A phase estimation method, a signal processing channel and a storage medium

Abstract

A phase estimation method, a signal processing channel and a storage medium are applied to the technical field of signal processing. The phase estimation method comprises the following steps: obtaining an original input signal and a coarse interval to-be-tested phase table; performing traversal test based on the coarse interval to-be-tested phase table to obtain M1 amplitude estimation values corresponding to M1 phase values; obtaining a target phase corresponding to an amplitude estimation target value in the M1 amplitude estimation values, generating a fine interval to-be-tested phase table according to the target phase; performing traversal test based on the fine interval to-be-tested phase table to obtain M2 amplitude estimation values corresponding to M2 phase values, and obtaining a phase corresponding to an amplitude estimation minimum value based on the M2 amplitude estimation values and the corresponding phase values. Since the amplitude estimation value of the to-be-tested signal is analyzed to perform phase estimation, the phase estimation process is simplified, the complexity of phase estimation is reduced based on the combination of the coarse interval to-be-tested phase table and the fine interval to-be-tested phase table, and the estimated phase can be more accurately obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal processing, in particular to a phase estimation method, a signal processing channel and a storage medium. BACKGROUND

[0002] A digital-to-analog converter (DAC) is an important device for converting digital signals into analog signals and is widely used in various industries. However, due to the influence of internal component mismatch and other nonlinear factors of the DAC, the output end of the DAC always contains other signals in addition to the main signal of the input signal, thereby affecting the spurious free dynamic range (SFDR) of the DAC. Among them, the harmonics corresponding to the main signal in the output signal of the DAC and the spurs have a greater impact on the SFDR.

[0003] In the current technical solution, other analysis instruments are mainly used to analyze the analog signal output by the DAC to directly analyze the harmonic phase of the harmonics or the spur phase of the spurs, but the accuracy of the analysis instrument is relatively high, the device cost of the high-precision analysis instrument is also relatively high, and the direct analysis process is complex and not suitable for large-scale applications. Therefore, for obtaining the phase of the harmonics or the spurs generated by the DAC, a new technical solution needs to be proposed. SUMMARY

[0004] The technical problem solved by the present application is how to simplify the acquisition of the phase of the harmonics or the spurs generated by the DAC.

[0005] According to a first aspect, in an embodiment, a phase estimation method is provided, comprising:

[0006] obtaining an original input signal and a coarse interval to-be-measured phase table; wherein the coarse interval to-be-measured phase table includes M1 phase values, and M1 is a positive integer greater than 1;

[0007] based on the harmonic frequency and the harmonic amplitude value of the harmonics of the original input signal or based on the spur frequency and the spur amplitude value of the spurs of the original input signal, and any phase value in the to-be-measured phase table, generating a cancellation signal; superimposing the cancellation signal and the original input signal to obtain a digital to-be-measured signal; inputting the digital to-be-measured signal into a DAC for digital-to-analog conversion to obtain an analog to-be-tested signal, and performing spectrum analysis on the analog to-be-tested signal to obtain an amplitude estimation value of the harmonic frequency or the spur frequency corresponding to the any phase value; traversing the cancellation signal corresponding to each phase value in the to-be-measured phase table to obtain each amplitude estimation value corresponding to each phase value;

[0008] obtaining M1 amplitude estimation values corresponding to the M1 phase values, and determining a target phase corresponding to an amplitude estimation target value in the M1 amplitude estimation values;

[0009] generating a fine interval to-be-tested phase table according to the target phase; wherein the fine interval to-be-tested phase table comprises M2 phase values, and the M2 is a positive integer greater than 1;

[0010] performing the traversal test based on the fine interval to-be-tested phase table to obtain M2 amplitude estimation values corresponding to the M2 phase values, and obtaining a phase corresponding to an amplitude estimation minimum value based on the M2 amplitude estimation values and corresponding phase values.

[0011] In some embodiments, the obtaining of the target phase corresponding to the amplitude estimation target value in the M1 amplitude estimation values comprises:

[0012] obtaining an average value of the M1 amplitude estimation values;

[0013] determining whether the average value is greater than the harmonic amplitude value or the spurious amplitude value of the original input signal;

[0014] if yes, obtaining a phase corresponding to a maximum value in the M1 amplitude estimation values as the target phase corresponding to the amplitude estimation target value;

[0015] if no, obtaining a phase corresponding to a minimum value in the M1 amplitude estimation values as the target phase corresponding to the amplitude estimation target value.

[0016] In some embodiments, the obtaining of the phase corresponding to the amplitude estimation minimum value based on the M2 amplitude estimation values and corresponding phase values comprises:

[0017] if the phase corresponding to the minimum value in the M1 amplitude estimation values is obtained, determining a phase corresponding to a minimum value in the M2 amplitude estimation values as the phase corresponding to the amplitude estimation minimum value;

[0018] if the phase corresponding to the maximum value in the M1 amplitude estimation values is obtained, obtaining a phase corresponding to a maximum value in the M2 amplitude estimation values, and determining the phase corresponding to the amplitude estimation minimum value according to the phase corresponding to the maximum value.

[0019] In some embodiments, the determining of the phase corresponding to the amplitude estimation minimum value according to the phase corresponding to the maximum value comprises:

[0020] shifting the phase corresponding to the maximum value in the M2 amplitude estimation values by a preset phase, so that the shifted phase corresponds to the amplitude estimation minimum value;

[0021] outputting a phase after the translation, the phase after the translation being a phase corresponding to the amplitude estimation minimum value.

[0022] In some embodiments, if a phase value corresponding to a maximum value in the M2 amplitude estimation values is between [0, π), the preset phase after the translation is π;

[0023] If a phase value corresponding to a maximum value in the M2 amplitude estimation values is between [π, 2π), the preset phase after the translation is -π.

[0024] In some embodiments, the coarse interval phase table to be tested is generated by:

[0025] dividing M1 phase values from a phase range [a, a+π] according to a preset first phase interval to generate the coarse interval phase table to be tested; wherein a is a phase greater than or equal to 0 and less than or equal to π;

[0026] Alternatively,

[0027] obtaining an estimated phase empirical value, and generating the coarse interval phase table to be tested according to the estimated phase empirical value.

