Iterative Amplitude Equalization for Frequency Estimation (IAE-DFT)

The accurate frequency estimation of sinusoidal signals remains a key requirement in precision instrumentation and signal analysis, particularly in applications where noise and spectral leakage affect the measurement accuracy. This paper introduces a new frequency-domain technique, called IAE-DFT (Iterative Amplitude Equalization in the Frequency Domain), which estimates the true frequency of a sinusoidal component by iteratively adjusting two dominant spectral points until their amplitudes become balanced. Both spectral components are shifted together in the same direction according to amplitude dominance, and the step size is halved each time the amplitude relationship reverses, ensuring smooth and deterministic convergence. Experimental results demonstrate that IAE-DFT achieves superior performance at 0 dB SNR, outperforming the state-of-the-art methods, while maintaining comparable accuracy at 20 dB and 40 dB. Its precision and robustness make it a promising candidate for frequency-output biosensors and resonant sensing applications, where accurate tracking of small frequency shifts is critical. Future work will focus on optimizing the iteration control strategy, particularly the selection of the initial step size and the adaptive adjustment rate, to further enhance convergence speed and accuracy.