Receiver performance test method and system, electronic equipment and program product

Abstract

The invention provides a receiver performance test method and system, electronic equipment and a program product, and the method comprises the steps: modulating the power of a designed test signal, transmitting the modulated test signal to a tested receiver, carrying out the time domain coarse alignment and time domain fine alignment of a first time domain signal of the tested receiver and the test signal, enabling the coarse alignment to provide an initial synchronization reference for the fine alignment, and enabling the fine alignment to provide an initial synchronization reference for the fine alignment; the search range is greatly reduced; the fine alignment is based on the result of the coarse alignment, high-precision calibration is achieved, and closed-loop iteration is formed. Through coarse alignment and fine alignment, the alignment efficiency can be improved on the premise that the alignment precision is ensured, constellation points are subsequently extracted to calculate the EVM value, and real-time processing of performance testing of the tested receiver is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of information transmission, and in particular, to a method, a system, an electronic device, and a program product for testing the performance of a receiver. Background Art

[0002] Error Vector Magnitude (EVM) is a comprehensive performance index widely used in communication systems and is established as a core parameter for compliance testing of wireless local area networks and mobile communication devices by mainstream communication standards such as WLAN 802.11, 4G LTE, and 5G. In addition, it is also an extremely useful system-level index that can quantify the comprehensive impact of all potential impairments in the system through a simple and understandable value. EVM is a simple index that quantifies the comprehensive impairment of all signals in the system. Devices using digital modulation often define this index, which can be represented by an in-phase (I) and quadrature (Q) vector diagram (also known as a constellation diagram). Generally, the way to calculate EVM is to find the ideal constellation position for each received signal. By calculating the root mean square of all error vector magnitudes between the position of the received signal and its closest ideal constellation position, the EVM value of the receiver can be obtained. However, the existing EVM test schemes take a long time to ensure accuracy and cannot achieve real-time processing. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a method, a system, an electronic device, and a program product for testing the performance of a receiver, so as to solve the problem that the existing EVM test schemes take a long time to ensure accuracy and cannot achieve real-time processing.

[0004] A method for testing the performance of a receiver provided by the embodiments of the present application includes:

[0005] Adjust the transmission power of the test signal and then send it to the receiver under test;

[0006] Sample the first time-domain signal received by the receiver under test;

[0007] Perform time-domain coarse alignment and then time-domain fine alignment on the first time-domain signal and the test signal to obtain a second time-domain signal;

[0008] After performing channel equalization on the second time-domain signal, extract the equalized constellation points;

[0009] Extract the original data constellation points according to the test signal;

[0010] Obtain the EVM value of the received signal of the receiver under test at the transmission power according to the equalized constellation points and the original data constellation points.

[0011] In this technical solution, a designed test signal is modulated in power and transmitted to the receiver under test. The receiver's first time-domain signal is then coarsely and finely aligned with the test signal. Coarse alignment provides an initial synchronization reference for fine alignment, significantly narrowing the search range. Fine alignment, based on the coarse alignment results, achieves high-precision calibration, forming a closed-loop iteration. This combination of coarse and fine alignment improves alignment efficiency while ensuring accuracy. Constellation points are then extracted and EVM values are calculated, enabling real-time performance testing of the receiver under test.

[0012] In some optional implementations, adjusting the transmission power of the test signal and then sending it to the receiver under test includes:

[0013] The test signal is sent to the receiver under test after adjusting the transmit power according to a power scanning strategy; wherein the power scanning strategy includes: adjusting the transmit power in corresponding steps in different power intervals.

[0014] In some optional implementations, adjusting the transmit power in corresponding steps in different power intervals includes:

[0015] In the low power area, adjust the transmit power in the first step;

[0016] In the medium power range, adjust the transmit power in the second step;

[0017] In the high power area, adjust the transmit power in the third step;

[0018] Among them, the first step is greater than the second step, and the first step is greater than the third step.

[0019] In the above technical solution, the power scanning strategy involves sending test signals at different transmit power levels to evaluate the performance of the receiver under different signal strengths.

[0020] Specifically, subcarrier-level EVM calculation:

[0021]

[0022] Where Ik and Qk are the actual I and Q components of the received signal on the kth subcarrier; are the reference I and Q components of the ideal signal on the kth subcarrier; P avg is the average symbol power, M is the total number of subcarriers.

[0023] In some optional implementations, the power scanning strategy is refined into three different power ranges, each with its own specific step size and dominant signal impairment type. This strategy helps to more comprehensively evaluate the receiver's performance under different signal strengths and accurately identify the main factors affecting receiver performance at different power levels. Specifically, it includes:

[0024] Low-power range (-40dBm to -30dBm): The step size is 10dB. Noise is the dominant factor. In this power range, signal strength is relatively low, so noise becomes the primary factor affecting receiver performance. By adjusting the transmit power in 10dB steps, you can more quickly cross the noise-dominated region, while reducing unnecessary test points and improving test efficiency.

[0025] Mid-power range (-25dBm to -20dBm): The step size is 5dB. The dominant factor is the coupling of noise and distortion. Within this power range, noise and distortion (such as linear distortion and phase noise) begin to couple with each other, jointly affecting receiver performance. Therefore, using a smaller step size (5dB) can more precisely capture the changes in these effects, providing a more accurate reference for receiver design.