[0028] In some embodiments, the obtaining of the estimated phase empirical value comprises:

[0029] obtaining a phase estimation value corresponding to a harmonic frequency or a spur frequency of a known input signal after the known input signal is input into the DAC;

[0030] obtaining the estimated phase empirical value corresponding to a harmonic of the original input signal from the phase estimation value based on a frequency relationship between the known input signal and the original input signal; or,

[0031] obtaining the estimated phase empirical value corresponding to a spur of the original input signal from the phase estimation value based on a frequency relationship between the known input signal and the original input signal, and a frequency relationship between a spur frequency of a spur of the known input signal and a spur frequency of a spur of the original input signal.

[0032] In some embodiments, the generating of the coarse interval phase table to be tested according to the estimated phase empirical value comprises:

[0033] dividing M2 phase values from a nearby range [b-c, b+c] of the estimated phase empirical value according to a preset second phase interval to generate the coarse interval phase table to be tested; wherein b is the estimated phase empirical value, and c is a preset phase value.

[0034] In some embodiments, the phase interval between the M1 phase values is greater than the phase interval between the M2 phase values; and / or, the phase range covered by the M1 phase values is greater than the phase range covered by the M2 phase values, and the value of M1 is less than the value of M2.

[0035] In some embodiments, the spectrum analysis of the simulated to-be-tested signal comprises:

[0036] inputting the simulated to-be-tested signal into a spectrum analyzer for spectrum analysis;

[0037] or,

[0038] inputting the simulated to-be-tested signal into an analog-to-digital converter for analog-to-digital conversion processing and then performing Fourier transform processing to perform spectrum analysis.

[0039] In some embodiments, for a harmonic, the frequency of the corresponding cancellation signal is the harmonic frequency of the harmonic of the original input signal; for a spur, the frequency of the corresponding cancellation signal is the spur frequency of the spur of the original input signal.

[0040] According to a second aspect, an embodiment provides a signal processing channel for implementing the phase estimation method according to the first aspect, the signal processing channel comprising at least two DDS phase accumulators, each of the DDS phase accumulators being connected in parallel between signal processing lines, and the number of parallel connections defining an integer H greater than 1;

[0041] wherein the signal processing line containing one DDS phase accumulator generates the original input signal after phase-amplitude conversion processing and attenuation processing, and the remaining signal processing lines containing DDS phase accumulators generate the harmonic corresponding cancellation signal or the spur corresponding cancellation signal based on the phase values in the corresponding to-be-tested phase table.

[0042] In some embodiments, the signal processing channel is applied to process multiple harmonics, or multiple spurs, or at least one harmonic and at least one spur, and if the value of H is greater than or equal to 3, the remaining signal processing lines containing DDS phase accumulators are used to generate multiple harmonic corresponding cancellation signals, or multiple spur corresponding cancellation signals, or at least one harmonic and at least one spur corresponding cancellation signal, respectively.

[0043] wherein the maximum number of invocations of the remaining signal processing lines containing DDS phase accumulators is equal to twice the sum of the number of harmonics and the number of spurs.

[0044] In some embodiments, the signal processing channel further comprises a phase counter and a memory, the phase counter is configured to accumulate the M1 phase values or the M2 phase values corresponding to the cancellation signal when traversing, and the memory is configured to store each phase value in the to-be-tested phase table and its corresponding amplitude estimation value.

[0045] In some embodiments, the total number L of the to-be-processed harmonics and spurs is obtained.

[0046] The total number L is divided by H-1 and rounded up to obtain the number of times of calling the signal processing channel.

[0047] According to the number of times of calling the signal processing channel, the phase counter and the memory are reset to clear the historically stored amplitude estimation values and their corresponding phase values.

[0048] According to a third aspect, an embodiment provides a computer readable storage medium, wherein a program is stored in the medium, and the program can be executed by a processor to implement the method according to the first aspect.

[0049] According to the phase estimation method, the signal processing channel and the storage medium, when the original input signal and the cancellation signal are superimposed, if the phase of the harmonic frequency or the spur frequency corresponding to the original input signal is in phase with the phase of the harmonic frequency or the spur frequency corresponding to the cancellation signal, the amplitude estimation value of the harmonic frequency or the spur frequency corresponding to the phase reaches the maximum value, and vice versa, if the phase is opposite, the amplitude estimation value of the harmonic frequency or the spur frequency corresponding to the phase reaches the minimum value. Wherein, the to-be-tested phase table of coarse interval is traversed first to obtain the target phase of the approximate phase position, then the to-be-tested phase table of fine interval is generated based on the target phase, and the to-be-tested phase table of fine interval is traversed again to obtain the phase corresponding to the minimum amplitude estimation value. Since the cancellation signal and the original input signal are superimposed, and the amplitude estimation value corresponding to the harmonic frequency or the spur frequency in the simulated test signal is analyzed, the phase corresponding to the minimum amplitude estimation value can be obtained, so that the phase estimation process is simplified. At the same time, the coarse estimation of the phase based on the to-be-tested phase table of coarse interval and the fine estimation of the phase based on the to-be-tested phase table of fine interval are combined, which reduces the complexity of the phase estimation and can obtain the estimated phase more accurately. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 The structure diagram of the signal processing channel of an embodiment;

[0051] Figure 2 The structure diagram of the signal processing channel of another embodiment;

[0052] Figure 3A phase estimation flow chart for a signal processing channel of one embodiment;

[0053] Figure 4 A plot of harmonic amplitudes for one embodiment;

[0054] Figure 5 A plot of harmonic amplitudes for another embodiment;

[0055] Figure 6 A flow diagram of a phase estimation method of one embodiment. DETAILED DESCRIPTION

[0056] The present application is further described by the following non-limiting examples with reference to the accompanying drawings. Like elements in the drawings are denoted by like reference numerals for consistency. In the following description, numerous specific details are recited in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced without these specific details. In other instances, well-known methods have not been described in detail in order to avoid unnecessarily obscuring the present application. Reference in the specification to "one embodiment", "an embodiment", "another embodiment" or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0057] In addition, the features, operations, or functions described in the specification can be implemented in any suitable manner. Moreover, the illustrations of a particular order to the steps within methods of operations are shown in a particular order for ease of understanding, and do not necessarily represent a particular order in which the steps must be performed. The order of steps in the methods can be changed, and other steps can be added, performed simultaneously, or deleted, unless a particular order is explicitly described herein. Accordingly, the methods described herein and throughout the specification are used as schema illustrations and can be executed or performed with other steps in other sequences than those illustrated or other order than those described.

