Mutually Orthogonal Golay Complementary Sequences in Synthetic Aperture Imaging Systems

Abstract

The main objective of this study is to improve the ultrasound image by employing a new algorithm based on transducer array element beam pattern correction implemented in the synthetic transmit aperture (STA) method combined with emission of mutually orthogonal complementary Golay sequences. Orthogonal Golay sequences can be transmitted and received by different transducer elements simultaneously, thereby decreasing the time of image reconstruction, which plays an important role in medical diagnostic imaging.The paper presents the preliminary results of computer simulation of the synthetic aperture method combined with the orthogonal Golay sequences in a linear transducer array. The transmission of long waveforms characterized by a particular autocorrelation function allows to increase the total energy of the transmitted signal without increasing the peak pressure. It can also improve the signal-to-noise ratio and increase the visualization depth maintaining the ultrasound image resolution.In the work, the 128-element linear transducer array with a 0.3 mm pitch excited by 8-bits Golay coded sequences as well as one cycle at nominal frequencies of 4 MHz were used. The comparison of 2D ultrasound images of the phantoms is presented to demonstrate the benefits of a coded transmission. The image reconstruction was performed using the synthetic STA algorithm with transmit and receive signals correction based on a single element directivity function.

Archives of Acoustics

“…If the 4-or 8-order mutually orthogonal set will be used, the 4 or 8 image lines can be constructed after two transmissions. This principle was described in details in the work (Trots, 2015;Trots et al, 2015). This enables increasing the data acquisition rate in comparison with the CGCS or even with the short pulse, if more than two MOGCS sets are used simultaneously (Trots et al, 2004).…”

Acoustic sensing method for an occlusion area with super-directional sound sources and multiple modulation signal

“…Generally, the Golay code is used for sensing by phase modulation of the carrier wave. 22,23) Let G t a ( ) be the signal phase that is modulated to the carrier wave by the Golay code g t a ( ) in Fig. makes the sidelobe value zero and it improves the S/N of the signal by 2N g .…”

Signal-to-noise ratio of diverging waves in multiscattering media: Effects of signal duration and divergence angle

“…33 Using CGSs and orthogonal CGSs with DW transmission enables SNR improvement compared to uncoded DW transmission. [35][36][37] The studies on coded excitation employ different chip lengths such as half, 34 one, 24,28,34,36 one and a half, 35,37 two, 27,[30][31][32][33] and five-cycle/chip. 29 The other studies 25,26 reviewed in this work have no relevant data on chip length.…”