Compensation method, device and equipment for carrier frequency offset of modulation signal

Abstract

The invention provides a compensation method, device and equipment for carrier frequency deviation of a modulation signal, which can be applied to the technical field of signal processing. The compensation method comprises the following steps: removing redundant data in an initial modulation signal to obtain a power signal; processing the power signal, and determining a target frequency conversion interval; performing linear frequency modulation z transformation on the power signal according to the target frequency transformation interval to obtain a target frequency spectrum; and determining a first peak amplitude from the target frequency spectrum, and obtaining an estimated value for compensating the carrier frequency offset according to the first peak amplitude and an adjacent amplitude corresponding to an adjacent frequency point of the frequency point where the first peak amplitude is located.

Description

Technical Field

[0001] The present disclosure relates to the technical field of signal processing, and more particularly, to a method, apparatus, and device for compensating for carrier frequency offset of a modulated signal. Background Art

[0002] QAM (Quadrature Amplitude Modulation) signals are widely used in both wired and wireless communications. However, in an actual communication channel, the carrier frequency of a QAM signal is subject to deviation due to various factors, which in turn affects the quality of signal demodulation. Therefore, it is necessary to estimate and compensate for the carrier frequency offset to ensure the accuracy and stability of demodulation.

[0003] In the process of implementing the concept of the present disclosure, it has been found through research that there are at least technical problems of low accuracy or large computational complexity in estimating the carrier frequency offset in the related art. Summary of the Invention

[0004] In view of this, the present disclosure provides a method, apparatus, and device for compensating for carrier frequency offset of a modulated signal.

[0005] One aspect of the present disclosure provides a method for compensating for carrier frequency offset of a modulated signal, including:

[0006] Removing redundant data from an initial modulated signal to obtain a squared signal; processing the squared signal to determine a target frequency transformation interval; performing a chirp z-transform on the squared signal according to the target frequency transformation interval to obtain a target spectrum; determining a first peak amplitude from the target spectrum, and obtaining an estimated value for compensating the carrier frequency offset according to the first peak amplitude and adjacent amplitudes corresponding to adjacent frequency points of the frequency point where the first peak amplitude is located.

[0007] According to an embodiment of the present disclosure, the adjacent amplitudes include a first adjacent amplitude and a second adjacent amplitude. Determining a first peak amplitude from the target spectrum, and obtaining an estimated value for compensating the carrier frequency offset according to the first peak amplitude and adjacent amplitudes corresponding to adjacent frequency points of the frequency point where the first peak amplitude is located, includes: determining the peak spectrum value in the target spectrum as the first peak amplitude; determining the spectrum value corresponding to the frequency point α - 1 adjacent to the frequency point α where the first peak amplitude is located as the first adjacent amplitude and determining the spectrum value corresponding to the frequency point α + 1 adjacent to the frequency point α where the first peak amplitude is located as the second adjacent amplitude; calculating a carrier frequency offset error according to the first peak amplitude, the first adjacent amplitude, and the second adjacent amplitude; and obtaining an estimated value for compensating the carrier frequency offset according to the carrier frequency offset error.

[0008] According to an embodiment of the present disclosure, calculating a carrier frequency offset error based on a first peak amplitude, a first adjacent amplitude, and a second adjacent amplitude includes: calculating a first ratio of the first adjacent amplitude to the first peak amplitude and a second ratio of the second adjacent amplitude to the first peak amplitude; constructing a tangent function regarding the carrier frequency offset error according to the first ratio and the second ratio; and calculating the carrier frequency offset error according to the tangent function.

[0009] According to an embodiment of the present disclosure, processing a power signal to determine a target frequency transformation interval includes: performing a Fourier transform on the power signal to obtain a Fourier transform spectrum corresponding to the power signal; determining a peak spectrum value as a second peak amplitude from the Fourier transform spectrum; and determining the target frequency transformation interval according to an index corresponding to the frequency point where the second peak amplitude is located.

[0010] According to an embodiment of the present disclosure, the target frequency transformation interval is expressed as the following formula (I):

[0011] (I)

[0012] where y’ is the index corresponding to the frequency point where the second peak amplitude is located, q is a relevant control parameter, N is the number of sampling points, and T S is the sampling duration of a single coded symbol.

