CAJ | 학술논문

通过分析Candan算法和2N点DFT算法的性能，本文提出了一种改进的基于DFT的正弦信号频率估计算法。在对原始信号进行必要的离散化预处理后，在粗估计阶段利用Candan算法估计出频率偏差，利用该频偏对原始信号进行频率修正。然后对修正后的原始信号进行2N点DFT算法精估计。由于增加了对原始信号的频率修正步骤，该算法发挥了Candan算法和2N点DFT算法的优点，同时增加了算法的复杂度。仿真结果表明，在相对频偏为任意值时，改进算法频率估计的均方根误差均接近克拉美罗下限，并且估计性能优于现有的频率估计算法。
통과분석Candan산법화2N점DFT산법적성능，본문제출료일충개진적기우DFT적정현신호빈솔고계산법。재대원시신호진행필요적리산화예처리후，재조고계계단이용Candan산법고계출빈솔편차，이용해빈편대원시신호진행빈솔수정。연후대수정후적원시신호진행2N점DFT산법정고계。유우증가료대원시신호적빈솔수정보취，해산법발휘료Candan산법화2N점DFT산법적우점，동시증가료산법적복잡도。방진결과표명，재상대빈편위임의치시，개진산법빈솔고계적균방근오차균접근극랍미라하한，병차고계성능우우현유적빈솔고계산법。
In this paper,a fine resolution algorithm based on Discrete Fourier Transform (DFT)for frequency estimation of sinusoidal signals is proposed by combining the Candan algorithm with the 2N-point DFT algorithm.The proposed algo-rithm first employs the Candan algorithm to get a coarse estimate of the frequency,which is used to refine the incoming sig-nal.The refined incoming signal is further input to the 2N-point DFT algorithm and a fine estimate of the possible residue frequency-offset can be well extracted.By taking the advantages of both algorithms,the proposed algorithm can perform better than either of the algorithms.The reason can be attributed to the additional frequency-offset step.As the proposed al-gorithm must run two component algorithms sequentially,it simply takes the sum of two individual algorithms in complexity. Simulation results show that the Root Mean Square Error (RMSE)of the proposed frequency estimator performs very close to the Cramer-Rao lower bound (CRLB).