High-precision calibration system and method for multi-channel ADC

Abstract

This invention provides a high-precision calibration system and method for a multi-channel ADC, relating to the field of communication technology. The system includes a digital transmitter, a DAC module, a calibration loop, and a multi-channel ADC module connected sequentially. It also includes a correlation module, a parameter estimation module, and a compensation module. The correlation module is connected to both the digital transmitter and the multi-channel ADC module. The parameter estimation module is connected to both the correlation module and the compensation module. The compensation module is also connected to the multi-channel ADC module. The calibration loop connects the end of the transmit link and the beginning of the receive link. This invention combines the analog and digital domains through the calibration loop, achieving deviation compensation by performing a single cross-correlation operation and parameter estimation on the local reference signal and multiple sub-signals. This method eliminates the need to redesign analog circuits and does not rely on external instruments for calibration. It features low hardware complexity, high stability, and a short estimation cycle, without affecting normal service operation.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a high-precision calibration system and method for a multi-channel ADC. Background Technology

[0002] With the rapid development of wireless communication technologies such as 5G and Wi-Fi 6 / 7, the demand for high-resolution, high-bandwidth ADCs (Analog-to-Digital Converters) is increasing, with sampling rates rising from hundreds of megasamples per second (Msps) to gigabits per second (Gsps). To meet the high-speed sampling requirements, multi-channel interpolation ADC architectures are widely adopted. This architecture samples through independent multiple ADC channels (such as 4 / 8 / 16 channels) in a time-interleaved manner and uses a phase-shifted clock to drive each channel to work in turn, thereby increasing the overall system sampling rate to several times that of a single channel.

[0003] The sampling signals from multiple sub-channels are merged into a single signal (the same signal) through clock synchronization, significantly improving the system sampling rate. However, due to the inherent characteristics of analog devices, distortions such as gain deviation, bias voltage deviation, and sampling clock deviation are introduced between sub-channels, leading to a deterioration in overall signal quality. Therefore, error detection and compensation for multi-channel ADCs are particularly important.

[0004] Currently, the commonly used calibration methods in the industry mainly fall into three categories: First, analog self-test systems, which correct the quality of the sampled signal by adjusting ADC parameters, but require redesigning the analog circuit, resulting in insufficient accuracy and low reliability; second, digital domain back-end compensation based on adaptive algorithms such as LMS (Least Mean Squares) or RLS (Recursive Least Squares), which can dynamically estimate errors, but has high hardware implementation complexity and is prone to convergence stability issues; and third, methods using statistical algorithms and iterative feedback, which extract error parameters by inputting a fixed voltage or sequence signal, and after compensation, use a feedback network to judge the error elimination effect, thereby correcting or converging, but this method has problems such as long estimation cycle and high complexity, and may block normal business operations. Summary of the Invention

[0005] The purpose of this invention is to provide a high-precision calibration system and method for multi-channel ADCs, so as to at least solve one of the above-mentioned problems.

[0006] In a first aspect, the present invention provides a high-precision calibration system for a multi-channel ADC, comprising a digital transmitter, a DAC module, a calibration loop, and a multi-channel ADC module connected in sequence, and further comprising a correlation module, a parameter estimation module, and a compensation module. The correlation module is connected to the digital transmitter and the multi-channel ADC module respectively, the parameter estimation module is connected to the correlation module and the compensation module respectively, and the compensation module is also connected to the multi-channel ADC module; the calibration loop is used to connect the end of the transmit link and the front end of the receive link.

[0007] The digital transmitter generates a calibration signal when it receives a self-calibration command and sends the corresponding local reference signal to the relevant module. The calibration signal passes through the DAC module and the calibration loop to reach the multi-path ADC module. The local reference signal includes an odd-path reference signal and an even-path reference signal obtained by splitting the calibration signal into odd and even paths.

[0008] The multi-channel ADC module is used to output multiple sub-signals corresponding to the calibration signal to the relevant modules;

[0009] The correlation module is used to perform cross-correlation calculations on the local reference signal and multiple sub-signals to obtain the correlation results, and then send the correlation results to the parameter estimation module.

[0010] The parameter estimation module is used to calculate the amplitude deviation and sampling time deviation of the odd and even paths in the multi-path sub-signals based on the relevant results, obtain the deviation parameter data, and send the deviation parameter data to the compensation module.

[0011] The compensation module is used to compensate for the amplitude deviation of the odd and even channels and the sampling time deviation of the multi-channel sub-signals based on the deviation parameter data.

[0012] In an optional implementation, the multi-path ADC includes a four-path ADC, and the multiple sub-signals include in-phase even-path signals and odd-path signals, as well as orthogonal even-path signals and odd-path signals; the relevant modules are specifically used for:

[0013] The odd-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, to obtain the in-phase four-path cross-correlation result;

[0014] The odd-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, and the even-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, to obtain the orthogonal four-path cross-correlation results.

