Methods, systems, apparatus, processors, and computer-readable storage media thereof for achieving IQ imbalance mirror leakage calibration

Abstract

This invention relates to a method for calibrating IQ unbalanced image leakage, comprising the following steps: establishing a mathematical relationship model between image leakage power and system IQ unbalance parameters and external compensation; acquiring multi-point measurement data; constructing a nonlinear residual equation system; using a nonlinear least squares algorithm to iteratively solve for the optimal parameters; and calculating the optimal amplitude compensation factor and the optimal phase compensation amount. By employing the method, system, device, processor, and computer-readable storage medium of this invention for calibrating IQ unbalanced image leakage, and by establishing an accurate mathematical model of image leakage, only a small amount of image power data under different compensation conditions needs to be collected. Through an efficient numerical solution algorithm, the inherent amplitude and phase unbalance of the system can be calculated accurately in one step, directly determining the optimal compensation value.

Description

Technical Field

[0001] This invention relates to the fields of wireless communication, radar systems, and test and measurement instruments, and particularly to the fields of radio frequency and microwave technology. Specifically, it relates to a method, system, device, processor, and computer-readable storage medium for calibrating IQ unbalanced image leakage. Background Technology

[0002] In modern digital communication systems, quadrature modulation and demodulation (QDM) technology is widely used. It utilizes a pair of orthogonal carriers (i.e., the I-branch and Q-branch) with a strict 90-degree phase difference to carry two independent signals, thus efficiently utilizing spectrum resources. In an ideal quadrature system, the signal amplitudes of the I-branch and Q-branch should be exactly equal, and the phase difference should be strictly 90 degrees. Under these ideal conditions, the image frequency components of the modulated signal can be completely suppressed.

[0003] However, in practical RF and microwave hardware circuits, due to factors such as manufacturing tolerances, temperature drift, and inconsistent frequency responses of analog components like amplifiers, mixers, and filters, amplitude and phase imbalances between the I and Q branches are almost unavoidable. This non-ideal orthogonality causes image frequency components that should be suppressed to leak out, forming what is known as "image leakage." Image leakage severely degrades the performance of communication systems; for example, it interferes with adjacent channels, worsens the error vector magnitude (EVM) of the signal, and reduces the signal-to-noise ratio and sensitivity of the receiver. Therefore, to ensure high system performance, precise calibration and compensation of the IQ imbalance are essential.

[0004] Currently, a common IQ imbalance calibration technique in the industry is based on a traversal search (or scanning search) method. Its basic principle is as follows: Amplitude compensation and phase compensation values ​​are progressively scanned within a preset two-dimensional parameter space, either digitally or analogically. For each combination point (amplitude compensation, phase compensation), the system performs a complete image rejection measurement (typically using a spectrum analyzer to measure the power of the image component). After traversing all preset compensation points, the set of compensation values ​​that minimizes image leakage power is found by comparing all measurement results and used as the optimal calibration parameters.

[0005] Although this traversal search method is intuitive and easy to implement, it has the following significant drawbacks in practical applications:

[0006] 1. Low calibration efficiency and long time consumption: To obtain high calibration accuracy, a small compensation step and a wide search range need to be set, which leads to a sharp increase in the number of measurement points (for example, 100 amplitude scan points and 100 phase scan points require a total of 100 x 100 = 10,000 measurements). The entire process is very time-consuming, which may take several minutes or even longer, seriously affecting the efficiency of product development, production testing and other stages.

[0007] 2. High measurement complexity and heavy resource consumption: This method requires frequent resetting of compensation parameters and triggering of measuring instruments during calibration, placing high demands on the control logic of the automated testing system. Furthermore, the prolonged use of expensive testing equipment such as spectrum analyzers increases testing costs.

[0008] 3. The trade-off between accuracy and speed: Calibration accuracy directly depends on the step size of the traversal scan. Using a larger step size to shorten time may miss the true optimal point, leading to decreased calibration accuracy and suboptimal system performance. Conversely, pursuing high accuracy requires sacrificing time efficiency. This inherent contradiction makes it difficult for current technologies to simultaneously meet the requirements of fast and accurate calibration.

