Noise cancellation method based on WIFI7 standard protocol and application thereof

Abstract

The invention belongs to the technical field of communication measurement noise cancellation, and particularly relates to a noise cancellation method based on a WIFI7 standard protocol and application thereof. A real-time measurement average noise cancellation algorithm is adopted, and a noise coefficient is calculated by capturing internal noise when no signal is input and capturing average extracted total noise signals for multiple times, so that external noise is estimated, and single-time captured signals are corrected. According to the invention, a noise cancellation method based on measurement averaging is adopted, so that not only can inherent noise of the signal analyzer be eliminated, but also ircoherent noise in the signal can be eliminated; a convolution correlation algorithm is adopted for synchronization, and the method is suitable for more complex noise environments; and a real-time dynamic averaging method is adopted, so that the stability of the offset effect can be ensured, and the algorithm efficiency is improved. In addition, the method is low in implementation cost and complexity, can be implemented in an FPGA (Field Programmable Gate Array) or a DSP (Digital Signal Processor) in a software mode, has good reconstruction capability and is very suitable for various application environments.

Description

Technical Field

[0001] This invention belongs to the field of communication measurement noise cancellation technology, specifically relating to a noise cancellation method based on the WIFI7 standard protocol and its application. Background Technology

[0002] With the rapid development of communication technology, protocols such as Wi-Fi 7 and 5G are showing a trend towards larger signal bandwidth and higher-order modulation, which places extremely stringent requirements on the error vector amplitude (EVM) performance of equipment. Wideband receiver noise is one of the key factors affecting the residual EVM of signal and spectrum analyzers, and it increases with increasing bandwidth. Therefore, the development of noise cancellation technology is urgently needed.

[0003] In the field of test and measurement for signal reception and analysis, commonly used noise reduction techniques include vector averaging and noise compensation. Vector averaging calculates noise by averaging the I / Q data after time and phase calibration, effectively reducing the impact of irrelevant noise in the entire signal path on the measurement results. However, vector averaging assumes that all measured signals are aligned at the center frequency and sampling frequency without additional center frequency and sampling frequency calibration, thus requiring high equipment synchronization and having limited adaptability to complex noise environments. Traditional noise compensation techniques calculate the difference between the total noise power with the measured signal and the noise power without an external signal, separating and canceling noise interference in the test system to extract the true noise power of the device under test. This technique relies on accurate measurement of ambient temperature and bandwidth and lacks robustness to external interference.

[0004] In addition, domestic research on noise cancellation mainly focuses on hardware circuit design. While optimizing hardware circuit design can reduce the generation of internal noise sources, this approach is complex and has limited ability to eliminate noise interference, making it difficult to meet the research and testing needs of 5G millimeter wave and future 6G communication technologies. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a noise cancellation method based on the WIFI7 standard protocol. It employs a noise cancellation algorithm based on real-time measurement averaging. This method extracts the overall noise signal by capturing internal noise when there is no signal input and averaging multiple captured measurement signals. Synchronization is performed using a convolutional correlation algorithm, the noise figure is calculated, and the single captured signal is corrected. This eliminates the inherent noise of the signal analyzer and incoherent noise in the signal, improving residual EVM performance and thus enhancing the overall performance of the transceiver.

[0006] The technical solution adopted by the present invention to solve its technical problem is as follows: a noise cancellation method based on the WIFI7 standard protocol, which adopts a real-time measurement and averaging noise cancellation algorithm. It calculates the noise figure by capturing internal noise when there is no signal input and extracting the overall noise signal by averaging multiple captures, so as to estimate external noise and correct the single capture signal.

[0007] Preferably, the steps include the following: S1, Single measurement, capture measurement signal ; S2, Multiple captures and average the synchronized measurement signal. avg ; S3. Estimate external noise using noise figure. Where w represents the noise figure; S4. Calculate the corrected signal ( ): .

[0008] Preferably, the noise figure is determined based on the external noise power and the total noise power, where the external noise power equals the total noise power minus the internal noise power.