[0013] According to an embodiment of the present disclosure, the tangent function regarding the carrier frequency offset error is expressed as the following formula (II):

[0014] (II)

[0015] where is the tangent function, δ is the carrier frequency offset error, j is the imaginary unit, M is the refinement multiple, k m is the index corresponding to the frequency point where the first peak amplitude is located, R(k m + 1) is the second adjacent amplitude, R(k m - 1) is the first adjacent amplitude, and R(k m ) is the first peak amplitude.

[0016] According to an embodiment of the present disclosure, the process of calculating the carrier frequency offset error according to the tangent function is expressed as the following formula (III).

[0017] (III)

[0018] According to an embodiment of the present disclosure, the redundant data includes a modulation amplitude and a noise signal. Removing the redundant data from the initial modulation signal to obtain a power signal includes: performing a power operation on the initial modulation signal according to a predetermined power number to remove the modulation amplitude and obtain an initial power signal; removing the noise signal from the initial power signal to obtain the power signal.

[0019] Another aspect of the present disclosure provides a compensation device for carrier frequency offset of a modulation signal, including:

[0020] An operation module for removing redundant data from the initial modulation signal to obtain a power signal;

[0021] A determination module for processing the power signal to determine a target frequency transformation interval;

[0022] A transformation module for performing a chirp z-transform on the power signal according to the target frequency transformation interval to obtain a target spectrum;

[0023] An obtaining module for determining a first peak amplitude from the target spectrum and obtaining an estimated value for compensating the carrier frequency offset according to the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point.

[0024] Another aspect of the present disclosure provides an electronic device, including:

[0025] One or more processors;

[0026] A memory for storing one or more programs,

[0027] wherein, when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described above.

[0028] According to an embodiment of the present disclosure, the power signal after removing the redundant signal is processed, and a chirp z-transform is performed according to the obtained target frequency transformation interval to obtain a target spectrum. The first peak amplitude is determined from the target spectrum, and an estimated value for compensating the carrier frequency offset is obtained according to the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point. Since the refinement factor is not adjusted to improve the estimation resolution, the technical problem of large computational complexity is solved. At the same time, the estimated value of the carrier frequency offset for compensation is obtained through the first peak amplitude of the target spectrum and the adjacent amplitudes of its adjacent frequency points, which can comprehensively consider the local characteristics of the target spectrum and is not limited by the size of the signal-to-noise ratio and the size of the carrier frequency offset, thereby improving the estimation accuracy of the carrier frequency offset and contributing to improving the demodulation quality of the modulation signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description of the embodiments of the present disclosure with reference to the accompanying drawings. In the drawings:

[0030] Figure 1 Schematically shows a flowchart of a method for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure.

[0031] Figure 2 Schematically shows a diagram of the mean square error of the method for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure and the estimation method in the related art varying with the signal-to-noise ratio.

[0032] Figure 3 Schematically shows a diagram of the mean square error of the method for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure and the estimation method in the related art varying with the carrier frequency offset amount.

[0033] Figure 4 Schematically shows a block diagram of a device for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure.

[0034] Figure 5 Schematically shows a block diagram of an electronic device suitable for implementing a method for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure. Detailed Embodiments

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is obvious that one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure.

[0036] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0037] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0038] In the case of using expressions such as "at least one of A, B, and C", generally, it should be interpreted according to the meaning usually understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0039] In the embodiments of the present disclosure, in aspects such as the collection, update, analysis, processing, use, transmission, provision, disclosure, storage, etc. of the involved data (for example, including but not limited to user personal information), they all comply with the provisions of relevant laws and regulations, are used for legal purposes, and do not violate public order and good customs. In particular, necessary measures are taken for user personal information to prevent illegal access to user personal information data and to maintain the security of user personal information and network security.

[0040] In the process of implementing the inventive concept of the present disclosure, through research, it is found that currently, the estimation of carrier frequency offset is mainly divided into the differential frequency offset estimation method (Differential Frequency Offset Estimation, diff - FOE) based on differential phase and the frequency estimation method based on discrete Fourier transform (DFT). Among them, diff - FOE requires a large amount of data to obtain a relatively accurate frequency offset.

[0041] In order to improve the estimation accuracy, it can be improved based on the Fourier transform (FFT), such as the interpolated discrete Fourier transform, the zero - padding method, and the chirp z - transform (CZT).