[0009] In summary, existing IQ imbalance calibration methods based on traversal search suffer from problems such as numerous measurements, long processing time, and high resource consumption. There is an urgent need for a technical solution that can quickly and accurately complete IQ imbalance calibration to meet the demands of modern communication systems for high-efficiency and low-cost testing. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, apparatus, processor and computer-readable storage medium for achieving IQ imbalance mirror leakage calibration with high efficiency, low cost and wide applicability.

[0011] To achieve the above objectives, the present invention provides a method, system, apparatus, processor, and computer-readable storage medium for calibrating IQ unbalanced mirror leakage, as follows:

[0012] The main feature of this method for achieving IQ imbalance mirror leakage calibration is that the method includes the following steps:

[0013] (1) Establish a mathematical relationship model between the mirror leakage power and the system IQ imbalance parameters and external compensation quantities;

[0014] (2) Conduct multi-point measurement data acquisition;

[0015] (3) Based on the mathematical relationship model and multiple sets of measurement data, construct a set of nonlinear residual equations;

[0016] (4) The nonlinear least squares algorithm is used to iteratively solve for the optimal parameters and obtain the inherent amplitude and phase imbalance parameters of the system;

[0017] (5) Based on the calculated inherent amplitude and phase imbalance parameters of the system, the optimal amplitude compensation factor and the optimal phase compensation amount are directly calculated and applied to the system to be calibrated.

[0018] Preferably, the mathematical relational model established in step (1) is specifically as follows:

[0019] The mathematical relationship model is established based on the following formula:

[0020] ;

[0021] Where y is the measured image power, r and C represents the equivalent amplitude imbalance and equivalent phase imbalance of the system after applying external compensation, and C is the system constant offset.

[0022] Preferably, step (2) specifically includes:

[0023] Apply n sets of preset amplitude and phase compensation values ​​to the system to be calibrated, and use a measuring device to measure the image power value of the system output under each set of compensation to obtain n sets of measurement data; where n is an integer greater than or equal to 3.

[0024] Preferably, the value of n is between 5 and 10.

[0025] Preferably, step (4) specifically includes the following steps:

[0026] (4.1) Set a set of initial guess values ​​for the parameters to be determined;

[0027] (4.2) Calculate the residual vector and Jacobian matrix, and solve a correction equation to obtain the parameter update. And update the parameters;

[0028] (4.3) If the change in parameter update amount or residual sum of squares is less than the preset minimum threshold, the iteration stops and the algorithm has converged to the optimal solution;

[0029] (4.4) Output the optimal parameter estimate after convergence.

[0030] Preferably, the nonlinear least squares algorithm in step (4) is the Levenberg-Marquardt algorithm.

[0031] Preferably, the optimal amplitude compensation factor is calculated in step (5). and optimal phase compensation amount Specifically:

[0032] The optimal amplitude compensation factor is calculated using the following formula. :

[0033] ;

[0034] ;

[0035] The optimal phase compensation amount is calculated using the following formula. :

[0036] ;

[0037] in, The optimal estimate is in logarithmic form, representing the amplitude imbalance. This represents the optimal phase error after convergence. This is the optimal compensation value for amplitude imbalance.

[0038] The system for calibrating IQ imbalance mirror leakage using the above method includes:

[0039] A module to be calibrated, used to implement programmable amplitude and phase compensation functions;

[0040] A measurement module for measuring the mirror power of the output signal of the module to be calibrated;

[0041] A control and calculation module, connected to the module to be calibrated and the measurement module, is used to set preset compensation values, read image power measurement values, calculate the inherent imbalance parameters of the system, calculate the optimal compensation value and apply it.

[0042] Preferably, the control and calculation module controls the module to be calibrated to sequentially set n different preset compensation values; where n is an integer greater than or equal to 3;

[0043] Read the image power measurement value under each set of compensation from the measurement module;

[0044] Based on the pre-set mathematical model and the collected measurement data, the inherent imbalance parameters of the system are calculated using a nonlinear least squares algorithm.