[0015] In an optional implementation, the digital transmitter includes a sine wave sequence generator, and the calibration signal includes a sine wave sequence; the parameter estimation module is specifically used for:

[0016] For the in-phase four-way cross-correlation results and the orthogonal four-way cross-correlation results respectively, the amplitude deviation and sampling time deviation of the odd and even paths are calculated using the following formulas:

[0017] ;

[0018] ;

[0019] Where, ∆ t Indicates the sampling time deviation, ∆ A Indicates amplitude deviation. f This represents the frequency of the sinusoidal wave sequence. t s Indicates the sampling clock period. Indicates even-path signal AND path reference signal Cross-correlation results Indicates odd-path signal AND path reference signal The cross-correlation results Indicates even-path signal Reference signal with Qilu The cross-correlation results Indicates odd-path signal Reference signal with Qilu The cross-correlation results.

[0020] In an optional implementation, the compensation module includes two compensation units, one of which is located in one of the output paths of the in-phase even-path signal and the odd-path signal, and the other of which is located in one of the output paths of the orthogonal even-path signal and the odd-path signal.

[0021] The compensation unit includes an amplitude compensator and a fractional time delay filter. The amplitude compensator is used to compensate for the amplitude deviation between the odd and even paths, and the fractional time delay filter is used to compensate for the sampling time deviation between the odd and even paths.

[0022] In an optional implementation, the system further includes a self-calibration trigger module connected to the digital transmitter, which sends a self-calibration command to the digital transmitter when a self-calibration event is detected.

[0023] In an optional implementation, the self-calibration event includes one or more of the following: the real-time temperature value exceeds the preset temperature range, a specified time is reached, and a manual calibration command is received. The self-calibration trigger module includes one or more of the following: a temperature sensor, a timer, and a manual trigger button.

[0024] In an alternative implementation, the calibration loop includes interconnected power amplifiers and low-noise amplifiers.

[0025] Secondly, the present invention provides a high-precision calibration method for a multi-channel ADC, applicable to the high-precision calibration system for a multi-channel ADC in any of the foregoing embodiments; the method includes:

[0026] When the digital transmitter receives a self-calibration command, it generates a calibration signal and sends the corresponding local reference signal to the relevant module. The calibration signal passes through the DAC module and the calibration loop to reach the multi-path ADC module. The local reference signal includes the odd-path reference signal and the even-path reference signal obtained by splitting the calibration signal into odd and even paths.

[0027] The multi-path ADC module outputs multiple sub-signals corresponding to the calibration signal to the relevant modules;

[0028] The correlation module performs cross-correlation calculations on the local reference signal and multiple sub-signals to obtain the correlation results, and then sends the correlation results to the parameter estimation module;

[0029] Based on the relevant results, the parameter estimation module calculates the amplitude deviation and sampling time deviation of the odd and even paths in the multi-path sub-signals, obtains the deviation parameter data, and sends the deviation parameter data to the compensation module.

[0030] The compensation module performs amplitude deviation compensation and sampling time deviation compensation for multiple sub-signals based on the deviation parameter data.

[0031] In an optional implementation, the multi-path ADC includes a four-path ADC, and the multiple sub-signals include in-phase even-path signals and odd-path signals, as well as orthogonal even-path signals and odd-path signals; the correlation module performs cross-correlation operations on the local reference signal and the multiple sub-signals to obtain the correlation results, including:

[0032] The odd-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, to obtain the in-phase four-path cross-correlation result;

[0033] The odd-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, and the even-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, to obtain the orthogonal four-path cross-correlation results.

[0034] In an optional implementation, the system further includes a self-calibration trigger module connected to a digital transmitter; the method further includes:

[0035] When the self-calibration trigger module detects a self-calibration event, it sends a self-calibration command to the digital transmitter.

[0036] The multi-channel ADC high-precision calibration system and method provided by this invention includes a digital transmitter, a DAC module, a calibration loop, and a multi-channel ADC module connected in sequence. It also includes a correlation module, a parameter estimation module, and a compensation module. The correlation module is connected to both the digital transmitter and the multi-channel ADC module. The parameter estimation module is connected to both the correlation module and the compensation module. The compensation module is also connected to the multi-channel ADC module. The calibration loop connects the end of the transmit link and the beginning of the receive link. The digital transmitter generates a calibration signal upon receiving a self-calibration command and sends the corresponding local reference signal to the correlation module. The calibration signal passes through the DAC module and the calibration loop to reach… The multi-path ADC module uses a local reference signal consisting of an odd-path reference signal and an even-path reference signal obtained by splitting the calibration signal into odd and even paths. The multi-path ADC module outputs multiple sub-signals corresponding to the calibration signal to a correlation module. The correlation module performs cross-correlation operations on the local reference signal and the multiple sub-signals to obtain the correlation result, which is then sent to a parameter estimation module. The parameter estimation module calculates the amplitude deviation and sampling time deviation of the odd and even paths in the multiple sub-signals based on the correlation result, obtaining deviation parameter data, which is then sent to a compensation module. The compensation module compensates for the amplitude deviation of the odd and even paths and the sampling time deviation of the multiple sub-signals based on the deviation parameter data. This calibration loop combines the analog and digital domains, achieving deviation compensation through a single cross-correlation operation and parameter estimation of the local reference signal and multiple sub-signals. This method eliminates the need to redesign analog circuits and does not rely on external instruments for calibration, resulting in low hardware complexity, high stability, and a short estimation cycle without affecting normal business operations. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a multi-channel ADC high-precision calibration system provided in an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of another multi-channel ADC high-precision calibration system provided in an embodiment of the present invention;

