针对中国北斗比GPS等其他导航系统独有的短报文双向通信功能,研发了适配北斗短报文信道的600 bit/s声码器。声码器采用正弦激励线性预测(sinusoidal excitation linear prediction,SELP)算法,实现了通信质量清晰的语音通信,并进一步设...针对中国北斗比GPS等其他导航系统独有的短报文双向通信功能,研发了适配北斗短报文信道的600 bit/s声码器。声码器采用正弦激励线性预测(sinusoidal excitation linear prediction,SELP)算法,实现了通信质量清晰的语音通信,并进一步设计了一种处理定位信息的坐标压缩算法,为语音编码数据提供了更大的传输空间。基于以上研究,实现了仅用北斗导航系统完成双向保密语音和定位同传的通信系统。该系统首先利用语音转换程序将声码器编解码模块获取的语音编码数据转换为北斗短报文数据格式;然后利用语音编码解析程序与经纬度解析程序从北斗短报文数据中解析出语音编码与位置信息;最后,在北斗短报文收发器上验证了语音通信与定位传输实验效果,主观MOS测试评分表明该研究为北斗短报文语音通信实用化铺平了道路。展开更多
The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients ar...The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients around the zero value are very few, so we cannot sparsely represent low-frequency image information. The low-frequency component contains the main energy of the image and depicts the profile of the image. Direct fusion of the low-frequency component will not be conducive to obtain highly accurate fusion result. Therefore, this paper presents an infrared and visible image fusion method combining the multi-scale and top-hat transforms. On one hand, the new top-hat-transform can effectively extract the salient features of the low-frequency component. On the other hand, the multi-scale transform can extract highfrequency detailed information in multiple scales and from diverse directions. The combination of the two methods is conducive to the acquisition of more characteristics and more accurate fusion results. Among them, for the low-frequency component, a new type of top-hat transform is used to extract low-frequency features, and then different fusion rules are applied to fuse the low-frequency features and low-frequency background; for high-frequency components, the product of characteristics method is used to integrate the detailed information in high-frequency. Experimental results show that the proposed algorithm can obtain more detailed information and clearer infrared target fusion results than the traditional multiscale transform methods. Compared with the state-of-the-art fusion methods based on sparse representation, the proposed algorithm is simple and efficacious, and the time consumption is significantly reduced.展开更多
文摘针对中国北斗比GPS等其他导航系统独有的短报文双向通信功能,研发了适配北斗短报文信道的600 bit/s声码器。声码器采用正弦激励线性预测(sinusoidal excitation linear prediction,SELP)算法,实现了通信质量清晰的语音通信,并进一步设计了一种处理定位信息的坐标压缩算法,为语音编码数据提供了更大的传输空间。基于以上研究,实现了仅用北斗导航系统完成双向保密语音和定位同传的通信系统。该系统首先利用语音转换程序将声码器编解码模块获取的语音编码数据转换为北斗短报文数据格式;然后利用语音编码解析程序与经纬度解析程序从北斗短报文数据中解析出语音编码与位置信息;最后,在北斗短报文收发器上验证了语音通信与定位传输实验效果,主观MOS测试评分表明该研究为北斗短报文语音通信实用化铺平了道路。
基金Project supported by the National Natural Science Foundation of China(Grant No.61402368)Aerospace Support Fund,China(Grant No.2017-HT-XGD)Aerospace Science and Technology Innovation Foundation,China(Grant No.2017 ZD 53047)
文摘The high-frequency components in the traditional multi-scale transform method are approximately sparse, which can represent different information of the details. But in the low-frequency component, the coefficients around the zero value are very few, so we cannot sparsely represent low-frequency image information. The low-frequency component contains the main energy of the image and depicts the profile of the image. Direct fusion of the low-frequency component will not be conducive to obtain highly accurate fusion result. Therefore, this paper presents an infrared and visible image fusion method combining the multi-scale and top-hat transforms. On one hand, the new top-hat-transform can effectively extract the salient features of the low-frequency component. On the other hand, the multi-scale transform can extract highfrequency detailed information in multiple scales and from diverse directions. The combination of the two methods is conducive to the acquisition of more characteristics and more accurate fusion results. Among them, for the low-frequency component, a new type of top-hat transform is used to extract low-frequency features, and then different fusion rules are applied to fuse the low-frequency features and low-frequency background; for high-frequency components, the product of characteristics method is used to integrate the detailed information in high-frequency. Experimental results show that the proposed algorithm can obtain more detailed information and clearer infrared target fusion results than the traditional multiscale transform methods. Compared with the state-of-the-art fusion methods based on sparse representation, the proposed algorithm is simple and efficacious, and the time consumption is significantly reduced.
