Dual-channel TIADC sampling moment mismatch calibration method based on positive and negative discrimination and product

Abstract

The invention specifically discloses a dual-channel TIADC sampling moment mismatch calibration method based on positive and negative discrimination and a product, and relates to the technical field of high-speed analog-to-digital conversion. On one hand, digital calibration and mismatch delay are carried out on the output signal of the calibrated sub analog-to-digital converter, on the other hand, the difference between the output signal of the reference sub analog-to-digital converter and the delay signal corresponding to the calibrated sub analog-to-digital converter is carried out, and derivation is carried out on the output signal of the multiplexer; determining the positive and negative of the sampling time mismatch according to the positive and negative of the sampling time mismatch and constructing two types of error sequences with different positive and negative conditions, and then calculating a mean value parameter which is opposite to the positive and negative of the sampling time mismatch error based on the error sequences so as to adjust the mismatch compensation amount to carry out next round of calibration; therefore, the sampling moment mismatch error is iteratively estimated from the three output signals of the dual-channel TIADC in a multi-round calibration mode, and calibration is further realized. The method is low in calculation complexity and suitable for the whole Nyquist input bandwidth.

Description

Technical Field

[0001] This invention relates to the field of high-speed analog-to-digital conversion technology, specifically to: 1. a method for mismatch calibration of sampling time of a dual-channel TIADC based on positive and negative discrimination; 2. a computer program product. Background Technology

[0002] A dual-channel TIADC (Time-Interleaved Analog-to-Digital Converter) employs two sub-analog-to-digital converters (denoted as Sub_ADC1~Sub_ADC2). See also... Figure 1 The overall sampling rate of the dual-channel TIADC is fs Sub_ADC1~Sub_ADC2 are respectively at frequencies with equal phase difference (180°) of... fs / 2 sampling clock drive (i.e.) fs The clock network splits the signal into two paths, one of which... fs / 2 directly affects Sub_ADC1, one path fs After a 180° phase adjustment of / 2, it is applied to Sub_ADC2 to the input signal. Vin Sampling is performed, and finally, the quantization results of two sub-analog-to-digital converters are output sequentially through a multiplexer (MUX) to obtain the final digital output. This can increase the overall sampling rate by 2 times without affecting the conversion accuracy, thus breaking the design limitations of traditional single-channel ADCs between sampling rate and conversion accuracy. However, mismatches between the analog and clock networks in a dual-channel TIADC are inevitable—including offset mismatch, gain mismatch, and sampling timing mismatch.

[0003] Among them, sampling time mismatch (represented as) τ The impact on dynamic performance increases significantly with increasing input frequency, introducing spurious components into the output spectrum, becoming a key limiting factor for high-speed TIADC applications. Specifically, in conjunction with... Figures 1 to 2 It demonstrates the dual-channel TIADC τ Causes: such as Figure 1 As shown, it illustrates the ideal sampling scenario—Sub_ADC1~Sub_ADC2 operate at a fixed sampling period. T s Alternate input signals Vin Sampling is performed, and the sampling times of the two sub-analog-to-digital converters are perfectly coordinated to jointly constitute a complete and distortion-free sampling of the input signal. For example... Figure 2As shown, this illustrates a real-world sampling scenario. In actual sampling, factors such as clock jitter and inconsistent channel circuit delays can cause sampling timing mismatches. Assuming Sub_ADC1 is used as the reference channel and its sampling timing is considered ideal with no mismatch, then Sub_ADC2 exhibits a sampling timing mismatch relative to Sub_ADC1. Since the ideal sampling point data of Sub_ADC2 cannot be directly obtained in the actual circuit, it is difficult to directly estimate the difference between the ideal signal of Sub_ADC2 and the signal with... τ Between the actual signals of Sub_ADC2 τ It's worth it. And, τ The direction is also uncertain, it may be to the left ( Figure 2 This demonstrates the case of left bias (where the actual sampled signal of Sub_ADC2 is prematurely sampled) and right bias (where the actual sampled signal of Sub_ADC2 is delayedly sampled), which also increases the difficulty of calibration. Summary of the Invention

[0004] Based on this, it is necessary to address the problem of positive or negative sampling time mismatch in existing dual-channel TIADC systems in the background technology, which requires calibration. Therefore, a dual-channel TIADC sampling time mismatch calibration method and product based on positive and negative discrimination is proposed.

