A Short-wave Predistortion System and Method Based on a Coupler Circuit

Abstract

The present invention relates to the technical field of short-wave predistortion, and specifically discloses a short-wave predistortion system and method based on a coupler circuit. The method includes the following steps: S1: Periodically obtain signal parameters within a preset inspection period, and calculate signal values according to the signal parameters; S2: Determine coordinate points according to the signal values, and perform fitting on the coordinate points to obtain a fitting curve; Calculate the average signal value according to the fitting curve, and use the straight line passing through the point where the average signal value is located on the y-axis and parallel to the x-axis as the desired line; Statistically calculate the proportion of the domain corresponding to the target curve above the desired line in the domain of the target curve; S3: Calculate a judgment value, and determine the optimal predistortion method according to the judgment value. The present invention can determine the optimal predistortion method according to the actual effect of predistortion, and improve the transmission quality of signals.

Description

Technical Field

[0001] The present invention relates to the technical field of short-wave predistortion, and particularly relates to a short-wave 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 part of the signal by inserting a "coupling port" on the main signal path without significantly affecting the transmission of the main signal. Coupler circuits are usually applied in radio and communication systems, mainly for monitoring, detecting, separating, or feeding back signals.

[0003] Short-wave predistortion is a technology applied in short-wave communication systems, mainly used to compensate for the nonlinear distortion of power amplifiers. Its main purpose is to perform "predistortion" processing on the signal before it enters the power amplifier, so that after being nonlinearly amplified by the amplifier, the signal can be restored to be close to the ideal original form.

[0004] Conventional short-wave 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, etc. 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 changes little, while dynamic predistortion can handle scenarios where the signal changes rapidly, such as complex signal modulation in broadband communication systems. However, in actual use, it is still necessary to select a suitable predistortion method according to the actual effect of 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, and solve the following technical problems:

[0006] Select a suitable predistortion method according to the actual effect of predistortion, thereby improving the signal transmission quality.

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

[0008] A short-wave predistortion method based on a coupler circuit includes the following steps:

[0009] S1: Set m inspection periods with the same length, where m is the total number of predistortion methods. Periodically obtain signal parameters within the inspection period. The signal parameters include the out-of-band rejection ratio Ady of the signal, the error vector magnitude Awc, and the normalized mean square error Agy. 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 ), where C b represents the signal value when the time interval from the start point of the monitoring period is b, and fit the coordinate points to obtain the fitting curve f(t);

[0011] Calculate the average signal value The time interval [T sta , T end represents the domain of the fitting curve. Take the straight line passing through (0, CAVE i ) and parallel to the x-axis as the expected line, where CAVE i represents the average signal value corresponding to the i-th test period;

[0012] Take the test periods other than the i-th test period as the target periods, and take the fitting curves corresponding to the target periods as the target curves. Statistically calculate the proportion b of the abnormal interval in the domain of the target curve. The abnormal interval represents the domain of the target curve above the expected line;

[0013] S3: Calculate the judgment value K = ε * (1 + b) * max(f(t) - CAVE i ), where ε represents the preset correction coefficient, and determine the optimal predistortion method according to the judgment value.

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

[0015] Obtain the minimum judgment value Ki min = min(Ki jh ), where Ki jh = (K i，1 , K i，2 , …, K i，m-1 ), and K i，m-1 represents the judgment value between the i-th test period and the (m - 1)-th target period;

[0016] Obtain the minimum value Y of the minimum judgment value, determine the test period Yjy where the average signal value corresponding to the minimum value Y is located, and take the predistortion method corresponding to the test period Yjy 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, determine the minimum judgment values that are the same and are the minimum values, take the corresponding predistortion methods as the candidate methods, and take the candidate method with the lowest cost as the optimal predistortion method.

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

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

[0020] As a further solution of the present invention: in the step S2, when the proportion b of the abnormal interval in the domain of the target curve is b<0.2, the i-th inspection period does not participate in the subsequent steps.

