Signal processing method and system

Abstract

The invention provides a signal processing method and system, and the method comprises the steps: carrying out the frequency multiplication of an initial signal, and obtaining a frequency multiplication signal containing a preset frequency; performing filtering processing on the frequency multiplication signal to obtain a filtering signal corresponding to the frequency multiplication signal; carrying out iteration frequency mixing processing on the same-frequency signal of the initial signal and the filtering signal to obtain a frequency mixing signal meeting a preset condition; obtaining the amplitude of a direct current signal in the frequency mixing signal, and determining the phase drift amount of the filtering signal according to the amplitude; and performing phase correction on the filtered signal according to the phase drift distance to obtain a target signal. According to the invention, the problem of phase drift of the signal after frequency multiplication and filtering processing can be effectively solved, and the accuracy of the target signal is improved.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and more specifically, to a signal processing method and system. Background Art

[0002] At present, in the process of signal processing, in order to obtain the target signal that meets the requirements, it is usually necessary to perform frequency doubling on the conventional sinusoidal signal. However, in the frequency doubling process, not only the required target signal is generated, but also many harmonics are generated. Therefore, it is also necessary to filter the signal after frequency doubling, that is, to use a filter to eliminate the influence of harmonics on the target signal. Ideally, the result after filtering can completely retain the signal of a specific frequency and filter out other signals, so as to obtain the target signal.

[0003] However, in the process of frequency doubling and filtering the signal, the target signal after the frequency multiplier and filter will drift in phase due to the influence of factors such as external temperature. The signal phase drift has a great impact on the further improvement of the phase-based time transfer synchronization accuracy. Therefore, it is also necessary to perform phase correction processing on the filtered signal.

[0004] Therefore, there is an urgent need for a signal processing solution that can perform phase drift correction processing on the signal after frequency multiplication and filtering. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a signal processing method and system to solve the phase drift problem existing in existing signals after frequency doubling and filtering processing.

[0006] The signal processing method provided by the present invention comprises: performing frequency doubling processing on an initial signal to obtain a frequency doubling signal containing a preset frequency; performing filtering processing on the frequency doubling signal to obtain a filtered signal corresponding to the frequency doubling signal; performing iterative mixing processing on a same-frequency signal of the initial signal and a filtered signal to obtain a mixed signal that meets preset conditions; obtaining the amplitude of a DC signal in the mixed signal, and determining a phase drift of the filtered signal according to the amplitude; and performing phase correction on the filtered signal according to the phase drift to obtain a target signal.

[0007] In addition, an optional technical solution is to perform frequency doubling processing on the initial signal, and the step of obtaining a frequency doubling signal containing a preset frequency includes: generating an initial signal with a frequency of f1 by a signal generator, and the formula of the initial signal is:

[0008] S1=A1sin(2πf1t+θ)

[0009] Wherein, S1 represents the initial signal, A1 represents the amplitude of the initial signal, f1 represents the frequency of the initial signal, and θ represents the phase of the initial signal; the initial signal S1 is frequency-multiplied to obtain a frequency-multiplied signal.

[0010] In addition, an optional technical solution is that the formula for filtering the signal is:

[0011] S3=A3sin(2πf3t+φ0)

[0012] Among them, S3 represents the filtered signal, A3 represents the amplitude of the filtered signal, f3 represents the frequency of the filtered signal, and f3=nf1, n represents the frequency multiplication factor, which is a positive integer, f1 represents the frequency of the initial signal, and φ0 represents the phase value of the initial signal generated in the frequency multiplication processing and filtering processing.

[0013] In addition, an optional technical solution is to perform iterative mixing processing on the co-frequency signal of the initial signal and the filtered signal, and the steps of obtaining a mixed signal that meets the preset conditions include: performing a first mixing processing on the co-frequency signal of the initial signal and the filtered signal to obtain a first mixing signal containing a frequency f4; performing a second mixing processing on the co-frequency signal of the initial signal and the first mixing signal to obtain a second mixing signal containing a frequency f5; repeating the above process until a DC signal appears in the mixed signal.