[0058] The serial numbers of components in the present application, such as "first", "second", etc., are used only for distinguishing the described objects, and do not have any sequence or technical meaning. The "connection" or "coupling" in the present application includes direct and indirect connection (coupling) unless otherwise specified.

[0059] In some embodiments of the present application, two signals of the same frequency are used. When the two signals are superimposed, if the two signals are in phase, the superimposed amplitude will increase, and if the two signals are out of phase, the superimposed amplitude will be cancelled. The original input signal and the cancellation signal are obtained, and then the cancellation signal and the original input signal are superimposed, and then the digital-to-analog conversion is performed by the DAC, and finally the analog signal output by the digital-to-analog converter is analyzed to obtain the amplitude estimation value corresponding to the harmonic frequency or the spurious frequency. If the phase of the harmonic frequency or the spurious frequency corresponding to the original input signal is in phase with the phase of the harmonic frequency or the spurious frequency corresponding to the cancellation signal, the amplitude estimation value of the harmonic frequency or the spurious frequency corresponding to the phase reaches the maximum value, and vice versa, if the phase is out of phase, the amplitude estimation value of the harmonic frequency or the spurious frequency corresponding to the phase reaches the minimum value. Wherein, the target phase of the approximate phase position is obtained by traversing the coarse interval to-be-measured phase table, and then the fine interval to-be-measured phase table is generated based on the target phase, and the phase corresponding to the minimum amplitude estimation value is obtained by traversing the fine interval to-be-measured phase table. Since the cancellation signal and the original input signal are superimposed, and the amplitude estimation value corresponding to the harmonic frequency or the spurious frequency in the analog test signal is analyzed, the phase corresponding to the minimum amplitude estimation value can be obtained, so that the phase estimation process is simplified. At the same time, the coarse estimation of the phase is performed based on the coarse interval to-be-measured phase table, and the fine estimation of the phase is performed based on the fine interval to-be-measured phase table, which reduces the complexity of the phase estimation and can more accurately obtain the estimated phase.

[0060] Some embodiments provide a signal processing channel, please refer to Figure 1 The signal processing channel includes at least two DDS phase accumulators 10, each of which is in parallel in the signal processing line, and the number of parallel connections is defined as an integer H greater than 1.

[0061] The DDS phase accumulator 10 is used to complete the accumulation of the phase value according to the received frequency control word to obtain the phase accumulation value. Please refer to Figure 2 In some embodiments, the components in the signal processing line of each DDS phase accumulator 10 are connected in series, for example, the DDS phase accumulator 10 includes a phase adder and a phase register connected in series, the phase register is used to output the current accumulated phase to the phase adder, the phase adder adds the frequency control word and the accumulated phase output by the phase register, and sends the added result to the phase register for the next phase accumulation. In some embodiments, the frequency control word can be generated based on a processor, wherein the processor can also be used to adjust the initial phase of the phase register. In some embodiments, the processor can be implemented based on a device with data processing capability such as CPU, FPGA, single-chip microcomputer, etc. Wherein, the frequency control word is determined by the frequency of the input signal, the clock frequency and the total number of bits of the DDS phase accumulator 10.

[0062] In some embodiments, each signal processing line containing a DDS phase accumulator 10 can be configured with a phase-amplitude mapping module 20, which is configured to obtain a corresponding signal amplitude according to the phase accumulation value output by the corresponding DDS phase accumulator 10, and output a corresponding digital waveform signal. In some embodiments, the phase-amplitude mapping module 20 can obtain the signal amplitude corresponding to the phase accumulation value based on a phase lookup table, for example, a sine lookup table. In some embodiments, the phase-amplitude mapping module 20 can also calculate the signal amplitude corresponding to the phase accumulation value in real time based on algorithms such as coordinate rotation.

[0063] In some embodiments, the signal processing lines containing the respective DDS phase accumulators 10 can also share a phase-amplitude mapping module 20, for example, the phase-amplitude mapping module 20 is multiplexed between the respective DDS phase accumulators 10.

[0064] In some embodiments, the digital waveform signal output by the phase-amplitude mapping module 20 can be converted into an analog waveform signal by a digital-to-analog conversion unit 30. In some embodiments, the digital-to-analog conversion unit 30 can implement the digital-to-analog conversion of the signal based on an analog-to-digital converter. In some embodiments, the digital-to-analog conversion unit 30 can further include a signal adder, which is configured to superimpose multiple digital waveform signals and then output the superimposed signals to the analog-to-digital converter, so as to implement the digital-to-analog conversion of the superimposed signals.

[0065] In the above embodiments, each signal processing line containing a DDS phase accumulator 10 is configured to generate a digital waveform signal, so that each time the signal processing line is activated, a digital waveform signal can be generated to correspond to a harmonic or spurious cancellation signal, and each time the signal processing channel is activated, a plurality of digital waveform signals corresponding to the number of DDS phase accumulators 10 can be generated to correspond to a plurality of harmonics, or a plurality of spurs, or spurs and harmonics.

[0066] The above is a description of the signal processing channel. For details, please refer to Figure 3 The following describes the phase estimation process based on the signal processing channel.

[0067] Obtain the original input signal, wherein the signal processing line containing the DDS phase accumulator 10 in the signal processing channel is processed by the phase-amplitude conversion and attenuation to generate the original input signal.

[0068] In some embodiments, the signal processing line can further include an attenuator, so that the signal attenuation is performed based on the attenuator.

[0069] In some embodiments, the harmonics of the original input signal can include one harmonic or multiple harmonics, for example, can include the second harmonic or the third harmonic, or can include multiple harmonics such as the second harmonic and the third harmonic, and thus the cancellation signal can be a signal corresponding to the second harmonic or the third harmonic, or can be a signal corresponding to multiple harmonics such as the second harmonic and the third harmonic. In some embodiments, the spur of the original input signal can include one spur or multiple spurs, and thus the cancellation signal can be a signal corresponding to one spur, or can be a signal corresponding to multiple spurs. In the present embodiment, the harmonics and the spur of the original input signal refer to the harmonics and the spur generated after the original input signal is input into the DAC.

