An RF calibration device, RF calibration method and non-transitory computer readable storage medium thereof for calibrating RF system

Abstract

This invention discloses a radio frequency (RF) calibration method for calibrating an RF system. The RF calibration method includes providing a combination of complex calibration parameter intervals corresponding to complex Markov states from the calibration database of the decision processing module of the RF calibration device to the calibration control module of the RF calibration device via an edge computing processor. The RF calibration method also includes receiving the output signal of the RF system via a calibration analysis module of the RF calibration device. Furthermore, the RF calibration method includes the calibration control module using the system processor of the RF system to calibrate the RF system using the combination of complex calibration parameter intervals until the suppression degree of the output signal received by the calibration analysis module is greater than a threshold.

Description

[Technical Field]

[0001] This invention relates to a calibration technique for a radio frequency (RF) system, and more particularly to an RF calibration device, RF calibration method and non-transitory computer-readable storage medium for calibrating an RF system. [Previous Technology]

[0002] In today's market, the radio frequency signal in the radio frequency system can be decomposed into two component signals, I (in-phase) and Q (quadratic-phase), for processing. Radio frequency systems with chips that have the function of synthesizing IQ signals (i.e., with DAC converter function) can use the built-in configurable register to adjust the radio frequency output signal and calibrate the radio frequency system (e.g., Texas Instruments' DAC38J84), or add additional hardware design and specific algorithms to the radio frequency system to calibrate the radio frequency system.

[0003] In the prior art, a closed-loop technique is used for signal fine-tuning. The system typically uses a feedback signal for calibration comparison to measure the actual DC offset and IQ mismatch after each calibration. Furthermore, current technology usually treats DC offset and IQ imbalance correction as two independent events, performing IQ imbalance correction only after DC offset correction is completed.

[0004] Conversely, when a specific RF system (e.g., a discrete design) cannot be calibrated using a closed-loop method, an open-loop method must be used. In the open-loop method, since there is no feedback signal for calibration reference, each parameter must be adjusted step by step within its adjustable range until the output signal meets the calibration requirements. For example, if there are four parameters that need adjustment, each adjustable from 0 to 63, it may require up to 16,777,216 (64 4) adjustments to complete the calibration.

[0005] Furthermore, if DC offset and IQ imbalance are corrected separately, and considering that the effects of DC offset and IQ imbalance on the RF system will vary with frequency (i.e., frequency-dependence, rather than flatness), the correction processing time for each frequency of the RF system may be as long as several hours.

[0006] Therefore, the technology that can shorten the calibration processing time and be applicable to automated production and testing environments when using an open-loop method for RF system calibration has become a technology needed by the industry. [Summary of the Invention]

[0007] The technology provided by this invention relates to the IQ transmission path calibration in a radio frequency (RF) system. It can utilize edge computing to build a Markov chain database during mass production, so as to use an open-loop method to calibrate the RF system and accelerate the RF calibration process to save costs.

[0008] According to a first aspect of the present invention, a radio frequency (RF) calibration device is provided for calibrating an RF system. The RF calibration device includes a calibration control module coupled to a system processor of the RF system. The RF calibration device also includes a calibration analysis module coupled to the calibration control module and the RF system to receive an output signal from the RF system. The RF calibration device also includes a decision operation module coupled to the calibration control module. The decision operation module provides a combination of complex calibration parameter intervals from complex Markov chain data to the calibration control module. The calibration control module provides the complex calibration parameter intervals to the system processor, causing the system processor to use the combination of complex calibration parameter intervals to calibrate the RF system until the suppression degree of the output signal received by the calibration analysis module is greater than a threshold.

[0009] According to a second aspect of the present invention, a radio frequency (RF) calibration method is provided for calibrating an RF system. The RF calibration method includes providing a combination of complex calibration parameter intervals from complex Markov chain data to a calibration control module of the RF calibration device via a decision processing module. The RF calibration method also includes receiving an output signal from the RF system via a calibration analysis module of the RF calibration device. The RF calibration method further includes providing the complex calibration parameter intervals to a system processor of the RF system via the calibration control module, so that the system processor uses the combination of complex calibration parameter intervals to calibrate the RF system until the suppression degree of the output signal received by the calibration analysis module is greater than a threshold.

[0010] According to a third aspect of the present invention, a non-transitory computer-readable storage medium is provided, comprising a plurality of instructions. The plurality of instructions cause a controller, computer device, or computer to perform a radio frequency calibration method for calibrating a radio frequency system as described in the second aspect of the present invention.

