (ground equipment or aerial equipment) - the final attenuation value Kf of the adjustable attenuator.

[0119] It can be seen from the embodiments that the present invention at least includes the following beneficial effects:

[0120] (1) Provides two device receiving sensitivity test methods: uplink aerial device receiving sensitivity test and downlink ground device receiving sensitivity test, which can be expanded to test the receiving sensitivity of multiple devices;

[0121] (2) Provide high-power protection function by using a 30dB / 50W fixed attenuator to protect airborne equipment, ground equipment, and spectrum analyzers. The fixed attenuator value can be selected according to the transmission power of the equipment at both ends;

[0122] (3) Provides software configuration function for transmission attenuation, realizing transmission attenuation configuration for airborne equipment and ground equipment, and can also expand software configuration functions such as receiving gain;

[0123] (4) Provide a function for testing the bidirectional receiving sensitivity simultaneously. By configuring the end with higher transmitting power through software, the transmitting power of the devices at both ends is basically equal. The value of the adjustable attenuator is adjusted to calculate the bidirectional receiving sensitivity of the devices at both ends.

[0124] The above solution is only an illustration of a preferred embodiment, but is not limited thereto. When implementing the present invention, appropriate replacements and / or modifications can be made according to user needs.

[0125] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0126] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A data link system receiving sensitivity test system, comprising a receiver and a matching signal input device, characterized in that: Also includes: A matching power splitter is provided between the signal input device and the receiver, and the power splitter is also connected to a spectrum analyzer for testing; Wherein, a matching adjustable attenuator is provided between the power divider and the signal input device; The receiver, spectrum analyzer, power splitter, signal input device, and adjustable attenuator are connected to each other through a plurality of matching first radio frequency cables to obtain a corresponding test environment; It also includes: using the test environment to perform a one-way or two-way test of the receiving sensitivity of the uplink and / or downlink of the data link system; The test process of the test system is configured to include: Step 1: Measure the loss of each accessory in the test environment; Step 2: Set the transmission attenuation of the ground equipment and the aerial equipment through the host computer, and measure the transmission power of the signal input device through the spectrum analyzer; Step 3: Obtain an initial value Pc of the power sent by the signal input device to the receiver RF port by measurement or calculation; Step 4: Connect all accessories in the test environment, adjust the adjustable attenuator, and calculate the receiver sensitivity based on the following formula: Receiving sensitivity Kf = initial power value Pc - final attenuation value Kf of adjustable attenuator; In step 4, the method for obtaining the final attenuation value of the adjustable attenuator is configured to include: S40, performing initial stepping by the first adjustment knob, and when the receiver host computer cannot communicate with the air unit, calling back one step to complete the coarse adjustment; S41, performing a second stepping by using the second adjustment knob, and when the receiver loses synchronization with the signal input device, calling back one step at a time until the receiver is synchronized with the signal input device and fine adjustment is completed when no error frames increase; S42, the final attenuation value Kf of the adjustable attenuator = the first adjustment knob value + the second adjustment knob value; When performing a two-way simultaneous test of the receiving sensitivity of the aerial device in the uplink and the split ground system in the downlink, it is also necessary to set the attenuation value on the host computer of the ground device. The attenuation value = the transmit power of the ground device - the transmit power of the aerial device + the default transmit attenuation setting of the split ground system. When performing a one-way test of the receiving sensitivity of the aerial device in the uplink, the aerial device is used as the receiver and the ground device is used as the signal input device; In step 2, when testing the receiving sensitivity of the aerial device, the transmit attenuation of the split ground system is set to 17dB by default; When performing a one-way test of the receiving sensitivity of the ground equipment in the downlink of the data link system, the ground equipment is used as the receiver and the airborne equipment is used as the signal input device; In step 2, when testing the receiver sensitivity of the split ground system, the transmit attenuation of the aerial device is set to 4dB by default; A first fixed attenuator is provided between the power divider and the receiver, and a second fixed attenuator is provided between the adjustable attenuator and the signal input device; The first fixed attenuator and the power divider, and the second fixed attenuator and the signal input device are connected respectively via matching second RF cables; The adjustable attenuator is configured to have a first adjustment knob with a 10-fold step and a second adjustment knob with a 1-fold step; In step 1, the loss measurement is obtained by performing a calibration test on a vector analyzer.

2. The receiving sensitivity test system of the data link system according to claim 1, characterized in that: In step 3, the initial power value is measured by directly connecting the spectrum analyzer, the second fixed attenuator, and the signal input device for testing; The calculation of the initial power value is obtained by the following formula: The initial power value Pc = the transmit power Pf of the input device - the total loss of each RF cable - the total attenuation value of each fixed attenuator - the power divider loss Gf - the initial attenuation value Kc of the adjustable attenuator.

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