[0070] Obtain a coarse interval to-be-measured phase table. The coarse interval to-be-measured phase table includes M1 phase values, and M1 is a positive integer greater than 1.

[0071] In some embodiments, M1 evenly distributed phase values are divided from the phase range [a, a+π] according to the first phase interval to generate the coarse interval to-be-measured phase table. In the present embodiment, a is a phase value greater than or equal to 0 and less than or equal to π, and in some embodiments, a can be 0. In the present embodiment, when the original input signal is superimposed with the cancellation signal, the amplitude estimation value corresponding to the harmonic or the spur and the phase value in the to-be-measured phase table have a specific relationship, for example, the phase value and the phase of the corresponding harmonic or the spur are the same, and the amplitude estimation value reaches the maximum value, and vice versa, when the phases are opposite, the amplitude estimation value reaches the minimum value, and the change of the amplitude estimation value is symmetrical based on the change of the phase value in the to-be-measured phase table, that is, the change of the amplitude estimation value corresponding to any π range of phase values is symmetrical with the change of the amplitude estimation value corresponding to another π range of phase values, and thus the coarse interval to-be-measured phase table is generated based on any π range, and the phase estimation can be performed based on the symmetry, thereby reducing the calculation amount and simplifying the complexity of the process. In some embodiments, the selected phase can form a corresponding to-be-measured phase table and be stored, and thus subsequent adjustment can be directly based on the phase in the to-be-measured phase table.

[0072] In some embodiments, an estimated phase empirical value is obtained, and the coarse interval to-be-measured phase table is generated based on the estimated phase empirical value. In some embodiments, M1 evenly distributed phase values can be selected based on the front and back ranges of the estimated phase empirical value to generate the coarse interval to-be-measured phase table, for example, M1 evenly distributed phase values are selected based on a preset range greater than the estimated phase empirical value and a preset range less than the estimated phase empirical value with the estimated phase empirical value as the center position. In some embodiments, for each original input signal without an estimated phase empirical value, a coarse interval to-be-measured phase table generated based on the phase range [a, a+π] can be shared, and for each original input signal with an estimated phase empirical value, a coarse interval to-be-measured phase table generated based on the estimated phase empirical value can be used.

[0073] In some embodiments, the phase estimation value corresponding to the harmonic frequency or the spur frequency of the known input signal is obtained after the known input signal is input into the DAC. Since there is a certain relationship between the frequency of a signal and the phase of the signal, the phase corresponding to the harmonic frequency or the spur frequency of the original input signal can be estimated based on the frequency of the known input signal and the phase estimation value corresponding to the harmonic frequency or the spur frequency of the known input signal. For example, if the frequency of the known input signal is different from that of the original input signal, the estimated phase value corresponding to the harmonic of the original input signal is obtained from the phase estimation value corresponding to the harmonic of the known input signal based on the frequency relationship between the known input signal and the original input signal, or the estimated phase value corresponding to the spur of the original input signal is obtained from the phase estimation value corresponding to the spur of the known input signal based on the frequency relationship between the known input signal and the original input signal and the frequency relationship between the spur frequency of the spur of the known input signal and the spur frequency of the spur of the original input signal. For example, if the frequency of the known input signal is the same as that of the original input signal, the phase estimation value corresponding to the harmonic is taken as the estimated phase value corresponding to the harmonic of the original input signal. For example, the spur frequency of the spur of the known input signal is also the same as the spur frequency of the spur of the original input signal, and the phase estimation value corresponding to the spur frequency is taken as the estimated phase value corresponding to the spur of the original input signal.

[0074] In the above embodiments, when signals of the same frequency are input into the same DAC, the phases corresponding to the harmonics generated are basically the same. Therefore, for the known input signal for which the phase estimation has been completed, the subsequent processing can be performed based on the obtained estimated phase value, and repeated obtaining is not needed. In addition, for the original input signal for which the phase estimation has not been completed, the phase corresponding to the harmonic of the original input signal can be predicted based on the phase of the harmonic of the known input signal, and then the phase estimation of the original input signal is performed based on the predicted phase, so that the complexity of obtaining can be further simplified, and the accuracy of the phase estimation can be improved.

[0075] In some embodiments, when the coarse-interval to-be-measured phase table is generated based on the estimated phase value, M2 phase values are divided from the range [b-c, b+c] near the estimated phase value according to a preset second phase interval, so as to generate the coarse-interval to-be-measured phase table, where b is the estimated phase value, and c is a preset phase value. In this embodiment, since the estimated phase value has been obtained, the coarse-interval to-be-measured phase table can be generated in a smaller phase range. In some embodiments, the preset second phase interval can be the same as or different from the preset first phase interval.

[0076] The coarse interval based test phase table is traversed. That is, the phase values in the coarse interval based test phase table are selected in turn, the corresponding cancellation signal is generated based on the phase value, and is superimposed with the original input signal to input the DAC, and then the analog signal output by the DAC is analyzed to obtain the amplitude estimation value of the harmonic frequency or the spur frequency corresponding to the phase value.

[0077] In some embodiments, when the cancellation signal is obtained, the signal processing circuit containing the DDS phase accumulator 10 in the remaining other paths in the signal processing channel is based on the phase value in the corresponding test phase table to generate the harmonic corresponding cancellation signal or the spur corresponding cancellation signal through the amplitude-phase conversion processing.

[0078] In some embodiments, before the cancellation signal is obtained, the original input signal can be input to the digital-to-analog converter for digital-to-analog conversion to obtain the analog input signal corresponding to the digital-to-analog converter output, and then the analog input signal is analyzed to obtain the amplitude estimation value of the harmonic of the original input signal. Alternatively, the spur frequency and the spur amplitude value of the spur of the original input signal are obtained, for example, based on the spur frequency and the spur amplitude value of the spur of the original input signal known by other measurement equipment.