[0045] The optimal compensation value is calculated based on the solved inherent imbalance parameters, and the module to be calibrated is controlled to apply the calculated optimal compensation value.

[0046] Preferably, the module to be calibrated is an IQ modulator or an IQ demodulator, and the measurement module is a spectrum analyzer.

[0047] The main feature of this apparatus for calibrating IQ imbalance mirror leakage is that the apparatus comprises:

[0048] A processor is configured to execute computer-executable instructions;

[0049] The memory stores one or more computer-executable instructions that, when executed by the processor, implement the steps of the method described above for implementing IQ imbalance mirror leakage calibration.

[0050] The processor for implementing IQ imbalance mirror leakage calibration is characterized in that the processor is configured to execute computer-executable instructions, which, when executed by the processor, implement the various steps of the method for implementing IQ imbalance mirror leakage calibration described above.

[0051] The computer-readable storage medium is characterized in that it stores a computer program thereon, which can be executed by a processor to implement the various steps of the above-described method for implementing IQ imbalance mirror leakage calibration.

[0052] The present invention employs a method, system, apparatus, processor, and computer-readable storage medium for IQ imbalance mirror leakage calibration. By establishing an accurate mathematical model of mirror leakage, only a small amount of mirror power data under different compensation conditions needs to be collected. Through an efficient numerical calculation algorithm, the inherent amplitude and phase imbalance of the system can be calculated accurately in one step, thereby directly determining the optimal compensation value. This invention aims to completely replace the inefficient traversal search mode, achieving faster, more accurate, and lower-cost IQ imbalance calibration. Attached Figure Description

[0053] Figure 1 This is a flowchart of the method for implementing IQ unbalanced mirror leakage calibration according to the present invention.

[0054] Figure 2 This is a schematic diagram of the structure of the IQ unbalanced mirror leakage calibration system of the present invention. Detailed Implementation

[0055] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0056] The method for achieving IQ imbalance mirror leakage calibration according to the present invention includes the following steps:

[0057] (1) Establish a mathematical relationship model between the mirror leakage power and the system IQ imbalance parameters and external compensation quantities;

[0058] (2) Conduct multi-point measurement data acquisition;

[0059] (3) Based on the mathematical relationship model and multiple sets of measurement data, construct a set of nonlinear residual equations;

[0060] (4) The nonlinear least squares algorithm is used to iteratively solve for the optimal parameters and obtain the inherent amplitude and phase imbalance parameters of the system;

[0061] (5) Based on the calculated inherent amplitude and phase imbalance parameters of the system, the optimal amplitude compensation factor and the optimal phase compensation amount are directly calculated and applied to the system to be calibrated.

[0062] As a preferred embodiment of the present invention, the mathematical relationship model established in step (1) is specifically as follows:

[0063] The mathematical relationship model is established based on the following formula:

[0064] ;

[0065] Where y is the measured image power, r and C represents the equivalent amplitude imbalance and equivalent phase imbalance of the system after applying external compensation, and C is the system constant offset.

[0066] In a preferred embodiment of the present invention, step (2) specifically comprises:

[0067] Apply n sets of preset amplitude and phase compensation values ​​to the system to be calibrated, and use a measuring device to measure the image power value of the system output under each set of compensation to obtain n sets of measurement data; where n is an integer greater than or equal to 3.

[0068] In a preferred embodiment of the present invention, the value of n is 5 to 10.

[0069] In a preferred embodiment of the present invention, step (4) specifically includes the following steps:

[0070] (4.1) Set a set of initial guess values ​​for the parameters to be determined;

[0071] (4.2) Calculate the residual vector and Jacobian matrix, and solve a correction equation to obtain the parameter update. And update the parameters;

[0072] (4.3) If the change in parameter update amount or residual sum of squares is less than the preset minimum threshold, the iteration stops and the algorithm has converged to the optimal solution;

[0073] (4.4) Output the optimal parameter estimate after convergence.

[0074] As a preferred embodiment of the present invention, the nonlinear least squares algorithm in step (4) is the Levenberg-Marquardt algorithm.

