CAJ | 학술논문

针对基于FFT系数实部的频率插值算法在峰值谱线相位接近于±π/2时频率估计误差较大的问题，提出了一种改进的正弦信号频率估计算法。该算法首先利用FFT系数的实部和虚部序列索引出峰值谱线位置，然后根据峰值谱线的相位，选取实部与虚部序列中幅度较大的序列进行频率插值。仿真结果表明：在信噪比为3 dB、采样点为128的情况下，整个频段上归一化频率估计误差均方根小于0.02，接近Cramer Rao下限，整体性能优于基于FFT系数实部的频率插值算法和Rife算法。改进的算法频率估计精度高，计算量小，易于硬件实现。
침대기우FFT계수실부적빈솔삽치산법재봉치보선상위접근우±π/2시빈솔고계오차교대적문제，제출료일충개진적정현신호빈솔고계산법。해산법수선이용FFT계수적실부화허부서렬색인출봉치보선위치，연후근거봉치보선적상위，선취실부여허부서렬중폭도교대적서렬진행빈솔삽치。방진결과표명：재신조비위3 dB、채양점위128적정황하，정개빈단상귀일화빈솔고계오차균방근소우0.02，접근Cramer Rao하한，정체성능우우기우FFT계수실부적빈솔삽치산법화Rife산법。개진적산법빈솔고계정도고，계산량소，역우경건실현。
Larger frequency estimation error will appear when a peak spectrum line phase is closed to ±p/2 using frequency interpolation algorithm based on the real part of fast Fourier transform (FFT) coefficient. So an improved sine signal frequency estimation algorithm is proposed. The postion of peak spectrum line is firstly indexed by using the real part and imaginary part sequence of FFT coefficient. And then according to the phase of peak spectrum line, the se-quences with larger amplitude in real and imaginary part sequences are selected to participate in frequency interpolation. Simulation results show that at the condition of SNR=3 dB and sampling number N=128, the root mean square of normalized frequency estimation error at the whole frequency band is less than 0.02 and closed to Cramer-Rao lower bound (CRB). The total performance of the improved algorithm is better than the frequency interpolation and Rife al-gorithm based on the real part of FFT coefficient. The improved algorithm has the characteristics of high frequency estimation precision and few computation amounts and it is easy to implement in hardware.