Mirrored motion compensation for complementary-coded ultrasonic imaging

Ultrasonic imaging using complementary coded pulses offers the SNR improvements of signal coding without the filter side-lobes introduced by single-transmit codes. Motion in the medium, however, can introduce high side-lobes due to misalignment. An approach to the filtering and motion compensation of complementary-coded imaging signals was presented previously by the authors. It was shown to be robust to the effects of non-ideal transducers on the signals, to reduce side-lobe levels and increase coding gain and range resolution compared to systems using FM-coded signals of similar length. In addition, motion compensation allows the adoption of complementary coded imaging pulses with no reduction in frame-rate. The method is extended here to use image-line segmentation to deal with the effects of inhomogeneous motion and mirrored compensation stages to reduce the impact of estimation error.