[0011] The foregoing description is not intended to represent every embodiment or aspect of the invention. Rather, the foregoing description merely provides examples of some novel aspects and features of the invention. The foregoing features and advantages, as well as other features and advantages, will become apparent from the following detailed description of representative embodiments and modes of implementation when taken in conjunction with the accompanying drawings and the claims. Other aspects of the invention will be apparent to those skilled in the art from the detailed description of various embodiments with reference to the drawings and the brief description provided below.

[0012] In order to better understand the above and other aspects of the present invention, specific embodiments are described below in conjunction with the accompanying drawings:

Implementation Method

[0014] The various embodiments of the present invention will be described in detail below, with reference to the accompanying drawings. In addition to these detailed descriptions, the present invention can be widely implemented in other embodiments, and any easy substitutions, modifications, or equivalent changes to the described embodiments are included within the scope of the present invention and are subject to the following patent claims. In the description of the specification, many specific details and implementation examples are provided to give the reader a more complete understanding of the present invention; however, these specific details and implementation examples should not be considered as limitations on the present invention. Furthermore, well-known steps or elements are not described in the details to avoid unnecessary limitations on the present invention. In the drawings, the same or similar element symbols are used to represent the same or similar elements.

[0015] FIG1 illustrates a schematic diagram of the architecture of a discrete example radio frequency system 200 according to multiple embodiments of the present invention. The radio frequency system 200 includes a system processor 210, a radio frequency processor 220, a modulation / demodulation circuit 230, a switching circuit 240, and antennas 250-1 to 250-n. The system processor 210 can be used to control the radio frequency output signal (TX) generated by the radio frequency processor 220 and the modulation / demodulation circuit 230, or the received radio frequency input signal (RX), through calibration parameters. As shown in Figure 1, along the RF transmission path, the RF processor 220 can be equipped with RF processing modules 221-1 to 221-n (with digital-to-analog converter (DAC) function) at different frequency points (frequency points f1~fn). These modules can process the two component signals I (in-phase) and Q (quadratic-phase), and modulate and synthesize them into single-tone output signals (output signals TX1 to TXn) at the corresponding modulation / demodulation circuits 230 through output circuits 231-1 to 231-n. These signals are then output to the corresponding antennas 250-1 to 250-n. The output circuits can also be considered as modulator circuits. In the RF receiving path, the RF processor 220 can also be equipped with RF processing modules 222-1 to 222-n (with analog-to-digital converter (ADC) function) according to different frequency points (frequency points f1 to fn). These modules can be used to process the monotonic input signals (input signals RX1 to RXn) received by the corresponding antennas 250-1 to 250-n. After filtering and modulation by the input circuits 232-1 to 232-n in the corresponding modulation / demodulation circuits 230, the signals are decomposed into I and Q component signals. The input circuits can also be referred to as demodulator circuits.

[0016] In detail, for the synthesis of the I and Q component signals (e.g., via the RF processing module 221-1 and the output circuit 231-1), the amplitude and phase of the I and Q signals may exhibit asymmetry during the circuit generation process, known as IQ mismatch (or IQ imbalance). This leads to unexpected noise generated during signal transmission, such as an image signal appearing at the image frequency. Such noise (image signal) affects the signal transmission quality of the RF system, such as worsening the signal-to-noise ratio (SNR) and error vector magnitude (EVM), or increasing the bit error rate (BER), resulting in the output signal being unable to be demodulated.

[0017] Furthermore, the IQ signals may experience DC offset, which worsens the rejection between the local oscillator (LO) signal and the monotonic signal at the output, affecting the quality of the final output signal. Therefore, it is necessary to correct the IQ signals at each frequency point in the RF system, especially during production, to ensure that the RF system meets the basic functional requirement of transmitting an output signal of a certain quality.

[0018] When calibrating the RF system, the monotonic signal ST output by the RF system can be set as X(t), and X(t) can be expressed by the following equation (1): ................... Equation (1)

[0019] For an ideal radio frequency system, the I (in-phase) and Q (quadrature) components of the output monotonic signal can be represented by the following equations (2) and (3) respectively:......................Equation (2)......................Equation (3)

[0020] However, for non-ideal RF systems, the amplitude () and phase () of the output monotonic signal IQ signal will be mismatched (ΔA and Δ). That is, based on the above equation (2), it can be expressed by the following equation (4): .................Equation (4)

[0021] For simplification, the amplitude of the signal can be normalized. Therefore, the two component signals I and Q can be represented by the following equations (5) and (6) respectively: .........................Equation (5) .........................Equation (6)