[0042] Among them, the CZT method can adjust the frequency resolution by adjusting the refinement factor. Theoretically, as long as the refinement factor is large enough, an ideal resolution can be obtained, but this also leads to technical problems such as a large amount of calculation.

[0043] In view of this, the embodiments of the present disclosure provide a method for compensating the carrier frequency offset of a modulated signal, including: removing redundant data in the initial modulated signal to obtain a squared signal; processing the squared signal to determine a target frequency transformation interval; performing a chirp z - transform on the squared signal according to the target frequency transformation interval to obtain a target spectrum; determining a first peak amplitude from the target spectrum, and obtaining an estimated value for compensating the carrier frequency offset based on the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point.

[0044] Figure 1 Schematically shows a flowchart of a method for compensating the carrier frequency offset of a modulated signal according to an embodiment of the present disclosure.

[0045] As Figure 1As shown, the method 100 includes operations S110 to S140.

[0046] In operation S110, redundant data in the initial modulation signal is removed to obtain a power signal.

[0047] In operation S120, the power signal is processed to determine a target frequency transformation interval.

[0048] In operation S130, according to the target frequency transformation interval, a chirp z-transform is performed on the power signal to obtain a target spectrum.

[0049] In operation S140, a first peak amplitude is determined from the target spectrum, and an estimated value for compensating the carrier frequency offset is obtained based on the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point.

[0050] According to an embodiment of the present disclosure, the initial modulation signal may be a QAM signal. Removing the redundant data in the initial modulation signal is to avoid interference from features unrelated to the carrier frequency to subsequent processing, affecting the estimation accuracy or causing signal distortion.

[0051] According to an embodiment of the present disclosure, the target frequency transformation interval may represent an interval that is relatively related to the carrier frequency information. Performing a chirp z-transform only within the target frequency transformation interval avoids waste of computing resources.

[0052] According to an embodiment of the present disclosure, the chirp z-transform (CZT) is a powerful signal processing tool that can convert the power signal from the time domain to the frequency domain, perform high-resolution frequency analysis on the signal, and obtain a high-precision target spectrum. The target spectrum includes detailed frequency information of the power signal within the target frequency interval, providing a basis for subsequent frequency estimation.

[0053] According to an embodiment of the present disclosure, considering the adjacent amplitudes of the first peak amplitude can reduce the influence of the fence effect, improve the robustness of the estimation, and ensure the stability and reliability of the communication system.

[0054] To demonstrate that the above method for compensating the carrier frequency offset of the modulation signal still has high estimation accuracy under different signal-to-noise ratios and carrier frequency offsets, the following will be through Figure 2 and Figure 3 for further proof.

[0055] Figure 2 Schematically shows a schematic diagram of the mean square error of the method for compensating the carrier frequency offset of the modulation signal according to an embodiment of the present disclosure and the estimation method in the related art changing with the signal-to-noise ratio.

[0056] Figure 3Schematically shows a schematic diagram of the mean square error of the compensation method for the carrier frequency offset of a modulated signal varying with the carrier frequency offset amount according to an embodiment of the present disclosure and the estimation method in the related art.

[0057] As Figure 2 and Figure 3 shown, IpDFT represents a frequency offset estimation method using the Interpolated Discrete Fourier Transform (IpDFT) in the related art, FFT represents an estimation method using the Discrete Fourier Transform in the related art, CZT represents an estimation method using the Chirp Z-Transform in the related art, and ICZT represents an estimation method in the compensation method for the carrier frequency offset of a modulated signal in the present application.

[0058] As Figure 2 shown, when the carrier frequency is constant, for any SNR value, the normalized mean square error (NMSE) of the carrier frequency offset estimation value corresponding to ICZT is less than that of the other three related technologies, that is, the estimation accuracy is higher.

[0059] As Figure 3 shown, when the SNR is constant, for any carrier frequency offset value, the normalized mean square error (NMSE) of the estimation value corresponding to ICZT is less than that of the other three related technologies, that is, the estimation accuracy is higher.

