An Jeongha, Ra Hyungin, Youn Changhyun, Kim Kiman
Department of Radio Communication Engineering, Korea Maritime and Ocean University, 727 Taejong-ro, Yeongdo-gu, Busan 49112, Korea.
Sensors (Basel). 2021 Oct 29;21(21):7194. doi: 10.3390/s21217194.
In this paper, we propose underwater acoustic (UWA) communications using a generalized sinusoidal frequency modulation (GSFM) waveform, which has a distinct ambiguity function (AF) and correlation function characteristic. For these reasons, it is more robust in multipath channels than the conventional chirp spread spectrum (CSS) with a linear frequency modulation (LFM) waveform. Four types of GSFM waveforms that are orthogonal to each other are applied for each symbol in the proposed method. To evaluate the performance of the proposed method, we compared the performances of the proposed method and conventional method by conducting diverse experiments: simulations, lake trials and sea trials. In the simulation results, the proposed method shows better performance than the conventional method. The lake trial was conducted with a distance of 300~400 m between the transmitter and receiver. As a result of the experiment, the average bit error rate (BER) of the proposed method is 3.52×10-2 and that of the conventional method is 3.52×10-1, which shows that the proposed method is superior to the conventional method. The sea trial was conducted at a distance of approximately 20 km between the transmitter and receiver at a depth of 1500 m, and the receiver was composed of 16 vertical line arrays (VLAs) with a hydrophone. The proposed method had a BER of 0.3×10-2 in one channel and was error free in the other.
在本文中，我们提出使用广义正弦频率调制（GSFM）波形进行水下声学（UWA）通信，该波形具有独特的模糊函数（AF）和相关函数特性。由于这些原因，在多径信道中，它比具有线性频率调制（LFM）波形的传统线性调频扩频（CSS）更稳健。在所提出的方法中，四种相互正交的GSFM波形应用于每个符号。为了评估所提出方法的性能，我们通过进行各种实验（模拟、湖泊试验和海上试验）比较了所提出方法和传统方法的性能。在模拟结果中，所提出的方法表现出比传统方法更好的性能。湖泊试验在发射器和接收器之间距离为300~400米的情况下进行。实验结果表明，所提出方法的平均误码率（BER）为3.52×10-2，而传统方法的平均误码率为3.52×10-1，这表明所提出的方法优于传统方法。海上试验在发射器和接收器之间距离约20公里、深度为1500米的情况下进行，接收器由带有水听器的16个垂直线列阵（VLA）组成。所提出的方法在一个信道中的误码率为0.3×10-2，在另一个信道中无差错。