[0009] Preferably, the calculation of total noise power, Measurement signal Represented as: ; in, This represents the baseband transmitted signal, which is also the reference signal; G represents the system gain. This represents the total noise, which consists of both internal instrument noise and external system noise. Measurement signal captured in a single shot Using convolutional correlation methods and reference signals Achieve precise synchronization; For periodic signals, the average value of the synchronized measurement signal is taken through multiple captures. Ideally, ;s avg This represents the signal after averaging. The total noise n can be obtained by subtraction. total : ; Total noise power N total Based on the total noise signal n total Calculated: Where N represents the total number of data points.

[0010] Preferably, the internal noise signal n of the instrument RXIt can be obtained by capturing the measurement signal without an external signal source and with an external 50-ohm resistor, and then calculating the receiver noise power N. RX : Where N represents the number of data points; N RX That is, internal noise power.

[0011] Preferably, the noise figure w is calculated as follows: ;in, This indicates the external noise power.

[0012] Preferably, the external noise n is estimated using the noise figure. external : ; Therefore, the corrected signal can be calculated. : .

[0013] The application of the above-mentioned noise cancellation method based on the WIFI7 standard protocol is characterized by its applicability to complex noise environments.

[0014] Compared with existing technologies, the advantages of this invention are as follows: This invention employs a noise cancellation method based on measurement averaging, which can eliminate not only the inherent noise of the signal analyzer but also incoherent noise in the signal; it uses a convolutional correlation algorithm for synchronization, making it suitable for more complex noise environments; and it uses a real-time dynamic averaging method, which not only ensures the stability of the cancellation effect but also improves algorithm efficiency. Furthermore, this invention has low implementation cost and complexity, can be implemented in software on FPGAs or DSPs, has good reconfiguration capabilities, and is highly suitable for various application environments. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a noise cancellation method based on the WIFI7 standard protocol.

[0016] Figure 2 The diagram shows the overall noise and internal noise results in Example 1.

[0017] Figure 3 The spectrum of the WIFI 7320MHz bandwidth signal before noise cancellation in Example 1.

[0018] Figure 4 The image shows the signal noise cancellation pattern of the WIFI 7320MHz bandwidth signal in Example 1.

[0019] in, Figure 3 and Figure 4 In the middle, the top left is the spectrum diagram, the top right is the time-domain power diagram, the bottom left is the constellation diagram, and the bottom right is a summary diagram of indicators such as EVM. Detailed Implementation

[0020] To facilitate understanding of the present invention, it will be described in more detail below with reference to the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0021] Example 1: A noise cancellation method based on the WIFI7 standard protocol, combined with Figure 1 The algorithm employs a real-time measurement and averaging noise cancellation method. By capturing internal noise when there is no signal input and extracting the overall noise signal through multiple captures and averaging, the noise figure is calculated and the single capture signal is corrected. This eliminates the inherent noise of the signal analyzer and incoherent noise in the signal, thereby improving the performance of the residual EVM.

[0022] The specific technical solution is described below: 1. First, perform a single measurement to capture the measurement signal. The signal contains all noise components: ; in, This represents the baseband transmitted signal, which is also the reference signal; G represents the system gain. This represents the total noise, which consists of both internal instrument noise and external system noise.

[0023] 2. Measurement signal captured in a single acquisition Using convolutional correlation methods and reference signals Perform precise synchronization.

[0024] 3. For periodic signals like WLAN, by capturing multiple times and averaging the synchronized measurement signals, the overall noise can be almost eliminated under ideal conditions. avg (This represents the signal after averaging) .

[0025] 4. Based on the above formula, the total noise (n) can be obtained by subtracting the values. total ): ; 5. Calculate the total noise power (N) total ), N total Based on the total noise signal n total Calculated: ; Where N represents the total number of data points.

[0026] 6. Internal noise signal of the instrument (nRX The receiver noise power (N) can be obtained by capturing the measurement signal without an external signal source and with an external 50-ohm resistor connected, and then calculating the receiver noise power. RX ): ; Where N represents the number of data points. The single measurement signal, the calculated total noise, and the captured internal noise are as follows: Figure 2 As shown.

[0027] 7. Based on the above, N total and N RX It is known that the ratio of external noise power to total noise power can be determined based on this: ; Where w represents the noise figure. This indicates the external noise power.

[0028] Therefore, the external noise (n) can be estimated using the noise figure. external ): ; From this, the corrected signal can be calculated. ): .