[0060] According to an embodiment of the present disclosure, the power signal with redundant signals removed is processed, and a Chirp Z-Transform is performed according to the obtained target frequency transformation interval to obtain a target spectrum. The first peak amplitude is determined from the target spectrum, and an estimated value for compensating the carrier frequency offset is obtained based on the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point. Since the refinement factor is not adjusted to improve the estimation resolution, the technical problem of large computational complexity is solved. At the same time, the estimated value of the carrier frequency offset for compensation is obtained through the first peak amplitude of the target spectrum and the adjacent amplitudes of its adjacent frequency points, which can comprehensively consider the local characteristics of the target spectrum and is not limited by the size of the SNR and the size of the carrier frequency offset, thereby improving the estimation accuracy of the carrier frequency offset and contributing to improving the demodulation quality of the modulated signal.

[0061] According to an embodiment of the present disclosure, the redundant data includes the modulation amplitude and the noise signal. Removing the redundant data from the initial modulation signal to obtain a power signal includes: performing a power operation on the initial modulation signal according to a predetermined power number to remove the modulation amplitude and obtain an initial power signal; removing the noise signal from the initial power signal to obtain a power signal.

[0062] According to an embodiment of the present disclosure, the initial modulation signal xn It can be expressed as the following formula (1).

[0063] (1)

[0064] Where A n represents the modulation amplitude, ϕ n represents the modulation phase, represents the carrier frequency offset, n represents the index of the sampling sequence, T S represents the sampling duration of a single coded symbol, T S can take 10 -6 s, represents the noise signal.

[0065] According to an embodiment of the present disclosure, for a QAM signal, the predetermined power number is 4. Therefore, the process of performing a fourth-power operation on the initial modulation signal of the above formula (1) can be expressed as the following formula (2).

[0066] (2)

[0067] Where represents the power signal, the non-zero constant A = , e n represents the noise signal, which conforms to a mean Gaussian distribution and can be ignored in subsequent processing.

[0068] According to an embodiment of the present disclosure, processing the power signal to determine the target frequency transformation interval includes: performing a Fourier transform on the power signal to obtain a Fourier transform spectrum corresponding to the power signal; determining the peak spectrum value as the second peak amplitude from the Fourier transform spectrum; and determining the target frequency transformation interval according to the index corresponding to the frequency point where the second peak amplitude is located.

[0069] According to an embodiment of the present disclosure, performing a Fourier transform on the power signal to obtain a Fourier transform spectrum corresponding to the power signal The process can be expressed as the following formula (3).

[0070] (3)

[0071] Where N is the total number of samples, y is the Fourier transform index, and y .

[0072] According to an embodiment of the present disclosure, the carrier frequency offset estimation value obtained only by performing a Fourier transform on the power signal can be expressed as the following formula (4).

[0073] (4)

[0074] Among them, y’ represents the index corresponding to the frequency point where the second peak amplitude is located.

[0075] According to an embodiment of the present disclosure, due to the fence effect, the estimated value at this time is not accurate. Therefore, the target frequency transformation interval can be determined according to y’ in the above formula (4) to further process the power signal.

[0076] According to an embodiment of the present disclosure, the target frequency transformation interval is expressed as the following formula (5).

[0077] (5)

[0078] Among them, q is a relevant control parameter and can be 1.

[0079] According to an embodiment of the present disclosure, the target frequency transformation interval for the subsequent chirp z-transform is determined by Fourier transform, so that the subsequent signal processing can focus on the key range related to the carrier frequency offset. Compared with the indiscriminate processing of the entire frequency domain, it can reduce unnecessary computational complexity and improve processing efficiency.

[0080] According to an embodiment of the present disclosure, performing a chirp z-transform on the power signal to obtain the target spectrum R CZT (q) can be expressed as the following formula (6).

[0081] (6)

[0082] Among them, M is the refinement multiple and k is the chirp z-transform index. .

[0083] According to an embodiment of the present disclosure, Z k can be expressed as the following formula (7).

[0084] (7)

[0085] Among them, the starting complex number , S0 is the starting sampling amplitude, θ0 is the starting sampling angle and , f s is the sampling frequency, the frequency step complex number , W0 is the amplitude between adjacent sampling points. represents the angle between adjacent sampling points and , and S0 = 1, w0 = 1 can be taken.

[0086] According to an embodiment of the present disclosure, searching the target spectrum, the change index K corresponding to the first peak amplitude m .