[0022] Here, ΔA / can be defined as Δ, that is, the variable with mismatched gain. Then, equation (6) can be expressed as the following equation (7): ................ Equation (7)

[0023] When considering the DC offset of each of the I and Q signals, and using δI and δQ to represent the DC offset of the I and Q components respectively, equations (5) and (7) can be expressed by the following equations (8) and (9):.....................Equation (8)............Equation (9)

[0024] FIG2 illustrates a schematic diagram of an RF module 270 of an RF system (e.g., RF system 200 of FIG1) according to multiple embodiments of the present invention. RF modules 270 corresponding to the same frequency point may include an RF processing module 221 (e.g., any one of RF processing modules 221-1 to RF processing modules 221-n of FIG1) and an output circuit 231 (e.g., one of output circuits 231-1 to 231-n corresponding to any one of RF processing modules 221-1 to RF processing modules 221-n of FIG1). The output circuit 231 includes a complex adder 233, a complex multiplier 234, and a complex amplifier 235. As shown in Figure 2, when calibrating the RF module 270 in the RF system, the monotonic signal ST of the IQ signal on the output path is calibrated mainly by adjusting the in-phase signal DC offset correction parameter, quadrature signal DC offset correction parameter, gain correction parameter, and phase correction parameter in the output circuit 231 to achieve the required accuracy. The in-phase signal DC offset correction parameter and the quadrature signal DC offset correction parameter are used to correct the DC offset of the two component signals IQ, respectively. The gain correction parameter and the phase correction parameter are used to correct the gain and phase of the two component signals IQ to improve the gain and phase mismatch between the two. The relationship between the monotonic signal ST and the two component signals IQ (XI(t) and XQ(t)) and the above-mentioned correction parameters can be referred to equations (1) to (9) listed above. It should be noted that, ideally, the local oscillation signal LO provided by the system should not contain obvious signals at the frequency point of the local oscillation signal LO in the output monotonic signal ST. However, due to the potential DC offset between the I and Q signals, the monotonic signal ST may couple to the frequency point of the local oscillation signal, resulting in a local oscillation signal at the output. Therefore, during correction, it is necessary to minimize (or almost eliminate) the local oscillation signal in the monotonic signal ST.

[0025] It is understood that the values ​​of the calibration parameters used in the above calibration process may differ due to the different RF processing modules (e.g., any one of RF processing modules 221-1 to 221-n in Figure 1) and output circuits (e.g., one of output circuits 231-1 to 231-n in Figure 1 corresponding to any one of RF processing modules 221-1 to 221-n). Therefore, it is necessary to determine the values ​​of the calibration parameters required for each frequency point before calibration, or to consider only a single frequency point and use the same calibration parameter values ​​for all frequency points. However, this will cause a difference in the quality of the output signal at different frequency points, that is, the output signal at some frequency points may be worse. The present invention further provides a technique using Markov decision to determine the calibration parameters required for each frequency point, which will be described in detail below with reference to Figures 3 to 6.

[0026] FIG3 illustrates a functional block diagram of an example radio frequency calibration device 100 for calibrating a radio frequency system 200 according to multiple embodiments of the present invention. As shown in FIG3, the example radio frequency calibration device 100 includes: a decision operation module (e.g., a Markov decision operation module) 110, a calibration control module 120, and a calibration analysis module 130. The calibration analysis module 130 is coupled to the calibration control module 120, and the calibration control module 120 is coupled to the decision operation module 110. The calibration control module 120 and the calibration analysis module 130 are respectively coupled to the RF system 200 to be calibrated (or can be referred to as the device under test, DUT). For example, the calibration control module 120 is coupled to the system processor of the RF system 200 (e.g., the system processor 210 in Figure 1) so that the system processor of the RF system 200 can use different values ​​of calibration parameters (e.g., within different calibration parameter ranges) to calibrate and adjust the output signal of the RF module (e.g., the RF module 270 in Figure 2) corresponding to a specific frequency point in the RF system. The calibration analysis module 130 is coupled to the output terminal of the RF system 200 (e.g., one of the antennas 250-1 to 250-n in Figure 1) to receive the output signal (e.g., the output monotonic signal ST) of the output terminal of the RF module corresponding to a specific frequency point in the RF system, and to determine whether the output signal at the specific frequency point meets the quality requirements.

