Design of Dynamic Adaptive Calibration Algorithm for Frequency Offset of Standard Meter Chip Facing Electromagnetic Pulse Interference

The frequency offset caused by factors such as temperature drift, crystal oscillator aging, and circuit noise during chip operation has time-varying and nonlinear characteristics, and traditional fixed threshold calibration methods are difficult to achieve real-time tracking compensation. And the measurement process requires extremely high frequency deviation, and the phase error caused by small frequency deviation in short-term measurement is often masked by noise, resulting in insufficient detection sensitivity. To this end, design a standard table chip frequency offset dynamic adaptive calibration algorithm. By using the discrete Fourier transform to transform the standard table chip information stream into binary digital information, the frequency domain decay vector on the subcarriers facing electromagnetic pulse interference is clarified through a finite impulse response filter, and the chip signal sequence is obtained; Using historical data as the training sequence, first estimate and pre compensate for larger frequency offsets, and then continuously expand the phase difference of the remaining small frequency offsets using cyclic prefix method to obtain corresponding estimated values for adaptive calibration. The experimental results show that after the designed algorithm calibration, the signal constellation diagram of the standard meter chip is expressed compactly, the chip signal error rate is low, and the measurement error of the standard meter is effectively reduced.