CN107147392B - TIADC mismatch error calibration method based on adaptive filtering and Taylor series - Google Patents
TIADC mismatch error calibration method based on adaptive filtering and Taylor series Download PDFInfo
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Abstract
The invention discloses a TIADC mismatch error calibration method based on adaptive filtering and Taylor series, which comprises the steps of channel signal acquisition, estimation of bias error of sampling data of a channel 1, correction of bias error of the channel 1, fractional delay filtering, estimation of gain error and time phase error of the channel 1 by using an adaptive filter, and correction of gain error and time phase error of the channel 1. The invention has the characteristics of less sampling points, less calculated amount and the like, and is suitable for portable acquisition equipment such as a handheld oscilloscope and the like.
Description
Technical Field
The invention relates to a TIADC mismatch error calibration method, in particular to a TIADC mismatch error calibration method based on adaptive filtering and Taylor series, and belongs to the field of instruments.
Background
Parallel sampling systems (TIADC) can produce offset errors, gain errors, and time phase errors due to non-ideal characteristics of the devices. The two-channel TIADC model is shown in FIG. 1 below, with a sampling rate fsWith a sampling period of Ts. Parameter g0,o0,Δt0Gain error, bias error and time phase error of channel 0, respectively, parameter g1,o1,Δt1Respectively, gain error, bias error, and time phase error for channel 1. In actual operation, channel 0 is used as a reference channel, and gain error, bias error and time phase error g of channel 1 are required1,o1,Δt1Estimate and correct to finally make g1=g0,o1=o0And Δ t1=Δt0Thereby completing the mismatch error correction for the entire system.
As shown in fig. 1, the standard signal source simultaneously inputs channel 0 and channel 1, and with channel 0 as a reference, the data of the two channels after discretization by the ADC is represented as follows:
wherein X0(k) Sample data, X, represented as channel 01(k) Represented as sampled data for channel 1. The relationship between data for channel 1 and data for channel 0 can be expressed as
X1(k)=(1+g1)X0(k+0.5-Δt1/2)+o1 (2)
The correction techniques for the three major errors in the TIADC focus on two large directions, namely the non-blind estimation and correction algorithm and the blind estimation and correction algorithm for mismatch errors. The non-blind estimation and correction algorithm of mismatch errors needs to inject excitation signals into the acquisition system periodically to obtain error parameters of the system, and the non-blind estimation and correction algorithm influences the real-time performance of the operation of the acquisition system. The blind estimation and correction algorithm does not need to inject excitation signals into the acquisition system regularly, and the estimation and correction of system error parameters are completed while the acquisition system measures the measured signals. The existing blind estimation and correction algorithm mostly adopts a closed loop mode to estimate parameters in the estimation process of three main errors. Although the blind estimation and correction algorithm does not need to inject excitation signals into the acquisition system regularly, the sampling point number required by the existing blind estimation and correction algorithm is very large. The number of sampling points needed in the one-time estimation and correction process is mostly more than 10000, and the calculated amount is complex, so that higher requirements are generated on the calculation and storage of an acquisition system, and the method is not suitable for being used in portable instruments such as a handheld oscilloscope. In fact, for a TIADC system with a good hardware design, three mismatch errors of the system do not change drastically in a short time, and system parameters obtained by calculation after one correction of a non-blind estimation correction algorithm can still bring improvement of a signal-to-noise ratio to the whole TIADC system within a certain time.
Disclosure of Invention
The invention aims to provide a TIADC mismatch error calibration method based on adaptive filtering and Taylor series.