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

[0022] A short-wave predistortion system based on a coupler circuit, comprising:

[0023] Acquisition module: Set m inspection periods of the same length, where m is the total number of predistortion methods. Periodically obtain signal parameters within the inspection period. The signal parameters include out-of-band rejection ratio Ady, error vector magnitude Awc, and normalized mean square error Agy of the signal. Calculate the signal value C = μ(Ady + Awc + Agy), where μ is a preset signal value coefficient;

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

[0025] Calculate the average signal value The time interval [T sta , T end represents the domain of the fitting curve. The straight line passing through (0, CAVE i ) and parallel to the x-axis is used as the desired line, and CAVEi represents the average signal value corresponding to the i-th inspection period;

[0026] Take the inspection periods except the i-th inspection period as target periods, take the fitting curves corresponding to the target periods as target curves, and count the proportion b of the abnormal interval in the domain of the target curve. The abnormal interval represents the domain of the target curve above the desired line;

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

[0028] Advantages of the present invention: In the present invention, by obtaining signal parameters and calculating signal values, which are used to reflect the comprehensive situation of the signal. The smaller the signal value, the better the predistortion effect, thus 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 change trend of the signal value within the test period. The average signal value is calculated to measure the expected situation of the signal value within the test period. Then, the expected line is determined, and the ratio b of the domain of the target curve above the expected line to the domain of the target curve is determined. It should be noted that the expected line reflects the expected effect of a certain predistortion method. The larger the ratio b, the worse the effect of the remaining predistortion methods compared with the predistortion method in the i-th test period (that is, there are more cases where the signal value is greater than the expected situation in the i-th test period). Then, the judgment value is calculated, and the optimal predistortion method is determined according to the judgment value. It can be understood that the ratio b is relative to a certain target curve, and the judgment value also reflects the effect of the predistortion method in the i-th test period compared with another predistortion method. The smaller the judgment value, the better the effect of the predistortion method in the i-th test period compared with another predistortion method. The present invention can determine the optimal predistortion method according to the actual effect of predistortion, and improve the transmission quality of the signal. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0030] Figure 1 is a schematic flow chart of a short-wave predistortion method based on a coupler circuit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figure 1 As shown, the present invention is a short-wave predistortion method based on a coupler circuit, including the following steps:

[0033] S1: Set m inspection periods of the same length, where m is the total number of predistortion methods. Periodically obtain signal parameters within the inspection periods. The signal parameters include out-of-band rejection ratio Ady of the signal, error vector magnitude Awc, and normalized mean square error Agy. 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 ), where C b represents the signal value when the time interval from the start point of the monitoring period is b. Fit the coordinate points to obtain a fitting curve f(t);

[0035] Calculate the average signal value The time interval [T sta , T end represents the domain of the fitting curve. Use the line passing through (0, CAVEi) and parallel to the x-axis as the desired line, where CAVE i represents the average signal value corresponding to the i-th inspection period;

[0036] Take the inspection periods other than the i-th inspection period as target periods, and take the fitting curves corresponding to the target periods as target curves. Statistically calculate the proportion b of the abnormal interval in the domain of the target curve. The abnormal interval represents the domain of the target curve above the desired line;

[0037] S3: Calculate the judgment value K = ε*(1 + b)*max(f(t) - CAVE i ), where ε represents a preset correction coefficient. Determine the optimal predistortion method according to the judgment value.

[0038] It should be noted that by obtaining signal parameters and calculating signal values, which are used to reflect the comprehensive situation of the signal, the smaller the signal value, the better the pre-distortion effect, thus 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 change trend of signal values within the test period, and the average signal value is calculated to measure the expected situation of signal values within the test period; then the expected line is determined, and the proportion b of the domain of the target curve above the expected line in the domain of the target curve is determined; it should be noted 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 compared with the pre-distortion method in the i-th test period (that is, there are more cases where 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 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] Obtain 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 test period and the (m - 1)-th target period;

[0041] Obtain the minimum value Y of the minimum judgment value, determine the test period Yjy where the average signal value corresponding to the minimum value Y is located, and use the pre-distortion method corresponding to the test period Yjy as the optimal pre-distortion method.