[0040] Figure 3 This is a flowchart illustrating a high-precision calibration method for a multi-channel ADC provided in an embodiment of the present invention.

[0041] Figure 4 This is a flowchart illustrating another high-precision calibration method for a multi-channel ADC provided in an embodiment of the present invention.

[0042] Icons: 100 - Self-calibration trigger module; 110 - Digital transmitter; 111 - Sine wave sequence generator; 120 - DAC module; 130 - Calibration loop; 131 - Up-converter; 132 - Power amplifier; 133 - Low-noise amplifier; 134 - Down-converter; 140 - Multi-channel ADC module; 141 - Four-channel ADC; 150 - Correlation module; 160 - Parameter estimation module; 170 - Compensation module; 171 - Amplitude compensator; 172 - Fractional delay filter. Detailed Implementation

[0043] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0044] In the implementation of multi-channel ADCs, several factors contribute to discrepancies. These include inherent tolerances in semiconductor manufacturing processes, the drift of capacitor and resistor parameters in analog circuits over time and temperature, and the difficulty in achieving perfect consistency in signal path length and impedance matching within the PCB (Printed Circuit Board) wiring. These factors lead to variations in key parameters such as gain coefficients, bias voltages, and sampling clocks between channels. When these parameters are inconsistent, the conversion results of the same input signal from different channels deviate, introducing signal distortion and inter-channel mismatch errors, ultimately affecting the system's reception quality and signal recovery accuracy.

[0045] Among existing multi-channel ADC calibration technologies, analog integrated solutions require circuit redesign and have low accuracy and stability in self-testing and adjustment; adaptive estimation methods in the digital domain have high hardware complexity and are prone to convergence problems; statistical algorithms require long-term statistical analysis of specific sequences, which not only consumes time in the calibration process but also requires feedback network decision-making and correction, which can easily block services.

[0046] Based on this, the present invention provides a high-precision calibration system and method for a multi-channel ADC, which adopts a high-precision, low-complexity calibration and compensation method, which can significantly improve distortion and enhance signal quality. It is also a closed-loop self-calibration system with the advantages of real-time monitoring and parameter updates. The calibration and compensation algorithm is simple and reliable to implement, has strong stability, is easy to implement in hardware, and has low resource consumption.

[0047] To facilitate understanding of this embodiment, a detailed description of a multi-channel ADC high-precision calibration system disclosed in this embodiment of the invention will be provided first.

[0048] This invention provides a high-precision calibration system for a multi-channel ADC, which can be applied to wireless communication chips such as Wi-Fi chips and 5G chips.

[0049] like Figure 1 As shown, the multi-channel ADC high-precision calibration system provided in this embodiment of the invention includes a digital transmitter 110, a DAC module 120, a calibration loop 130, and a multi-channel ADC module 140 connected in sequence. It also includes a correlation module 150, a parameter estimation module 160, and a compensation module 170. The correlation module 150 is connected to the digital transmitter 110 and the multi-channel ADC module 140, respectively. The parameter estimation module 160 is connected to the correlation module 150 and the compensation module 170, respectively. The compensation module 170 is also connected to the multi-channel ADC module 140. The calibration loop 130 is used to connect the end of the transmit link and the front end of the receive link.

[0050] Specifically, the digital transmitter 110 is used to generate a calibration signal when it receives a self-calibration command, and send the local reference signal corresponding to the calibration signal to the relevant module; wherein, the calibration signal passes through the DAC module 120 and the calibration loop 130 and reaches the multi-path ADC module 140, and the local reference signal includes an odd path reference signal and an even path reference signal obtained by splitting the calibration signal into odd and even paths.

[0051] The multi-path ADC module 140 is used to output multiple sub-signals corresponding to the calibration signal to the related module 150;

[0052] The correlation module 150 is used to perform cross-correlation calculations on the local reference signal and multiple sub-signals to obtain the correlation results, and then send the correlation results to the parameter estimation module 160.