[0026] High-power range (-15dBm to -10dBm): The step size is 5dB. Nonlinear distortion is the dominant factor. In this power range, signal strength is high, and nonlinear distortion (such as harmonic distortion and intermodulation distortion) becomes the main factor affecting receiver performance. Using the same 5dB step size ensures accurate measurement and evaluation of the impact of this nonlinear distortion on receiver performance.

[0027] This power sweep strategy systematically evaluates receiver performance at varying signal strengths and identifies the dominant types of signal impairments at different power levels. This helps receiver designers and engineers more accurately understand receiver performance limitations and optimize receiver design to improve overall performance. Furthermore, this strategy provides strong support for communication system testing and verification, ensuring stable operation and meeting performance requirements in real-world applications.

[0028] In some optional implementations, after obtaining the EVM value of the received signal of the receiver under test at the transmit power, the method further includes:

[0029] In the low power region, the SINAD and ENOB of the received signal of the receiver under test at the transmit power are calculated based on the EVM value of the received signal.

[0030] In the high power area, according to ΔEVM and ΔP in , calculate the IIP3 of the received signal of the receiver under test at the transmit power;

[0031] Among them, ENOB is the effective bit width of the analog-to-digital converter, SINAD is the ratio of signal to noise, IIP3 is the third-order intercept point of the RF link, ΔEVM is the change of EVM value with input power change, ΔP in is the step change of input power.

[0032] Specifically, the system noise model (low power area):

[0033] SINAD = -20log 10 (EVM / 100)

[0034] Nonlinear distortion model (high power area):

[0035]

[0036] Among them, ENOB is the effective bit width of the analog-to-digital converter, which represents the impact of quantization noise on performance. SINAD is the ratio of signal to noise. EVM is the error vector magnitude, which reflects the signal demodulation accuracy. IIP3 is the third-order intermodulation intercept point of the RF link, which measures the degree of nonlinear distortion. in is the input signal power. ΔEVM is the change in EVM value as the input power changes. ΔP in is the step change of input power.

[0037] SINAD is an important metric for measuring signal-to-noise ratio (SNR). It takes into account factors such as signal power, noise power, harmonic distortion, and intermodulation distortion. In low-power environments, where noise is the dominant factor, calculating SINAD provides a more accurate assessment of receiver performance in noisy environments.

[0038] ENOB is a key performance metric for analog-to-digital converters (ADCs). It indicates the number of bits the ADC can effectively convert in real-world applications. By using the EVM value and noise characteristics of the received signal, the ADC's effective bit width can be calculated, thereby evaluating the ADC's performance.

[0039] IIP3 is an important indicator for measuring the nonlinear distortion capability of a radio frequency link. It indicates the point at which the power of the third-order intermodulation product is equal to the input signal power when the input signal power increases to a certain level.

[0040] In the high power region, nonlinear distortion becomes the dominant factor. By calculating ΔEVM (the change in EVM value with input power) and ΔP in (the amount of step change in input power), the IIP3 value can be derived to evaluate the nonlinear distortion performance of the RF link.

[0041] In the above technical solution, in addition to calculating the EVM value of the received signal, the EVM value and other relevant parameters are further used to evaluate other key performance indicators of the receiver. These additional calculations help to more comprehensively understand the performance of the receiver and provide more valuable references for receiver design and optimization.

[0042] In some alternative embodiments, the test signal is a periodic physical downlink shared channel, and a blank segment is reserved in each basic time unit of the test signal to form a time-domain empty window.

[0043] In some alternative embodiments, the time-domain coarse alignment includes:

[0044] Perform sliding window energy calculation on the first time-domain signal to locate the blank segment of the first time-domain signal;

[0045] Adjust the signal start point of the first time-domain signal according to the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal to obtain a coarsely aligned signal.

[0046] Specifically, the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal is the coarse alignment time delay TAcoarse:

[0047]

[0048] where TAcoarse is the time delay estimation value after coarse alignment, representing the signal start position. D is the start index of the sliding window, used to traverse the possible start positions of the time-domain signal. y(n) is the complex sample value of the received time-domain signal at the nth sampling point. M is the number of sampling points of the blank segment.

[0049] In the above technical solution, PDSCH is a channel used for downlink data transmission in a communication system. Its periodic design enables the receiving end to anticipate the arrival time and format of the signal. A blank segment is reserved in each basic time unit to form a time-domain empty window. This empty window can be used by the receiving end for signal synchronization and time-domain alignment because the signal power within the empty window is zero or very low and is easy to identify. Perform sliding window energy calculation on the received first time-domain signal. The size and step of the sliding window can be adjusted according to system parameters and signal characteristics. By calculating the signal energy within each window, the blank segment in the signal can be identified because the energy of the blank segment will be significantly lower than that of the part with signal. Locate the blank segment in the first time-domain signal according to the result of the sliding window energy calculation. These blank segments should correspond in time to the blank segments in the test signal. Adjust the signal start point of the first time-domain signal according to the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal. This adjustment process is called coarse alignment, which can roughly align the received signal with the test signal in time.

