Depth-dependent mismatched filtering using ultrasonic attenuation as a filter design parameter

We present a depth-dependent mismatched-filter pulse compression technique which uses the tissue attenuation as a parameter for appropriate compression filter design. The estimation of the attenuation solely from the reflected signal is performed using a least-squares approach in the frequency domain. Based on this estimation, a set of mismatched-filters is calculated to achieve the desired main-lobe width, SNR and sidelobe characteristics. Simulations and first experimental results are used to demonstrate the technique. The numerical effort necessary for the estimation algorithm is discussed.