[0053] The parameter estimation module 160 is used to calculate the amplitude deviation and sampling time deviation of the odd and even paths in the multi-path sub-signals according to the relevant results, obtain the deviation parameter data, and send the deviation parameter data to the compensation module 170.

[0054] The compensation module 170 is used to perform amplitude deviation compensation and sampling time deviation compensation for multiple sub-signals based on deviation parameter data.

[0055] The multi-channel ADC high-precision calibration system provided in this embodiment of the invention combines the analog and digital domains through calibration loop 130. It can achieve deviation compensation by performing a single cross-correlation operation and parameter estimation on the local reference signal and multiple sub-signals. This method does not require redesigning the analog circuit or relying on external instruments for calibration. It has low hardware complexity, high stability, and short estimation cycle, and does not affect normal business operation.

[0056] Optionally, such as Figure 2 As shown, the aforementioned digital transmitter 110 may include a sine wave sequence generator 111, which generates a calibration signal that is a sine wave sequence. After the sine wave sequence is split into odd and even paths (splitting according to the parity of the sampling time), an odd path sine wave sequence (composed of signals sampled at odd sampling times) and an even path sine wave sequence (composed of signals sampled at even sampling times) can be obtained. That is, at this time, the odd path reference signal is the odd path sine wave sequence, and the even path reference signal is the even path sine wave sequence. Here, the two are collectively referred to as the odd-even sine wave sequence.

[0057] It should be noted that the calibration signal mentioned above is not limited to a sine wave sequence. Other types of sequences can also be used in other embodiments, such as pseudo-random binary sequences, multi-tone signals, frequency sweep signals, or single-frequency continuous waves.

[0058] Optionally, such as Figure 2 As shown, the calibration loop 130 may include an interconnected power amplifier 132 and a low-noise amplifier 133. The power amplifier 132, also known as a PA (Power Amplifier), is used to simulate the actual transmit path in the calibration loop 130, providing sufficient signal strength for subsequent components. The low-noise amplifier 133, also known as an LNA (Low Noise Amplifier), is used to simulate the receive path in the calibration loop 130, ensuring that the received signal is strong enough for accurate bias analysis and bias compensation.

[0059] Furthermore, the aforementioned calibration loop 130 may also include an up-converter 131 and a down-converter 134, with the up-converter 131, power amplifier 132, low-noise amplifier 133, and down-converter 134 connected in sequence. The up-converter 131 converts the calibration signal into a high-frequency signal for transmission via an antenna. The down-converter 134 converts the signal processed by the power amplifier 132 and low-noise amplifier 133 back to a frequency range suitable for analysis, facilitating deviation assessment and calibration.

[0060] Optionally, such as Figure 2As shown, the aforementioned multi-channel ADC140 can be a four-channel ADC141, which includes four ADCs (i.e., ADC1, ADC2, ADC3, and ADC4), each outputting one sub-signal. Specifically, the multiple sub-signals output by the four-channel ADC141 are in-phase even-path signals (I even) and odd-path signals (I odd), as well as orthogonal even-path signals (Q even) and odd-path signals (Q odd). It should be noted that the embodiments of the present invention do not limit the number of paths of the multi-channel ADC140. In other embodiments, the multi-channel ADC140 can also be a six-channel ADC, an eight-channel ADC, a twelve-channel ADC, or a sixteen-channel ADC, etc.

[0061] When the multi-channel ADC140 is a four-channel ADC141, the aforementioned correlation module 150 is specifically used to: perform cross-correlation operations on the odd-path reference signal with the in-phase even-path signal and the odd-path signal respectively, and perform cross-correlation operations on the even-path reference signal with the in-phase even-path signal and the odd-path signal respectively, to obtain the in-phase four-path cross-correlation result; perform cross-correlation operations on the odd-path reference signal with the orthogonal even-path signal and the odd-path signal respectively, and perform cross-correlation operations on the even-path reference signal with the orthogonal even-path signal and the odd-path signal respectively, to obtain the orthogonal four-path cross-correlation result.

[0062] Furthermore, when the calibration signal uses a sine wave sequence, this embodiment of the invention provides a specific estimation algorithm used by the parameter estimation module 160. Specifically, the parameter estimation module 160 is used for:

[0063] For the in-phase four-way cross-correlation results and the orthogonal four-way cross-correlation results respectively, the amplitude deviation and sampling time deviation of the odd and even paths are calculated using the following formulas:

[0064] ;

[0065] ;

[0066] Where, ∆ t Indicates the sampling time deviation, ∆ A Indicates amplitude deviation. f Represents the frequency of a sine wave sequence. t s Indicates the sampling clock period. Indicates even-path signal AND path reference signal Cross-correlation results Indicates odd-path signal AND path reference signal The cross-correlation results Indicates even-path signal Reference signal with Qilu The cross-correlation results Indicates odd-path signal Reference signal with Qilu The cross-correlation results.