[0042] It should be noted that among all test periods, the detection period yjy corresponding to the minimum judgment value Y indicates that the signal deviation or distortion of the pre-distortion method in this period is the smallest, so its signal quality is closest to the expected ideal state, which means that this pre-distortion method can better meet the current signal optimization requirements, thereby improving the quality of signal transmission.

[0043] In another preferred embodiment of the present invention, during 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, determine the minimum judgment value that is the same and is the minimum value, use the corresponding pre-distortion method as the candidate method, and use the candidate method with the lowest cost as the optimal pre-distortion method.

[0044] It can be understood that when the judgment values of multiple pre-distortion methods are the same and are all the minimum values, it means that these methods have the same signal optimization effect, that is, their signal stability and deviation control reach the same level; by preferentially selecting the pre-distortion method with the lowest cost, it is possible to further reduce the resource consumption of implementation while ensuring the best signal effect, achieving a higher cost performance; introducing the cost standard also makes the selection of the pre-distortion method more practical and effective, meeting the requirements of engineering practice. Ultimately, it is ensured that while meeting signal stability and optimization effects, 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 step S1, within the inspection period, different pre-distortion methods are used to process the signal, and one inspection period corresponds to one pre-distortion method.

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

[0047] It should be noted that when the proportion b of the abnormal interval in the domain of definition of the target curve is b≥0.8, it means that most of the region of the signal curve in the current inspection period is above the expected line, and the expected line represents the effect benchmark of a certain pre-distortion method. The larger the signal region above the expected line, the worse the effect of the pre-distortion method in the current inspection period compared to the method corresponding to the expected line, indicating that the pre-distortion method in the current inspection period will not be the optimal pre-distortion method. Therefore, it can be directly removed to reduce the subsequent computational resource consumption.

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

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

[0050] It is worth noting that non - linear fitting is a mathematical method used to find the non - linear function curve that best fits a set of data points. Different from linear fitting, the model of non - linear fitting is not a straight line but can be a more complex curve (such as exponential, logarithmic, power function, polynomial or other non - linear functions). In this solution, the fitting curve obtained through non - linear fitting is to more precisely capture the signal change trend. The non - linear fitting curve can better adapt to the actual fluctuations 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 short - wave predistortion system based on a coupler circuit, comprising:

[0052] An acquisition module: Set m inspection periods of the same length, where m is the total number of predistortion methods. Periodically obtain signal parameters within the inspection period. The signal parameters include the out - of - band rejection ratio Ady of the signal, the error vector magnitude Awc, and the normalized mean square error Agy. Calculate the signal value C = μ(Ady + Awc + Agy), where μ is a preset signal value coefficient.

[0053] An analysis module: Determine the coordinate point (b, C b ), where C b represents the signal value when the time interval from the start point of the monitoring period is b, and perform fitting on the coordinate points to obtain the fitting curve f(t).

[0054] Calculate the average signal value The time interval [T sta , T end represents the domain of the fitting curve. Take the straight line passing through (0, CAVE i ) and parallel to the x - axis as the expected line, where CAVE i represents the average signal value corresponding to the i - th inspection period.

[0055] Take the inspection periods except the i - th inspection period as the target periods, take the fitting curves corresponding to the target periods as the target curves, and count the proportion b of the abnormal interval in the domain of the target curve. The abnormal interval indicates the domain of the target curve corresponding to the part above the expected line.

[0056] A decision - making module: Calculate the judgment value K = ε*(1 + b)*max(f(t)-CAVE i ), where ε represents a preset correction coefficient, and determine the optimal predistortion method according to the judgment value.