[0027] In some embodiments, the decision processing module 110 includes a calibration database 111 and an edge processing processor 112. The calibration database 111 stores calibration parameters (i.e., in-phase signal DC offset calibration parameters, quadrature signal DC offset calibration parameters, gain calibration parameters, and phase calibration parameters) from multiple machines on various production lines in a region (such as a factory). The edge processing processor 112 is communicatively connected to the calibration database 111 to obtain the calibration parameters of the multiple machines and then perform edge processing to form Markov chain data. The Markov chain data has multiple Markov states (as shown in Figures 5 and 6), and the multiple Markov states are used as combinations of multiple calibration parameter intervals to provide to the calibration control module 120. Specifically, each combination of calibration parameter intervals contains the calibration parameter intervals of each calibration parameter. Therefore, the correction control module 120 can provide the complex correction parameter range combination generated by the decision operation module 110 to the radio frequency system 200, so that the system processor of the radio frequency system 200 can correct the output signal of the radio frequency system 200 at each frequency point.

[0028] In some embodiments, the RF calibration device 100 can be implemented using a desktop computer, laptop, mobile device, server, or other device that can provide the same functionality. In some embodiments, the decision computing module 110 can be coupled to a cloud system 300 having a cloud database 310. The cloud database 310 can store data on combinations of calibration parameter ranges for RF calibration of corresponding RF systems provided by decision computing modules in different regions, and provide corresponding combinations of calibration parameter ranges to different decision computing modules for use in other corresponding RF systems that need calibration.

[0029] Figure 4 illustrates a schematic diagram of a cloud system 300 and multiple decision operation modules (decision operation modules 110-1 to 110-3) according to multiple embodiments of the present invention. Specifically, the technology provided by the present invention can use Markov models as the decision basis for selecting parameter adjustment ranges, and use edge computing architecture (e.g., edge computing processors 112-1 to 112-3) to generate Markov chain data required for Markov decision-making, and store it in corresponding correction databases (e.g., correction databases 111-1 to 111-3). These correction databases 111-1 to 111-3 are communicatively connected to the cloud system 300 to store the Markov chain data (including multiple correction parameter range combinations) in the cloud system 300.

[0030] In this embodiment, as shown in FIG4, the cloud system 300 can connect to calibration databases 111-1 to 111-3 in different regions A to C (e.g., calibration databases located in different regions / production bases) to aggregate Markov chain data (including combinations of complex calibration parameter ranges) of all radio frequency systems with the same or similar characteristics from different production bases. Therefore, when the radio frequency calibration device (RF calibration device 100 in FIG1) in one of the complex regions A to C lacks calibration data (i.e., Markov chain data), the decision operation modules 110-1 to 10-3 of the radio frequency calibration device corresponding to one of the complex regions A to C can obtain the calibration data of the others in the complex regions A to C through the cloud system 300, thereby calibrating its radio frequency system.

[0031] Therefore, each decision computing module can simultaneously support the operation of multiple production lines in the local production base. In addition to collecting the calibration data (i.e. Markov chain data) used locally, it can also use calibration data from other regions through the cloud system 300 for reference in order to calibrate the corresponding radio frequency systems in different regions.

[0032] In some embodiments, each calibration data database 111-1 to 111-3 can store the calibration data (i.e. Markov chain data) used by each RF system in the calibration process, that is, it includes all process steps from the start of calibration to the completion of calibration, and can update the values ​​of calibration parameters used by the RF system that has completed calibration to each calibration data database 111-1 to 111-3 in real time, and can provide them to the cloud database 310 of the cloud system 300.

[0033] Figure 5 illustrates a schematic diagram of an example Markov chain 500 according to multiple embodiments of the present invention. In some embodiments, each state (state S1 and state S2) of the Markov chain used to correct the RF system may include four factors: in-phase signal DC offset correction parameter, quadrature signal DC offset correction parameter, gain correction parameter, and phase correction parameter. The maximum adjustable range of these four factors is determined by the number of bits listed below, as shown in Figure 5. The number of bits for can be expressed as , the number of bits for can be expressed as , the number of bits for can be expressed as , and the number of bits for can be expressed as . Therefore, the adjustment ranges of the four factors are respectively . For simplicity, it can be assumed that each factor has 8 bits, so the adjustable range of each factor is between 0 and 255. However, the actual correction value corresponding to the bit jump of each factor varies depending on the actual product design. For example, assuming the phase correction range is in the ± ω / 4 range, the adjustment change of each stage is approximately 0.18 degrees.

[0034] In the example of Figure 5, each factor value in each state (state S1 and state S2) of the Markov chain is a continuous range. For example, the initial state can be represented as [the initial values ​​of the four factors representing the Markov decision of the decision operation module are set in the above-mentioned combination of correction parameters, and the correction control module (e.g., the correction control module 120 in Figure 3) will only use the above-mentioned combination of correction parameters to start calibrating the RF system (or DUT) until the calibration is completed in this state or the state needs to be changed (e.g., from state S1 to state S2).

