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计算机工程 ›› 2025, Vol. 51 ›› Issue (12): 161-170. doi: 10.19678/j.issn.1000-3428.0069553

• 人工智能与模式识别 • 上一篇    下一篇

基于插值修正的I-Rife频率估计算法

闻丹1,2, 易辉跃1,*(), 张武雄1, 许晖1   

  1. 1. 中国科学院上海微系统与信息技术研究所微系统技术实验室, 上海 200050
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2024-03-13 修回日期:2024-08-26 出版日期:2025-12-15 发布日期:2024-10-15
  • 通讯作者: 易辉跃
  • 基金资助:
    国家自然科学基金(62071450); 新疆维吾尔自治区重点研发任务专项(2022B01009)

I-Rife Frequency Estimation Algorithm Based on Interpolation Modification

WEN Dan1,2, YI Huiyue1,*(), ZHANG Wuxiong1, XU Hui1   

  1. 1. Key Laboratory of Science and Technology on Micro-System, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2024-03-13 Revised:2024-08-26 Online:2025-12-15 Published:2024-10-15
  • Contact: YI Huiyue

摘要:

频率估计是信号处理中的关键技术。当信号频率接近快速傅里叶变换(FFT)的离散频点时, I-Rife算法的频率估计误差较大。针对该问题, 提出基于插值修正的I-Rife频率估计算法。首先, 利用I-Rife算法插值的2条谱线判断频率修正方向, 在该修正方向上进行单点插值, 并将I-Rife算法中最大谱线和次大谱线之间的区域划分为3个小区域。然后, 通过比较该单点插值和I-Rife算法中2条谱线的幅值判断信号频率位于哪个小区域, 并计算更精确的频移因子。最后, 利用Rife算法计算出修正后的频率估计值。通过理论分析可知, 所提算法使信号频率始终接近相邻离散频点的中心区域, 克服了现有I-Rife算法当信号频率接近离散频点时估计误差大的问题, 从而提高了频率估计精度。仿真结果表明, 所提算法在低信噪比(SNR)并且信号频率接近离散频点时的频率估计精度高于I-Rife算法, 且误差更接近克拉美罗下界(CRLB)。而且, 所提算法比现有算法具有更好的稳定性。

关键词: Rife算法, I-Rife算法, 频率估计, 插值修正, 克拉美罗下界

Abstract:

Frequency estimation is a crucial signal-processing technology. The I-Rife algorithm exhibits large frequency estimation errors when the signal frequency is close to the frequency samples of the Fast Fourier Transform (FFT). To address this, an I-Rife frequency estimation algorithm based on interpolation modification is proposed. First, two frequency samples interpolated by I-Rife are utilized to determine the direction of frequency correction. A single-point frequency sample is interpolated in this direction, and the region between the maximum and second maximum frequency samples in the I-Rife algorithm is divided into three smaller regions. Subsequently, by comparing the magnitudes of the interpolated frequency sample and the two frequency samples in the I-Rife algorithm, a smaller region where the signal frequency is located is determined and a more accurate frequency-shifting factor is calculated. Finally, the Rife algorithm is used to obtain the corrected frequency estimation value. Theoretical analysis indicates that the proposed algorithm maintains the signal frequency close to the central region of two neighboring discrete frequency samples and thus effectively overcomes the issue of large estimation errors in the I-Rife algorithm when the signal frequency is close to the frequency samples. Simulation results show that the proposed algorithm achieves a higher frequency estimation accuracy than the I-Rife algorithm when the Signal-to-Noise Ratio (SNR) is low and the signal frequency is close to the frequency samples. Additionally, compared to that of the existing algorithms, its estimation error is closer to the Cramér-Rao Lower Bound (CRLB). Moreover, the proposed algorithm has better stability than existing algorithms.

Key words: Rife algorithm, I-Rife algorithm, frequency estimation, interpolation correction, Cramér-Rao Lower Bound (CRLB)