[0029] The principle of the algorithm flow of this scheme is as follows: Figure 1 As shown, this method is based on real-time averaging noise cancellation technology. It captures internal noise when there is no signal input and extracts the overall noise signal through multiple captures and averaging. The noise figure is calculated, and the single-capture signal is corrected to eliminate the inherent noise of the signal analyzer and incoherent noise in the signal, thus improving the residual EVM performance. The real-time averaging method ensures no hysteresis in the averaged signal, guaranteeing the stability of the improved EVM performance. Synchronization of the single measurement signal is achieved through a convolutional correlation algorithm. It can be applied to WIFI7, 5G, and other protocols.

[0030] Error Vector Magnitude (EVM): A core indicator for measuring signal quality in digital communication systems, reflecting the degree of deviation between the actual received signal and the ideal signal (noise-free signal). The smaller the EVM value, the less signal distortion and the better the communication quality.

[0031] Taking a WIFI7320 signal modulated with 4096QAM bandwidth as an example, and considering the impact of signal quality on the error vector amplitude (EVM) under different generation powers, the average signal strength under different generation powers is obtained. The noise figure w was calculated and the signal was corrected. EVM measurements were then performed on the corrected signal under the following conditions: 6.5 GHz frequency, generation power -10 dBm. The results are as follows: Figure 3-4 As shown. Among them, Figure 3 Before noise cancellation, i.e., a single captured signal, EVM=-47.58dB; Figure 4 After noise cancellation testing, EVM = -51.90dB, an improvement of 4.32dB compared to before. According to window 2, the noise floor power is reduced, and the signal-to-noise ratio is improved. The WIFI7 signal error vector amplitude (EVM) corrected using this noise cancellation technology is reduced by more than 4dB, meeting the testing requirements of the WIFI7 standard and improving the testing performance of the transceiver.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A noise cancellation method based on the WIFI7 standard protocol, characterized in that, A noise cancellation algorithm based on real-time measurement and averaging is employed. By capturing internal noise when there is no signal input and extracting the overall noise signal from multiple captures and averaging, the noise figure is calculated to estimate external noise and correct the single capture signal.

2. The noise cancellation method based on the WIFI7 standard protocol according to claim 1, characterized in that, The steps include the following: S1, Single measurement, capture measurement signal ; S2, Multiple captures and average the synchronized measurement signal. avg ; S3. Estimate external noise using noise figure. Where w represents the noise figure; S4. Calculate the corrected signal. : .

3. The noise cancellation method based on the WIFI7 standard protocol according to claim 2, characterized in that, The noise figure is determined based on the external noise power and the total noise power. The external noise power is equal to the total noise power minus the internal noise power.

4. The noise cancellation method based on the WIFI7 standard protocol according to claim 3, characterized in that, Calculation of total noise power, Measurement signal Represented as: ; in, This represents the baseband transmitted signal, which is also the reference signal; G represents the system gain. This represents the total noise, which consists of both internal instrument noise and external system noise. Measurement signal captured in a single shot Using convolutional correlation methods with reference signals Achieve precise synchronization; For periodic signals, the average value of the synchronized measurement signal is taken through multiple captures. Ideally, ;s avg This represents the signal after averaging. The total noise n can be obtained by subtraction. total : ; Total noise power N total Based on the total noise signal n total Calculated: Where N represents the total number of data points.

5. The noise cancellation method based on the WIFI7 standard protocol according to claim 4, characterized in that, Internal noise signal n of the instrument RX It can be obtained by capturing the measurement signal without an external signal source and with an external 50-ohm resistor, and then calculating the receiver noise power N. RX : Where N represents the number of data points; N RX That is, internal noise power.

6. The noise cancellation method based on the WIFI7 standard protocol according to claim 5, characterized in that, Calculation of noise figure w: ;in, This indicates the external noise power.

7. The noise cancellation method based on the WIFI7 standard protocol according to claim 6, characterized in that, The external noise n is estimated using the noise figure. external : ; Therefore, the corrected signal can be calculated. : 。 8. The application of the noise cancellation method based on the WIFI7 standard protocol as described in any one of claims 1-7, characterized in that, Suitable for complex noisy environments.

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