[0014] In addition, an optional technical solution is that the formula of the primary mixing signal is:

[0015] S4=A4sin[2π(n-1)f4t+φ1]+S'4

[0016] Among them, f4=f3-f1 and f3=nf1, S4 represents the first mixing signal, A4 represents the amplitude of S4, (n-1)f1 represents the frequency of S4, S'4 represents the signal contained in S4 with a frequency higher than (n-1)f1, and φ1 represents the phase value of the initial signal generated in the frequency doubling process, filtering process and first mixing process.

[0017] In addition, an optional technical solution is that the formula of the DC signal is:

[0018] S0=Asin(φ n )

[0019] Among them, S0 represents the DC signal obtained after mixing, the known quantity A represents the amplitude of the DC signal, φ n Indicates the phase value of the initial signal produced by frequency doubling, filtering, and multiple mixing.

[0020] In addition, an optional technical solution is to obtain the amplitude of the DC signal in the mixing signal, and the step of determining the phase drift of the filtered signal according to the amplitude includes: adjusting the phase of the DC signal to obtain the maximum amplitude A0 of the DC signal; determining the phase drift of the filtered signal according to the maximum amplitude A0, wherein the formula of the phase drift is:

[0021]

[0022] Wherein, A represents the amplitude of the DC signal, and A0 represents the maximum amplitude of the DC signal.

[0023] In addition, an optional technical solution is a process of adjusting the phase of a DC signal, including: adjusting the phase of the DC signal through a phase shifter; or adjusting the phase of the DC signal by adjusting the cable length of a mixer used for mixing processing.

[0024] In addition, an optional technical solution is that the same-frequency signal of the initial signal is obtained through distribution processing by a power divider.

[0025] On the other hand, the present invention also provides a signal processing system, including: a frequency doubling processing unit, used to perform frequency doubling processing on an initial signal to obtain a frequency doubling signal containing a preset frequency; a filtering processing unit, used to perform filtering processing on the frequency doubling signal to obtain a filtered signal corresponding to the frequency doubling signal; a mixing processing unit, used to perform iterative mixing processing on the same-frequency signal and the filtered signal of the initial signal to obtain a mixed signal that meets preset conditions; a drift determination unit, used to obtain the amplitude of the DC signal in the mixing signal, and determine the phase drift of the filtered signal according to the amplitude; and a correction unit, used to perform phase correction on the filtered signal according to the phase drift to obtain a target signal.

[0026] By using the above-mentioned signal processing method and system, the frequency-doubled and filtered signals are iteratively mixed through the same-frequency signal of the initial signal to obtain a mixed signal that meets the preset conditions (the presence of a DC signal in the mixed signal), and then the amplitude of the DC signal in the mixed signal is obtained. The phase drift of the filtered signal is determined according to the amplitude, and the phase of the filtered signal is corrected according to the phase drift to obtain the final target signal. This method and system can be applied to various situations where harmonic signals may be generated, such as frequency doubling, to monitor the phase drift of the filtered signal and provide a basis for phase calibration. The measurement and correction results of the phase drift meet the requirements of high-precision signal transmission.

[0027] In order to achieve the above and related purposes, one or more aspects of the present invention include the features that will be described in detail later. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easy to understand. In the accompanying drawings:

[0029] Figure 1 The flow chart of the signal processing method according to the embodiment of the present invention is as follows: Figure 1 ;

[0030] Figure 2 The flow chart of the signal processing method according to the embodiment of the present invention is as follows: Figure 2 ;

[0031] Figure 3 4 is a system principle diagram of a signal processing method according to an embodiment of the present invention.

[0032] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details. In other examples, for ease of describing one or more embodiments, known structures and devices are shown in the form of block diagrams.

[0035] To solve the problems of phase drift in existing signals after frequency doubling and filtering. The present invention provides a signal processing method and system, which performs iterative mixing processing on the frequency-doubled and filtered signals through the same-frequency signal of the initial signal until a DC signal appears in the mixed signal, and then determines the phase drift of the filtered signal according to the amplitude of the DC signal, and performs phase correction on the filtered signal according to the phase drift to obtain the final target signal. It can determine the phase drift of the signal after filtering, and can be applied to various situations where harmonic signals may be generated, such as frequency doubling, to monitor the phase drift of the filtered signal, and provide a basis for phase calibration. The measurement and correction results of the phase drift meet the requirements of high-precision signal transmission.