[0087] According to an embodiment of the present disclosure, the adjacent amplitudes include a first adjacent amplitude and a second adjacent amplitude. A first peak amplitude is determined from a target spectrum, and an estimated value for compensating the carrier frequency offset is obtained based on the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of its frequency point, including: determining the peak spectrum value in the target spectrum as the first peak amplitude; determining the spectrum value corresponding to the frequency point α - 1 adjacent to the frequency point α where the first peak amplitude is located as the first adjacent amplitude and determining the spectrum value corresponding to the frequency point α + 1 adjacent to the frequency point α where the first peak amplitude is located as the second adjacent amplitude; calculating a carrier frequency offset error based on the first peak amplitude, the first adjacent amplitude, and the second adjacent amplitude; and obtaining an estimated value for compensating the carrier frequency offset based on the carrier frequency offset error.

[0088] According to an embodiment of the present disclosure, based on the change index K corresponding to the frequency point α where the first peak amplitude is located m , the frequency offset estimated value of the following formula (8) can be obtained .

[0089] (8)

[0090] where δ is the carrier frequency offset error and δ ∈ [-0.5, 0.5].

[0091] According to an embodiment of the present disclosure, the first peak amplitude can be expressed as the following formula (9).

[0092] (9)

[0093] According to an embodiment of the present disclosure, the first adjacent amplitude can be expressed as the following formula (10).

[0094] (10)

[0095] According to an embodiment of the present disclosure, the second adjacent amplitude can be expressed as the following formula (11).

[0096] (11)

[0097] According to an embodiment of the present disclosure, calculating the carrier frequency offset error based on the first peak amplitude, the first adjacent amplitude, and the second adjacent amplitude includes: calculating a first ratio of the first adjacent amplitude to the first peak amplitude and a second ratio of the second adjacent amplitude to the first peak amplitude; constructing a tangent function regarding the carrier frequency offset error based on the first ratio and the second ratio; and calculating the carrier frequency offset error according to the tangent function.

[0098] According to an embodiment of the present disclosure, the first ratio can be expressed as the following formula (12).

[0099] (12)

[0100] According to an embodiment of the present disclosure, according to a similar calculation rule, the second ratio can be expressed as the following formula (13).

[0101] (13)

[0102] According to an embodiment of the present disclosure, in order to construct a tangent function regarding the carrier frequency offset error, the above formulas (12) and (13) can be deformed to respectively obtain the following formulas (14) and (15).

[0103] (14)

[0104] (15)

[0105] According to an embodiment of the present disclosure, the tangent function regarding the carrier frequency offset error is expressed as the following formula (16).

[0106] (16)

[0107] According to an embodiment of the present disclosure, according to the tangent function, the process of calculating the carrier frequency offset error is expressed as the following formula (17).

[0108] (17)

[0109] According to an embodiment of the present disclosure, by using the peak spectral value in the target spectrum as the first peak amplitude, and simultaneously considering the first adjacent amplitude and the second adjacent amplitude corresponding to its adjacent frequency points, the local characteristics of the spectrum are fully utilized, breaking through the technical barrier of only considering the peak spectral value in the related art and avoiding the fence effect. At the same time, only the spectral values corresponding to three frequency points need to be obtained to calculate the carrier frequency offset error. Therefore, the carrier frequency offset can be accurately estimated while the calculation amount is small.

[0110] Figure 4 Schematically shows a block diagram of a compensation device for the carrier frequency offset of a modulation signal according to an embodiment of the present disclosure.

[0111] As Figure 4 shown, the device 400 includes an operation module 410, a determination module 420, a transformation module 430, and an obtaining module 440.

[0112] An operation module 410 is configured to remove redundant data in an initial modulation signal to obtain a power signal.

[0113] A determination module 420 is configured to process the power signal to determine a target frequency transformation interval.

[0114] A transformation module 430 is configured to perform a chirp z-transform on the power signal according to the target frequency transformation interval to obtain a target spectrum.

[0115] An obtaining module 440 is configured to determine a first peak amplitude from the target spectrum, and obtain an estimated value for compensating a carrier frequency offset according to the first peak amplitude and adjacent amplitudes corresponding to adjacent frequency points of the frequency point where the first peak amplitude is located.

[0116] According to an embodiment of the present disclosure, the operation module 410 includes a first obtaining sub-module and a second obtaining sub-module.