[0035] As discussed above, the Markov chain used in the technology provided by this invention is established by each decision-making module based on data accumulated from local production. The data from each decision-making module can be collected and analyzed via a cloud system to optimize the range of correction parameters in each state, minimizing the time required for correction in each state. For example, with 10,000 correction data entries, analysis reveals 6,300 entries of […], another 3,500 entries of […]. The last 200 entries are […]. In some embodiments, as shown in Figure 5, the Markov chain can set the initial state to […] to cover a 97% (0.97) success rate. The remaining 3% (0.03) then enter the state set to […] for testing, covering a 90% (0.9) success rate.

[0036] FIG6 illustrates a schematic diagram of another example Markov chain 600 according to a plurality of embodiments of the present invention. Since the Markov chain data in the Markov chain 600 shown in FIG6 has a large number of states (states S1 to S4), the range of correction parameter intervals contained in each state is relatively small. Therefore, compared to the Markov chain data in the Markov chain 500 of FIG5, the decision operation module of the RF correction device uses the Markov chain of FIG6 to correct the RF system, which can shorten the correction time. The representation of the Markov chain data in the Markov chain 600 shown in FIG6 is similar to that in the Markov chain 500 of FIG5, and will not be repeated here.

[0037] In some embodiments, based on the Markov chain of Figures 5 and 6 above, the calibration control module of the RF calibration device may include at least a processor and a network interface. Through the network interface, the calibration control module can simultaneously couple the RF system under test (or DUT) and the decision-making and calibration analysis modules of the RF calibration device. The calibration control module can calibrate the RF system according to the calibration parameter range combination provided in the Markov chain state (e.g., controlling and adjusting the RF system through the system processor of the RF system). At the same time, the feedback data received by the calibration analysis module is used to determine whether the original calibration parameter range combination can continue to be used for calibration or whether the state must be changed to adopt the calibration parameter range combination in other states of the Markov chain.

[0038] In some embodiments, the calibration analysis module of the RF calibration apparatus may include a physical machine or a virtual machine with RF signal analysis capabilities. The physical machine may be, for example, a standalone signal analyzer (SA) or a combination of a signal analyzer and a signal generator (SG). The virtual machine may be a device with signal analysis capabilities written in software, such as MATLAB, Python, LabVIEW, or other programmable application software.

[0039] Figure 7 illustrates a schematic diagram of the suppression relationship between the monotonic signal of the radio frequency output signal and the corresponding local oscillation signal and the mapped signal according to multiple embodiments of the present invention. The radio frequency correction technology provided by the present invention determines whether the correction at a specific frequency point is successful based on the suppression between the monotonic signal (e.g., the output signal of the radio frequency module corresponding to the specific frequency point in the radio frequency system 200) received by the correction analysis module 130 and the local oscillation signal coupled to the monotonic signal (appearing at the output terminal), and the suppression between the monotonic signal and the generated mapped signal (noise). That is, during the correction process, both the suppression degree and the suppression degree must be higher than the threshold for the correction of the radio frequency module (or the entire radio frequency system) corresponding to the specific frequency point to be considered successful.

[0040] In some embodiments, the threshold is 50 dB. In some embodiments, the threshold can be adjusted according to actual needs (e.g., the quality requirements of the output signal). If the calibration analysis module detects that the suppression level is higher than the threshold, it means that the RF module 270 corresponding to a specific frequency point has been completed. The calibration control module 120 will record the calibration process of this RF module 270 (e.g., store the corresponding calibration parameter range combination used in the calibration database), and will continue to perform calibration of RF modules corresponding to other frequency points until the calibration of the corresponding RF modules at all frequency points in all RF systems 200 is completed.

[0041] As discussed above, due to potential IQ mismatch during circuit generation, a mapped signal (noise) may appear at the mapped frequency position, and a local oscillation signal may occur at the output due to the DC offset of the IQ signal. Therefore, a higher suppression degree and suppression level mean that the output monotonic signal is higher than the mapped signal and the local oscillation signal, which can improve the quality of the RF system output signal. Accordingly, the RF correction technology provided by this invention uses the aforementioned suppression degree and suppression level between the output monotonic signal and the local oscillation signal and the mapped signal as the basis for judging whether the correction is successful.

[0042] FIG8 illustrates a flowchart of an example radio frequency calibration procedure 800 for calibrating a radio frequency module according to a plurality of embodiments of the present invention.