[0036] To describe the structure of the signal processing method and system of the present invention in detail, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] Figure 1 The flowchart of the signal processing method according to the embodiment of the present invention is shown.

[0038] like Figure 1 As shown, the signal processing method of the embodiment of the present invention mainly includes:

[0039] S100: performing frequency multiplication processing on the initial signal to obtain a frequency multiplication signal including a preset frequency;

[0040] Among them, the initial signal (also called the original signal) with a frequency of f1 can be generated by a signal generator. The original signal is a known standard signal, and its amplitude and phase are both known. As a known quantity, it participates in subsequent signal processing. The expression formula of the initial signal is:

[0041] S1=A1sin(2πf1t+θ)

[0042] Wherein, S1 represents the initial signal, A1 represents the amplitude of the initial signal, f1 represents the frequency of the initial signal, and θ represents the phase of the initial signal; the initial signal S1 is frequency-multiplied to obtain a frequency-multiplied signal. In high-precision time transmission, a signal with a specified frequency is required, so the frequency-multiplied signal S2 containing the specified frequency can be obtained by frequency-multiplying the initial signal.

[0043] S200: Filter the frequency-doubled signal to obtain a filtered signal corresponding to the frequency-doubled signal;

[0044] Among them, due to the frequency doubling process, the frequency doubling signal S2 contains not only the specified frequency signal but also a variety of harmonic signals of different frequencies. At this time, the redundant harmonic signals can be filtered and eliminated by a filter, thereby obtaining a filtered signal S3 with a frequency of f3 and a phase drift after frequency doubling and filtering.

[0045] Specifically, the expression formula of the filtered signal is:

[0046] S3=A3sin(2πf3t+φ0)

[0047] Among them, S3 represents the filtered signal, A3 represents the amplitude of the filtered signal, f3 represents the frequency of the filtered signal, and f3=nf1, n represents the frequency multiplication factor, which is a positive integer, f1 represents the frequency of the initial signal, and φ0 represents the phase value of the initial signal generated in the frequency multiplication processing and filtering processing.

[0048] S300: performing iterative mixing processing on the same-frequency signal of the initial signal and the filtered signal to obtain a mixed signal that meets a preset condition;

[0049] Among them, the same-frequency signal of the initial signal and the filtered signal can be mixed once to obtain a first mixed signal containing a frequency f4; then, the same-frequency signal of the initial signal and the first mixed signal can be mixed twice to obtain a second mixed signal containing a frequency f5; the above process is repeated until a DC signal appears in the mixed signal.

[0050] Specifically, the mixing process can be completed by using a mixer or other methods. Taking a single mixing as an example, the formula of the corresponding single mixing signal is expressed as:

[0051] S4=A4sin[2π(n-1)f4t+φ1]+S'4

[0052] Among them, f4=f3-f1 and f3=nf1, S4 represents the first mixing signal, A4 represents the amplitude of S4, (n-1)f1 represents the frequency of S4, S'4 represents the signal contained in S4 with a frequency higher than (n-1)f1, and φ1 represents the phase value of the initial signal generated in the frequency doubling process, filtering process and first mixing process.

[0053] Then, the above steps are repeated to perform secondary mixing processing using the same frequency signal of the initial signal and the primary mixing signal until a DC signal appears in the mixed signal, and the DC signal is filtered out through a low-pass filter.

[0054] The formula for the DC signal is:

[0055] S0=Asin(φ n )

[0056] In the above formula, S0 represents the DC signal obtained after the last mixing, the known quantity A represents the amplitude of the DC signal, and φ n Indicates the phase value of the initial signal produced by frequency doubling, filtering, and multiple mixing.

[0057] S400: Acquire the amplitude of the DC signal in the mixed signal, and determine the phase shift of the filtered signal according to the amplitude;

[0058] After obtaining the DC signal, the maximum amplitude and the minimum amplitude of the DC signal can be obtained by phase adjustment means. The process of adjusting the phase of the DC signal may include: adjusting the phase of the DC signal by a phase shifter; or adjusting the phase of the DC signal by adjusting the cable length of the mixer used for mixing processing, by increasing the phase φ n Make the amplitude of S0 reach the maximum, and then reduce φ n The amplitude of S0 is 0, and the phase of the DC signal is also 0. After the phase of the DC signal is adjusted to 0, the frequency multiplication and filtering processing are affected by environmental factors, which will cause signal phase drift. This is the value we need to determine.