[0117] The first obtaining sub-module is configured to perform a power operation on the initial modulation signal according to a predetermined power number to remove a modulation amplitude and obtain an initial power signal.

[0118] The second obtaining sub-module is configured to remove a noise signal from the initial power signal to obtain a power signal.

[0119] According to an embodiment of the present disclosure, the obtaining module 440 includes a first determination sub-module, a second determination sub-module, a calculation sub-module, and an obtaining sub-module.

[0120] The first determination sub-module is configured to determine a peak spectrum value in the target spectrum as the first peak amplitude.

[0121] The second determination sub-module is configured to determine a spectrum value corresponding to a frequency point n - 1 adjacent to the frequency point where the first peak amplitude is located as the first adjacent amplitude, and determine a spectrum value corresponding to a frequency point n + 1 adjacent to the frequency point where the first peak amplitude is located as the second adjacent amplitude.

[0122] The calculation sub-module is configured to calculate a carrier frequency offset error according to the first peak amplitude, the first adjacent amplitude, and the second adjacent amplitude.

[0123] The obtaining sub-module is configured to obtain an estimated value for compensating a carrier frequency offset according to the carrier frequency offset error.

[0124] According to an embodiment of the present disclosure, the calculation sub-module includes a first calculation unit, a construction unit, and a second calculation unit.

[0125] The first calculation unit is configured to calculate a first ratio of the first adjacent amplitude to the first peak amplitude and a second ratio of the second adjacent amplitude to the first peak amplitude.

[0126] A construction unit for constructing a tangent function regarding the carrier frequency offset error according to a first ratio and a second ratio.

[0127] A second calculation unit for calculating the carrier frequency offset error according to the tangent function.

[0128] According to an embodiment of the present disclosure, the determination module 420 includes a transformation sub-module, a first determination sub-module, and a second determination sub-module.

[0129] The transformation sub-module is used to perform a fast Fourier transform on the power signal to obtain a Fourier transform spectrum corresponding to the power signal.

[0130] The first determination sub-module is used to determine that the peak spectrum value in the Fourier transform spectrum is the second peak amplitude.

[0131] The second determination sub-module is used to determine a target frequency transformation interval according to the index corresponding to the frequency point where the second peak amplitude is located.

[0132] According to the embodiments of the present disclosure, any plurality of the modules, sub-modules, units, and sub-units, or at least part of the functions of any of them can be implemented in one module. Any one or more of the modules, sub-modules, units, and sub-units according to the embodiments of the present disclosure can be split into multiple modules for implementation. Any one or more of the modules, sub-modules, units, and sub-units according to the embodiments of the present disclosure can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on chip, a system on substrate, a system on package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware in any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation manners of software, hardware, and firmware, or in an appropriate combination of any several of them. Alternatively, one or more of the modules, sub-modules, units, and sub-units according to the embodiments of the present disclosure can be at least partially implemented as a computer program module, and when the computer program module runs, it can execute the corresponding functions.

[0133] For example, any combination of the operation module 410, the determination module 420, the transformation module 430, and the obtaining module 440 can be combined and implemented in one module / unit / sub-unit, or any one of the modules / units / sub-units can be split into multiple modules / units / sub-units. Alternatively, at least part of the functions of one or more of these modules / units / sub-units can be combined with at least part of the functions of other modules / units / sub-units and implemented in one module / unit / sub-unit. According to an embodiment of the present disclosure, at least one of the operation module 410, the determination module 420, the transformation module 430, and the obtaining module 440 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on chip, a system on substrate, a system on package, an application specific integrated circuit (ASIC), or any other reasonable way of integrating or packaging circuits, etc., implemented by hardware or firmware, or implemented in any one of the three implementation manners of software, hardware, and firmware, or in any appropriate combination of several of them. Alternatively, at least one of the operation module 410, the determination module 420, the transformation module 430, and the obtaining module 440 can be at least partially implemented as a computer program module, which can execute corresponding functions when the computer program module is run.

[0134] It should be noted that the part of the compensation device for carrier frequency offset of the modulated signal in the embodiments of the present disclosure corresponds to the part of the compensation method for carrier frequency offset of the modulated signal in the embodiments of the present disclosure. For the description of the compensation device part, please refer to the compensation method part specifically, and details will not be repeated here.