[0005] This invention is achieved using the following technical solution: In a first aspect, the present invention discloses a dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination, which is used to calibrate the sampling time mismatch of the second analog-to-digital converter Sub_ADC2 with the first analog-to-digital converter Sub_ADC1 as a reference. τ .

[0006] The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination includes: Based on sampling period T s The output signals of Sub_ADC1, Sub_ADC2, and multiplexer MUX are acquired multiple times; based on the corresponding first-order signals of Sub_ADC1, Sub_ADC2, and MUX... i Secondary output signal y 1,i [ n ]、 y 2,i [ n ]、 y i [ n [Proceed to the first] i Wheel calibration; n Indicates the sampling point number; i ≥1.

[0007] Among them, the i Wheel calibration methods include: S100, according to the... i Wheel mismatch compensation C err,i-1 right y 2,i [ n Digital calibration is performed to obtain the calibration signal. y 2_cal,i [ n ];right y 2_cal,i [ n Interpolation delay is applied to delay the signal. T s Obtain the delayed signal y 2_int,i [ n ]; S200, Calculation y 1,i [ n ]、 y 2_int,i [ n The difference Δ y i [ n ];right y i [ n Perform differentiation; based on y i [ n The derivative of ], Δ y i [ n The sign of the symbol determines the value of the symbol. τ The positive and negative, and in y i [ n When the derivative of ] is positive, Δ y i [ n [Included in error sequence D1, in] y i [ n When the derivative of ] is negative, Δ y i [ n [Included in error sequence D2;] S300, Calculate the mean parameter based on D1 and / or D2 avg i and guarantee avg i and τ Keep the positive and negative signs opposite; avg i As an iteration parameterC err,i-1 Iteration yields the first... i +1 round of mismatch compensation C err,i ; like C err,i If convergence has been achieved, then the calibration is complete and will... C err,i As τ Otherwise, calibration is incomplete and the next step is required. i +1 round of calibration.

[0008] The implementation of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination is a method or process according to an embodiment of this disclosure.

[0009] Secondly, the present invention discloses a computer program product, comprising a computer program. When executed by a processor, the computer program implements the steps of the dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination as disclosed in the first aspect.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention performs digital calibration and mismatch delay on the output signal of the sub-analog-to-digital converter (ADC) being calibrated. Simultaneously, it subtracts the output signal of the reference ADC from the corresponding delayed signal of the ADC being calibrated, differentiates with respect to the output signal of the multiplexer, and determines the sign of the sampling time mismatch based on the signs of both. It then constructs two types of error sequences with different sign conditions. Based on these error sequences, it calculates a mean parameter that is opposite in sign to the sampling time mismatch error to adjust the mismatch compensation for the next round of calibration. Thus, without introducing an external reference, iteratively estimates the sampling time mismatch error from the three output signals of the dual-channel TIADC through multiple rounds of calibration, thereby achieving calibration. This invention does not introduce an external reference, has low computational complexity, and is applicable to the entire Nyquist input bandwidth.

[0011] 2. This invention also proposes a method to accelerate iteration. Based on the positive and negative signs of the derivative of the output signal of the multiplexer, two types of error sequences with different positive and negative conditions are constructed. By subtracting the two, the signals are superimposed in phase and the energy is multiplied, which is then used as the mean parameter to increase the adjustment amount of the mismatch compensation in each iteration and improve the convergence rate. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a signal distribution diagram of a dual-channel TIADC under ideal sampling conditions; Figure 2 This is a signal distribution diagram showing the left bias in actual sampling of a dual-channel TIADC. Figure 3 This is a data flow diagram of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination provided in Embodiment 1 of the present invention; Figure 4 for Figure 3 Data flow diagram for digital calibration; Figure 5 for Figure 3 Data flow diagram for mismatch parameter estimation using conventional methods; Figure 6 for Figure 3 Data flow diagram for mismatch parameter estimation when using acceleration method; Figure 7 Simulation results provided for Embodiment 2 of the present invention Figure One ; Figure 8 Simulation results provided for Embodiment 2 of the present invention Figure Two ; Figure 9 Simulation results provided for Embodiment 2 of the present invention Figure Three . Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0017] Example 1 Please refer to Figure 3 , Figure 3 The diagram shows the data flow of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination proposed in Example 1. It also illustrates the simplified process of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination.