[0059] The formula for phase drift is:

[0060]

[0061] Wherein, A represents the amplitude of the DC signal, and A0 represents the maximum amplitude of the DC signal.

[0062] S500: Perform phase correction on the filtered signal according to the phase drift to obtain the target signal.

[0063] In addition, it should be noted that the same-frequency signal of the initial signal can be obtained through the distribution processing of the power divider, and in different mixing processes, the same-frequency signal after the last distribution can be further power distributed by the power divider to obtain a new same-frequency signal.

[0064] As a specific example, Figure 2 Another schematic flow chart of a signal processing method according to an embodiment of the present invention is shown.

[0065] like Figure 2 As shown, the signal processing method according to the embodiment of the present invention includes:

[0066] 1. Start processing and obtain the initial signal through the signal generator to obtain signal S1;

[0067] 2. Perform frequency multiplication processing on the initial signal S1 to obtain signal S2;

[0068] 3. Filter the signal S2 to obtain a filtered signal S3;

[0069] 4. Performing iterative mixing processing on the initial signal S1 and the filtered signal S3 until a DC signal appears in the mixed signal;

[0070] 5. Measure the signal amplitude of the DC signal and calculate the phase drift based on the signal amplitude.

[0071] 6. Correct the signal according to the phase drift, determine the target signal and end.

[0072] Further, Figure 3 The system principle of the signal processing method according to the embodiment of the present invention is shown.

[0073] like Figure 3 As shown, in the signal processing method of the embodiment of the present invention, after obtaining the initial signal S1, the frequency multiplier can be used to obtain the frequency multiplied signal S2, and then the filter signal S3 can be obtained through the filtering process of the filter. In the mixing process, the power divider, that is, the cooperation of the power distributor and the mixer, can be used to obtain the final DC signal S0 through iterative mixing processing, and then the phase drift amount is determined according to the amplitude of the DC signal S0, and the phase correction is performed to obtain the target signal S. In the specific application process, the number of mixing operations can generally be controlled within 10 times to ensure that the influence of the mixer on the signal phase is controllable.

[0074] Corresponding to the above-mentioned signal processing method, the present invention also provides a signal processing system, including: a frequency doubling processing unit, used to perform frequency doubling processing on an initial signal to obtain a frequency doubling signal containing a preset frequency; a filtering processing unit, used to perform filtering processing on the frequency doubling signal to obtain a filtered signal corresponding to the frequency doubling signal; a mixing processing unit, used to perform iterative mixing processing on the same-frequency signal and the filtered signal of the initial signal to obtain a mixed signal that meets preset conditions; a drift determination unit, used to obtain the amplitude of the DC signal in the mixing signal, and determine the phase drift of the filtered signal according to the amplitude; and a correction unit, used to perform phase correction on the filtered signal according to the phase drift to obtain a target signal.

[0075] It should be noted that the embodiments of the above-mentioned signal processing system can refer to the description in the embodiment of the signal processing method, which will not be described in detail here.

[0076] According to the above-mentioned signal processing method and system, the monitoring of signal phase drift can be completed at a relatively low cost, and a reliable basis can be provided for phase calibration. It can be applicable to various scenarios in which harmonic signals are generated. The measurement and correction results of the phase drift amount can meet the requirements of high-precision signal transmission at the moment.

[0077] The signal processing method and system according to the present invention are described above by way of example with reference to the accompanying drawings. However, it should be understood by those skilled in the art that various improvements can be made to the signal processing method and system proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A signal processing method, characterized in that: The method comprises: Performing frequency multiplication processing on the initial signal to obtain a frequency multiplication signal containing a preset frequency; Performing filtering processing on the frequency-doubled signal to obtain a filtered signal corresponding to the frequency-doubled signal; Performing iterative mixing processing on the same-frequency signal of the initial signal and the filtered signal to obtain a mixed signal that meets preset conditions; Acquire the amplitude of the DC signal in the mixing signal, and determine the phase drift of the filtering signal according to the amplitude; The phase of the filtered signal is corrected according to the phase drift to obtain a target signal.

