一种基于GA优化的TIADC误差检测与校正方法研究

Research on TIADC error detection and correction method based on GA optimization

分时交替模数转换器(TIADC)通道中存在偏置、增益以及时间失配误差,严重影响了系统的信噪失真比(SNDR)、无杂散动态范围(SFDR)和有效量化位数(ENOB)。文中提出一种基于遗传算法(GA)优化的TIADC误差检测与校正方法。其中,正弦拟合算法用于对输入信号进行一次估计和粗校正,GA用于对频域滤波处理后的信号进行通道失配误差的二次检测和精校正。通过校正前、后信号的频谱对比结果证明该校正算法的有效性。实验结果表明,该算法简单、易实现,将TIADC系统的SNDR提高到92.24 dB,SFDR提高到102.05 dB,ENOB提高到15.03 bit,校正效果较优。该校正方法适用于16 bit以上的TIADC系统,为高分辨率TIADC系统的误差检测及校正研究提供了一种新思路。

As there are offset,gain and time mismatch errors in the channels of time⁃interleaved analog⁃to⁃digital converter(TIADC)systems,which severely affect the signal⁃to⁃noise and distortion ratio(SNDR),spurious⁃free dynamic range(SFDR)and effective number of bits(ENOB),a TIADC error detection and correction method based on optimization of genetic algorithm(GA)is proposed in this paper.The algorithm based on sine fitting is used for the first estimation and rough correction of the input signal,and GA is used for the secondary detection and fine correction of channel mismatch errors of the signal after frequency domain filtering.The spectrum comparison results of the signal before and after the correction prove the effectiveness of the correction algorithm.The experimental result shows that the algorithm is simple and easy to implement,which can increase the TIADC system's SNDR to 92.24 dB,the SFDR to 102.05 dB,and the ENOB to 15.03 bit.Its correction effect is fine.This method is suitable for TIADC systems with more than 16 bit,and can provide a new idea for error detection and correction of high resolution TIADC systems.