[0018] As described in the background section... Figure 3 In this diagram, Sub_ADC1 represents the first sub-analog-to-digital converter (ADC) of the dual-channel TIADC, Sub_ADC2 represents the second sub-ADC of the dual-channel TIADC, Clock represents the clock network used by the dual-channel TIADC, and MUX represents the multiplexer used by the dual-channel TIADC. The sampling periods of Sub_ADC1 and Sub_ADC2 are the same, both being... T s In other words, T s In fact, it is the sampling period of the dual-channel TIADC.

[0019] It should be noted that this calibration method supports calibrating the sampling time mismatch of Sub_ADC2 using Sub_ADC1 as a reference across the entire Nyquist bandwidth. τ ,Right now τ It refers to Sub_ADC2 in relation to Sub_ADC1.

[0020] So, if Figure 3 As shown, a dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination specifically includes: Based on sampling period T s The output signals of Sub_ADC1, Sub_ADC2, and MUX are acquired multiple times.

[0021] It should be noted that, as mentioned in the background section, Sub_ADC1 and Sub_ADC2 respond to the input signal Vin Sampling is performed to obtain the corresponding output signal, which is then passed through a MUX to output the corresponding output signal. Vin It can be a single-tone signal or a multi-tone signal.

[0022] based on y 1,i [ n ]、 y 2,i [ n ]、 y i [ n [Proceed to the first] i Wheel calibration (i.e., estimating the amount of mismatch compensation); n Indicates the sampling point number; i ≥1.

[0023] in, y 1,i [ n ] is the first of Sub_ADC1 i Secondary output signal; y 2,i [ n ] is the first of Sub_ADC2 i Secondary output signal; y i [ n [The first] is the MUX i Secondary output signal.

[0024] It is important to note that n ∈[0, N ]; N This represents the total number of sampling points used in each output signal of a single sub-analog-to-digital converter; then n As the sampling point number, it is equivalent to a discrete-time index, pointing to... N The Middle n One sampling point.

[0025] Since the principle of each calibration round is similar, then taking the first round as an example... i Taking wheel calibration as an example, the specific methods include: S100, according to the... i Wheel mismatch compensation C err,i-1 right y 2,i [ n Digital calibration is performed to obtain the calibration signal. y 2_cal,i [ n ]; right y 2_cal,i [ n Interpolation delay is applied to delay the signal. T s Obtain the delayed signal y 2_int,i [ n ].

[0026] S100 is the one y 2,i [ n Progressive digital calibration and interpolation delay processing are performed to obtain... y 2_int,i [ n It will be closer to y 1,i [ n ].

[0027] Among them, see Figure 4 According to Article i Wheel mismatch compensation C err,i-1 right y 2,i [ n Digital calibration is performed to obtain the calibration signal. y 2_cal,i [ n The recommended process is as follows: First to y 2,i [ n Take the derivative and compare it with... C err,i-1 Multiply, then from y 2,i [ n Subtracting the product yields the result. y 2_cal,i [ n ].

[0028] For ease of understanding, the above process can be expressed by the following formula: ; In the formula, express y 2,i [ n The derivative of ]; t Indicates time; express y 2,i [ n In the n Approximate discrete derivative values ​​at each sampling point.

[0029] It is important to note that when i When =1, C err,0 Set it to 0; that is to say, in the actual first round of calibration, y 2_cal,1 [ n ]and y 2[ n They are the same.

[0030] In this embodiment 1: 1. It is recommended to use a DMC digital calibrator for calibration. y 2,i [ n Digital calibration is performed. Among other things, C err,i-1 As the first i The configuration parameters used by the DMC digital calibrator during round calibration. In other words, y 2,i [ n After configuration parameters are C err,i-1 After processing by the DMC digital calibrator, the result is y 2_cal,i [ n ].