[0050] In some alternative embodiments, the time-domain fine alignment includes:

[0051] Performing OFDM demodulation on the coarse alignment signal to extract the fine alignment delay estimation value;

[0052] Specifically, the fine alignment delay estimation value (unit: sampling point):

[0053]

[0054] where TAfine is the sub-sampling level delay estimation value after fine alignment. τ is the sub-sampling level delay variable to be optimized. H(k) is the frequency-domain response of the channel on the k-th sub-carrier, obtained by OFDM demodulation. N is the number of FFT points for FFT conversion in the OFDM demodulation process.

[0055] If the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the coarse alignment signal with a step precision of 1 sampling point to obtain the shifted coarse alignment signal;

[0056] Continue to extract the fine alignment delay estimation value from the shifted coarse alignment signal, and when the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the coarse alignment signal with a step precision of 1 sampling point; repeat this process until the absolute value of the fine alignment delay estimation value is less than 1 sampling point, and use the coarse alignment signal at this time as the second time-domain signal.

[0057] In the above technical solution, OFDM (Orthogonal Frequency Division Multiplexing) demodulation is performed on the coarse alignment signal. OFDM demodulation can convert the time-domain signal into a frequency-domain signal, making it easier to identify the delay information in the signal.

[0058] During the demodulation process, the fine alignment delay estimation value will be extracted, which represents the small deviation in time between the received signal and the test signal. Determine whether the absolute value of the fine alignment delay estimation value is greater than 1 sampling point. If it is greater than 1 sampling point, it means that there is still a large deviation in time between the received signal and the test signal, and further adjustment is required. If the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the coarse alignment signal with a step precision of 1 sampling point. The cyclic shift can adjust the starting point of the signal, thereby reducing the delay deviation between the received signal and the test signal. The shifted coarse alignment signal will be used as the new input signal, and continue to perform OFDM demodulation and extraction of the fine alignment delay estimation value.

[0059] Repeat the above process, that is, continue to extract the fine alignment delay estimate value for the shifted coarsely aligned signal, and when the absolute value of the fine alignment delay estimate value is greater than 1 sampling point, perform a cyclic shift on the coarsely aligned signal with a step precision of 1 sampling point. This process will be repeated until the absolute value of the fine alignment delay estimate value is less than 1 sampling point. At this time, the received signal and the test signal have reached a high alignment precision in time. Take the coarsely aligned signal at this time as the second time-domain signal. This signal has gone through two steps of coarse alignment and fine alignment and is highly consistent with the test signal in time, and can be used for subsequent signal processing and analysis.

[0060] Through this method, the accuracy of time-domain alignment can be further improved to ensure the consistency between the received signal and the test signal in time.

[0061] In some alternative embodiments, it further includes:

[0062] For the test signal, adjust the transmission power according to the power scan strategy and then send it to the spectrum analyzer;

[0063] Analyze the test signal through the spectrum analyzer to obtain the EVM value of the test signal;

[0064] Subtract the EVM value of the test signal from the EVM value of the received signal to obtain the EVM degradation value of the receiver under test at the transmission power.

[0065] In the above technical solution, subtract the EVM value of the test signal from the EVM value of the received signal to obtain the EVM degradation value of the receiver under test at the transmission power. The EVM degradation value represents the degree of signal quality degradation due to the processing of the receiver. The EVM degradation value is an important performance indicator, which directly reflects the signal processing ability of the receiver. The smaller the EVM degradation value, the stronger the signal processing ability of the receiver and the smaller the degree of signal quality degradation. By analyzing the EVM degradation values at different power levels, the performance of the receiver under different signal intensities can be evaluated, providing an important reference for the design and optimization of the receiver.

[0066] A receiver performance test system provided by an embodiment of the present application includes: a signal generator, a receiver under test, and a test device; the receiver under test is connected to the test device, and the signal generator is connected to the test device;

[0067] The signal generator is configured to: adjust the transmission power of the test signal and then send it to the receiver under test;

[0068] The receiver under test is configured to: sample the first time-domain signal received by the receiver under test;

[0069] A test device is used to: perform time-domain rough alignment and time-domain fine alignment on a first time-domain signal and a test signal successively to obtain a second time-domain signal; extract equalized constellation points after performing channel equalization on the second time-domain signal; extract original data constellation points according to the test signal; and obtain the EVM value of the received signal of the receiver under test at the transmit power according to the equalized constellation points and the original data constellation points.

[0070] An electronic device provided by an embodiment of the present application includes: a processor and a memory, where the memory stores machine-readable instructions executable by the processor, and when the machine-readable instructions are executed by the processor, the method described in any of the above is executed.

[0071] A computer program product provided by an embodiment of the present application includes computer programs / instructions, and when the computer programs / instructions are executed by a processor, the steps of the method described in any of the above are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0073] Figure 1 It is a flowchart of the steps of a receiver performance test method provided by an embodiment of the present application;

[0074] Figure 2 It is a schematic diagram of the working process of a receiver performance test system provided by this embodiment;

[0075] Figure 3 It is a possible structural diagram of an electronic device provided by an embodiment of the present application.