[0075] In a preferred embodiment of the present invention, the optimal amplitude compensation factor is calculated in step (5). and optimal phase compensation amount Specifically:

[0076] The optimal amplitude compensation factor is calculated using the following formula. :

[0077] ;

[0078] ;

[0079] The optimal phase compensation amount is calculated using the following formula. :

[0080] ;

[0081] in, The optimal estimate is in logarithmic form, representing the amplitude imbalance. This represents the optimal phase error after convergence. This is the optimal compensation value for amplitude imbalance.

[0082] The system of the present invention for calibrating IQ imbalance mirror leakage using the above method, wherein the system comprises:

[0083] A module to be calibrated, used to implement programmable amplitude and phase compensation functions;

[0084] A measurement module for measuring the mirror power of the output signal of the module to be calibrated;

[0085] A control and calculation module, connected to the module to be calibrated and the measurement module, is used to set preset compensation values, read image power measurement values, calculate the inherent imbalance parameters of the system, calculate the optimal compensation value and apply it.

[0086] In a preferred embodiment of the present invention, the control and calculation module controls the module to be calibrated to sequentially set n different preset compensation values; wherein, n is an integer greater than or equal to 3;

[0087] Read the image power measurement value under each set of compensation from the measurement module;

[0088] Based on the pre-set mathematical model and the collected measurement data, the inherent imbalance parameters of the system are calculated using a nonlinear least squares algorithm.

[0089] The optimal compensation value is calculated based on the solved inherent imbalance parameters, and the module to be calibrated is controlled to apply the calculated optimal compensation value.

[0090] In a preferred embodiment of the present invention, the module to be calibrated is an IQ modulator or an IQ demodulator, and the measurement module is a spectrum analyzer.

[0091] The apparatus for implementing IQ imbalance mirror leakage calibration of the present invention, wherein the apparatus comprises:

[0092] A processor is configured to execute computer-executable instructions;

[0093] The memory stores one or more computer-executable instructions that, when executed by the processor, implement the steps of the method described above for implementing IQ imbalance mirror leakage calibration.

[0094] The processor of the present invention for implementing IQ unbalanced mirror leakage calibration is configured to execute computer-executable instructions, which, when executed by the processor, implement the various steps of the above-described method for implementing IQ unbalanced mirror leakage calibration.

[0095] The computer-readable storage medium of the present invention stores a computer program thereon, which can be executed by a processor to implement the various steps of the above-described method for implementing IQ imbalance mirror leakage calibration.

[0096] This invention relates to the field of radio frequency and microwave technology, and more specifically, to an IQ (in-phase / quadrature) imbalance calibration method and system for use in wireless communication, radar systems, test and measurement instruments and other equipment.

[0097] In view of the shortcomings of existing IQ (in-phase / quadrature) imbalance calibration methods mentioned in the background art, this invention aims to solve the following core technical problems:

[0098] This invention addresses the problem of low efficiency and excessive time consumption in traditional traversal search methods for calibration. Existing technologies require point-by-point measurements of a large number of compensation parameter combinations, resulting in calibration processes that take several minutes or even longer, severely restricting research and development and production efficiency.

[0099] This invention solves the dilemma of how to overcome the trade-off between calibration accuracy and calibration speed. In traditional methods, improving accuracy requires increasing the number of scan points, which sacrifices time; while reducing time requires using coarse steps, leading to a decrease in calibration accuracy.

[0100] This invention addresses how to reduce the resource consumption and cost of the calibration process. Time-consuming traversal scanning occupies expensive equipment such as spectrum analyzers for extended periods, increasing the testing cost per unit product.

[0101] The core principle of this invention lies in abandoning the traditional, inefficient traversal search method and instead adopting a technical approach based on a precise mathematical model and efficient numerical optimization. The basic idea is to first establish a theoretical model that accurately describes the relationship between the IQ (in-phase / quadrature) imbalance parameter, the external compensation amount, and the final mirror leakage power. This model forms the mathematical foundation of the entire calibration method.

