A Robust Doppler Imaging Method Using Log-step Multicarrier Ultrasonic Signals

Recently, the authors described a new algorithm for ultrasonic Doppler imaging and velocity estimation using log-step multicarrier signals. The algorithm achieved a velocity estimation precision that was some 20 times better than that using an existing method, but the problem of estimation deficiency in low-SNR conditions remained. In this work, we improve the availability of the algorithm in low-SNR conditions by utilizing the systematic temporal shift of the log-step multicarrier signals, which expresses approximately the amount of Doppler shift in the sensed signal. A computer simulation shows high availability for the algorithm, even for SNR values below -10 dB.