[0076] Icons: 1 - Processor, 2 - Memory, 3 - Communication interface, 4 - Communication bus. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0077] The following will describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. <F

[0078] Please refer to Figure 1 , Figure 1 It is a flowchart of the steps of a receiver performance test method provided by an embodiment of the present application, including:

[0079] Step 100: Adjust the transmit power of the test signal and then send it to the receiver under test;

[0080] Among them, the test signal is predefined to simulate the signal in actual communication. To achieve subsequent time-domain alignment, a blank segment can be reserved in the test signal to facilitate subsequent alignment through the blank segment.

[0081] Step 200: Sample the first time-domain signal received by the receiver under test.

[0082] Among them, the receiver under test first performs acquisition through an ADC, and then the FPGA provides real-time acquisition data to the test equipment according to certain sampling requirements. The first time-domain signal is the signal sampled by the receiver under test, and this signal is sent to the receiver under test by the signal generator after adjusting the transmission power of the test signal.

[0083] Step 300: Perform time-domain coarse alignment and time-domain fine alignment on the first time-domain signal and the test signal successively to obtain a second time-domain signal.

[0084] Among them, the methods for time-domain alignment include: reserving a blank segment in the test signal and performing time-domain alignment by aligning the blank segments of the first time-domain signal and the test signal; or performing time-domain alignment through channel estimation feedback.

[0085] Step 400: After performing channel equalization on the second time-domain signal, extract the equalized constellation points.

[0086] Among them, channel equalization is implemented through OFDM demodulation. Specifically, the channel estimation result H(k) is used to perform equalization compensation on the data subcarriers.

[0087] Step 500: Extract the original data constellation points according to the test signal.

[0088] Step 600: Obtain the EVM value of the received signal of the receiver under test at the transmission power according to the equalized constellation points and the original data constellation points.

[0089] Specifically, the subcarrier-level EVM calculation:

[0090]

[0091] Among them, Ik and Qk are the actual I and Q components of the received signal on the k-th subcarrier; are the reference I and Q components of the ideal signal on the k-th subcarrier; P avg is the average symbol power, M is the total number of subcarriers.

[0092] In an embodiment of the present application, a designed test signal is modulated in power and sent to the receiver under test. The first time-domain signal of the receiver under test is then coarsely aligned and finely aligned with the test signal. Coarse alignment provides an initial synchronization reference for fine alignment, significantly narrowing the search range. Fine alignment, based on the coarse alignment results, achieves high-precision calibration, forming a closed-loop iteration. Coarse and fine alignment improves alignment efficiency while ensuring accuracy. Constellation points are then extracted and EVM values are calculated, enabling real-time processing of the receiver under test's performance test.

[0093] In some optional implementations, adjusting the transmission power of the test signal and then sending it to the receiver under test includes:

[0094] The test signal is sent to the receiver under test after adjusting the transmit power according to a power scanning strategy; wherein the power scanning strategy includes: adjusting the transmit power in corresponding steps in different power intervals.

[0095] In some optional embodiments, the transmit power is adjusted with corresponding steps in different power ranges, including: in the low power area, the transmit power is adjusted with a first step; in the medium power area, the transmit power is adjusted with a second step; in the high power area, the transmit power is adjusted with a third step; wherein the first step is greater than the second step, and the first step is greater than the third step.

[0096] In some optional embodiments, the power scanning strategy includes: in the low power region of -40dBm to -30dBm, with a 10dB step, quantization noise dominates; in the medium power region of -25dBm to -20dBm, with a 5dB step, noise coupling region; in the high power region of -15dBm to -10dBm, with a 5dB step, nonlinear distortion dominates.

[0097] In this embodiment, the power scanning strategy is refined into three different power ranges, each with its own specific step size and dominant signal impairment type. This strategy helps to more comprehensively evaluate the receiver's performance under different signal strengths and accurately identify the main factors affecting receiver performance at different power levels.

[0098] Low-power range (-40dBm to -30dBm): The step size is 10dB. Noise is the dominant factor. In this power range, signal strength is relatively low, so noise becomes the primary factor affecting receiver performance. By adjusting the transmit power in 10dB steps, you can more quickly cross the noise-dominated region, while reducing unnecessary test points and improving test efficiency.

[0099] Mid-power range (-25dBm to -20dBm): The step size is 5dB. The dominant factor is the coupling of noise and distortion. Within this power range, noise and distortion (such as linear distortion and phase noise) begin to couple with each other, jointly affecting receiver performance. Therefore, using a smaller step size (5dB) can more precisely capture the changes in these effects, providing a more accurate reference for receiver design.

[0100] High-power range (-15dBm to -10dBm): The step size is 5dB. Nonlinear distortion is the dominant factor. In this power range, signal strength is high, and nonlinear distortion (such as harmonic distortion and intermodulation distortion) becomes the main factor affecting receiver performance. Using the same 5dB step size ensures accurate measurement and evaluation of the impact of this nonlinear distortion on receiver performance.