[0135] Figure 5 Schematically shown is a block diagram of an electronic device suitable for implementing a method for compensating carrier frequency offset of a modulated signal according to an embodiment of the present disclosure. Figure 5 The shown electronic device is only an example and should not impose any limitation on the functions and usage scope of the embodiments of the present disclosure.

[0136] As Figure 5 shown, the electronic device 500 according to an embodiment of the present disclosure includes a processor 501, which can perform various appropriate actions and processes according to a program stored in a read only memory (ROM) 502 or a program loaded from a storage section 508 into a random access memory (RAM) 503. The processor 501 can include, for example, a general microprocessor (such as a CPU), an instruction set processor, and / or a related chipset, and / or a dedicated microprocessor (such as an application specific integrated circuit (ASIC)), etc. The processor 501 can also include on-board memory for caching purposes. The processor 501 can include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0137] In the RAM 503, various programs and data required for the operation of the electronic device 500 are stored. The processor 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. The processor 501 performs various operations of the method flow according to the embodiments of the present disclosure by executing the programs in the ROM 502 and / or the RAM 503. It should be noted that the programs may also be stored in one or more memories other than the ROM 502 and the RAM 503. The processor 501 may also perform various operations of the method flow according to the embodiments of the present disclosure by executing the programs stored in the one or more memories.

[0138] According to an embodiment of the present disclosure, the electronic device 500 may further include an input / output (I / O) interface 505, and the input / output (I / O) interface 505 is also connected to the bus 504. The electronic device 500 may further include one or more of the following components connected to the input / output (I / O) interface 505: an input portion 506 including a keyboard, a mouse, etc.; an output portion 507 including, for example, a cathode ray tube (CRT), a liquid crystal display (LCD), etc. and a speaker, etc.; a storage portion 508 including a hard disk, etc.; and a communication portion 509 including a network interface card such as a LAN card, a modem, etc. The communication portion 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the input / output (I / O) interface 505 as needed. A removable medium 511, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 510 as needed so that a computer program read therefrom is installed into the storage portion 508 as needed.

[0139] According to an embodiment of the present disclosure, the method flow according to the embodiments of the present disclosure may be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes program codes for performing the method shown in the flowchart. In such an embodiment, the computer program may be downloaded and installed from a network via the communication portion 509, and / or installed from the removable medium 511. When the computer program is executed by the processor 501, the above-described functions defined in the system according to the embodiments of the present disclosure are executed. According to an embodiment of the present disclosure, the above-described systems, devices, apparatuses, modules, units, etc. may be implemented by computer program modules.

[0140] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the foregoing embodiments; or may exist separately without being assembled into the device / apparatus / system. The foregoing computer-readable storage medium carries one or more programs, and when the one or more programs are executed, the method according to the embodiments of the present disclosure is implemented.

[0141] According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium. For example, it may include but is not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the present disclosure, the computer-readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or in combination with an instruction execution system, apparatus, or device.

[0142] For example, according to an embodiment of the present disclosure, the computer-readable storage medium may include the above-described ROM 502 and / or RAM 503 and / or one or more memories other than ROM 502 and RAM 503.

[0143] Embodiments of the present disclosure further include a computer program product, which includes a computer program. The computer program includes program code for executing the method provided in the embodiments of the present disclosure. When the computer program product runs on an electronic device, the program code is used to cause the electronic device to implement the method for compensating the carrier frequency offset of a modulated signal provided in the embodiments of the present disclosure.

[0144] When the computer program is executed by the processor 501, the above functions defined in the system / apparatus of the embodiments of the present disclosure are executed. According to an embodiment of the present disclosure, the above-described systems, apparatuses, modules, units, etc. may be implemented by computer program modules.

[0145] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices and magnetic storage devices. In another embodiment, the computer program may also be transmitted and distributed in the form of a signal on a network medium, and be downloaded and installed through the communication part 509, and / or be installed from the removable medium 511. The program code included in the computer program may be transmitted by any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the foregoing.

[0146] According to embodiments of the present disclosure, program code for executing the computer programs provided by the embodiments of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. The programming languages include, but are not limited to, programming languages such as Java, C++, Python, the "C" language, or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., by connecting through the Internet using an Internet service provider).

