面向高速运动情景的采用高相对带宽的隐秘性通信技术

项目名称： 面向高速运动情景的采用高相对带宽的隐秘性通信技术

项目编号： No.61302140

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 许涛

作者单位： 中国人民解放军国防科学技术大学

项目金额： 26万元

中文摘要： 高相对带宽，是指通信系统的绝对带宽与中心频率的比值大于25%，其典型例子包括超宽带雷达系统、超低频通信系统、水下声波通信系统等。高速运动情景，是指通信终端处于高速运动状态，如机载无线电台或者潜艇水声收发器等，其引发的多普勒效应导致信道的时变性。本项目从多普勒效应本质出发推演出新颖的时变信道模型，较之以往采用多普勒频移的近似时变水声信道建模方式具有明显优化。隐秘性通信，是指通信链路被第三方侦测到的概率低，故通信系统工作需在低信噪比条件下并发送与背景噪声类似的波形。本课题结合浅水环境下的水声实测数据，研究自适应接收机的信号处理算法。通过巧妙的借助纠错编码、信道多样性、自适应滤波、频偏自动补偿等多方面因素提高接收机的灵敏度和通信链路的鲁棒性。需要指出的是，该项目虽然以水声通信为研究案例，但也适用于其他具有高相对带宽特性的基带信号系统，具有更广泛的研究意义。

中文关键词： 高相对带宽；水声通信；高速运动；保密性；

英文摘要： Large Relative bandwidth means a more than 25% ratio of the absolute bandwidth divided by the central frequency，whose typical systems include Ultra-wideband Radar systems, Super Low-frequency Communications, Underwater Acoustic Communications (UAC), etc. High velocity scenarios mean that the communication terminals remain high mobility, such as airborne radio station and submarine acoustic transceiver, which induces the time variation of communication channels due to the Doppler effects. This project starts from the foundation of the Doppler effects to derive a novel channel modeling method based on the scaling of the acoustic signal. Such model yields a superior performance for time-varying underwater acoustic channels compared to previous modeling methods which adopt Doppler frequency shifts to approximate the Doppler effects. Covert communications mean a low detection possibility of the communication link by the third party, requiring that the system should work under the condition of a low signal-to-noise ratio (SNR) and the transmitted signal should have a similar shaping to the background noise. This project relies on sea trial data obtained in shallow water scenarios to study signal processing algorithms for adaptive receiver designs. It smartly adopts several techniques, including using error-correcting

英文关键词： high relative-bandwidth；underwater acoustic communication；high velocity；secrecy performance；