Design of orthogonal coded excitation for synthetic aperture imaging in ultrasound systems

This paper presents a new digital front-end architecture for synthetic aperture ultrasound (SAU) imaging using orthogonal chirps and orthogonal Golay codes. Compared to existing systems that perform decoding before beamforming, the proposed systems have comparable performance and significantly lower computation and space complexity. Unfortunately the proposed systems suffer loss in performance in the presence of body motion. To address this problem, we propose a simple motion compensation scheme that improves both the SNR and the RSLL performance. A comparison of the complexity of both the systems shows that while Golay code-based system has lower computation complexity than chirp-based system, if motion compensation is included, then the complexity of the two systems are comparable.