[0147] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a portion of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and combinations of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions. Those skilled in the art can understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.

[0148] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present disclosure.

Claims

1. A method for compensating carrier frequency offset of a modulated signal, characterized in that, Including: Removing redundant data in the initial modulation signal to obtain a power signal; Processing the power signal to determine a target frequency transformation interval; Performing a chirp z-transform on the power signal according to the target frequency transformation interval to obtain a target spectrum; Determining a first peak amplitude from the target spectrum, and obtaining an estimated value for compensating carrier frequency offset according to the first peak amplitude and adjacent amplitudes corresponding to adjacent frequency points of its frequency point where it is located.

2. The method according to claim 1, wherein The adjacent amplitudes include a first adjacent amplitude and a second adjacent amplitude. The determining a first peak amplitude from the target spectrum, and obtaining an estimated value for compensating carrier frequency offset according to the first peak amplitude and adjacent amplitudes corresponding to adjacent frequency points of its frequency point where it is located includes: Determining the peak spectrum value in the target spectrum as the first peak amplitude; Determining the spectrum value corresponding to the frequency point α-1 adjacent to the frequency point α where the first peak amplitude is located as the first adjacent amplitude and determining the spectrum value corresponding to the frequency point α+1 adjacent to the frequency point α where the first peak amplitude is located as the second adjacent amplitude; Calculating a carrier frequency offset error according to the first peak amplitude, the first adjacent amplitude and the second adjacent amplitude; Obtaining an estimated value for compensating carrier frequency offset according to the carrier frequency offset error.

3. The method according to claim 2, wherein The calculating a carrier frequency offset error according to the first peak amplitude, the first adjacent amplitude and the second adjacent amplitude includes: Calculating a first ratio of the first adjacent amplitude to the first peak amplitude and a second ratio of the second adjacent amplitude to the first peak amplitude; Constructing a tangent function about the carrier frequency offset error according to the first ratio and the second ratio; Calculating the carrier frequency offset error according to the tangent function.

4. The method according to claim 1, wherein Processing the power signal to determine a target frequency transformation interval includes: Performing a Fourier transform on the power signal to obtain a Fourier transform spectrum corresponding to the power signal; Determining the peak spectrum value in the Fourier transform spectrum as a second peak amplitude; Determining the target frequency transformation interval according to an index corresponding to the frequency point where the second peak amplitude is located.

5. The method according to claim 4, characterized in that, The target frequency transformation interval is expressed as the following formula (I): (I) where y’ is the index corresponding to the frequency point of the second peak amplitude, q is a relevant control parameter, N is the number of sampling points, and T S is the sampling duration of a single coded symbol.

6. The method according to claim 5, characterized in that, The tangent function about the carrier frequency offset error is expressed as the following formula (II): (2) Among them, is the tangent function, δ is the carrier frequency offset error, j is the imaginary unit, M is the refinement multiple, and k m is the index corresponding to the frequency point of the first peak amplitude, R(k m + 1) is the second adjacent amplitude, R(k m - 1) is the first adjacent amplitude, and R(k m ) is the first peak amplitude.

7. The method according to claim 6, wherein The process of calculating the carrier frequency offset error according to the tangent function is expressed as the following formula (III): (III).

8. The method according to claim 1, wherein The redundant data includes a modulation amplitude and a noise signal. The removing redundant data in the initial modulation signal to obtain a power signal includes: Performing a power operation on the initial modulation signal according to a predetermined power number to remove the modulation amplitude to obtain an initial power signal; Removing the noise signal from the initial power signal to obtain the power signal.

9. A compensation device for carrier frequency offset of a modulation signal, including: An operation module, configured to remove redundant data in the initial modulation signal to obtain a power signal; A determination module, configured to process the power signal to determine a target frequency transformation interval; A transformation module, configured to perform a chirp z-transform on the power signal according to the target frequency transformation interval to obtain a target spectrum; An obtaining module, configured to determine a first peak amplitude from the target spectrum, and obtain an estimated value for compensating for the carrier frequency offset according to the first peak amplitude and the adjacent amplitudes corresponding to the adjacent frequency points of the frequency point where the first peak amplitude is located.

10. An electronic device, comprising: One or more processors; A memory, configured to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 8.

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