[0031] The DMC digital calibrator includes: one derivative filter, one multiplier, and one subtractor. Referring to the principles above, the DMC digital calibrator contains: a derivative filter... y 2,i [ n Digital differentiation is performed to achieve differentiation; the multiplier converts the derivative filter output... y 2,i [ n The derivative of ] and C err,i-1 Multiplication; Subtraction will y 2,i [ n Subtract the multiplication result from the multiplier output to obtain y 2_cal,i [ n ].

[0032] Of course, other devices or digital circuits can also be used to implement the above digital calibration process, but the processing effect should be guaranteed to meet the requirements.

[0033] 2. It is recommended to use an interpolation delay filter. y 2,i [ n Interpolation delay is performed, which can... y 2,i [ n Overall implementation of one Ts The delay, to obtain y 2_int,i [ n ].

[0034] S200, Calculation y 1,i [ n ]、 y2_int,i [ n The difference Δ y i [ n ] (i.e., Δ y i [ n ] = y 1,i [ n ]- y 2_int,i [ n ]).

[0035] right y i [ n Perform differentiation (i.e.) , express y i [ n The derivative of ].

[0036] So, on the one hand: combining y i [ n The derivative of ], Δ y i [ n The sign of ] is used to determine τ The positive and negative.

[0037] Among them, due to y 1,i [ n ]、 y 2_int,i [ n ]、 y i [ n All of these are knowable, therefore y i [ n The derivative of ], Δ y i [ n The sign of ] can also be determined.

[0038] On the other hand: In y i [ n When the derivative of ] is positive, Δ y i [ n ] can be included in the error sequence D1, and Δ can also be included in the error sequence D1. y i [ n Simultaneously, placeholder data with a value of 0 is generated in D2 when the data is added to D1; y i [n When the derivative of ] is negative, Δ y i [ n ] can be included in the error sequence D2, and Δ can also be included in the error sequence D2. y i [ n Simultaneously, placeholder data with a value of 0 is generated in D1 when the data is assigned to D2.

[0039] Specifically, as can be seen from S100, y 2_int,i [ n It is close to y 1,i [ n The difference between the two can reflect the error of the sampling time mismatch. Therefore, by analyzing... y i [ n By determining the sign of the derivative of the signal, we can identify whether the sampling point is located at the rising or falling edge of the signal. This is because the sign of the error due to sampling mismatch differs depending on the slope direction: ① If y i [ n The derivative of ] is positive, indicating that the sampling point is located at the rising edge of the signal; ②, if y i [ n The derivative of [] is negative, indicating that the sampling point is located at the falling edge of the signal. Therefore, distinguishing in advance whether the sampling point is located at the rising or falling edge of the signal helps improve the accuracy of subsequent error extraction. D1 and D2 are in y i [ n The derivative of ] is constructed under different conditions of positive and negative values—D1 includes Δ at the sampling point on the rising edge. y i [ n Sample; D2 includes Δ at the falling edge sampling point. y i [ n ]sample.

[0040] It is important to note that y i [ n The sign of the derivative of ], Δ y i [ n The positive and negative of ] τ There is a specific relationship between positive and negative signs: exist y i [ n When the derivative of Δ is positive: y i [ nA positive value indicates that it carries [positive value]. τ The actual Sub_ADC2 signal precedes the ideal Sub_ADC2 signal, therefore τ It is a negative value; if Δ y i [ n A negative value indicates that it contains... τ The actual Sub_ADC2 signal lags behind the ideal Sub_ADC2 signal, therefore τ It is a positive value.

[0041] On the contrary, in y i [ n When the derivative of Δ is negative: y i [ n A positive value indicates that it carries [positive value]. τ The actual Sub_ADC2 signal lags behind the ideal Sub_ADC2 signal, therefore τ If Δ is positive; y i [ n A negative value indicates that it contains... τ The actual Sub_ADC2 signal precedes the ideal Sub_ADC2 signal, therefore τ It is a negative value.

