Short-wave pre-distortion system and method based on coupler circuit

Abstract

The invention relates to the technical field of short-wave predistortion, and particularly discloses a short-wave predistortion system and method based on a coupler circuit, and the method comprises the following steps: S1, periodically obtaining signal parameters in a preset detection period, and calculating a signal value according to the signal parameters; s2, determining coordinate points according to the signal values, and fitting the coordinate points to obtain a fitted curve; calculating an average signal value according to the fitting curve, and taking a straight line which passes through a point where the average signal value on the y axis is located and is parallel to the x axis as an expected line; counting the proportion of a definition domain corresponding to the target curve above the expected line in the definition domain of the target curve; and S3, calculating a judgment value, and determining an optimal pre-distortion method according to the judgment value. According to the invention, the optimal pre-distortion method can be determined according to the actual pre-distortion effect, and the signal transmission quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of shortwave predistortion, and in particular to a shortwave predistortion system and method based on a coupler circuit. Background Art

[0002] A coupler circuit is a circuit element used to extract or separate signal energy in a radio frequency (RF) or microwave circuit. It obtains a small portion of the signal by inserting a "coupling port" into the main signal path without significantly affecting the transmission of the main signal. Coupler circuits are usually used in radio and communication systems, mainly for monitoring, detection, separation, or feedback signals.

[0003] Shortwave predistortion is a technology used in shortwave communication systems. It is mainly used to compensate for the nonlinear distortion of power amplifiers. Its main purpose is to perform "pre-distortion" processing on the signal before it enters the power amplifier, so that after nonlinear amplification by the amplifier, the signal can be restored to a nearly ideal original form.

[0004] Conventional shortwave predistortion methods mainly focus on using different mathematical models and algorithms to compensate for the nonlinear distortion of the amplifier, such as static predistortion and dynamic predistortion. Although these methods have different characteristics and applicable scenarios: static predistortion is suitable for situations where the nonlinear distortion is relatively stable and the environment does not change much, while dynamic predistortion can cope with scenarios where the signal changes rapidly, such as complex signal modulation in broadband communication systems. However, in actual usage, it is also necessary to select an appropriate predistortion method based on the actual effect of the predistortion to improve the signal transmission quality. Summary of the invention

[0005] The purpose of the present invention is to provide a short wave predistortion system and method based on a coupler circuit to solve the following technical problems:

[0006] The appropriate predistortion method is selected according to the actual effect of predistortion to improve the transmission quality of the signal.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A shortwave predistortion method based on a coupler circuit comprises the following steps:

[0009] S1: Set m test periods of the same length, where m is the total number of predistortion methods, and periodically obtain signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc, and the normalized mean square error Agy, and calculate the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient;

[0010] S2: Determine the coordinate point (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t);

[0011] Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, which will pass through (0, CAVE i ) and the straight line parallel to the x-axis is taken as the desired line, CAVE i represents the average signal value corresponding to the i-th inspection period;

[0012] The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line;

[0013] S3: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i ), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

[0014] As a further solution of the present invention: in the step S3, the process of determining the optimal pre-distortion method according to the judgment value specifically includes:

[0015] Get the minimum judgment value Ki min =min(Ki jh ), Ki jh =(K i，1 , K i，2 , …, K i，m-1 ), K i，m-1 represents the judgment value between the i-th inspection cycle and the m-1-th target cycle;

[0016] The minimum value Y of the minimum judgment value is obtained, the test period Yjy where the average signal value corresponding to the minimum value Y is located is determined, and the predistortion method corresponding to the test period Yjy is used as the optimal predistortion method.

[0017] As a further solution of the present invention: in the process of determining the minimum value of the minimum judgment value, when there are two or more minimum judgment values ​​that are the same and are the minimum values, the minimum judgment values ​​that are the same and are the minimum values ​​are determined, and the corresponding pre-distortion methods are used as candidate methods, and the candidate method with the lowest cost is used as the optimal pre-distortion method.