[0102] Unlike existing technologies that require measuring thousands of compensation points one by one, this invention only requires strategically selecting a few sets (typically 5 to 10 sets) of different amplitude and phase compensation values ​​and configuring the system. At each preset compensation point, the corresponding mirror leakage power is measured using instruments such as a spectrum analyzer. This yields a small but information-rich "compensation-power" dataset. Subsequently, using this sparse measurement data, the calibration problem is transformed into a nonlinear least-squares optimization problem by constructing a set of nonlinear residual equations.

[0103] Finally, efficient and robust numerical algorithms such as the Levenberg-Marquardt (LM) algorithm are employed to solve this optimization problem. This algorithm can quickly and accurately deduce the inherent, unknown amplitude and phase imbalances of the system from the measurement data. Once these two core parameters are determined, the optimal compensation value that completely cancels out the system's inherent imbalance can be directly calculated without any further search or measurement. Setting this optimal compensation value into the system allows for a one-time, high-precision, and rapid calibration.

[0104] Figure 1 This is a schematic diagram of the steps of the present invention. The workflow between the modules implementing the above calibration method of the present invention is as follows: Figure 2 As shown.

[0105] This invention provides an IQ imbalance mirror leakage calibration method based on multi-point measurement and nonlinear least squares fast solution. Its core lies in establishing an accurate physical model and using an efficient numerical optimization algorithm to quickly and accurately inverse the system's intrinsic imbalance parameters from a small amount of measurement data, thereby directly calculating the optimal compensation value.

[0106] Step 1: Establish a theoretical model for mirror leakage power

[0107] This invention first establishes a mathematical model relating the image leakage power to the system imbalance parameters and external compensation quantities based on theoretical analysis of orthogonal modulation systems. This model forms the basis for subsequent parameter estimation.

[0108] In IQ modulation systems, the actual amplitude imbalance (amplitude ratio is 1 / 2) exists. ) and phase imbalance (phase error is This is the root cause of image leakage. When a set of known calibration compensations (amplitude compensation factors) is applied to the system... and phase compensation amount After that, the remaining equivalent imbalance parameters of the system can be expressed as:

[0109] Equivalent amplitude imbalance: ;

[0110] Equivalent phase imbalance: ;

[0111] Based on theoretical derivation, the power of the mirror signal output by the system at this time can be accurately described by the following formula:

[0112] ;

[0113] in, The image power value (in dB) observed by the measuring instrument. It is a constant offset term, representing the system's fixed power gain or attenuation independent of IQ imbalance, and is also one of the unknowns to be solved.

[0114] Step 2: Collect multi-point measurement data

[0115] Unlike traditional traversal methods, this invention does not require scanning the entire parameter space. Instead, it strategically selects parameters within a wider range. Group( (Integers greater than or equal to 3, usually 5 to 10 are sufficient) Different preset combinations of amplitude and phase compensation And configure the system for each set of compensation conditions.

[0116] For the Second-rate Measurement:

[0117] 1. The first Group amplitude compensation value and phase compensation value Load it into the IQ modulation or demodulation system to be calibrated.

[0118] 2. Drive the system to operate, and use measuring equipment such as a spectrum analyzer to measure the power value at the mirror frequency of the output signal at this time, denoted as . ;

[0119] By performing the above operations This will give you a set of... Measurement dataset of data points: ;

[0120] Step 3: Construct a system of nonlinear residual equations

[0121] The goal of this step is to utilize the data collected in the second step. Based on the theoretical model established in the first step, a set of nonlinear equations is constructed using the measured data to construct a system of equations concerning the parameters to be solved. The unknowns to be solved are the inherent amplitude ratios of the system. Phase error and constant offset To optimize the stability of numerical calculations, it is common practice to use... As an intermediate variable. For the first... The theoretical image power value of the set of measurement data. It can be represented as:

[0122] ;

[0123] Define the residual at this point The difference between the measured value and the theoretical value:

[0124] ;

[0125] All Substituting the measurement data into the dataset will yield a result from... A system of nonlinear residual equations consisting of [number] equations. ;

[0126] Step 4: Solve for the optimal parameters using a nonlinear least squares algorithm.