[0042] Therefore, combining y i [ n The derivative of ], Δ y i [ n The sign of ] can determine τ Positive and negative: like y i [ n The derivative of ] is positive, Δ y i [ n If the value is positive, then τ It is a negative value; like y i [ n The derivative of ] is positive, Δ y i [ n If the value is negative, then τ It is a positive value; like y i [ n The derivative of ] is negative, Δ y i [ n If the value is positive, then τIt is a positive value; like y i [ n The derivative of ] is negative, Δ y i [ n If the value is negative, then τ It is a negative value.

[0043] In this embodiment 1: It is recommended to use a derivative filter. y i [ n The derivative is calculated and its sign is determined. Furthermore, to save hardware resources, the derivative filter used in the S200 can be reused in the DMC digital calibrator used in the S100.

[0044] S300, Calculate the mean parameter based on D1 and / or D2 avg i and guarantee avg i and τ The positive and negative signs remain opposite; Will avg i As an iteration parameter C err,i-1 Iteration yields the first... i +1 round of mismatch compensation C err,i ; like C err,i If convergence has been achieved, then the calibration is complete and will... C err,i As τ Then use the estimated τ (Right now C err,i ) to calibrate y 2,i [ n ]get y 2_cal,i [ n ], and then with y 1,i [ n When input together into the MUX, the MUX will sequentially output the quantization results of the two sub-analog-to-digital converters, thus obtaining the final digital output. y i [ n Otherwise, calibration is incomplete and the next step is required. i +1 round of calibration.

[0045] in, C err,i The iterative formula is: C err,i = C err,i-1 - μ * avg i ; In the formula, μ Represents the iteration coefficients; μ ∈(0,1), it is generally recommended to take 2. -1 .

[0046] Therefore, as shown in the above iterative formula, the iterative process is actually the mismatch compensation amount of the current round minus the weighted iterative parameters of the current round. Since the goal is to minimize the mismatch compensation amount... C err,i Eventually converges to τ This requires that the direction of iterative updates must conform to the negative feedback adjustment mechanism—assuming τ If the value is negative (i.e., Sub_ADC2 is sampled prematurely in the actual system), then to make the initial value 0... C err,i After multiple iterations, the value gradually decreased and approached the negative value. τ This requires that a positive number be subtracted from the iterative formula, that is, that the value at this point must be... avg i It must be greater than 0 and be a positive value. Similarly, if τ If it is a positive value (the overall delay sampling of Sub_ADC2 in the actual system), then in order to make C err,i For the iterative formula to converge by accumulating in the positive direction, a negative number must be subtracted from iterative formula. avg i It must be less than 0 and negative. Therefore, it is necessary to ensure... avg i and τ The positive and negative signs are kept opposite, thus ensuring C err,i It is a correct iteration.

[0047] In this embodiment 1: It is recommended to use the LMS adaptive engine filter. C err,i-1 The process is iterative, and the above calculation process is implemented based on the LMS algorithm. Among other things, avg i , μ These are the configuration parameters used by the LMS adaptive engine filter during the i-th round of calibration.

[0048] avg iThis directly reflects the overall trend of sampling time mismatch, effectively suppresses random noise, and provides a more stable and reliable gradient direction for subsequent iterations. It should be noted that... avg i The calculation can be performed using either a conventional method or an accelerated method.

[0049] ① See Figure 5 The conventional method is: Calculate the average of D1 separately and use it directly as... avg i .

[0050] Alternatively, calculate the average value of D2 separately, and then invert its polarity as the average value. avg i .

[0051] Combined with S200 τ From the conclusion of the positive and negative judgment, we can see that: D1 and τ The signs are always opposite, therefore the average value of its D1 is the same as... τ The signs are always opposite; the average value of D2 is... τ The sign of D2 is always the same, therefore the average value of D2 is the same as... τ The positive and negative values ​​are always the same.

[0052] It should be noted that the conventional approach can choose to use the average value based on D1 or the average value based on D2, but it is not recommended to switch after the iteration has started—as this will prolong the convergence time.