[0043] In step S810, the edge computing processor of the decision computing module of the radio frequency correction device (e.g., the edge computing processor 112 of the decision computing module 110 of the radio frequency correction device 100 in FIG3) provides the complex correction parameter interval combination (e.g., state S1 to state S2 in FIG5 or state S1 to state S2 in FIG6) in the correction database of the decision computing module (e.g., the correction database 111 of the decision computing module 110 in FIG3) to the correction control module of the radio frequency correction device (e.g., the correction control module 120 of the radio frequency correction device 100 in FIG3).

[0044] In step S820, the calibration analysis module of the radio frequency calibration device (e.g., the calibration analysis module 130 of the radio frequency calibration device 100 in FIG3) receives the output signal (e.g., monotonic signal ST) of the radio frequency module (e.g., the radio frequency module 270 in FIG2) corresponding to a specific frequency point of the radio frequency system (e.g., the radio frequency system 200 in FIG1).

[0045] In step S830, the calibration control module uses a combination of complex calibration parameter ranges to calibrate the radio frequency system through the system processor of the radio frequency system (e.g., the system processor 210 in Figure 1) until the suppression degree of the output signal received by the calibration analysis module (e.g., the suppression degree and suppression degree in Figure 7) is greater than the threshold (e.g., 50dB).

[0046] In some specific configurations, the edge processing processor of the decision processing module obtains complex correction parameters from the correction database of the decision processing module and generates complex Markov chain data based on the complex correction parameters. Each of the complex correction parameter range combinations includes in-phase signal DC offset correction parameters, quadrature signal DC offset correction parameters, gain correction parameters, and phase correction parameters. The complex Markov chain data includes complex correction parameter range combinations formed by the complex correction parameters, and the complex correction parameter range combinations include the range values ​​of the complex correction parameters.

[0047] In some specific settings, the suppression level includes image signal suppression and local oscillation signal suppression. Image signal suppression is the difference between the output signal of the RF module and the image signal generated by the RF module at other frequencies. Local oscillation signal suppression is the difference between the output signal of the RF module and the local oscillation signal coupled to the output signal. Image signal suppression is related to gain correction parameters and phase correction parameters, and local oscillation signal suppression is related to in-phase signal DC offset correction parameters and quadrature signal DC offset correction parameters.

[0048] In some specific settings, when the suppression degree of the output signal received by the correction analysis unit is greater than the threshold, the edge computing processor updates the corresponding value of the multiple correction parameter interval combinations used in the correction database.

[0049] In some specific configurations, the system further includes providing corresponding Markov chain data or multiple Markov chain data to the cloud system from the calibration database of the radio frequency calibration device and multiple other radio frequency calibration devices, and providing multiple calibration parameter range combinations in the Markov chain data or multiple other Markov chain data to the radio frequency calibration device or multiple other radio frequency calibration devices from the cloud system, and the cloud system receiving the updated Markov chain data or multiple other Markov chain data from the radio frequency calibration device or multiple other radio frequency calibration devices.

[0050] According to the above-described multiple embodiments, the RF calibration technology provided by the present invention uses an open-loop approach to correct the IQ DC offset and IQ mismatch of an RF system (or DUT), and employs a Markov decision method to determine the adjustment range for each parameter. It can be applied to RF systems designed with discrete architectures or other architectures. The RF calibration technology provided by the present invention can shorten and optimize the time for IQ calibration of an RF system using an open-loop approach, and uses a Markov model as the basis for optimizing calibration decisions. A Markov chain database is established in a cloud and edge computing environment to correct the IQ DC offset and IQ mismatch of the RF system. Furthermore, the RF calibration technology provided by the present invention does not directly measure the amplitude and phase values ​​of the corrected DC offset and IQ, but rather analyzes the suppression levels between monotonic signals and local oscillation signals, as well as mapped signals. This significantly shortens the calibration time, reduces costs, and is suitable for automated production testing environments.

[0051] This invention and other examples can be implemented as one or more computer program products, for example, one or more computer program instructions encoded on a computer-readable medium are executed by a data processing device or control the operation of the data processing device. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, or one or more of the above. The term "data processing device" includes all means, apparatus, and machines for processing data, including, for example, a programmable processor, a computer, or a plurality of processors or computers. In addition to hardware, this means may include program code that establishes the execution environment of the computer program in question, such as program code constituting processor firmware, a protocol stack, a database management system, an operating system, or one or more of the above.