[0127] Solving for the inherent imbalance parameters of the system The process is transformed into a classic nonlinear least squares optimization problem, namely, finding a set of optimal solutions. This minimizes the sum of squares of all residuals:

[0128] ;

[0129] This invention employs the Levenberg-Marquardt (LM) algorithm to solve this optimization problem. This algorithm has a fast convergence speed and good robustness, and it finds the optimal solution through iteration.

[0130] 1. Initialization: Parameters to be determined Set a set of initial guesses, for example .

[0131] in, It is an intermediate variable used to optimize the stability of numerical computation, and it is related to the inherent amplitude imbalance of the system. The relationship is .in, It refers to the actual amplitude imbalance that exists in the IQ modulation system and needs to be solved, expressed as the amplitude ratio.

[0132] It refers to the inherent phase imbalance of the system that needs to be solved, also known as phase error, and the unit is usually radians.

[0133] C is a constant offset term that represents a fixed power gain or attenuation in the test system, independent of the IQ imbalance itself, such as fixed losses or gains introduced by test cables, amplifiers, etc. It is also treated as an unknown quantity to be solved during the calculation process.

[0134] 2. Iterative Solution: In each iteration, the algorithm calculates the residual vector and the Jacobian matrix (the partial derivative matrix of the residuals with respect to each parameter), and then solves a correction equation to obtain the parameter update. And update the parameters.

[0135] 3. Convergence judgment: When the change in parameter update or residual sum of squares is less than the preset minimum threshold, the iteration stops and the algorithm is considered to have converged to the optimal solution.

[0136] Finally, the algorithm outputs the converged optimal parameter estimates. .in, For the optimal estimate of the unbalanced logarithmic form (g = lnρ), This represents the optimal phase error after convergence. This is the optimal constant offset term after convergence.

[0137] Step 5: Determine and apply the optimal compensation value

[0138] Based on the optimal system imbalance parameters calculated in step four, the best compensation value that can suppress mirror leakage to the greatest extent can be directly calculated:

[0139] Optimal amplitude imbalance (linear value): ;

[0140] Optimal phase imbalance (radians): ;

[0141] In theory, to completely counteract the inherent imbalance of the system, a compensation of equal value but opposite effect should be applied. Therefore, the optimal compensation is ultimately determined as follows:

[0142] Optimal amplitude compensation factor: ;

[0143] Optimal phase compensation amount: ;

[0144] This set of optimal compensation values Once set into the system to be calibrated, the entire rapid calibration process can be completed.

[0145] Corresponding to the method of the present invention, the present invention also provides an IQ unbalanced mirror leakage calibration system, the system comprising:

[0146] A module to be calibrated, such as an IQ modulator or demodulator, has programmable amplitude and phase compensation values.

[0147] A measurement module, such as a spectrum analyzer, is used to measure the mirror power of the output signal of the module to be calibrated.

[0148] A control and calculation module (CPU-based) stores and executes the above method steps. Its specific functions are:

[0149] Control the module to be calibrated, and set it sequentially. Group preset compensation value .

[0150] Read the image power measurement values ​​for each set of compensation from the measurement module. .

[0151] Based on the collected data, the nonlinear least squares algorithm described in step four is executed to calculate the optimal imbalance parameters. .

[0152] The final optimal compensation value is calculated based on the solution results. .

[0153] The optimal compensation value is then embedded into the module to be calibrated, thus completing the calibration.

[0154] The measurement efficiency of this invention is greatly improved. By adopting multi-point sampling based on theoretical models and nonlinear least squares solution, high-precision calibration can be completed with only 6 to 10 sets (amplitude and phase) compensation presets. Compared with the 10,000 measurements required by traditional 100×100 grid scanning, the number of measurement points is reduced by about 99.9%.

[0155] In the actual test of the 1GHz radio frequency transceiver system, the entire process (issuing commands, setting compensation, triggering measurement, calculating the optimal result and writing it back) took ≤0.8s, while the traditional traversal method took 3 to 5 minutes under the same accuracy requirements, which is more than 200 times shorter.