[0067] Optionally, for the four-channel ADC141, the compensation module 170 may include two compensation units: one compensation unit located in one of the output paths of the in-phase even-path signal and the odd-path signal, and the other compensation unit located in one of the output paths of the orthogonal even-path signal and the odd-path signal. Further, both compensation units are positioned on the output paths of the odd-path signal / even-path signal, which facilitates processing by the parameter estimation module 160.

[0068] Further optional, such as Figure 2 As shown, the compensation unit includes an amplitude compensator 171 and a fractional time delay filter 172. The amplitude compensator 171 is used to compensate for the amplitude deviation between the odd and even paths, and the fractional time delay filter 172 is used to compensate for the sampling time deviation between the odd and even paths. For example, Figure 2 Both amplitude compensators 171 and fractional delay filters 172 are set on the output path of the odd-path signal.

[0069] Further optional, such as Figure 2 As shown, the system also includes a self-calibration trigger module 100 connected to the sine wave sequence generator 111. The self-calibration trigger module 100 sends a self-calibration command to the sine wave sequence generator 111 when a self-calibration event is detected. This achieves automatic triggering of the calibration mode.

[0070] To ensure the sampling quality of the high-precision ADC during long-term use, the aforementioned self-calibration events can include one or more of the following: a real-time temperature value exceeding a preset temperature range, reaching a specified time, and receiving a manual calibration command. Based on this, the self-calibration trigger module 100 can include one or more of the following: a temperature sensor, a timer, and a manual trigger button. Specifically, the temperature sensor can trigger a self-calibration command when it detects that the real-time temperature value exceeds the preset temperature range, i.e., the temperature change exceeds a set threshold. The timer can trigger a self-calibration command when a specified time is reached, i.e., the set time is exceeded. The manual trigger button can trigger a self-calibration command when pressed by the user.

[0071] As can be seen, the embodiments of the present invention propose a calibration system that combines analog and digital domains. Through algorithm optimization, high-precision correlation and estimation algorithms can be used to estimate parameters such as gain deviation (i.e., amplitude deviation) and sampling clock deviation (i.e., sampling time deviation) in a single operation, and then real-time compensation is performed by the compensation module 170. Furthermore, the system can automatically trigger the calibration mode based on the temperature sensor or timer to improve parameter drift caused by temperature drift or device aging. The algorithm estimation and compensation accuracy can meet the requirements of ultra-high resolution ADCs, and the hardware complexity is low.

[0072] This invention provides a novel ADC self-calibration system, which, combined with optimized autocorrelation calculation and estimation algorithms, enables high-precision extraction and compensation of distortion parameters for multi-channel ADCs. For ease of understanding, the following describes... Figure 2 The working principle of the system will be introduced.

[0073] 1. Self-calibration is triggered based on feedback from the temperature sensor (temperature change exceeds the set threshold) or the timer (exceeds the set time);

[0074] 2. The sine wave sequence generator 111 generates a sine wave sequence and simultaneously sends the local odd and even sine wave sequences to the relevant module 150.

[0075] 3. The sine wave sequence passes through DAC module 120, upconverter 131, power amplifier 132, low noise amplifier 133 and downconverter 134, etc., and arrives at the four-channel ADC 141;

[0076] 4. The four-channel ADC141 samples the analog signal and outputs four sub-signals: in-phase-even signal (I even), in-phase-odd signal (I odd), quadrature-even signal (Q even), and quadrature-odd signal (Q odd).

[0077] 5. The four sub-signals are sent to the correlation module 150 and cross-correlation is performed with the local odd and even sine sequences of the sine wave sequence generator 111;

[0078] 6. The relevant results are sent to the parameter estimation module 160, and the compensation coefficient (i.e. the deviation parameter data) is calculated according to the estimation algorithm of the distortion parameter.

[0079] 7. After the coefficients are updated, they are fed into the amplitude compensator 171 and the fractional delay filter 172;

[0080] 8. Amplitude compensator 171 is used to compensate for the amplitude deviation between the odd and even paths, and fractional delay filter 172 is used to compensate for the sampling time deviation;

[0081] 9. Signal merging: The compensation units are all placed on the odd-path signal for compensation. The compensated odd-path signal is interleaved and merged with the even-path signal to output in-phase signal-quadrature signal, namely I-path signal and Q-path signal.

[0082] The self-calibration system proposed in this invention does not require redesigning analog circuits or relying on external instruments for calibration. Through algorithm optimization and innovation, it can calculate high-precision error parameters (i.e., amplitude deviation and sampling time deviation) in a single operation using only autocorrelation calculation and estimation algorithms. It has low complexity and high stability. Furthermore, by monitoring temperature drift or time timing in real time, it can automatically trigger the calibration mode, ensuring the sampling quality of the high-precision ADC during long-term use.

[0083] For ease of understanding, the following is based on Figure 2 The structure shown introduces the algorithm for estimating distortion parameters.