[0079] In some embodiments, the analog input signal can be converted into a corresponding digital signal based on the analog-to-digital converter, and then the digital signal is transformed from the time domain to the frequency domain based on the processor or the external data processing equipment, for example, through the fast Fourier transform (FFT) processing, and then the transformed frequency domain signal is analyzed to obtain the amplitude estimation value of the harmonic of the original input signal. Since the frequency of the FFT may be deviated, the amplitude estimation value obtained can be selected as the amplitude value corresponding to the harmonic frequency of the harmonic, or can be selected as the maximum amplitude value in the frequency range around the harmonic frequency.

[0080] Then the cancellation signal is generated based on the harmonic frequency and the harmonic amplitude value of the harmonic of the original input signal or based on the spur frequency and the spur amplitude value of the spur of the original input signal, and any phase value in the corresponding test phase table.

[0081] In some embodiments, when the cancellation signal is generated, for the harmonic, the frequency of the corresponding cancellation signal is the harmonic frequency of the harmonic of the original input signal, and for the spur, the frequency of the corresponding cancellation signal is the spur frequency of the spur of the original input signal.

[0082] In some embodiments, when the original input signal is attenuated to obtain the digital test signal, the amplitude of the original input signal superimposed with the digital test signal after cancellation can satisfy or be less than the maximum input range of the digital-to-analog converter. In some embodiments, when the amplitude of the digital test signal satisfies the maximum input range of the digital-to-analog converter, the digital-to-analog converter can be fully utilized to improve the accuracy of subsequent data processing. In some embodiments, the amplitude of the original input signal attenuation can be controlled by the processor or by an external data processing device.

[0083] In some embodiments, the signal processing circuit of the remaining other paths containing the DDS phase accumulator 10 can be used to generate a cancellation signal corresponding to a harmonic or a cancellation signal corresponding to a spur. In some embodiments, the signal processing circuit of the remaining other paths containing the DDS phase accumulator 10 can be used to generate a plurality of cancellation signals corresponding to a plurality of harmonics, or a plurality of cancellation signals corresponding to a plurality of spurs, or a cancellation signal corresponding to at least one harmonic and at least one spur, respectively. The plurality of cancellation signals can be generated based on a plurality of signal processing circuits containing the DDS phase accumulator 10, or can be generated based on multiplexing of a single signal processing circuit containing the DDS phase accumulator 10.

[0084] For example, if the value of H is greater than or equal to 3, the signal processing circuit of the remaining other paths containing the DDS phase accumulator 10 can be used to generate a plurality of cancellation signals corresponding to a plurality of harmonics, or a plurality of cancellation signals corresponding to a plurality of spurs, or a cancellation signal corresponding to at least one harmonic and at least one spur, respectively. The maximum number of invocations of the signal processing circuit of the remaining other paths containing the DDS phase accumulator 10 is equal to the sum of the number of harmonics and the number of spurs, and each invocation of the signal processing circuit generates a cancellation signal corresponding to a harmonic or a cancellation signal corresponding to a spur.

[0085] The cancellation signal and the original input signal are then superimposed to obtain the digital test signal, which is input to the DAC for digital-to-analog conversion to obtain the analog test signal. The analog test signal is then subjected to spectral analysis to obtain the amplitude estimate value corresponding to the harmonic frequency or the spur frequency at any phase value.

[0086] In some embodiments, the analog test signal can also be subjected to analog-to-digital conversion based on the analog-to-digital converter to obtain a corresponding digital signal. The processor or external data processing device can then perform time-to-frequency domain conversion on the digital signal, such as fast Fourier transform (FFT) processing. The frequency domain signal after conversion can then be analyzed to obtain the amplitude estimate value corresponding to the harmonic frequency or the spur frequency in the analog test signal. In some embodiments, the analog test signal can also be directly input to a spectrum analyzer for spectral analysis.

[0087] Finally, each phase value in the corresponding to-be-tested phase table is traversed to obtain each amplitude estimation value corresponding to each phase value.

[0088] In some embodiments, when performing the traversal test, a phase counter and a memory can be further included in the signal processing channel, the phase counter is used to accumulate and count the M phase values corresponding to the cancellation signal when traversing, and the memory is used to save each phase value in the corresponding to-be-tested phase table and each amplitude estimation value corresponding thereto.

[0089] In some embodiments, when performing the traversal test based on the to-be-tested phase table with coarse intervals, M1 amplitude estimation values corresponding to M1 phase values can be obtained, and a target phase corresponding to an amplitude estimation target value in the M1 amplitude estimation values is determined.

[0090] In some embodiments, when determining the target phase corresponding to the amplitude estimation target value in the M1 amplitude estimation values, an average value of the M1 amplitude estimation values is obtained, and it is determined whether the average value is greater than the harmonic amplitude value of the original input signal. If yes, a phase corresponding to a maximum value in the M1 amplitude estimation values is obtained and used as the target phase corresponding to the amplitude estimation target value. If not, a phase corresponding to a minimum value in the M1 amplitude estimation values is obtained and used as the target phase corresponding to the amplitude estimation target value.

[0091] In this embodiment, since the amplitude estimation values change regularly with the change of the phase values, for example, they change like a sine wave, first increase and then decrease or first decrease and then increase, the maximum value in the amplitude estimation values is usually the maximum value, and the minimum value in the amplitude estimation values is usually the minimum value. Therefore, when the average value of the M1 amplitude estimation values is greater than the harmonic amplitude value of the original input signal, it indicates that the M1 amplitude estimation values are closer to the maximum value, and vice versa. Thus, the phase range in which the phase to be estimated is located is determined according to the comparison result, and the phase search range is reduced, and the complexity of the phase estimation process is reduced.

[0092] A to-be-tested phase table with fine intervals is generated according to the target phase; wherein the to-be-tested phase table with fine intervals includes M2 phase values, and M2 is a positive integer greater than 1.

[0093] In some embodiments, M2 phase values can be selected based on the front and back ranges of the target phase to generate a fine interval test phase table, for example, M2 phase values can be selected uniformly around the target phase as the center position, and in the preset range greater than the target phase and the preset range less than the target phase. In some embodiments, the phase interval between M1 phase values is greater than the phase interval between M2 phase values, that is, the interval between each phase value in the fine interval test phase table is smaller, so that a more accurate phase estimation value can be determined. In some embodiments, the phase range covered by M1 phase values is greater than the phase range covered by M2 phase values, and the value of M1 is less than the value of M2, that is, the number of phase values in the fine interval test phase table is more, and the covered phase range is smaller, so that a more accurate phase estimation value can be determined.

