Symbol LMS algorithm and system for assembly line ADC calibration

Abstract

The present invention claims a symbol variable step size LMS algorithm (SVSS-LMS) and system. By judging the positive or negative deviation of an input transient error, a positive fixed constant valueis incremented or decremented for modification each time for step size iteration. The method and the system have the advantages of high calibration accuracy and fast convergence speed. Based on the traditional LMS algorithm, a symbol function sign is introduced to update a step factor mu(n) so as to achieve step size control. The size of the step factor mu(n) can be dynamically adjusted accordingto the speed of error convergence; therefore, the weight is updated faster by the error; the updated weight is fed back to an adaptive filter to improve the accuracy of the assembly line ADC output,so that the output of the assembly line to be calibrated gradually approaches the output of the low-speed but high-precision ADC.

Description

technical field [0001] The invention belongs to digital signal processing and digital integrated circuit design. Especially related to algorithm research and FPGA hardware structure design in digital signal processing. Background technique [0002] The analog-to-digital converter (ADC) is the front end of the digital signal processing system, and its performance directly affects the performance of the entire system. With the continuous improvement of digital signal processing capabilities, the requirements for digital output performance indicators of ADC devices serving as a bridge between analog systems and digital systems will become higher and higher. [0003] With the advancement of integrated circuit technology, the performance of ADC devices has been greatly improved. Under the conditions of the existing nanoscale integrated circuit manufacturing process, due to the precise control of the process equipment, the process error problems such as the mismatch of the CMOS ...

AI Technical Summary

Problems solved by technology

The traditional LMS (least mean square algorithm) algorithm used for pipeline ADC calibration uses a fixed step size to update the tap weight coefficient, which cannot reduce the contradiction between its convergence speed and offset accuracy

Part of the variable step size algorithm only slightly improves the convergence speed, but the misalignment accuracy will also increase, but it cannot achieve both convergence speed and misalignment accuracy

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