[0084] Suppose the sine wave sequence (referred to as the received sequence) received after passing through calibration loop 130 is as follows:

[0085] Ou Luwei Qilu is ;in, A e and A o For the amplitude of the odd and even paths, ∆ t Due to sampling time deviation, t s One cycle of the sampling clock, f The frequency of the sine wave sequence.

[0086] The reference sine wave sequence (referred to as the local sequence) generated by the sine wave sequence generator 111 is as follows:

[0087] The reference signal for the even path is The reference signal for the odd path is ;in, θ The phase difference between the received sequence and the local sequence.

[0088] This invention, through cross-correlation calculations and estimation algorithms, obtains the amplitude deviation ∆ between the odd and even paths. A and sampling time deviation ∆ t ,in, , ∆ t =Odd-path sampling time - Even-path sampling time - t s .

[0089] Cross-correlation of the local sequence and the received sequence yields four cross-correlation results:

[0090] (1)

[0091] (2)

[0092] (3)

[0093] (4)

[0094] Sampling time bias estimation:

[0095] Based on the cross-correlation results, after eliminating the amplitude term and simplifying, we obtain:

[0096] (5)

[0097] (6)

[0098] Then, in equations (5) and (6), 2π ft s Item elimination:

[0099] (7)

[0100] (8)

[0101] Eliminate the initial phase in (7) and (8) θ , to obtain ∆ t :

[0102] (9)

[0103] Therefore, the final formula for calculating the sampling time deviation is:

[0104] (10)

[0105] Amplitude deviation estimation:

[0106] Expand C c and C b :

[0107] (11)

[0108] (12)

[0109] Eliminate the first term of the expansion:

[0110] (13)

[0111] (14)

[0112] After eliminating the remaining phase terms and simplifying, we get:

[0113] (15)

[0114] (16)

[0115] Then the amplitude deviation can be obtained:

[0116] (17)

[0117] Therefore, the final formula for calculating the amplitude deviation is:

[0118] (18)

[0119] Therefore, by calculating the cross-correlation between the received sequence and the local sequence, four sets of cross-correlation results are obtained. Then, by using the estimation algorithms of the derived equations (10) and (18), the amplitude deviation parameter and the sampling time deviation parameter can be directly calculated.

[0120] The odd / even signal correlation and estimation algorithms presented in this invention feature simple hardware design and utilize sinusoidal wave sequence signals, offering advantages such as strong noise and interference resistance, high computational accuracy, and the elimination of iterative convergence or feedback judgment. Even in harsh scenarios with an SNR (Signal-to-Noise Ratio) <10 dB, the computational accuracy still achieves a sampling deviation error of 0.1 ps and an amplitude error accuracy of 0.01%, while ADC distortion and spurious emissions can be controlled below -70 dBc. Furthermore, the hardware correlation calculation and parameter estimation time for each self-calibration trigger can be controlled within microseconds (μs), without affecting service transmission and reception.

[0121] In summary, the multi-channel ADC high-precision calibration system proposed in this invention is a collaborative system of analog and digital domains, which does not rely on external instruments for calibration and does not require redesigning analog circuits. Furthermore, the proposed parity correlation algorithm and parameter estimation algorithm have advantages such as low hardware complexity, ease of implementation, high accuracy, and strong stability. Moreover, based on a temperature sensor and timer, microsecond-level self-calibration can be triggered, ensuring that the ADC sampling quality remains within a high range, covering various scenarios such as temperature changes and device aging, without affecting normal transmission and reception services.

[0122] This invention also provides a high-precision calibration method for a multi-channel ADC, which can be applied to the aforementioned high-precision calibration system for a multi-channel ADC. See also... Figure 3 The diagram shows a flowchart of a high-precision calibration method for a multi-channel ADC, which mainly includes the following steps S310 to S350:

[0123] In step S310, when the digital transmitter receives the self-calibration command, it generates a calibration signal and sends the local reference signal corresponding to the calibration signal to the relevant module.

[0124] The calibration signal passes through the DAC module and calibration loop to reach the multi-path ADC module. The local reference signal includes the odd-path reference signal and the even-path reference signal obtained by splitting the calibration signal into odd and even paths.

[0125] In step S320, the multi-channel ADC module outputs multiple sub-signals corresponding to the calibration signal to the relevant modules.

[0126] In step S330, the correlation module performs cross-correlation calculations on the local reference signal and the multiple sub-signals to obtain the correlation results, and sends the correlation results to the parameter estimation module.

[0127] In step S340, the parameter estimation module calculates the amplitude deviation and sampling time deviation of the odd and even channels in the multi-channel sub-signals based on the relevant results, obtains the deviation parameter data, and sends the deviation parameter data to the compensation module.

[0128] In step S350, the compensation module performs amplitude deviation compensation and sampling time deviation compensation for the multiple sub-signals based on the deviation parameter data.