[0094] The above traversal test is performed based on the fine interval test phase table to obtain M2 amplitude estimation values corresponding to the M2 phase values, and the phase corresponding to the minimum amplitude estimation value is obtained based on the M2 amplitude estimation values and the corresponding phase values.

[0095] In some embodiments, when the phase corresponding to the minimum amplitude estimation value is obtained based on the M2 amplitude estimation values and the corresponding phase values, if the phase corresponding to the minimum value in the M1 amplitude estimation values is obtained, the phase corresponding to the minimum value in the M2 amplitude estimation values is determined as the phase corresponding to the minimum amplitude estimation value. If the phase corresponding to the maximum value in the M1 amplitude estimation values is obtained, the phase corresponding to the maximum value in the M2 amplitude estimation values is obtained, and the phase corresponding to the minimum amplitude estimation value is determined according to the phase corresponding to the maximum value.

[0096] In some embodiments, when the phase corresponding to the minimum amplitude estimation value is determined according to the phase corresponding to the maximum value, the phase corresponding to the maximum value in the M2 amplitude estimation values is shifted by a preset phase, so that the shifted phase corresponds to the minimum amplitude estimation value, and the shifted phase is output as the phase corresponding to the minimum amplitude estimation value. In this embodiment, since the phase corresponding to the maximum value or the maximum value is opposite to the phase corresponding to the minimum value, the phase corresponding to the minimum amplitude estimation value can be determined according to the maximum value or the maximum value.

[0097] In some embodiments, if the phase value corresponding to the maximum value in the M2 amplitude estimation values is between [0, π), the preset phase of the shift is π, and if the phase value corresponding to the maximum value in the M2 amplitude estimation values is between [π, 2π), the preset phase of the shift is -π. The shifted phase is the sum of the phase value corresponding to the maximum value and the preset phase of the shift. In this embodiment, based on the phase range in which the phase value corresponding to the maximum value is located, different addition and subtraction operations are performed on the phase value corresponding to the maximum value, so that the shifted phase is always positive, facilitating subsequent use and calculation.

[0098] In the above embodiments, although the phase output by the final estimation is referred to as the estimated phase of the harmonic or the estimated phase of the spur, it is necessary to make it clear that it is the inverse phase of the phase of the real harmonic, and there is a phase difference of π between it and the phase of the real harmonic, so the output phase can be directly used when generating the cancellation signal corresponding to the harmonic or the spur.

[0099] In the above embodiments, the search of the coarse-interval phase table is performed first in the phase estimation process, and the search of the fine-interval phase table is performed again according to the search result of the coarse-interval phase table. This search idea can reduce the overall number of searches (corresponding to the number of phase values in the phase table) while obtaining a more accurate phase estimation result.

[0100] In the above embodiments, the signal processing channel can process at least one harmonic or spur, or can process both the harmonic and the spur. In some embodiments, the total number L of the harmonics and the spurs to be processed is obtained, the total number L is divided by H-1 and rounded up to obtain the number of times of calling the signal processing channel, and the phase counter and the memory are reset according to the number of times of calling the signal processing channel to clear the historically saved amplitude estimation value and the corresponding phase value. In this way, H-1 harmonics or spurs can be processed every two times of calling the signal processing channel.

[0101] In some embodiments, the reset operation is required when the signal processing channel is called to avoid mutual interference. For example, if it is detected that the clearing has been performed before the signal processing channel is called, the reset is not required; if it is detected that the clearing has not been performed before the signal processing channel is called, the reset is required. Therefore, when the phase counter and the memory are reset according to the number of times of calling the signal processing channel, the number of times of calling the signal processing channel can be the same as the number of times of resetting, for example, the reset is performed before the signal processing channel is called every time, and when it is detected that the clearing has been performed, the number of times of calling the signal processing channel can be less than the number of times of resetting.

[0102] The following is illustrated by specific embodiments.

[0103] Suppose that the input frequency f_in of the original input signal is 30 MHz, then the frequency control word is calculated based on the input frequency f_in, and the phase sequence output by the DDS phase accumulator 10 is calculated, the full-scale signal is obtained by addressing the sine lookup table according to the output phase sequence, and the full-scale signal is multiplied by the attenuation coefficient a = 0.95 and then input to the DAC. Assuming that the harmonics to be estimated are the second harmonic, the third harmonic and the fourth harmonic, their frequencies are f_2 = 2*f_in = 60 MHz, f_3 = 3*f_in = 90 MHz, and f_4 = 4*f_in = 120 MHz.

[0104] Let the selected phase points number M1=5 from the phase range [0, π], the phase value of the mth phase point in the coarse interval to-be-measured phase table is set as In some embodiments, when the estimated phase empirical value is obtained, then the phase value is selected in the vicinity of the estimated phase empirical value, for example, the estimated phase empirical value is π / 4, then

[0105] First, the original input signal is input into the DAC, and the output signal of the DAC is sampled by the ADC, and then FFT is performed, and the original amplitude estimation values of the second harmonic f_2, the third harmonic f_3, and the fourth harmonic f_4 are recorded. Since the frequency of the FFT may be deviated, the recorded amplitude values can be selected as the maximum values in a given range around f_2, f_3, and f_4.

[0106] The coarse interval to-be-measured phase table is traversed and tested, that is, a phase value θ_m is selected from the coarse interval to-be-measured phase table in order, and the cancellation signal of the corresponding harmonic is generated according to the second harmonic frequency f_2, the third harmonic frequency f_3, the fourth harmonic frequency f_4, and the corresponding original harmonic amplitude value. The generation process of the cancellation signal is similar to that of the original input signal, and the input frequency is the frequency of the harmonic, and then the frequency control word and the phase sequence are calculated in turn, and the full-scale signal, that is, the original amplitude estimation value, is obtained. The cancellation signal and the original input signal are superimposed and input into the DAC to obtain the analog phase test signal output by the DAC.