[0156] The calibration accuracy of this invention is high and independent of the measurement point. It utilizes precise theoretical formulas. Modeling is performed, and the amplitude, phase and system constant offset are simultaneously fitted using the LM algorithm. The amplitude imbalance residual can be controlled within ±0.2dB and the phase imbalance residual within ±0.3° within 0.5s.

[0157] In a batch test of 50 prototype units, the image suppression level improved from 28dB in the uncalibrated state to 52dB, an average improvement of 24dB; EVM improved by more than 30%.

[0158] This invention offers high economic and production benefits. The number of calibration pieces that a single production line testing instrument can complete per day has increased from 300 to 18,000, representing a 60-fold increase in production capacity and a reduction of over 95% in testing manpower and equipment time costs.

[0159] This invention has a wide range of applications and strong portability, and is applicable to various communication, radar, satellite and test and measurement equipment in the range of 100kHz to 20GHz.

[0160] The core idea of ​​this invention is "modeling + solution," which abandons the traditional search / iteration method and establishes an accurate nonlinear mathematical model that can describe the relationship between the mirror leakage power and the system imbalance parameters. Then, by collecting only a small number of data points and using a nonlinear least squares algorithm to perform a one-time, globally optimal numerical solution, the inherent imbalance of the system can be directly derived, thereby calculating the optimal compensation value. This is a direct and analytical solution path.

[0161] This invention employs a combination of multi-point measurement and nonlinear least squares solution. A system of equations is established through a small number of measurements, allowing for a one-time solution to determine the system's inherent imbalance parameters. The calibration speed of this invention is extremely fast (measured ≤0.8s), and speed is essentially independent of accuracy. Because the solution is model-based, high-precision results can be obtained with only a small number of data points, provided the model is accurate.

[0162] This invention achieves a paradigm shift, completely abandoning the "search" framework and instead adopting a "modeling + solution" approach. Although "nonlinear least squares" and "LM algorithm" are known mathematical tools in the prior art, their creative application to the field of IQ imbalance calibration to replace mainstream search methods, and the establishment of a precise nonlinear physical model that includes system constant offsets, are specific applications and combinations that are completely undisclosed or unreveled in the prior art.

[0163] The model proposed in this invention is the cornerstone of the entire "solution" method. Particularly noteworthy is the inclusion of a constant offset term C, which is treated as one of the unknowns to be solved. This is technically significant because it allows the calibration process to automatically adapt to and eliminate fixed gains or attenuations (such as cable loss, amplifier gain, etc.) in the test system that are unrelated to IQ imbalance, greatly enhancing the robustness of the algorithm and its accuracy in real-world physical environments.

[0164] The method of this invention is "solution". By transforming the physical problem into a mathematical problem of minimizing the sum of squared residuals, we can utilize a powerful and mature numerical optimization algorithm (LM algorithm) to achieve fast and accurate convergence. The LM algorithm combines the advantages of gradient descent and Gauss-Newton methods, exhibiting fast convergence speed and good stability, making it particularly suitable for solving such problems. This problem transformation and the specific selection and application of the solution algorithm directly result in a technical effect of "time ≤ 0.8s, a reduction of more than 200 times".

[0165] For the specific implementation scheme of this embodiment, please refer to the relevant descriptions in the above embodiments, which will not be repeated here.

[0166] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0167] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0168] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0169] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution device. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0170] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The corresponding program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0171] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0172] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0173] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0174] The present invention employs a method, system, apparatus, processor, and computer-readable storage medium for IQ imbalance mirror leakage calibration. By establishing an accurate mathematical model of mirror leakage, only a small amount of mirror power data under different compensation conditions needs to be collected. Through an efficient numerical calculation algorithm, the inherent amplitude and phase imbalance of the system can be calculated accurately in one step, thereby directly determining the optimal compensation value. This invention aims to completely replace the inefficient traversal search mode, achieving faster, more accurate, and lower-cost IQ imbalance calibration.