In order to solve the technical problems, the invention adopts the technical scheme that:
a TIADC mismatch error calibration method based on adaptive filtering and Taylor series comprises the following steps:
step 1: channel signal acquisition: a standard signal source X (t) sin (w)int) simultaneously inputting a channel 0 and a channel 1; angular frequency w of standard signal sourceinSatisfies the following conditions:
Tsfor the sample interval time, channel 0 is the reference channel, and channel 0 and channel 1 are separated by the sample interval time TsInterleaved sampling, channel 1 samples data X1(k) Comprises the following steps:
X1(k)=(1+g1)X0(k+0.5-Δt1/2)+o1 (2)
wherein X0(k) Is the sampled data of channel 0, g1,o1,Δt1Respectively is the gain error, the offset error and the time phase error of the channel 1, and k is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter;
Wherein E is an averaging operation;
and step 3: correction of offset error for channel 1:
and 4, step 4: fractional delay filtering: the offset error corrected sampling data of the channel 1Filtering by an input fractional delay filter, wherein the system transfer function of the fractional delay filter is as follows:
wherein h isid(k) K is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter, and M is the length of the filter;
the first order Taylor series expansion of the sampled data of the channel 1 after the fractional delay filtering processing is
In the formulaIs a first order Taylor series expansion, X 'of the sampled data of channel 1 after fractional delay filtering processing'0(k) Sampled data X for channel 00(k) The calculation method of the derivative of (2) is:
X'0(k)=[-X0(k+2)+8X0(k+1)-8X0(k-1)+X0(k-2)]/[(48×π×f0)/fs] (7)
in the formula f0Is the frequency of the input signal to be measured, fsIs the sampling rate of the TIADC system;
and 5: estimation of the gain error of channel 1 with an adaptive filterg1And the time phase error Δ t1。
The adaptive filter includes a weighting coefficient w0Adjusting unit, weighting factor w1Adjusting part, first to second accumulators, sampling data X of channel 00(k) Input weighting factor w0Adjustment component, derivative X 'of sampled data of channel 0'0(k) Input weighting factor w1Adjusting means, weighting factor w0Adjusting unit, weighting factor w1The output of the adjusting component is sent to a first accumulator, and the output of the first accumulator and the first-order Taylor series expansion of the sampling data of the channel 1 after the fractional delay filtering processingSubtracted in a second accumulator, the output of which is used to control the weighting factor w0Adjusting unit, weighting factor w1An adjusting component for adjusting the weighting coefficient w according to a preset adjusting step length0And a weighting factor w1Until the mean square error of the output of the second accumulator is not reduced;
gain error g1The estimated values of (c) are:
time phase error Δ t1The estimated values of (c) are:
step 6: correction of gain error and time phase error for channel 1:
in the formula (I), the compound is shown in the specification,for the corrected sample data of channel 1,for the system transfer function of the time phase error correction filter,in order to obtain the final calibration data,gain error g for channel 11Is determined by the estimated value of (c),is a time phase error Δ t1An estimate of (d).
The TIADC mismatch error calibration method based on the adaptive filtering and the Taylor series comprises 1 reference channel and more than 1 calibration channel, and each calibration channel adopts the same calibration method as the channel 1.
The technical effect obtained by adopting the technical scheme is as follows:
1. the invention has the characteristics of less sampling points, less calculated amount and the like, and is suitable for portable acquisition equipment such as a handheld oscilloscope and the like.
2. The invention is equally applicable to multi-channel TIADC systems.
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The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
FIG. 1 is a TIADC system model;
FIG. 2 is a flow chart of the present invention;
fig. 3 is a schematic block diagram of the adaptive filter of the present invention.
Detailed Description
Example 1:
as shown in fig. 2, a TIADC mismatch error calibration method based on adaptive filtering and taylor series includes the following steps:
step 1: channel signal acquisition: a standard signal source X (t) sin (w)int) simultaneously inputting a channel 0 and a channel 1; angular frequency w of standard signal sourceinSatisfies the following conditions:
Tsfor the sample interval time, channel 0 is the reference channel, and channel 0 and channel 1 are separated by the sample interval time TsInterleaved sampling, channel 1 samples data X1(k) Comprises the following steps:
X1(k)=(1+g1)X0(k+0.5-Δt1/2)+o1 (2)
wherein X0(k) Is the sampled data of channel 0, g1,o1,Δt1Respectively is the gain error, the offset error and the time phase error of the channel 1, and k is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter;
Wherein E is an averaging operation;
and step 3: correction of offset error for channel 1:
and 4, step 4: fractional delay filtering: the offset error corrected sampling data of the channel 1Filtering by an input fractional delay filter, wherein the system transfer function of the fractional delay filter is as follows:
wherein h isid(k) K is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter, and M is the length of the filter;
ignoring ripples in the passband of the fractional delay filter, the sampled data of the channel 1 after being processed by the fractional delay filtering is:
due to Δ t1Per 2 itself is a term much smaller than 1, and for a hardware well-designed TIADC system, Δ t is usually the case1The/2 is less than or equal to 0.05. So that the Taylor series expansion is performed on the formula (6) and terms with more than two orders are ignored to obtain
The first order Taylor series expansion of the sampled data of the channel 1 after the fractional delay filtering processing is
In the formulaIs a first order Taylor series expansion, X 'of the sampled data of channel 1 after fractional delay filtering processing'0(k) Sampled data X for channel 00(k) The derivative of (2) is calculated by using the sampling data of the channel 0, and the calculation method is as follows:
X'0(k)=[-X0(k+2)+8X0(k+1)-8X0(k-1)+X0(k-2)]/[(48×π×f0)/fs] (8)
in the formula f0Is the frequency of the input signal to be measured, fsIs the sampling rate of the TIADC system;
and 5: estimation of the bias error g for channel 1 with an adaptive filter1And the time phase error Δ t1。
As shown in FIG. 3, the adaptive filter includes a weighting coefficient w0Adjusting unit, weighting factor w1Adjusting part, first to second accumulators, sampling data X of channel 00(k) Input weighting factor w0Adjustment component, derivative X 'of sampled data of channel 0'0(k) Input weighting factor w1Adjusting means, weighting factor w0Adjusting unit, weighting factor w1The output of the adjusting component is sent to a first accumulator, and the output of the first accumulator and the first-order Taylor series expansion of the sampling data of the channel 1 after the fractional delay filtering processingSubtracted in a second accumulator, the output of which is used to control the weighting factor w0Adjusting unit, weighting factor w1An adjusting component for adjusting the weighting coefficient w according to a preset adjusting step length0And a weighting factor w1Until the mean square error of the output of the second accumulator is not reduced;
gain error g1The estimated values of (c) are:
time phase error Δ t1The estimated values of (c) are:
step 6: correcting the placement error and time phase error of channel 1:
in the formula (I), the compound is shown in the specification,for the corrected sample data of channel 1,for the system transfer function of the time phase error correction filter,in order to obtain the final calibration data,gain error g for channel 11Is determined by the estimated value of (c),is a time phase error Δ t1An estimate of (d).
Example 2: the difference from the embodiment 1 is that the channel 2 is also included, and the channel 2 adopts the same calibration method as the channel 1 in the embodiment 1.
Claims (3)
1. A TIADC mismatch error calibration method based on adaptive filtering and Taylor series is characterized in that: the method comprises the following steps:
step 1: channel signal acquisition: a standard signal source X (t) sin (w)int) simultaneously inputting a channel 0 and a channel 1; angular frequency w of standard signal sourceinSatisfies the following conditions:
Tsfor the sample interval time, channel 0 is the reference channel, and channel 0 and channel 1 are separated by the sample interval time TsInterleaved sampling, communicationTrack 1 sample data X1(k) Comprises the following steps:
X1(k)=(1+g1)X0(k+0.5-Δt1/2)+o1 (2)
wherein X0(k) Is the sampled data of channel 0, g1,o1,Δt1Respectively is the gain error, the offset error and the time phase error of the channel 1, and k is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter;
Wherein E is an averaging operation;
and step 3: correction of offset error for channel 1:
and 4, step 4: fractional delay filtering: the offset error corrected sampling data of the channel 1Filtering by an input fractional delay filter, wherein the system transfer function of the fractional delay filter is as follows:
wherein h isid(k) K is the number of discrete sampling points of the channel 1, the channel 0 and the fractional delay filter, and M is the length of the filter;
the first order Taylor series expansion of the sampled data of the channel 1 after the fractional delay filtering processing is
In the formulaIs a first order Taylor series expansion, X 'of the sampled data of channel 1 after fractional delay filtering processing'0(k) Sampled data X for channel 00(k) The calculation method of the derivative of (2) is:
X'0(k)=[-X0(k+2)+8X0(k+1)-8X0(k-1)+X0(k-2)]/[(48×π×f0)/fs] (7)
in the formula f0Is the frequency of the input signal to be measured, fsIs the sampling rate of the TIADC system;
and 5: estimation of the gain error g of channel 1 with an adaptive filter1And the time phase error Δ t1;
Step 6: correction of gain error and time phase error for channel 1:
in the formula (I), the compound is shown in the specification,for the corrected sample data of channel 1,for the system transfer function of the time phase error correction filter,in order to obtain the final calibration data,gain error g for channel 11Is determined by the estimated value of (c),is a time phase error Δ t1An estimate of (d).