[0018] As a further solution of the present invention: in the step S1, different pre-distortion methods are used to process the signal within the test period, and one test period corresponds to one pre-distortion method.

[0019] As a further solution of the present invention: in the step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is ≥ 0.8, the corresponding target cycle does not participate in the execution of subsequent steps.

[0020] As a further solution of the present invention: in the step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is less than 0.2, the i-th inspection cycle does not participate in the execution of subsequent steps.

[0021] As a further solution of the present invention: in the step S2, the coordinate points are fitted based on nonlinear fitting to obtain a fitting curve.

[0022] A shortwave predistortion system based on a coupler circuit, comprising:

[0023] Acquisition module: setting m test periods of the same length, where m is the total number of pre-distortion methods, periodically acquiring signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc and the normalized mean square error Agy, and calculating the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient;

[0024] Analysis module: Determine the coordinate points (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t);

[0025] Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, which will pass through (0, CAVE i ) and the straight line parallel to the x-axis is taken as the expected line, and CAVEi represents the average signal value corresponding to the i-th inspection cycle;

[0026] The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line;

[0027] Decision module: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

[0028] Beneficial effects of the present invention: In the present invention, by obtaining signal parameters and calculating signal values, the comprehensive situation of the signal is reflected. The smaller the signal value, the better the pre-distortion effect is, thereby providing a data basis for subsequent analysis; then, coordinate points are generated and a fitting curve is determined. The fitting curve is used to reflect the trend of signal value changes in the inspection period, and the expected situation of the signal value in the inspection period is measured by calculating the average signal value; then, the expected line is determined, and the ratio b of the definition domain corresponding to the target curve above the expected line to the definition domain of the target curve is determined; it is worth noting that the expected line reflects the expected effect of a certain pre-distortion method, and the larger the ratio b, the worse the effect of the remaining pre-distortion methods compared with the pre-distortion method in the i-th inspection period (that is, the signal value is greater than the expected situation in the i-th inspection period); then, the judgment value is calculated, and the optimal pre-distortion method is determined according to the judgment value; it can be understood that the ratio b is the expected line relative to a certain target curve, and the judgment value also reflects the effect of the pre-distortion method in the i-th inspection period compared with another pre-distortion method. The smaller the judgment value, the better the effect of the pre-distortion method in the i-th inspection period compared with another pre-distortion method. The present invention can determine the optimal predistortion method according to the actual effect of predistortion, thereby improving the transmission quality of the signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 It is a flow chart of a shortwave predistortion method based on a coupler circuit of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1 As shown, the present invention is a shortwave predistortion method based on a coupler circuit, comprising the following steps:

[0033] S1: Set m test periods of the same length, where m is the total number of predistortion methods, and periodically obtain signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc, and the normalized mean square error Agy, and calculate the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient;

[0034] S2: Determine the coordinate point (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t);

[0035] Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, and the straight line passing through (0, CAVEi) and parallel to the x-axis is taken as the expected line, CAVE i represents the average signal value corresponding to the i-th inspection period;

[0036] The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line;

[0037] S3: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i ), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

[0038] It should be noted that, by obtaining signal parameters and calculating signal values, the comprehensive situation of the signal is reflected. The smaller the signal value, the better the pre-distortion effect is, thereby providing a data basis for subsequent analysis; then, coordinate points are generated and a fitting curve is determined. The fitting curve is used to reflect the trend of signal value changes in the test period. The expected situation of the signal value in the test period is measured by calculating the average signal value; then, the expected line is determined, and the proportion b of the definition domain corresponding to the target curve above the expected line to the definition domain of the target curve is determined; it is worth noting that the expected line reflects the expected effect of a certain pre-distortion method. The larger the proportion b, the worse the effect of the remaining pre-distortion methods is compared with the pre-distortion method in the i-th test period (that is, the signal value is greater than the expected situation in the i-th test period). Then, the judgment value is calculated, and the optimal pre-distortion method is determined according to the judgment value; it can be understood that the proportion b is the expected line relative to a certain target curve, and the judgment value also reflects the effect of the pre-distortion method in the i-th test period compared with another pre-distortion method. The smaller the judgment value, the better the effect of the pre-distortion method in the i-th test period compared with another pre-distortion method.

