The key technology and main difficulty for optical fiber intrusion pre-warning systems (OFIPS) is the extraction of harmful-intrusion signals. After being processed by a phase-sensitive optical time-domain reflectom...The key technology and main difficulty for optical fiber intrusion pre-warning systems (OFIPS) is the extraction of harmful-intrusion signals. After being processed by a phase-sensitive optical time-domain reflectometer (O-0TDR), vibration signals can be preliminarily extracted. Generally, these include noises and intrusions. Here, intrusions can be divided into harmful and harmless intrusions. With respect to the close study of signal characteristics, an effective extraction method of harmful intrusion is proposed in the paper. Firstly, in the part of the background reconstruction, all intrusion signals are first detected by a constant false alarm rate (CFAR). We then reconstruct the backgrounds by extracting two-part information of alarm points, time and amplitude. This ensures that the detection background consists of intrusion signals. Secondly, in the part of the two-dimensional Kolmogorov-Smirnov (K-S) test, in order to extract harmful ones from all extracted intrusions, we design a separation method. It is based on the signal characteristics of harmful intrusion, which are shorter time interval and higher amplitude. In the actual OFIPS, the detection method is used in some typical scenes, which includes a lot of harmless intrusions, for example construction sites and busy roads. Results show that we can effectively extract harmful intrusions.展开更多
针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关...针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关性,构造不同时延向量下STBC-OFDM接收信号OFDM块的经验函数作为特征函数;最后通过改进K-S检测方法检验经验分布函数之间的距离盲识别STBC-OFDM信号。该方法不需要噪声信息、调制信息和信道系数,适合非合作通信场合。理论分析和实验验证了该方法的可行性。展开更多
文摘The key technology and main difficulty for optical fiber intrusion pre-warning systems (OFIPS) is the extraction of harmful-intrusion signals. After being processed by a phase-sensitive optical time-domain reflectometer (O-0TDR), vibration signals can be preliminarily extracted. Generally, these include noises and intrusions. Here, intrusions can be divided into harmful and harmless intrusions. With respect to the close study of signal characteristics, an effective extraction method of harmful intrusion is proposed in the paper. Firstly, in the part of the background reconstruction, all intrusion signals are first detected by a constant false alarm rate (CFAR). We then reconstruct the backgrounds by extracting two-part information of alarm points, time and amplitude. This ensures that the detection background consists of intrusion signals. Secondly, in the part of the two-dimensional Kolmogorov-Smirnov (K-S) test, in order to extract harmful ones from all extracted intrusions, we design a separation method. It is based on the signal characteristics of harmful intrusion, which are shorter time interval and higher amplitude. In the actual OFIPS, the detection method is used in some typical scenes, which includes a lot of harmless intrusions, for example construction sites and busy roads. Results show that we can effectively extract harmful intrusions.
文摘针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关性,构造不同时延向量下STBC-OFDM接收信号OFDM块的经验函数作为特征函数;最后通过改进K-S检测方法检验经验分布函数之间的距离盲识别STBC-OFDM信号。该方法不需要噪声信息、调制信息和信道系数,适合非合作通信场合。理论分析和实验验证了该方法的可行性。