2. The signal processing method according to claim 1, characterized in that: The step of performing frequency doubling processing on the initial signal to obtain a frequency doubling signal having a preset frequency includes: An initial signal with a frequency of f1 is generated by a signal generator, and the formula of the initial signal is: S1=A1sin(2πf1t+θ) Wherein, S1 represents the initial signal, A1 represents the amplitude of the initial signal, f1 represents the frequency of the initial signal, and θ represents the phase of the initial signal; The initial signal S1 is frequency-multiplied to obtain the frequency-multiplied signal.

3. The signal processing method according to claim 2, characterized in that: The formula of the filtered signal is: S3=A3sin(2πf3t+φ0) Among them, S3 represents the filtered signal, A3 represents the amplitude of the filtered signal, f3 represents the frequency of the filtered signal, and f3=nf1, n represents the frequency multiplication factor, which is a positive integer, f1 represents the frequency of the initial signal, and φ0 represents the phase value of the initial signal generated in the frequency multiplication processing and filtering processing.

4. The signal processing method according to claim 3, characterized in that: The step of performing iterative mixing processing on the same-frequency signal of the initial signal and the filtered signal to obtain a mixed signal that meets a preset condition comprises: Performing a mixing process on the same frequency signal of the initial signal and the filtered signal to obtain a mixed signal containing a frequency f4; Perform secondary mixing processing on the same-frequency signal of the initial signal and the primary mixing signal to obtain a secondary mixing signal having a frequency f5; The above process is repeated until a DC signal appears in the mixed signal.

5. The signal processing method according to claim 4, characterized in that: The formula of the primary mixing signal is: S4=A4sin[2π(n-1)f4t+φ1]+S'4 Among them, f4=f3-f1 and f3=nf1, S4 represents the first mixing signal, A4 represents the amplitude of S4, (n-1)f1 represents the frequency of S4, S'4 represents the signal contained in S4 with a frequency higher than (n-1)f1, and φ1 represents the phase value of the initial signal generated in the frequency doubling process, filtering process and the first mixing process.

6. The signal processing method according to claim 4, characterized in that: The formula of the DC signal is: S0=Asin(φ n ) Where S0 represents the DC signal obtained after mixing, the known quantity A represents the amplitude of the DC signal, φ n It represents the phase value of the initial signal generated by frequency doubling, filtering, and multiple mixing.

7. The signal processing method according to claim 6, characterized in that: The step of obtaining the amplitude of the DC signal in the mixing signal and determining the phase shift of the filtering signal according to the amplitude comprises: Adjusting the phase of the DC signal to obtain the maximum amplitude A0 of the DC signal; The phase drift of the filtered signal is determined according to the maximum amplitude A0, wherein the formula of the phase drift is: Wherein, A represents the amplitude of the DC signal, and A0 represents the maximum amplitude of the DC signal.

8. The signal processing method according to claim 7, characterized in that: The process of adjusting the phase of the DC signal includes: The phase of the DC signal is adjusted by a phase shifter; or, the phase of the DC signal is adjusted by adjusting the cable length of the mixer used for mixing processing.

9. The signal processing method according to claim 1, characterized in that: The same frequency signal of the initial signal is obtained through distribution processing of the power divider.

10. A signal processing system, characterized in that: include: A frequency multiplication processing unit, used for performing frequency multiplication processing on the initial signal to obtain a frequency multiplication signal containing a preset frequency; A filtering processing unit, used for filtering the frequency-doubled signal to obtain a filtered signal corresponding to the frequency-doubled signal; A mixing processing unit, used for performing iterative mixing processing on the same-frequency signal of the initial signal and the filtered signal to obtain a mixed signal that meets a preset condition; a drift determination unit, configured to obtain an amplitude of a DC signal in the mixed signal, and determine a phase drift of the filtered signal according to the amplitude; The correction unit is used to perform phase correction on the filtered signal according to the phase drift amount to obtain a target signal.

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