[0039] In another preferred embodiment of the present invention, in step S3, the process of determining the optimal pre-distortion method according to the judgment value specifically includes:

[0040] Get the minimum judgment value Ki min =min(Ki jh ), Ki jh =(K i，1 , K i，2 , …, K i，m-1 ), K i，m-1 represents the judgment value between the i-th inspection cycle and the m-1-th target cycle;

[0041] The minimum value Y of the minimum judgment value is obtained, the test period Yjy where the average signal value corresponding to the minimum value Y is located is determined, and the predistortion method corresponding to the test period Yjy is used as the optimal predistortion method.

[0042] It is worth noting that, among all the inspection cycles, the detection cycle yjy corresponding to the minimum judgment value Y indicates that the signal deviation or distortion of the pre-distortion method is the smallest within this cycle, so its signal quality is closest to the expected ideal state, which means that the pre-distortion method can better meet the optimization requirements of the current signal, thereby improving the quality of signal transmission.

[0043] In another preferred embodiment of the present invention, in the process of determining the minimum value of the minimum judgment value, when there are two or more minimum judgment values ​​that are the same and are the minimum values, the minimum judgment values ​​that are the same and are the minimum values ​​are determined, and the corresponding pre-distortion methods are used as candidate methods, and the candidate method with the lowest cost is used as the optimal pre-distortion method.

[0044] It is understandable that when the judgment values ​​of multiple pre-distortion methods are the same and are all minimum values, it means that these methods have the same signal optimization effect, that is, their signal stability and deviation control have reached the same level; by giving priority to the pre-distortion method with the lowest cost, the resource consumption of implementation can be further reduced while ensuring the best signal effect, achieving a higher cost performance; the introduction of cost standards also makes the selection of pre-distortion methods more practical and effective, and meets the needs of engineering practice. Ultimately, it ensures that while meeting the signal stability and optimization effect, the lowest cost solution is adopted, thereby achieving dual optimization of signal quality and economy.

[0045] In another preferred embodiment of the present invention, in the step S1, different pre-distortion methods are used to process the signal within the test period, and one test period corresponds to one pre-distortion method.

[0046] In another preferred embodiment of the present invention, in step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is ≥ 0.8, the corresponding target period does not participate in the execution of subsequent steps.

[0047] It should be noted that when the ratio of the abnormal interval to the definition domain of the target curve b≥0.8, it means that most of the signal curve in the current inspection cycle is above the expected line, and the expected line represents the effect benchmark of a certain pre-distortion method. The larger the signal area above the expected line, the worse the effect of the pre-distortion method in the current inspection cycle is than the method corresponding to the expected line, which means that the pre-distortion method in the current inspection cycle will not be the optimal pre-distortion method. Therefore, it can be directly removed, thereby reducing the subsequent computing resource consumption.

[0048] In another preferred embodiment of the present invention, in step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is less than 0.2, the i-th inspection cycle does not participate in the execution of subsequent steps.

[0049] In another preferred embodiment of the present invention, in the step S2, the coordinate points are fitted based on nonlinear fitting to obtain a fitting curve.

[0050] It is worth noting that nonlinear fitting is a mathematical method used to find the nonlinear function curve closest to a set of data points based on these points. Unlike linear fitting, the model of nonlinear fitting is not a straight line, but can be a more complex curve (such as exponential, logarithmic, power function, polynomial or other nonlinear functions); in this scheme, the fitting curve is obtained by nonlinear fitting in order to more accurately capture the signal change trend. The nonlinear fitting curve can better adapt to the actual fluctuation of the data, is more flexible than simple linear fitting, and can more accurately reflect the true characteristics of the signal within the detection period.