[0057] The above has described in detail an embodiment of the present invention, but the above content is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A short-wave predistortion method based on a coupler circuit, characterized in that, It includes the following steps: S1: Set m inspection periods with the same length, where m is the total number of pre-distortion methods. Periodically obtain signal parameters within the inspection periods. The signal parameters include out-of-band rejection ratio Ady of the signal, error vector magnitude Awc, and normalized mean square error Agy. 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 from the start point of the inspection period is b, and fitting the coordinate points to obtain a fitting curve f(t); Calculate the average signal value Time interval [T sta , T end represents the domain of the fitted curve. A line passing through (0, CAVE i ) and parallel to the x-axis is used as the expected line. CAVE i represents the average signal value corresponding to the i-th test period; Take the inspection periods except the i-th inspection period as target periods, take the fitting curve corresponding to the target periods as the target curve, and statistically calculate the proportion r of the abnormal interval in the domain of the target curve. The abnormal interval represents the domain of the target curve above the expected line; S3: Calculate the judgment value K = ε * (1 + r) * max(f(t) - CAVE i ), where ε represents a preset correction coefficient, and determine the optimal predistortion method according to the judgment value.

2. The short-wave pre-distortion method based on a coupler circuit according to claim 1, characterized in that, In step S3, the process of determining the optimal pre-distortion method according to the judgment value specifically includes: Obtain 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 period and the (m-1)-th target period; Obtain the minimum value Y of the minimum judgment value, determine the inspection period Yjy where the average signal value corresponding to the minimum value Y is located, and take the pre-distortion method corresponding to the inspection period Yjy as the optimal pre-distortion method.

3. A short-wave 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, determine the same and minimum judgment values, take the corresponding pre-distortion methods as candidate methods, and take the candidate method with the lowest cost as the optimal pre-distortion method.

4. A short-wave predistortion method based on a coupler circuit according to claim 2, characterized in that In step S1, within the inspection periods, the signal is processed using different pre-distortion methods, and one inspection period corresponds to one pre-distortion method.

5. A short-wave predistortion method based on a coupler circuit according to claim 1, characterized in that, In step S2, when the proportion r of the abnormal interval in the domain of the target curve is r ≥ 0.8, the corresponding target period does not participate in the subsequent steps.

6. A short-wave pre-distortion method based on a coupler circuit according to claim 1, characterized in that In step S2, when the proportion r of the abnormal interval in the domain of the target curve is r < 0.2, the i-th inspection period does not participate in the subsequent steps.

7. A short-wave predistortion method based on a coupler circuit according to claim 1, characterized in that, In step S2, perform non-linear fitting on the coordinate points to obtain a fitting curve.

8. A short-wave predistortion system based on a coupler circuit, characterized in that It includes: Acquisition module: Set m inspection periods with the same length, where m is the total number of pre-distortion methods. Periodically obtain signal parameters within the inspection periods. The signal parameters include out-of-band rejection ratio Ady of the signal, error vector magnitude Awc, and normalized mean square error Agy. Calculate the signal value C = μ(Ady + Awc + Agy), where μ is a preset signal value coefficient; Analysis module: Determine the coordinate point (b, C b ), C b represents the signal value when the time interval from the start point of the inspection period is b, and fits the coordinate point to obtain a fitting curve f(t); Calculate the average signal value The time interval [T sta , T end represents the domain of the fitting curve. A straight line passing through (0, CAVE i ) and parallel to the x-axis is used as the expected line. CAVE i represents the average signal value corresponding to the i-th test period; Take the inspection periods except the i-th inspection period as target periods, take the fitting curve corresponding to the target periods as the target curve, and statistically calculate the proportion r of the abnormal interval in the domain of the target curve. The abnormal interval represents the domain of the target curve above the expected line; Decision module: Calculate the judgment value K = ε * (1 + r) * max(f(t) - CAVE i ), where ε represents a preset correction coefficient, and determine the optimal predistortion method according to the judgment value.

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