2. The adaptive filtering and taylor series based TIADC mismatch error calibration method of claim 1, wherein:
the adaptive filter in step 5 comprises a weighting coefficient w0Adjusting unit, weighting factor w1Adjusting part, first to second accumulators, sampling data X of channel 00(k) Input weighting factor w0Adjustment component, derivative X 'of sampled data of channel 0'0(k) Input weighting factor w1Adjusting means, weighting factor w0Adjusting unit, weighting factor w1The output of the adjusting component is sent to a first accumulator, and the output of the first accumulator and the first-order Taylor series expansion of the sampling data of the channel 1 after the fractional delay filtering processingSubtracted in a second accumulator, the output of which is used to control the weighting factor w0Adjusting unit, weighting factor w1An adjusting component for adjusting the weighting coefficient w according to a preset adjusting step length0And a weighting factor w1Until the mean square error of the output of the second accumulator is not reduced;
gain error g1The estimated values of (c) are:
time phase error Δ t1The estimated values of (c) are:
3. the adaptive filtering and taylor series based TIADC mismatch error calibration method of claim 1, wherein: the method comprises 1 reference channel and more than 1 calibration channel, and each calibration channel adopts the same calibration method as the channel 1.
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CN108494403B (en) * | 2018-03-26 | 2022-02-15 | 中国人民解放军国防科技大学 | Double-channel TIADC sampling holding circuit mismatch self-adaptive calibration method |
CN108631315A (en) * | 2018-07-11 | 2018-10-09 | 太原科技大学 | Repetitive controller fractional delay filter design method based on Taylor series expansion |
CN110266311B (en) * | 2019-05-29 | 2020-12-25 | 中国科学技术大学 | TIADC system mismatch error calibration method, device, equipment and medium |
CN110896334B (en) * | 2019-11-06 | 2022-02-15 | 天津津航计算技术研究所 | High-precision channel calibration method based on channel phase noise statistics |
CN113063978B (en) * | 2021-06-03 | 2021-08-03 | 深圳市鼎阳科技股份有限公司 | Digital oscilloscope and sampling time mismatch correction method |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008002214A1 (en) * | 2006-06-30 | 2008-01-03 | Signal Processing Devices Sweden Ab | Time- interleaved analog-to-digital converter system |
CN102291141A (en) * | 2011-04-22 | 2011-12-21 | 合肥工业大学 | Time-interleaved split ADC (Analog-to-Digital Converter) calibration structure without redundant channel and adaptive calibration method thereof |
CN102857225A (en) * | 2012-09-13 | 2013-01-02 | 电子科技大学 | Mismatch error calibration method for multi-channel high-speed parallel alternate sampling system |
CN103746695A (en) * | 2013-12-27 | 2014-04-23 | 电子科技大学 | Mismatch correction method of time-interleaved analog-to-digital converter inter-channel sampling time |
CN103971029A (en) * | 2014-05-30 | 2014-08-06 | 电子科技大学 | Alternant iteration method for DOA (direction of arrival) estimation under grid mismatch |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7961123B2 (en) * | 2009-07-09 | 2011-06-14 | Texas Instruments Incorporated | Time-interleaved analog-to-digital converter |
-
2017
- 2017-05-05 CN CN201710311363.0A patent/CN107147392B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008002214A1 (en) * | 2006-06-30 | 2008-01-03 | Signal Processing Devices Sweden Ab | Time- interleaved analog-to-digital converter system |
CN102291141A (en) * | 2011-04-22 | 2011-12-21 | 合肥工业大学 | Time-interleaved split ADC (Analog-to-Digital Converter) calibration structure without redundant channel and adaptive calibration method thereof |
CN102857225A (en) * | 2012-09-13 | 2013-01-02 | 电子科技大学 | Mismatch error calibration method for multi-channel high-speed parallel alternate sampling system |
CN103746695A (en) * | 2013-12-27 | 2014-04-23 | 电子科技大学 | Mismatch correction method of time-interleaved analog-to-digital converter inter-channel sampling time |
CN103971029A (en) * | 2014-05-30 | 2014-08-06 | 电子科技大学 | Alternant iteration method for DOA (direction of arrival) estimation under grid mismatch |
Non-Patent Citations (1)
Title |
---|
宽带信号采样若干关键技术研究;王亚军;《中国博士学位论文全文数据库 信息科技辑》;20140115(第01期);第I136-105页 * |
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