[0053] ② See Figure 6 The acceleration method is as follows: Calculate the difference between D1 and D2 (which can be represented by D, i.e., D = D1 - D2), and then calculate their average as the mean. avg i .

[0054] It is important to note that the signs of D and D1 remain the same, therefore D and τ The positive and negative values ​​are always opposite.

[0055] This acceleration method utilizes the sign opposite of the mismatch error at the sampling time of the rising and falling edges of the signal: at the rising edge of the signal, D1 and... τ It shows a negative correlation (i.e., D1∝- τ ); at the falling edge of the signal, D1 and τ A positive correlation (i.e., D1∝) τ Therefore, the constructed D will be superimposed in phase due to the opposite signs of D1 and D2, making its amplitude equivalent to the sum of the absolute values ​​of the original errors (i.e., |D1| + |D2|), thus achieving in-phase superposition of signals and energy multiplication, thereby... avgi The amplitude also increased. See also C err,i The iterative formula, the weighted iterative parameters are derived from avg i It is determined together with μ. Therefore, when... avg i After increasing, in the same μ In each iteration, the amount of adjustment for the mismatch compensation also increases, which directly improves the convergence rate of the algorithm. Theoretically, this mechanism can improve the convergence speed by about 100% compared to conventional methods, and it can be achieved without additional hardware overhead, simply through the difference and averaging operations in the digital domain.

[0056] Example 2 This embodiment 2 verifies the method of embodiment 1: A dual-channel TIADC was modeled using MATLAB software. Parameters such as input signal, sampling frequency, and time mismatch were externally set. The results before and after processing using the method in Example 1 were then compared. N Take 2 12 =2096.

[0057] 1. See Figure 7 The diagram shows a comparison of the output signal spectrum before and after calibration of the single-tone signal. It can be seen that the spurious signals caused by sampling time mismatch are well suppressed, indicating that the calibration is successful; the SNDR (signal-to-noise ratio) has increased from 24.79dB to 62.12dB; and the SFDR (spurious-free dynamic range) has increased from 24.79dB to 87.94dB.

[0058] 2. See Figure 8 The diagram shows a comparison of the output signal spectrum before and after calibration of the multi-tone signal. It reveals that all spurious signals caused by sampling time mismatch are well suppressed, indicating that the calibration was successful and that the overall SNDR and SFDR are improved at different input frequencies.

[0059] 3. See Figure 9 The diagram shows the convergence curve of the mismatch compensation. It can be seen that: when using the conventional method, approximately 164K sampling points are required for the mismatch compensation to finally converge; when using the accelerated method, approximately 82K sampling points are required for the mismatch compensation to finally converge.

[0060] Example 3 This embodiment 3 discloses a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination disclosed in embodiment 1.

[0061] The computer equipment can be either a mobile terminal or a fixed terminal. Examples of the former include mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), and in-vehicle terminals (such as in-vehicle navigation terminals); examples of the latter include digital TVs and desktop computers.

[0062] This embodiment 3 also discloses a readable storage medium that stores computer program instructions. When the computer program instructions are read and run by a processor, the steps of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination disclosed in embodiment 1 are executed.

[0063] The readable storage medium may include, but is not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the above.

[0064] This embodiment 3 also discloses a computer program product, including a computer program. When executed by a processor, this computer program implements the steps of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination disclosed in embodiment 1.

[0065] It should be noted that the computer program used to execute the above can be written in one or more programming languages ​​or a combination thereof. These programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, and C++—as well as conventional procedural programming languages—such as C or similar languages. The computer program can be executed entirely on the user's computer, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer through any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN).