[0129] The high-precision calibration method for multi-channel ADCs provided in this invention combines the analog and digital domains through a calibration loop. Deviation compensation can be achieved by performing a single cross-correlation operation and parameter estimation on the local reference signal and multiple sub-signals. This method does not require redesigning the analog circuit or relying on external instruments for calibration. It has low hardware complexity, high stability, and a short estimation cycle, and does not affect normal business operations.

[0130] Furthermore, the aforementioned multi-path ADC includes a four-path ADC, and the multiple sub-signals include in-phase even-path signals and odd-path signals, as well as orthogonal even-path signals and odd-path signals; based on this, the aforementioned step S330 may include:

[0131] The odd-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, to obtain the in-phase four-path cross-correlation result;

[0132] The odd-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, and the even-path reference signal is cross-correlated with the orthogonal even-path and odd-path signals respectively, to obtain the orthogonal four-path cross-correlation results.

[0133] Furthermore, the aforementioned digital transmitter includes a sine wave sequence generator, and the calibration signal includes a sine wave sequence; based on this, step S340 may include:

[0134] For the in-phase four-way cross-correlation results and the orthogonal four-way cross-correlation results respectively, the amplitude deviation and sampling time deviation of the odd and even paths are calculated using the following formulas:

[0135] ;

[0136] ;

[0137] Where, ∆ t Indicates the sampling time deviation, ∆ A Indicates amplitude deviation. f Represents the frequency of a sine wave sequence. t s Indicates the sampling clock period. Indicates even-path signal AND path reference signal Cross-correlation results Indicates odd-path signal AND path reference signal The cross-correlation results Indicates even-path signal Reference signal with Qilu The cross-correlation results Indicates odd-path signal Reference signal with Qilu The cross-correlation results.

[0138] Furthermore, the aforementioned compensation module includes two compensation units: one compensation unit is located in one of the output paths of the in-phase even-path signal and the odd-path signal, and the other compensation unit is located in one of the output paths of the orthogonal even-path signal and the odd-path signal; the compensation unit includes an amplitude compensator and a fractional delay filter; based on this, the aforementioned step S350 may include: the amplitude compensator compensating for the amplitude deviation between the odd and even paths; and the fractional delay filter compensating for the sampling time deviation between the odd and even paths.

[0139] Furthermore, the system also includes a self-calibration trigger module connected to the digital transmitter; based on this, see [link to relevant documentation]. Figure 4 The flowchart shown is another high-precision calibration method for a multi-channel ADC, which may include the following steps S410 to S460:

[0140] In step S410, when the self-calibration trigger module detects a self-calibration event, it sends a self-calibration command to the digital transmitter.

[0141] In step S420, when the digital transmitter receives the self-calibration command, it generates a calibration signal and sends the local reference signal corresponding to the calibration signal to the relevant module.

[0142] In step S430, the multi-channel ADC module outputs multiple sub-signals corresponding to the calibration signal to the relevant modules.

[0143] In step S440, the correlation module performs cross-correlation calculations on the local reference signal and the multiple sub-signals to obtain the correlation results, and sends the correlation results to the parameter estimation module.

[0144] In step S450, the parameter estimation module calculates the amplitude deviation and sampling time deviation of the odd and even channels in the multi-channel sub-signals based on the relevant results, obtains the deviation parameter data, and sends the deviation parameter data to the compensation module.

[0145] In step S460, the compensation module performs amplitude deviation compensation and sampling time deviation compensation for the odd and even channels of the multi-channel sub-signals based on the deviation parameter data.

[0146] The method provided in this embodiment has the same implementation principle and technical effect as the aforementioned system embodiment. For the sake of brevity, any parts not mentioned in the method embodiment can be referred to the corresponding content in the aforementioned system embodiment.

[0147] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0148] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0149] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-path ADC high-precision calibration system, characterized in that, The system includes a digital transmitter, a DAC module, a calibration loop, and a multi-channel ADC module connected in sequence. It also includes a correlation module, a parameter estimation module, and a compensation module. The correlation module is connected to the digital transmitter and the multi-channel ADC module, respectively. The parameter estimation module is connected to the correlation module and the compensation module, respectively. The compensation module is also connected to the multi-channel ADC module. The calibration loop connects the end of the transmit link and the beginning of the receive link. The digital transmitter is used to generate a calibration signal when it receives a self-calibration command, and send the local reference signal corresponding to the calibration signal to the relevant module; wherein, the calibration signal passes through the DAC module and the calibration loop to reach the multi-path ADC module, and the local reference signal includes an odd-path reference signal and an even-path reference signal obtained by splitting the calibration signal into odd and even paths; The multi-path ADC module is used to output multiple sub-signals corresponding to the calibration signal to the relevant module; The correlation module is used to perform cross-correlation calculation on the local reference signal and the multi-channel sub-signals to obtain the correlation result, and send the correlation result to the parameter estimation module; The parameter estimation module is used to calculate the amplitude deviation and sampling time deviation of the odd and even paths in the multi-path sub-signals according to the relevant results, obtain deviation parameter data, and send the deviation parameter data to the compensation module. The compensation module is used to perform amplitude deviation compensation and sampling time deviation compensation for the multiple sub-signals based on the deviation parameter data.