[0052] A computer program (also known as a program, software, software application, instruction code, or program code) can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other module for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored as part of a file containing other programs or data (e.g., one or more instruction codes stored in a markup language document), in a single file dedicated to the program in question, or in a plurality of coordinated files (e.g., a file containing one or more modules, subroutines, or portions of program code). A computer program can be configured to execute on one or more computers. These computers may be located in one place or distributed across multiple locations and interconnected via a communication network.

[0053] The programs and logic flows described herein can be executed by one or more programmable processors that execute one or more computer programs to perform the functions described herein. The programs and logic flows can also be executed by special purpose logic circuitry, and the devices can also be implemented by special purpose logic circuitry, for example, field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs), or executed by a system-on-a-chip (SoC).

[0054] A processor suitable for executing computer programs includes, for example, both general-purpose microprocessors and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor receives instructions and data from read-only memory or random access memory or both. The basic elements of a computer may include a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer may also include or be operatively coupled to one or more mass storage devices for storing data, to receive data from or transfer data to or to such mass storage devices, or both. Examples of such mass storage devices are magnetic disks, magneto-optical disks, or optical disks. However, a computer does not need to have such devices. Computer-readable media suitable for storing computer program instructions and data may include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks. Processors and memory can be supplemented by dedicated logic circuits or incorporated into dedicated logic circuits.

[0055] Various embodiments are described with reference to the accompanying drawings, wherein all drawings use the same element reference numerals to denote similar or equivalent elements. The drawings are not necessarily drawn to scale and are provided only to illustrate aspects and features of the invention. Numerous specific details, relationships, and methods are set forth to provide a full understanding of certain aspects and features of the invention, although those skilled in the art will recognize that these aspects and features may be implemented without one or more of the specific details, relationships, or methods. In some cases, well-known structures or operations are not shown in detail for illustrative purposes. The various embodiments disclosed herein are not necessarily limited to the order of the described actions or events, as some actions may occur in a different order and / or simultaneously with other actions or events. Furthermore, not all actions or events in the drawings are necessary to realize certain aspects and features of the invention.

[0056] Although the invention has been described and illustrated with respect to one or more embodiments, other skilled in the art will recognize or understand equivalent changes and modifications upon reading and understanding this specification and the accompanying drawings. Furthermore, while a particular feature of the invention may be disclosed only for one of several embodiments, this feature may be combined with one or more other features of other embodiments, as these features may be desirable and advantageous for any given or particular application.

[0057] While various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitation. Various changes may be made to the disclosed embodiments based on the disclosure without departing from the spirit or scope of the invention. Therefore, the breadth and scope of the invention should not be limited by any of the above embodiments. Rather, the scope of the invention should be defined according to the appended claims and their equivalents. [Simplified Explanation of the Diagram]

[0013] Figure 1 is a schematic diagram illustrating the architecture of a discrete example radio frequency system according to multiple embodiments of the present invention. Figure 2 is a schematic diagram illustrating the radio frequency module of the radio frequency system according to multiple embodiments of the present invention. Figure 3 is a functional block diagram illustrating an example radio frequency calibration device for calibrating a radio frequency system according to multiple embodiments of the present invention. Figure 4 is a schematic diagram illustrating a cloud system and a complex decision operation module according to multiple embodiments of the present invention. Figure 5 is a schematic diagram illustrating an example Markov chain according to multiple embodiments of the present invention. Figure 6 is a schematic diagram illustrating another example Markov chain according to multiple embodiments of the present invention. Figure 7 is a schematic diagram illustrating the relationship between the monotonic signal of the radio frequency output signal and the suppression degree of the corresponding local oscillation signal and the mapped signal according to multiple embodiments of the present invention. Figure 8 is a flowchart illustrating an example radio frequency calibration procedure for calibrating a radio frequency module according to multiple embodiments of the present invention.

Claims

1. A radio frequency calibration device for calibrating a radio frequency system, comprising: A calibration control module is coupled to a system processor in the radio frequency system; A calibration analysis module is coupled to the calibration control module and the radio frequency system to receive an output signal from the radio frequency system; A decision processing module is coupled to the correction control module, and the decision processing module provides the correction control module with a combination of complex correction parameter intervals from the complex Markov chain data. The correction control module provides the complex correction parameter intervals to the system processor so that the system processor can use the combination of complex correction parameter intervals to correct the radio frequency system until a suppression degree of the output signal received by the correction analysis module is greater than a threshold.

