完全互補碼於超音波陣列訊號之應用

The Application of Complete Complementary Code for Ultrasound Array Signals

黃韻曄(Yun-Yeh Huang)

指導教授 ： 李穎 ； 鐘嘉德

元智大學/電機通訊學院/通訊工程學系/碩士(2009年)

https://doi.org/10.6838/YZU.2009.00068

摘要

格雷互補序列(Golay Complementary Sequence)與格雷互補集合(Golay Complementary Set of Sequences)被廣泛運用在超音波量測系統。格雷互補序列具有非週期自相關函數(Aperiodic Auto-correlation function)和為脈衝的特性，可以取代傳統短脈衝(short pulse)及相關函數近似脈衝的的其他二位元序列(例如:偽隨機序列)，提升超音波訊號在接收端偵測的準確度。
本論文探討由完全互補碼使用於超音波線性陣列的效能。完全互補碼具有各格雷互補集合彼此互相關函數和於各位移項為全零的正交特性，使用於超音波線性陣列(linear array)系統，陣列單元的發射訊號間不會互相干擾。我們觀察到當每個超音波陣列單元使用In phase/Quadrature 同時傳送成對的格雷互補序列-one burst one pair時，比傳統one burst one sequence的發送方式準確度相同且仍然能維持其正交性，訊號總傳送時間(Total Transmission Duration)降低，盲域(Blind Zone)大幅減小，可以有效提升超音波陣列訊號的接收品質。

關鍵字

完全互補碼 ； 超音波 ； 串音干擾

並列摘要

Golay Complementary Sequence(GCS) and Golay Complementary Sequence Sets(GCSS) have been widely used in ultrasound systems. Golay Complementary Sequences have the property that the sum of the Aperiodic Auto-Correlation Function (AACF) of pairing sequences is an impulse function, and they can replace short pulses or biphase pseudo random sequences to enhance the precision of ultrasound reception.
In this thesis, we explore the performance of Complete Complementary Code (CCC) in linear array ultrasound systems. A Complete Complementary Code contains several Golay Complementary Sequence Sets, each set contains multiple Golay Complementary Sequence Pairs. It has the property that the Golay Complementary Sequence Sets it contains are mutually orthogonal at all delay shifts, so there will be no interference when used in ultrasound arrays. We observe that when each transducer orthogonally transmit a Golay Complementary Pair simultaneously, the precision is the same as the existing method, where two Golay Sequences in a pair are transmitted one after the other. Our one burst one pair transmission method not only maintains orthogonality between signals from different transducers, but also reduces the total transmission duration and the site of the blind zone, effectively improves ultrasound array signal reception.

並列關鍵字

complete complementary code ； ultrasound ； cross talk

參考文獻

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