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination, which is used to calibrate the sampling time mismatch of the second analog-to-digital converter Sub_ADC2 with the first analog-to-digital converter Sub_ADC1 as a reference. τ Its characteristics are, It includes: Based on sampling period T s The output signals of Sub_ADC1, Sub_ADC2, and multiplexer MUX are acquired multiple times; based on the corresponding first-order signals of Sub_ADC1, Sub_ADC2, and MUX... i Secondary output signal y 1,i [ n ]、 y 2,i [ n ]、 y i [ n [Proceed to the first] i Wheel calibration; n Indicates the sampling point number; i ≥1; Among them, the i Wheel calibration methods include: S100, according to the... i Wheel mismatch compensation C err,i-1 right y 2,i [ n Digital calibration is performed to obtain the calibration signal. y 2_cal,i [ n ];right y 2_cal,i [ n Interpolation delay is applied to delay the signal. T s Obtain the delayed signal y 2_int,i [ n ]; S200, Calculation y 1,i [ n ]、 y 2_int,i [ n The difference Δ y i [ n ];right y i [ n Perform differentiation; Combination y i [ n The derivative of ], Δ y i [ n The sign of ] is used to determine τ The positive and negative, and in y i [ n When the derivative of ] is positive, Δ y i [ n [Included in error sequence D1, in] y i [ n When the derivative of ] is negative, Δ y i [ n [Included in error sequence D2;] S300, Calculate the mean parameter based on D1 and / or D2 avg i and guarantee avg i and τ Keep the positive and negative signs opposite; avg i As an iteration parameter C err,i-1 Iteration yields the first... i +1 round of mismatch compensation C err,i ; like C err,i If convergence has been achieved, then the calibration is complete and will... C err,i As τ Otherwise, calibration is incomplete and the next step is required. i +1 round of calibration.

2. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1, characterized in that, In S100, according to the first i Wheel mismatch compensation C err,i-1 right y 2,i [ n Digital calibration is performed to obtain the calibration signal. y 2_cal,i [ n ]include: First to y 2,i [ n Take the derivative and compare it with... C err,i-1 Multiply, then from y 2,i [ n Subtracting the product yields the result. y 2_cal,i [ n ].

3. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1 or 2, characterized in that, In S100, a DMC digital calibrator is used for... y 2,i [ n Perform digital calibration; in, C err,i-1 As the first i The configuration parameters used by the DMC digital calibrator during round calibration; i When =1, C err,0 Set to 0; Using interpolation delay filters y 2,i [ n Interpolation delay is applied; In S200, a derivative filter is used for... y i [ n Find the derivative and determine its sign.

4. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1, characterized in that, The derivative filter used in the S200 is multiplexed within the DMC digital calibrator used in the S100.

5. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1, characterized in that, In S200, if y i [ n The derivative of ] is positive, Δ y i [ n If the value is positive, then τ It is a negative value; like y i [ n The derivative of ] is positive, Δ y i [ n If the value is negative, then τ It is a positive value; like y i [ n The derivative of ] is negative, Δ y i [ n If the value is positive, then τ It is a positive value; like y i [ n The derivative of ] is negative, Δ y i [ n If the value is negative, then τ It is a negative value.

6. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1, characterized in that, In S200, if y i [ n The derivative of ] is positive, when Δ y i [ n Simultaneously, placeholder data with a value of 0 is generated in D2 when Δ is added to D1; otherwise, when Δ is added to D2, placeholder data with a value of 0 is generated in D2. y i [ n Simultaneously, placeholder data with a value of 0 is generated in D1 when the data is assigned to D2.

7. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 6, characterized in that, In S300, calculations are performed using either conventional or accelerated methods. avg i ; The conventional method is to calculate the average value of D1 separately and use it directly as... avg i Alternatively, calculate the average value of D2 separately, and then invert its polarity as the average value. avg i ; The acceleration method is as follows: calculate the difference between D1 and D2, and then take their average value as the result. avg i .

8. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 1, characterized in that, S300, C err,i The iterative formula is: C err,i = C err,i-1 - μ * avg i ； In the formula, μ This represents the iteration coefficient.

9. The dual-channel TIADC sampling time mismatch calibration method based on positive / negative discrimination according to claim 8, characterized in that, Using LMS adaptive engine filter C err,i-1 Perform iterations; in, avg i , μ These are the configuration parameters used by the LMS adaptive engine filter during the i-th round of calibration.

10. A computer program product, characterized in that, Includes a computer program; when the computer program is executed by a processor, it implements the steps of the dual-channel TIADC sampling time mismatch calibration method based on positive and negative discrimination as described in any one of claims 1-9.

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