[0101] This power sweep strategy systematically evaluates receiver performance at varying signal strengths and identifies the dominant types of signal impairments at different power levels. This helps receiver designers and engineers more accurately understand receiver performance limitations and optimize receiver design to improve overall performance. Furthermore, this strategy provides strong support for communication system testing and verification, ensuring stable operation and meeting performance requirements in real-world applications.

[0102] In some optional embodiments, after obtaining the received signal EVM value of the tested receiver at the transmit power, the method further includes: in the low power region, according to the received signal EVM value, calculating the SINAD and ENOB of the received signal of the tested receiver at the transmit power; in the high power region, according to ΔEVM and ΔP in , calculate the IIP3 of the received signal of the receiver under test at the transmit power;

[0103] Among them, ENOB is the effective bit width of the analog-to-digital converter, SINAD is the ratio of signal to noise, IIP3 is the third-order intercept point of the RF link, ΔEVM is the change of EVM value with input power change, ΔP in is the step change of input power.

[0104] Specifically, the system noise model (low power area):

[0105] SINAD = -20log 10 (EVM / 100)

[0106] Nonlinear distortion model (high power area):

[0107]

[0108] Among them, ENOB is the effective bit width of the analog-to-digital converter, which characterizes the impact of quantization noise on performance. SINAD is the signal-to-noise ratio. EVM is the error vector magnitude, which reflects the signal demodulation accuracy. IIP3 is the third-order intermodulation intercept point of the RF link, which measures the degree of nonlinear distortion. P in is the input signal power. ΔEVM is the change in the EVM value with respect to the change in the input power. ΔP in is the step change in the input power.

[0109] SINAD is an important indicator for measuring the signal quality-to-noise ratio. It takes into account factors such as signal power, noise power, harmonic distortion, and intermodulation distortion. In the low-power region, since noise is the dominant factor, calculating SINAD can more accurately evaluate the performance of the receiver in a noisy environment.

[0110] ENOB is an important performance indicator of the analog-to-digital converter (ADC). It represents the number of bits that the ADC can effectively convert in practical applications. By utilizing the EVM value and noise characteristics of the received signal, the effective bit width of the ADC can be calculated, thereby evaluating the performance of the ADC.

[0111] IIP3 is an important indicator for measuring the nonlinear distortion ability of the RF link. It represents the point at which the power of the third-order intermodulation product is equal to the power of the input signal when the input signal power increases to a certain extent.

[0112] In the high-power region, nonlinear distortion becomes the dominant factor. By calculating ΔEVM (the change in the EVM value with respect to the change in the input power) and ΔP in (the step change in the input power), the value of IIP3 can be deduced, thereby evaluating the nonlinear distortion performance of the RF link.

[0113] In the embodiments of the present application, in addition to calculating the EVM value of the received signal, the EVM value and other relevant parameters are further used to evaluate other key performance indicators of the receiver. These additional calculations help to more comprehensively understand the performance of the receiver and provide more valuable references for receiver design and optimization.

[0114] In some alternative embodiments, the test signal is a periodic physical downlink shared channel, and blank segments are reserved in each basic time unit of the test signal to form a time-domain empty window.

[0115] In some alternative embodiments, the time-domain rough alignment includes: calculating the sliding window energy of the first time-domain signal to locate the blank segment of the first time-domain signal; adjusting the signal start point of the first time-domain signal according to the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal to obtain a roughly aligned signal.

[0116] Specifically, the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal is the coarse alignment delay TAcoarse:

[0117]

[0118] Among them, TAcoarse is the delay estimation value after coarse alignment, representing the starting position of the signal. D is the starting index of the sliding window, used to traverse the possible starting positions of the time-domain signal. y(n) is the complex sampling value of the received time-domain signal at the nth sampling point. M is the number of sampling points of the blank segment.

[0119] In the embodiments of the present application, PDSCH is a channel used for downlink data transmission in a communication system. Its periodic design enables the receiving end to anticipate the arrival time and format of the signal. A blank segment is reserved within each basic time unit to form a time-domain empty window. This empty window can be used by the receiving end for signal synchronization and time-domain alignment because the signal power within the empty window is zero or very low, making it easy to identify. Calculate the energy of the sliding window for the received first time-domain signal. The size and step length of the sliding window can be adjusted according to system parameters and signal characteristics. By calculating the signal energy within each window, the blank segments in the signal can be identified because the energy of the blank segments will be significantly lower than that of the part with signal. Locate the blank segments in the first time-domain signal according to the result of the sliding window energy calculation. These blank segments should correspond in time to the blank segments in the test signal. Adjust the signal starting point of the first time-domain signal according to the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal. This adjustment process is called coarse alignment, which can roughly align the received signal with the test signal in time.

[0120] In some optional embodiments, the time-domain fine alignment includes: performing OFDM demodulation on the coarsely aligned signal to extract the fine alignment delay estimation value; if the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the coarsely aligned signal with a step precision of 1 sampling point to obtain the shifted coarsely aligned signal; continue to extract the fine alignment delay estimation value for the shifted coarsely aligned signal, and perform a cyclic shift on the coarsely aligned signal with a step precision of 1 sampling point when the absolute value of the fine alignment delay estimation value is greater than 1 sampling point; repeat this process until the absolute value of the fine alignment delay estimation value is less than 1 sampling point, and use the coarsely aligned signal at this time as the second time-domain signal.

