Research on doppler frequency shift estimation in low Echo-to-Reverberation Ratio condition

Using the relationship between the number of zero-crossings and signal frequency, A Variable Bandwidth Band-pass Filter-Zero-Crossing Detection is proposed. This method can be used to estimate the echo frequency in Doppler Velocity Measurement. According to computer simulation, the estimation error of echo is 2 Hz approximately (Echo-to-Reverberation Ratio is -15 dB, echo frequency is 10360 Hz); according to experiment, the estimation error of echo is 4 Hz approximately (Echo-to-Reverberation Ratio is -3 dB, echo frequency is 8080 Hz). The amount of calculation of this method is lower than FFT. Therefore, this method has a good application prospects.