[0175] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A method of implementing IQ imbalance image leakage calibration, the method comprising: The method comprises the following steps: (1) establishing a mathematical relationship model between the image leakage power and the system IQ imbalance parameters and the external compensation amount; (2) performing multi-point measurement data acquisition; (3) based on the mathematical relationship model and the multiple sets of measurement data, constructing a nonlinear residual equation set; (4) using a nonlinear least square algorithm to iteratively solve the optimal parameters to obtain the inherent amplitude and phase imbalance parameters of the system; (5) according to the calculated inherent amplitude and phase imbalance parameters of the system, directly calculating the optimal amplitude compensation factor and the optimal phase compensation amount, and applying them to the system to be calibrated. The mathematical relationship model established in step (1) is specifically: The mathematical relationship model is established according to the following formula: ； where y is the mirror power measurement, r and are the equivalent amplitude and phase imbalance of the system after applying the external compensation, and C is the constant offset of the system.

2. The method of calibrating for IQ imbalance image leakage according to claim 1, wherein, Step (2) is specifically: Apply n sets of preset, different amplitude and phase compensation values to the system to be calibrated, and use a measurement device to measure the image power value of the system output under each set of compensation to obtain n sets of measurement data; wherein n is an integer greater than or equal to 3.

3. The method of claim 2 to implement IQ imbalance image leakage calibration, wherein, The value of n is 5-10.

4. The method of claim 1, wherein, Step (4) specifically comprises the following steps: (4.1) setting a set of initial guess values for the parameters to be solved; (4.2) Compute the residual vector and Jacobian matrix, solve a correction equation to get the update of parameters and update the parameters; (4.3) if the parameter update amount or the change of the residual sum of squares is less than a preset threshold value, the iteration stops and the algorithm has converged to the optimal solution; (4.4) outputting the optimal parameter estimation value after convergence.

5. The method of claim 1, wherein, The nonlinear least square algorithm of step (4) is the Levenberg-Marquardt algorithm.

6. The method of claim 1 to implement IQ imbalance image leakage calibration, wherein, The step (5) calculates the best amplitude compensation factor and the best phase compensation amount , specifically: The optimal amplitude compensation factor is calculated according to the following formula : ； ； The optimum phase compensation amount is calculated according to the following formula : ； wherein, is the optimal estimate of the logarithmic form of the amplitude imbalance, is the converged optimal phase error, is the compensation value of the best amplitude imbalance.

7. A system for calibrating IQ imbalance image leakage using the method of claim 1, wherein, The system comprises: a calibration module for implementing programmable amplitude and phase compensation functions; a measurement module for measuring the image power of the output signal of the calibration module; a control and calculation module connected to the calibration module and the measurement module, for setting the preset compensation value, reading the image power measurement value, calculating the inherent imbalance parameters of the system, and calculating and applying the optimal compensation value.

8. The system of claim 7, wherein, The control and calculation module controls the calibration module to sequentially set n sets of different preset compensation values; wherein n is an integer greater than or equal to 3; read the image power measurement value under each set of compensation from the measurement module; based on the preset mathematical model and the collected measurement data, use the nonlinear least square algorithm to calculate the inherent imbalance parameters of the system; calculate the optimal compensation value based on the calculated inherent imbalance parameters, and control the calibration module to apply the calculated optimal compensation value.

9. The system of claim 7 to enable IQ imbalance image leakage calibration, wherein, The calibration module is an IQ modulator or an IQ demodulator, and the measurement module is a spectrum analyzer.

10. An apparatus for implementing IQ imbalance image leakage calibration, the apparatus comprising: The device comprises: a processor configured to execute computer executable instructions; a memory storing one or more computer executable instructions, which when executed by the processor, implement the steps of the method for calibrating IQ imbalance image leakage according to any one of claims 1-6.

11. A processor that implements IQ imbalance image leakage calibration, the processor comprising: The processor is configured to execute computer executable instructions, which when executed by the processor, implement the steps of the method for calibrating IQ imbalance image leakage according to any one of claims 1-6.

12. A computer-readable storage medium, characterized in that, A computer program product, comprising a computer readable medium having stored thereon the computer program, the computer program being executable by a processor for implementing the steps of the method of calibrating IQ imbalance image leakage according to any one of claims 1 to 6.

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