[0121] Specifically, the fine alignment delay estimation value (unit: sampling point):

[0122]

[0123] Among them, TAfine is the sub-sampling level delay estimation value after fine alignment. τ is the sub-sampling level delay variable to be optimized. H(k) is the frequency domain response of the channel on the k-th sub-carrier, which is obtained by OFDM demodulation. N is the number of FFT points for FFT conversion in the OFDM demodulation process.

[0124] In the embodiment of the present application, OFDM (Orthogonal Frequency Division Multiplexing) demodulation is performed on the roughly aligned signal. OFDM demodulation can convert the time domain signal into a frequency domain signal, making it easier to identify the delay information in the signal.

[0125] During the demodulation process, the fine alignment delay estimation value will be extracted. This value represents the small deviation in time between the received signal and the test signal. It is judged whether the absolute value of the fine alignment delay estimation value is greater than 1 sampling point. If it is greater than 1 sampling point, it indicates that there is still a large deviation in time between the received signal and the test signal, and further adjustment is required. If the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, a cyclic shift with a step precision of 1 sampling point is performed on the roughly aligned signal. The cyclic shift can adjust the starting point of the signal, thereby reducing the delay deviation between the received signal and the test signal. The shifted roughly aligned signal will be used as the new input signal, and OFDM demodulation and extraction of the fine alignment delay estimation value will continue.

[0126] Repeat the above process, that is, continue to extract the fine alignment delay estimation value from the shifted roughly aligned signal, and perform a cyclic shift with a step precision of 1 sampling point on the roughly aligned signal when the absolute value of the fine alignment delay estimation value is greater than 1 sampling point. This process will be repeated until the absolute value of the fine alignment delay estimation value is less than 1 sampling point. At this time, the received signal and the test signal have reached a high alignment accuracy in time domain. The roughly aligned signal at this time is used as the second time domain signal. This signal has gone through two steps of rough alignment and fine alignment, and is highly consistent with the test signal in time domain, and can be used for subsequent signal processing and analysis.

[0127] By this method, the accuracy of time domain alignment can be further improved to ensure the consistency in time between the received signal and the test signal.

[0128] In some alternative embodiments, it further includes: adjusting the transmission power of the test signal according to the power scanning strategy and then sending it to the spectrum analyzer; analyzing the test signal by the spectrum analyzer to obtain the EVM value of the test signal; subtracting the EVM value of the test signal from the EVM value of the received signal to obtain the EVM deterioration value of the receiver under test at the transmission power.

[0129] In the embodiment of the present application, the EVM value of the test signal is subtracted from the EVM value of the received signal to obtain the EVM degradation value of the receiver under test at the transmit power. The EVM degradation value indicates the degree to which the signal quality has degraded due to the processing of the receiver. The EVM degradation value is an important performance indicator that directly reflects the receiver's signal processing capability. The smaller the EVM degradation value, the stronger the receiver's signal processing capability and the smaller the degree of signal quality degradation. By analyzing the EVM degradation values at different power levels, the performance of the receiver under different signal strengths can be evaluated, providing an important reference for the design and optimization of the receiver.

[0130] An embodiment of the present application provides a receiver performance test system, comprising: a signal generator, a receiver under test, and a test device. The receiver under test is connected to the test device, and the signal generator is connected to the test device.

[0131] The signal generator is configured to adjust the transmit power of a test signal and transmit the resultant signal to a receiver under test. The receiver under test is configured to sample a first time domain signal received by the receiver under test. The test equipment is configured to sequentially perform coarse time domain alignment and fine time domain alignment on the first time domain signal and the test signal to obtain a second time domain signal. After performing channel equalization on the second time domain signal, equalized constellation points are extracted. The original data constellation points are extracted based on the test signal. The EVM value of the received signal of the receiver under test at the transmit power is obtained based on the equalized constellation points and the original data constellation points.

[0132] In some optional embodiments, the test device is further used to: adjust the transmission power of the test signal according to a power scanning strategy and then send it to the receiver under test; wherein the power scanning strategy includes: adjusting the transmission power in corresponding steps in different power intervals.

[0133] In some optional embodiments, the signal generator is further used to: adjust the transmit power with a first step in a low power area; adjust the transmit power with a second step in a medium power area; and adjust the transmit power with a third step in a high power area; wherein the first step is greater than the second step, and the first step is greater than the third step.

[0134] In some optional embodiments, the test equipment is further configured to: calculate the SINAD and ENOB of the received signal of the receiver under test at the transmit power according to the EVM value of the received signal in the low power region; calculate the SINAD and ENOB of the received signal of the receiver under test at the transmit power according to the ΔEVM and ΔP in the high power region; in , calculate the IIP3 of the received signal of the tested receiver at the transmit power; where ENOB is the effective bit width of the analog-to-digital converter, SINAD is the ratio of signal to noise, IIP3 is the third-order intercept point of the RF link, ΔEVM is the change in EVM value with input power change, ΔP inis the step change amount of the input power.

[0135] In some alternative embodiments, the test signal is a periodic physical downlink shared channel, and each basic time unit of the test signal reserves a blank segment to form a time-domain empty window.