[0051] A shortwave predistortion system based on a coupler circuit, comprising:

[0052] Acquisition module: setting m test periods of the same length, where m is the total number of pre-distortion methods, periodically acquiring signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc and the normalized mean square error Agy, and calculating the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient;

[0053] Analysis module: Determine the coordinate points (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t);

[0054] Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, which will pass through (0, CAVE i ) and the straight line parallel to the x-axis is taken as the desired line, CAVE i represents the average signal value corresponding to the i-th inspection period;

[0055] The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line;

[0056] Decision module: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i ), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

[0057] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A shortwave predistortion method based on a coupler circuit, characterized in that: The following steps are involved: S1: Set m test periods of the same length, where m is the total number of predistortion methods, and periodically obtain signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc, and the normalized mean square error Agy, and calculate the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient; S2: Determine the coordinate point (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t); Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, which will pass through (0, CAVE i ) and the straight line parallel to the x-axis is taken as the desired line, CAVE i represents the average signal value corresponding to the i-th inspection period; The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line; S3: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i ), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

2. A shortwave predistortion method based on a coupler circuit according to claim 1, characterized in that: In the step S3, the process of determining the optimal pre-distortion method according to the judgment value specifically includes: Get the minimum judgment value Ki min =min(Ki jh ), Ki jh =(K i，1 , K i，2 , …, K i，m-1 ), K i，m-1 represents the judgment value between the i-th inspection cycle and the m-1-th target cycle; The minimum value Y of the minimum judgment value is obtained, the test period Yjy where the average signal value corresponding to the minimum value Y is located is determined, and the predistortion method corresponding to the test period Yjy is used as the optimal predistortion method.

3. A shortwave predistortion method based on a coupler circuit according to claim 2, characterized in that: In the process of determining the minimum value of the minimum judgment value, when there are two or more minimum judgment values ​​that are the same and are the minimum values, the minimum judgment values ​​that are the same and are the minimum values ​​are determined, and the corresponding pre-distortion methods are used as candidate methods, and the candidate method with the lowest cost is used as the optimal pre-distortion method.

4. A shortwave pre-loss method based on a coupler circuit according to claim 2, characterized in that: In the step S1, different pre-distortion methods are used to process the signal within the test period, and one test period corresponds to one pre-distortion method.

5. The shortwave predistortion method based on a coupler circuit according to claim 1, characterized in that: In the step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is ≥ 0.8, the corresponding target period does not participate in the execution of subsequent steps.

6. A shortwave predistortion method based on a coupler circuit according to claim 1, characterized in that: In the step S2, when the ratio b of the abnormal interval to the definition domain of the target curve is less than 0.2, the i-th inspection cycle does not participate in the execution of subsequent steps.

7. The shortwave predistortion method based on a coupler circuit according to claim 1, characterized in that: In the step S2, the coordinate points are fitted based on nonlinear fitting to obtain a fitting curve.

8. A shortwave predistortion system based on a coupler circuit, characterized in that: include: Acquisition module: setting m test periods of the same length, where m is the total number of pre-distortion methods, periodically acquiring signal parameters within the test period, where the signal parameters include the signal out-of-band suppression ratio Ady, the error vector amplitude Awc and the normalized mean square error Agy, and calculating the signal value C=μ(Ady+Awc+Agy), where μ is a preset signal value coefficient; Analysis module: Determine the coordinate points (b, C b ), C b represents the signal value when the time interval between the start point of the monitoring period is b, and the coordinate points are fitted to obtain a fitting curve f(t); Calculate the average signal value Time interval [T sta , T end ] represents the domain of the fitting curve, which will pass through (0, CAVE i ) and the straight line parallel to the x-axis is taken as the desired line, CAVE i represents the average signal value corresponding to the i-th inspection period; The inspection cycle except the i-th inspection cycle is taken as the target cycle, the fitting curve corresponding to the target cycle is taken as the target curve, and the proportion b of the abnormal interval in the definition domain of the target curve is counted, and the abnormal interval represents the definition domain corresponding to the target curve above the expected line; Decision module: Calculate the judgment value K = ε*(1+b)*max(f(t)-CAVE i ), wherein ε represents a preset correction coefficient, and the optimal pre-distortion method is determined according to the judgment value.

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