[0107] When the original input signal is the θ_m related signal, the corresponding analog phase test signal is input into the DAC, and the output signal of the DAC is sampled by the ADC, and then FFT is performed, and the amplitude A_(m_2) corresponding to the second harmonic, the amplitude A_(m_3) corresponding to the third harmonic, and the amplitude A_(m_4) corresponding to the fourth harmonic are recorded, m=1, 2, …, 5. For example, refer to Figure 4 where the phase number is divided into the corresponding phase value in the coarse interval to-be-measured phase table, and the estimated amplitude value is the recorded amplitude corresponding to the phase number.

[0108] When the traversal test of all phase points in the coarse interval to-be-measured phase table is completed, the average values of all recorded second harmonic amplitudes, third harmonic amplitudes, and fourth harmonic amplitudes A_(m_2) / A_(m_3) / A_(m_4), m=1, 2, …, 5 are solved, respectively. If the average value is less than the corresponding original amplitude estimation value, the phase value corresponding to the minimum value is output, and the flag is set to 1. If the average value is greater than the corresponding original amplitude estimation value, the phase value corresponding to the maximum value is output, and the flag is set to 0.

[0109] M2 = 10, and the selection method is uniform interval sampling, to form a fine interval test phase table. Due to the periodicity of the phase, if the output phase value is the boundary point of [0, π], the phase can be extended and then uniformly sampled. The above traversal test is performed based on the fine interval test phase table. For example, please refer to Figure 5 , where the phase number is divided into 1-10 fine interval test phase table corresponding to the phase value, and the estimated amplitude value is the recorded amplitude corresponding to the phase number.

[0110] Determine if the flag is 1, if so, select the fine interval test phase table to record the minimum value in the phase traversal process, and select the corresponding phase value to output. If not, select the maximum value in the fine interval test phase table in the phase traversal process, and select the corresponding phase value to output after increasing π or subtracting π.

[0111] The above is a related description of the signal processing channel.

[0112] Some embodiments provide a phase estimation method, which can be applied to the above signal processing channel. Please refer to Figure 6 , the harmonic phase acquisition method comprises the following steps:

[0113] Step 100: Obtain the original input signal and the coarse interval test phase table. Wherein, the coarse interval test phase table includes M1 phase values, and M1 is a positive integer greater than 1.

[0114] Step 110: Based on the coarse interval test phase table, perform traversal test. Based on the harmonic frequency and harmonic amplitude value of the harmonic of the original input signal or based on the spur frequency and spur amplitude value of the spur of the original input signal, and any phase value in the corresponding test phase table to generate a cancellation signal; superimpose the cancellation signal and the original input signal to obtain a digital test signal; input the digital test signal into the DAC to perform digital-to-analog conversion to obtain an analog test signal, and perform spectrum analysis on the analog test signal to obtain the amplitude estimation value corresponding to the harmonic frequency or the spur frequency of any phase value; traverse the cancellation signal corresponding to each phase value in the corresponding test phase table to obtain each amplitude estimation value corresponding to each phase value.

[0115] Step 120: Determine the target phase corresponding to the amplitude estimation target value in the M1 amplitude estimation values, and generate a fine interval test phase table according to the target phase. Wherein, based on the coarse interval test phase table, traversal test is performed to obtain M1 phase values corresponding to M1 amplitude estimation values.

[0116] Step 130: traversing test is performed based on the fine interval based to-be-tested phase table to obtain M2 amplitude estimation values corresponding to M2 phase values, and a phase corresponding to an amplitude estimation minimum value is obtained based on the M2 amplitude estimation values and the corresponding phase values.

[0117] Some embodiments provide a computer readable storage medium, which stores a program capable of being executed by a processor to implement the above phase estimation method.

[0118] Those skilled in the art can understand that all or part of the functions of the various methods in the above embodiments can be implemented by hardware or by a computer program. When all or part of the functions in the above embodiments are implemented by a computer program, the program can be stored in a computer readable storage medium, which can include a read-only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, etc. The above functions are implemented by executing the program by a computer. For example, the program is stored in a memory of a device, and when the program in the memory is executed by a processor 30, the above all or part of the functions are implemented. In addition, when all or part of the functions in the above embodiments are implemented by a computer program, the program can also be stored in a server, another computer, a disk, an optical disk, a flash disk, a mobile hard disk, etc. The program is saved in a memory of a local device by downloading or copying, or the system of the local device is updated, and when the program in the memory is executed by a processor 30, the above all or part of the functions in the embodiments are implemented.

[0119] The above application is described by using specific examples, which is only used to help understand the application and does not limit the application. Those skilled in the art can make some simple deductions, deformations or substitutions according to the idea of the application.

Claims

1. A phase estimation method, characterized in that: include: Obtaining an original input signal and a coarse-interval phase table to be measured; wherein the coarse-interval phase table to be measured includes M1 phase values, and M1 is a positive integer greater than 1; Performing a traversal test on the phase table to be tested based on the coarse interval: generating a cancellation signal based on the harmonic frequencies and harmonic amplitude values ​​of the harmonics of the original input signal or based on the spurious frequencies and spurious amplitude values ​​of the spurious of the original input signal, and any phase value in the corresponding phase table to be tested; superimposing the cancellation signal and the original input signal to obtain a digital signal to be tested; inputting the digital signal to be tested into a DAC for digital-to-analog conversion to obtain an analog signal to be tested, performing spectrum analysis on the analog signal to be tested to obtain an amplitude estimation value of the harmonic frequency or spurious frequency corresponding to any phase value; traversing the cancellation signal corresponding to each phase value in the corresponding phase table to be tested to obtain each amplitude estimation value corresponding to each phase value; Obtaining M1 amplitude estimation values ​​corresponding to the M1 phase values, and determining a target phase corresponding to an amplitude estimation target value among the M1 amplitude estimation values; Generate a fine-interval phase table to be measured based on the target phase; wherein the fine-interval phase table to be measured includes M2 phase values, and M2 is a positive integer greater than 1; wherein the phase interval between the M1 phase values ​​is greater than the phase interval between the M2 phase values; and / or, the phase range included in the M1 phase values ​​is greater than the phase range included in the M2 phase values, and the value of M1 is less than the value of M2; The traversal test is performed based on the fine-interval phase table to be tested to obtain M2 amplitude estimation values ​​corresponding to M2 phase values, and the phase corresponding to the minimum amplitude estimation value is obtained based on the M2 amplitude estimation values ​​and the corresponding phase values.