[0136] In some alternative embodiments, the test device is further configured to: calculate the sliding window energy of the first time-domain signal to locate the blank segment of the first time-domain signal; adjust the signal start point of the first time-domain signal according to the position offset of the blank segment of the first time-domain signal compared to the blank segment of the test signal to obtain a roughly aligned signal.

[0137] In some alternative embodiments, the test device is further configured to: perform OFDM demodulation on the roughly aligned signal to extract the fine alignment delay estimation value; if the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the roughly aligned signal with a step precision of 1 sampling point to obtain a shifted roughly aligned signal; continue to extract the fine alignment delay estimation value from the shifted roughly aligned signal, and perform a cyclic shift on the roughly aligned signal with a step precision of 1 sampling point when the absolute value of the fine alignment delay estimation value is greater than 1 sampling point; repeat this process until the absolute value of the fine alignment delay estimation value is less than 1 sampling point, and use the roughly aligned signal at this time as the second time-domain signal.

[0138] In some alternative embodiments, a spectrum analyzer is further included. The signal generator also adjusts the transmission power of the test signal according to the power scanning strategy and then sends it to the spectrum analyzer. The spectrum analyzer is configured to analyze the test signal to obtain the EVM value of the test signal. The test device is further configured to: subtract the EVM value of the test signal from the EVM value of the received signal to obtain the EVM degradation value of the receiver under test at the transmission power.

[0139] Please refer to Figure 2 , Figure 2 is the schematic diagram of the working process of the receiver performance test system provided in this embodiment. This embodiment draws the receiver demodulation constellation diagram according to different received power levels and quantifies the EVM value. It can also synchronously quantify the effective bit width (ENOB) of the analog-to-digital converter (ADC), the non-linear distortion of the radio frequency link (such as the third-order intermodulation intercept point IIP3), and the channel delay and other characteristics, and is applicable to the performance test and fault diagnosis of devices such as 5G base stations and satellite communication payloads.

[0140] The signal generator includes a signal source and a control interface. Signal source: a vector signal generator, supporting the generation of multi-frequency point and multi-modulation format signals. Control interface: dynamically configure the power and modulation parameters through instrument operation instructions. The signal source can use the R&S SMW200A signal source.

[0141] The receiver under test includes a radio frequency front end, an ADC module, and an FPGA. Radio frequency front end: low noise amplifier (LNA), digital step attenuator (DSA), intermediate frequency filter, etc. ADC module: 14-bit resolution, system sampling rate, outputting raw I / Q data. FPGA: supporting the data acquisition requirements and providing real-time acquired data. The receiver under test can adopt a low-earth orbit satellite communication payload receiver. The spectrum analyzer can adopt a Keysight N9030B spectrum analyzer.

[0142] The test equipment performs time domain alignment, receiver demodulation, EVM analysis, parameter mapping algorithms, and generates a visualization report.

[0143] Among them, the iterative calibration process of time domain alignment includes:

[0144] Step 1, rough alignment (based on blank segment energy detection);

[0145] Signal design: Generate a periodic PDSCH signal, reserving 2 blank symbols in each Slot (basic time unit) to form a time domain empty window.

[0146] Energy detection: Perform sliding window energy calculation on the time domain signal acquired by the ADC, locate the position of the blank segment, and obtain the rough alignment delay TA coarse .

[0147] Cyclic shift: According to TA coarse Adjust the signal starting point to complete the rough alignment.

[0148] Step 2, fine alignment (based on channel estimation feedback);

[0149] Initial channel estimation: Perform OFDM demodulation (FFT → pilot extraction → channel equalization) on the roughly aligned signal, and extract the fine-grained delay TA fine .

[0150] If |TA fine | > 1, perform cyclic shift on the signal (step precision 1 sampling point).

[0151] Repeat the above steps until |TA fine | ≤ 1 sampling point to ensure complete time domain alignment.

[0152] Among them, if the multiple iterations do not converge, it is determined as a hardware failure (such as clock loss of lock), triggering an alarm and terminating the test.

[0153] Figure 3 Shows a possible structure of the electronic device provided by the embodiment of the present application. Referring to Figure 3 , the electronic device includes: a processor 1, a memory 2, and a communication interface 3, and these components are interconnected and communicate with each other through a communication bus 4 and / or other forms of connection mechanisms (not shown).

[0154] The memory 2 includes one or more (only one is shown in the figure), which can be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc. The processor 1 and other possible components can access the memory 2 and read and / or write data therein.

[0155] The processor 1 includes one or more (only one is shown in the figure), which can be an integrated circuit chip with signal processing capabilities. The above-mentioned processor 1 can be a general-purpose processor, including a central processing unit (CPU), a microcontroller unit (MCU), a network processor (NP) or other conventional processors; it can also be a special-purpose processor, including a neural network processor (NPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. Moreover, when there are multiple processors 1, some of them can be general-purpose processors and the other part can be special-purpose processors.

[0156] The communication interface 3 includes one or more (only one is shown in the figure) interfaces, which can be used to communicate directly or indirectly with other devices to exchange data. The communication interface 3 can include interfaces for wired and / or wireless communication.

