Blind Calibration Method for Two-Channel Time-Interleaved Analog-to-Digital Converters Based on FFT

Bai, Xu; Hu, Hui; Li, Wanjun; Liu, Fulu

doi:10.1007/s10836-018-5758-1

Cited by 6 publications

(5 citation statements)

References 19 publications

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“…A brief comparison indicating the hardware complexity of the proposed FFT-based mismatch calibration algorithm and the prior FFT-based methods in [14], [21], and [22] are presented in Table I. We assume the length of sample data for the calibration is N. Note that, for all these FFT-based techniques, the estimation accuracy increases with the number of N; however, a larger N will lead to greater computational complexity.…”

Section: B Digital Calibration Experimental Resultsmentioning

confidence: 99%

“…In Section V below that the mid-range method, (14), leads to a large reduction in the dynamic range resulting in better accuracy and higher production yields.…”

Section: Algorithm 1 Frequency Domain Methods For Estimating Gain And...mentioning

confidence: 99%

“…It is clear that choosing the mid-range as the time reference has a much better performance than using one sub-ADC as the time reference for the Taylor-based time-skew correction. Most previous FFT-based estimation methods [14], [22], [23] must use one sub-ADC as the time reference, which may degrade the performance of the time-skew correction.…”

Section: Monte Carlo Simulation For Time-skew Referencementioning

confidence: 99%

See 2 more Smart Citations

A Foreground Mismatch and Memory Harmonic Distortion Calibration Algorithm for TIADC

Shen

Blaq

John

et al. 2023

IEEE Trans. Circuits Syst. I

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This paper proposes a foreground digital calibration algorithm that estimates and corrects the offset, gain, and time-skew mismatches for time-interleaved analog-to-digital converters (TIADCs) furthermore our algorithm is designed to correct for harmonic distortion introduced by the presence of a nonlinear front-end. We propose a novel simplified non-linear model in place of the more complex conventional Volterra series based structure. The mismatch estimation technique based on the Fast Fourier Transform (FFT) is proposed to estimate the various time-interleaving mismatches simultaneously. A Taylorbased technique is applied to compensate for these mismatches. We also consider the choice of an appropriate time reference for the time-skew correction algorithm by theoretical analysis. The nonlinear distortion correction technique is based on estimating and inverting an assumed 3 rd order nonlinearity with a fractional delay. To do this, we design a customized filter in an offline process. Our algorithms are designed to operate in any Nyquist zone. The proposed techniques are verified by a Xilinx Zynq UltraScale+ RFSoC ZCU111 evaluation kit containing a 12-bit, 4.096 GHz TI-ADC with 8 sub-ADCs operating in the 2 nd Nyquist zone. Accordingly, we observed an improvement in SFDR of 14 dB for mismatch calibration alone and up to another 12 dB with nonlinear correction enabled.

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Section: B Digital Calibration Experimental Resultsmentioning

confidence: 99%

“…In Section V below that the mid-range method, (14), leads to a large reduction in the dynamic range resulting in better accuracy and higher production yields.…”

Section: Algorithm 1 Frequency Domain Methods For Estimating Gain And...mentioning

confidence: 99%

Section: Monte Carlo Simulation For Time-skew Referencementioning

confidence: 99%

See 1 more Smart Citation

A Foreground Mismatch and Memory Harmonic Distortion Calibration Algorithm for TIADC

Shen

Blaq

John

et al. 2023

IEEE Trans. Circuits Syst. I

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“…As for estimation algorithms, one effective approach is blind estimation [11][12][13][14][15]. In [11], two of the channels were regarded as the reference channels, and the mismatch value could then be obtained by a series of calculations and the least mean square (LMS) algorithm.…”

Section: Introductionmentioning

confidence: 99%

A Digital Timing-Mismatch Calibration Technique for Time-Interleaved ADCs Based on a Coordinate Rotational Digital Computer Algorithm

et al. 2023

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Timing-mismatch errors among channels in time-interleaved analog-to-digital converters (TIADCs) greatly degrade the whole performance of the system. Therefore, techniques for calibrating timing mismatch are indispensable, and a new fully-digital calibration technique is presented in this article. Based on a Hilbert filter, modified moving averagers (MMAs) and inverse cosine functions, the proposed estimation algorithm is fast (within 1200 sample points) and accurate. Meanwhile, the coordinate rotational digital computer (CORDIC) algorithm, which is used to implement inverse cosine functions, is also improved, giving it higher precision. In addition, a compensation method based on second-order Taylor series approximation with less hardware resource consumption is provided. Through analyses and simulations, this calibration technique proved to be suitable for TIADCs with an arbitrary number of channels, in which the signal-to-noise and distortion ratio (SNDR) and the spurious-free dynamic range (SFDR) were, respectively, improved from 24.06 dB and 24.57 dB to 67.96 dB and 85.69 dB.

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“…The authors of [21] utilised the reference signal to pre-process the received data in the frequency domain for calibration purposes. Some researchers have solved the gain, offset, and timing mismatches in timeinterleaved SDC (TIADC) systems [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Successive‐phase correction calibration method for modulated wideband converter system

Jiang

Deng

et al. 2019

IET signal process.

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The modulated wideband converter (MWC) is a sub-Nyquist sampling system recently proposed for sampling sparse multi-band signals. However, due to non-ideal analogue components, transfer-matrix calibration is required for the successful reconstruction. In practice, it is difficult to control the phases of the consecutive sinusoidal inputs precisely which are used to calibrate the transfer-matrix. Here, the authors propose a method of transfer-matrix calibration for the MWC with digital expanded channels when the phases of the sinusoidal inputs are unknown. As the oblique elements of the MWC transfer-matrix are equal, the authors can estimate the unknown phases first. The authors then obtain the actual transfer-matrix by phase correction. Finally, the validity of this method is verified by simulation and hardware experiment. The system performance is measured by computing the signal-to-noise ratio and the mean-square error between the original and reconstructed signals.

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Blind Calibration Method for Two-Channel Time-Interleaved Analog-to-Digital Converters Based on FFT

Cited by 6 publications

References 19 publications

A Foreground Mismatch and Memory Harmonic Distortion Calibration Algorithm for TIADC

A Foreground Mismatch and Memory Harmonic Distortion Calibration Algorithm for TIADC

A Digital Timing-Mismatch Calibration Technique for Time-Interleaved ADCs Based on a Coordinate Rotational Digital Computer Algorithm

Successive‐phase correction calibration method for modulated wideband converter system

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