水声信道的建模和估计方法的研究

发布时间：2018-04-30 05:00

本文选题：水声通信 + 信道建模　；参考：《南京邮电大学》2015年硕士论文

【摘要】：随着海洋研究与开发的进一步深入,对水声通信系统的性能要求越来越高。而水声信道具有长时延、可用带宽有限、环境背景噪声高、多径效应明显、多普勒频移及信道衰减等特点,这些复杂的影响因素,相互叠加并共同作用,严重影响了水声通信的质量,在下面两个方面限制了水声通信技术的应用和发展:传统的水声信道建模方法受制于应用环境条件等的限制,不能对水下声学环境进行有效的模拟;传统的水声信道估计方法,也因误差较大,估计的精度和效果受到了较大的影响。本文首先分析了水声信道的诸多重要特性,再简要说明了现阶段在水声通信领域中应用的技术,重点阐述了水声OFDM通信系统。在水声信道的建模方面,先研究传统的水声信道建模方法,然后重点研究基于BELLHOP模型的水声信道建模方法。在水声信道估计方面,本文将信号及信息处理领域中的新理论——压缩感知理论,应用到了水声信道估计中,并依此提出了基于压缩感知理论的水声OFDM通信系统信道估计方法,该方法通过线性内插法插入二维导频,用信道感知获取信道的频域响应的采样值,构造相应的过完备字典,并用压缩采样匹配追踪算法,对水声OFDM通信系统进行有效的信道估计。最后,本文对水声信道的建模及信道估计进行了系统实现和验证实验,实验结果表明:基于BELLHOP模型的水声信道建模方法,能够有效对海洋声学环境特性进行描述;基于压缩感知理论的水声OFDM通信系统信道估计方法,从信道估计的恢复精度、误码率、算法的复杂度和稳定性等综合因素考虑,其性能较现阶段的其他方法更有效,更适合在水声通信中应用。
[Abstract]:With the further development of ocean research and development, the performance of underwater acoustic communication system is becoming more and more demanding. The underwater acoustic channel has the characteristics of long delay, limited available bandwidth, high background noise, obvious multipath effect, Doppler frequency shift and channel attenuation. It seriously affects the quality of underwater acoustic communication, and restricts the application and development of underwater acoustic communication technology in the following two aspects: the traditional underwater acoustic channel modeling method is restricted by the application environment, etc. The underwater acoustic environment can not be effectively simulated and the accuracy and effect of the traditional underwater acoustic channel estimation methods are greatly affected because of the large error. In this paper, many important characteristics of underwater acoustic channel are analyzed, and then the technologies used in underwater acoustic communication field are briefly described, and the underwater acoustic OFDM communication system is emphasized. In the aspect of underwater acoustic channel modeling, the traditional underwater acoustic channel modeling method is studied first, and then the underwater acoustic channel modeling method based on BELLHOP model is emphatically studied. In the aspect of underwater acoustic channel estimation, compression sensing theory, a new theory in signal and information processing, is applied to underwater acoustic channel estimation, and a channel estimation method for underwater acoustic OFDM communication system based on compressed sensing theory is proposed. In this method, the two-dimensional pilot is inserted by linear interpolation, and the sampling value of the frequency domain response of the channel is obtained by channel perception, and the corresponding overcomplete dictionary is constructed, and the compressed sampling matching tracking algorithm is used. The channel estimation of underwater acoustic OFDM communication system is carried out. Finally, the system implementation and validation experiment of underwater acoustic channel modeling and channel estimation are carried out in this paper. The experimental results show that the underwater acoustic channel modeling method based on BELLHOP model can effectively describe the environmental characteristics of ocean acoustics. The channel estimation method of underwater acoustic OFDM communication system based on compressed sensing theory is more effective than other methods in the present stage, considering the comprehensive factors such as restoration accuracy, bit error rate, complexity and stability of the algorithm. It is more suitable for underwater acoustic communication.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.3

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