Computationally Efficient RF Band and Base band Beam-former for Coherent Plane Wave Imaging

This study presents computationally efficient implementations of radio frequency (RF) band and baseband receive beamforming and coherent compounding applied to multi-angle plane wave transmission. The impact of the sampling frequency on image quality has been measured by standard metrics on simulated data for both approaches. Moreover, the computational cost in terms of processing time and floating point operations has been evaluated. Finally, the memory and transfer bandwidth requirements have been estimated for both focalization data and acquired raw data. The results demonstrate that baseband beam-forming can achieve acceptable image quality with a sampling frequency reduced roughly by a factor of 4 with respect to RF band beamforming. The consequent 4-fold reduction of required transfer bandwidth and memory storage for raw data comes at the cost of a mild increase in computational load of about 50%.