[0157] One or more computer program instructions may be stored in the memory 2, and the processor 1 may read and execute these computer program instructions to implement the method provided in the embodiment of the present application.

[0158] Understandably, Figure 3 The structure shown is only for illustration, and the electronic device may also include Figure 3 More or fewer components than shown, or with Figure 3 Different structures are shown. Figure 3 The components shown in the figure can be implemented using hardware, software, or a combination thereof. The electronic device can be a physical device, such as a PC, laptop, tablet, mobile phone, server, embedded device, etc., or a virtual device, such as a virtual machine or virtualized container. Furthermore, the electronic device is not limited to a single device and can also be a combination of multiple devices or a cluster consisting of a large number of devices.

[0159] A computer program product provided in an embodiment of the present application includes a computer program / instruction, which implements the steps of any of the above methods when executed by a processor.

[0160] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0161] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0162] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0163] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0164] The above are only the embodiments of the present application and are not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for testing the performance of a receiver, characterized in that, Including: Adjust the transmission power of the test signal and then send it to the receiver under test; Sample the first time-domain signal received by the receiver under test; Perform time-domain coarse alignment and time-domain fine alignment on the first time-domain signal and the test signal successively to obtain a second time-domain signal; After performing channel equalization on the second time-domain signal, extract the equalized constellation points; Extract the original data constellation points according to the test signal; According to the equalized constellation points and the original data constellation points, obtain the EVM value of the received signal of the receiver under test at the transmission power; 2. The method according to claim 1, wherein The adjusting the transmission power of the test signal and then sending it to the receiver under test includes: Adjust the transmission power of the test signal according to the power scanning strategy and then send it to the receiver under test; wherein, the power scanning strategy includes adjusting the transmission power in corresponding steps in different power intervals.

3. The method according to claim 2, characterized in that The adjusting the transmission power in corresponding steps in different power intervals includes: In the low power region, adjust the transmission power in the first step; In the medium power region, adjust the transmission power in the second step; In the high power region, adjust the transmission power in the third step; Wherein, the first step is greater than the second step, and the first step is greater than the third step.

4. The method according to claim 1, characterized in that, After obtaining the EVM value of the received signal of the receiver under test at the transmission power, further including: In the low power region, calculate the SINAD and ENOB of the received signal of the receiver under test at the transmission power according to the EVM value of the received signal; In the high-power region, based on ΔEVM and ΔP in , calculate the IIP3 of the received signal of the DUT receiver at the transmit power; Among them, ENOB is the effective bit width of the analog-to-digital converter, SINAD is the signal-to-noise ratio, IIP3 is the third-order intermodulation intercept point of the RF link, ΔEVM is the change in the EVM value with respect to the change in the input power, and ΔP in is the step change in the input power.

5. The method according to claim 1, wherein The test signal is a periodic physical downlink shared channel, and blank segments are reserved in each basic time unit of the test signal to form a time-domain empty window.

6. The method according to claim 5, wherein The time-domain coarse alignment includes: Perform sliding window energy calculation on the first time-domain signal to locate the blank segment of the first time-domain signal; According to the position offset of the blank segment of the first time-domain signal compared with the blank segment of the test signal, adjust the signal start point of the first time-domain signal to obtain a coarsely aligned signal.

7. The method according to claim 6, wherein The time-domain fine alignment includes: Perform OFDM demodulation on the coarsely aligned signal to extract the fine alignment delay estimation value; If the absolute value of the fine alignment delay estimation value is greater than 1 sampling point, perform a cyclic shift on the coarsely aligned signal with a step precision of 1 sampling point to obtain a shifted coarsely aligned signal; Continue to extract the fine alignment delay estimation value from the shifted coarsely aligned signal, and perform a cyclic shift on the coarsely aligned signal with a step precision of 1 sampling point when the absolute value of the fine alignment delay estimation value is greater than 1 sampling point; repeat this process until the absolute value of the fine alignment delay estimation value is less than 1 sampling point, and use the coarsely aligned signal at this time as the second time-domain signal.

8. The method according to claim 1, characterized in that, Further including: Adjust the transmission power of the test signal according to the power scanning strategy and then send it to a spectrum analyzer; Analyze the test signal through the spectrum analyzer to obtain the EVM value of the test signal; Subtract the EVM value of the test signal from the EVM value of the received signal to obtain the EVM degradation value of the receiver under test at the transmission power.

9. A receiver performance testing system, characterized in that, Including: A signal generator, a receiver under test, and a test device; The receiver under test is connected to the test equipment, and the signal generator is connected to the test equipment; The signal generator is configured to: adjust the transmission power of a test signal and then send it to the receiver under test; The receiver under test is configured to: sample a first time-domain signal received by the receiver under test; The test equipment is configured to: perform time-domain coarse alignment and then time-domain fine alignment on the first time-domain signal and the test signal to obtain a second time-domain signal; after performing channel equalization on the second time-domain signal, extract the equalized constellation points; Extract the original data constellation points according to the test signal; Obtain the EVM value of the received signal of the receiver under test at the transmission power according to the equalized constellation points and the original data constellation points.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1-7 are implemented.

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