2. The radio frequency calibration apparatus as described in claim 1, wherein, The decision processing module includes: a calibration database storing complex calibration parameters; and an edge processing processor coupled to the calibration database to obtain the complex calibration parameters and generate complex Markov chain data based on the complex calibration parameters. The complex calibration parameters include a co-phase signal DC offset calibration parameter, a quadrature signal DC offset calibration parameter, a gain calibration parameter, and a phase calibration parameter. The complex Markov chain data includes a combination of complex calibration parameter intervals formed by the complex calibration parameters, and the combination of complex calibration parameter intervals includes the range values ​​of the complex calibration parameters.

3. The radio frequency calibration apparatus as described in claim 2, wherein, The suppression level includes a picture signal suppression level and a local oscillation signal suppression level. The picture signal suppression level is the difference between the output signal of the RF module and a picture signal generated by the RF module at other frequencies. The local oscillation signal suppression level is the difference between the output signal of the RF module and a local oscillation signal coupled to the output signal. The picture signal suppression level is related to the gain correction parameter and the phase correction parameter. The local oscillation signal suppression level is related to the in-phase signal DC offset correction parameter and the quadrature signal DC offset correction parameter.

4. The radio frequency calibration apparatus as described in claim 2, wherein, When the suppression degree of the output signal received by the correction analysis module is greater than the threshold, the edge computing processor updates the corresponding value of the complex correction parameter interval combination used to the complex correction parameter interval combination in the correction database.

5. The radio frequency calibration apparatus as described in claim 4, wherein, The decision processing module is coupled to a cloud system, and the cloud system is further coupled to a plurality of other radio frequency (RF) calibration devices. The calibration databases of the RF calibration devices and the plurality of other RF calibration devices provide corresponding Markov chain data or a plurality of other Markov chain data to the cloud system, so that the cloud system provides a combination of multiple calibration parameter ranges in the Markov chain data or the plurality of other Markov chain data to the RF calibration device or the plurality of other RF calibration devices. The cloud system also receives updated Markov chain data or a plurality of other Markov chain data from the RF calibration device or the plurality of other RF calibration devices.

6. A radio frequency calibration method for calibrating a radio frequency system, comprising: A decision processing module of an RF calibration device provides a combination of complex calibration parameter intervals from complex Markov chain data to a calibration control module of the RF calibration device; a calibration analysis module of the RF calibration device receives an output signal from the RF system; and the calibration control module provides the complex calibration parameter intervals to a system processor of the RF system, so that the system processor uses the combination of complex calibration parameter intervals to calibrate the RF system until a suppression degree of the output signal received by the calibration analysis module is greater than a threshold.

7. The radio frequency calibration method as described in claim 6 further includes obtaining complex calibration parameters from the calibration database of the decision processing module by the edge processing processor of the decision processing module, and generating the complex Markov chain data based on the complex calibration parameters, wherein, Each of the complex correction parameter range combinations includes a co-phase signal DC offset correction parameter, a quadrature signal DC offset correction parameter, a gain correction parameter, and a phase correction parameter. The complex Markov chain data includes the complex correction parameter range combination formed by the complex correction parameters, and the complex correction parameter range combination includes the range value of the complex correction parameters.

8. The radio frequency calibration method as described in claim 7, wherein, The suppression level includes a reflection signal suppression level and a local oscillation signal suppression level. The reflection signal suppression level is the difference between the output signal of the RF module and a reflection signal generated by the RF module at other frequencies. The local oscillation signal suppression level is the difference between the output signal of the RF module and a local oscillation signal coupled to the output signal. The reflection signal suppression level is related to the gain correction parameter and the phase correction parameter, and the local oscillation signal suppression level is related to the in-phase signal DC offset correction parameter and the quadrature signal DC offset correction parameter.

9. The radio frequency calibration method as described in claim 8 further includes, when the suppression degree of the output signal received by the calibration analysis module is greater than the threshold, the edge processing processor updates the complex calibration parameter interval combination in the calibration database with the corresponding value of the complex calibration parameter interval combination used.

10. The radio frequency calibration method as described in claim 9 further includes: The calibration database of the RF calibration device and a plurality of other RF calibration devices provides the corresponding Markov chain data or a plurality of other Markov chain data to a cloud system; and the cloud system provides the plurality of calibration parameter ranges in the Markov chain data or the plurality of other Markov chain data to the RF calibration device or the plurality of other RF calibration devices, and the cloud system receives the updated Markov chain data or the plurality of other Markov chain data from the RF calibration device or the plurality of other RF calibration devices.

11. A non-transitory computer-readable storage medium, comprising a plurality of instructions, wherein the plurality of instructions cause a controller, computer device, or computer to perform the radio frequency calibration method as described in claim 6.

Images