2. The system of claim 1, wherein, The multi-path ADC includes a four-path ADC, and the multi-path sub-signals include in-phase even-path signals and odd-path signals, as well as orthogonal even-path signals and odd-path signals; the related modules are specifically used for: The odd-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, to obtain the in-phase four-path cross-correlation result; The odd-path reference signal is cross-correlated with the orthogonal even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the orthogonal even-path signal and odd-path signal respectively, to obtain the orthogonal four-path cross-correlation result.

3. The system of claim 2, wherein, The digital transmitter includes a sine wave sequence generator, and the calibration signal includes a sine wave sequence; the parameter estimation module is specifically used for: For the in-phase four-way cross-correlation results and the orthogonal four-way cross-correlation results respectively, the amplitude deviation and sampling time deviation of the odd and even paths are calculated using the following formulas: ； ； Where, ∆ t Indicates the sampling time deviation, ∆ A Indicates amplitude deviation. f This represents the frequency of the sinusoidal wave sequence. t s Indicates the sampling clock period. Indicates even-path signal AND path reference signal Cross-correlation results Indicates odd-path signal AND path reference signal The cross-correlation results Indicates even-path signal Reference signal with Qilu The cross-correlation results Indicates odd-path signal Reference signal with Qilu The cross-correlation results.

4. The system according to claim 2, characterized in that, The compensation module includes two compensation units, one of which is located in one of the output paths of the in-phase even-path signal and the odd-path signal, and the other of which is located in one of the output paths of the orthogonal even-path signal and the odd-path signal. The compensation unit includes an amplitude compensator and a fractional time delay filter. The amplitude compensator is used to compensate for the amplitude deviation between the odd and even paths, and the fractional time delay filter is used to compensate for the sampling time deviation between the odd and even paths.

5. The system according to claim 1, characterized in that, The system also includes a self-calibration trigger module connected to the digital transmitter, which sends the self-calibration command to the digital transmitter when a self-calibration event is detected.

6. The system according to claim 5, characterized in that, The self-calibration event includes one or more of the following: the real-time temperature value exceeds the preset temperature range, a specified time is reached, and a manual calibration command is received. The self-calibration trigger module includes one or more of the following: a temperature sensor, a timer, and a manual trigger button.

7. The system according to any one of claims 1-6, characterized in that, The calibration loop includes interconnected power amplifiers and low-noise amplifiers.

8. A high-precision calibration method for a multi-channel ADC, characterized in that, The method is applied to the high-precision calibration system for a multi-channel ADC according to any one of claims 1-7; the method includes: When the digital transmitter receives a self-calibration command, it generates a calibration signal and sends the local reference signal corresponding to the calibration signal to the relevant module; wherein, the calibration signal passes through the DAC module and the calibration loop to reach the multi-path ADC module, and the local reference signal includes an odd-path reference signal and an even-path reference signal obtained by splitting the calibration signal into odd and even paths; The multi-path ADC module outputs multiple sub-signals corresponding to the calibration signal to the relevant module; The correlation module performs cross-correlation calculations on the local reference signal and the multiple sub-signals to obtain correlation results, and sends the correlation results to the parameter estimation module; The parameter estimation module calculates the amplitude deviation and sampling time deviation of the odd and even paths in the multi-path sub-signals based on the relevant results, obtains the deviation parameter data, and sends the deviation parameter data to the compensation module. The compensation module performs amplitude deviation compensation and sampling time deviation compensation on the multiple sub-signals based on the deviation parameter data.

9. The method according to claim 8, characterized in that, The multi-path ADC includes a four-path ADC, and the multi-path sub-signals include in-phase even-path signals and odd-path signals, as well as orthogonal even-path signals and odd-path signals. The correlation module performs cross-correlation operations on the local reference signal and the multiple sub-signals to obtain correlation results, including: The odd-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the in-phase even-path signal and odd-path signal respectively, to obtain the in-phase four-path cross-correlation result; The odd-path reference signal is cross-correlated with the orthogonal even-path signal and odd-path signal respectively, and the even-path reference signal is cross-correlated with the orthogonal even-path signal and odd-path signal respectively, to obtain the orthogonal four-path cross-correlation result.

10. The method according to claim 8, characterized in that, The system also includes a self-calibration trigger module connected to the digital transmitter; The method further includes: When the self-calibration trigger module detects a self-calibration event, it sends the self-calibration command to the digital transmitter.

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