2. The phase estimation method according to claim 1, wherein Determining a target phase corresponding to an amplitude estimation target value among the M1 amplitude estimation values ​​includes: Obtaining an average of the M1 amplitude estimation values; Determining whether the average value is greater than the harmonic amplitude value or the spurious amplitude value of the original input signal; If it is greater than, obtaining the phase corresponding to the maximum value among the M1 amplitude estimation values ​​and using it as the target phase corresponding to the amplitude estimation target value; If it is less than, the phase corresponding to the minimum value of the M1 amplitude estimation values ​​is obtained and used as the target phase corresponding to the amplitude estimation target value.

3. The phase estimation method according to claim 2, wherein: The obtaining, based on the M2 amplitude estimation values ​​and the corresponding phase values, a phase corresponding to a minimum amplitude estimation value, includes: If the phase corresponding to the minimum value among the M1 amplitude estimation values ​​is obtained, then the phase corresponding to the minimum value among the M2 amplitude estimation values ​​is determined to be the phase corresponding to the minimum amplitude estimation value; If the phase corresponding to the maximum value among the M1 amplitude estimation values ​​is obtained, the phase corresponding to the maximum value among the M2 amplitude estimation values ​​is obtained, and the phase corresponding to the minimum amplitude estimation value is determined based on the phase corresponding to the maximum value.

4. The phase estimation method according to claim 3, wherein: The determining, based on the phase corresponding to the maximum value, the phase corresponding to the amplitude estimation minimum value includes: Shifting the phase corresponding to the maximum value of the M2 amplitude estimation values ​​by a preset phase so that the shifted phase corresponds to the minimum value of the amplitude estimation; The shifted phase is output, where the shifted phase is the phase corresponding to the minimum value of the amplitude estimation.

5. The phase estimation method according to claim 4, wherein: If the phase value corresponding to the maximum value among the M2 amplitude estimation values ​​is between [0, π), the preset phase of the translation is π; If the phase value corresponding to the maximum value among the M2 amplitude estimation values ​​is between [π, 2π), the preset phase of the shift is -π.

6. The phase estimation method according to claim 1, wherein: The coarse interval phase table to be measured is generated in the following way: Dividing M1 phase values ​​from the phase range [a, a+π] according to a preset first phase interval to generate the coarse interval phase table to be measured; wherein a is a phase greater than or equal to 0 and less than or equal to π; or, An estimated phase empirical value is acquired, and the coarse-interval phase table to be measured is generated according to the estimated phase empirical value.

7. The phase estimation method according to claim 6, wherein: The obtaining of the estimated phase empirical value includes: Obtaining a phase estimation value corresponding to a harmonic frequency or a spurious frequency of a known input signal after the known input signal is input into the DAC; Based on the frequency relationship between the known input signal and the original input signal, the estimated phase empirical value corresponding to the harmonic of the original input signal is obtained from the phase estimation value; or, Based on the frequency relationship between the known input signal and the original input signal, and the frequency relationship between the spurious frequency of the known input signal and the spurious frequency of the original input signal, the estimated phase empirical value corresponding to the spur of the original input signal is obtained from the phase estimation value.

8. The phase estimation method according to claim 6, wherein: The generating the coarse-interval phase table to be measured according to the estimated phase empirical value includes: According to a preset second phase interval, M2 phase values ​​are divided from the nearby range [bc, b+c] of the estimated phase empirical value to generate the coarse interval phase table to be measured; wherein b is the estimated phase empirical value and c is the preset phase value.

9. The phase estimation method according to claim 1, wherein: The performing spectrum analysis on the simulated signal to be tested comprises: Inputting the simulated signal to be tested into a spectrum analyzer for spectrum analysis; or, The simulated signal to be tested is input into an analog-to-digital converter for analog-to-digital conversion and then subjected to Fourier transform processing for spectrum analysis.

10. The phase estimation method according to claim 1, wherein: For harmonics, the corresponding frequency of the cancellation signal is the harmonic frequency of the harmonic of the original input signal; for spurious signals, the corresponding frequency of the cancellation signal is the spurious frequency of the spurious signals of the original input signal.

11. A signal processing channel, characterized in that: Used to implement the phase estimation method according to any one of claims 1 to 10, the signal processing channel includes at least two DDS phase accumulators, and the signal processing circuits where each of the DDS phase accumulators is located are connected in parallel, and the number of parallel connections is defined as an integer H greater than 1; One of the signal processing circuits including a DDS phase accumulator generates the original input signal after phase-to-amplitude conversion and attenuation processing, and the remaining signal processing circuits including a DDS phase accumulator generate cancellation signals corresponding to harmonics or spurious signals after phase-to-amplitude conversion based on the corresponding phase values ​​in the phase table to be measured.

12. The signal processing channel according to claim 11, wherein: The signal processing channel is used to process multiple harmonics, or multiple spurious signals, or at least one harmonic and at least one spurious signal. If the value of H is ≥3, the remaining signal processing circuits including the DDS phase accumulator are used to generate cancellation signals corresponding to the multiple harmonics, or cancellation signals corresponding to the multiple spurious signals, or cancellation signals corresponding to at least one harmonic and at least one spurious signal. The maximum number of times the remaining signal processing circuits including the DDS phase accumulator are called is equal to twice the sum of the number of harmonics and the number of spurious signals.

13. The signal processing channel according to claim 12, wherein: The signal processing channel also includes a phase counter and a memory. The phase counter is used to accumulate and count the M1 phase values ​​or M2 phase values ​​corresponding to the cancellation signal during traversal, and the memory is used to store the corresponding phase values ​​in the phase table to be measured and their corresponding amplitude estimation values.

14. The signal processing channel according to claim 13, wherein: Obtain the total number L of harmonics and spurious signals to be processed; Divide twice the total number L by H-1 and round up to the nearest integer to obtain the number of times the signal processing channel is called; According to the number of times the signal processing channel is called, the phase counter and the memory are reset to clear the amplitude estimation value and the corresponding phase value stored in history.

15. A computer-readable storage medium, characterized in that The medium stores a program, which can be executed by a processor to implement the method according to any one of claims 1 to 10.

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