一种TIADC时间失配快速盲校正方法

A fast blind calibration method of time mismatch for TIADC

针对时间交错模/数转换器(TIADC)时间偏差的在线盲校正,提出一种全数字自适应方法,对于具有宽平稳带限输入的TIADC,可以三步迭代实现时间标定。仅用一阶统计量来估计时间失配,加/减法器和一个定系数导数滤波器来校正误差。采用一阶泰勒级数近似来进一步降低计算量,并在时间标定过程中,以变步长迭代补偿由于近似处理引起的误差。理论分析和实验表明:提出的方法具有复杂度低、收敛速度快等优点,在第一奈奎斯特频率内的无杂散动态范围和信噪比分别提高了44～52 d B和29～38 d B。

A full digital adaptive method is proposed for time deviation on-line blind calibration of the timeinterleaved analog-to-digital converter( TIADC). For TIADC with wide sense stationary( WSS) band-limited input,this method can achieve time calibration within three-step iterations. Only the first-order statistics are needed to estimate time mismatches and the adders/subtractors and one constant coefficient derivative filter to correct errors.The first-order Taylor series are employed to reduce computations,and the errors due to these approximations can be compensated by variable stepsize iteration manner during time calibration. Theoretical analysis and experiments show that the proposed method has the advantages of low complexity and fast convergence rate,the performances of the spurious free dynamic range( SFDR) and the signal-to-noise ratio( SNR) in the first Nyquist frequency can be improved about 44~ 52 d B and 29~ 38 d B,respectively.