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一种宽带短波波形的直接解扩处理方法
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作者 薛光伟 瞿文中 刘晶 《电讯技术》 北大核心 2022年第11期1644-1649,共6页
某短波协议定义了最新的宽带短波波形,其中零号波形采用了Walsh正交扩频加扰的复杂调制方式。针对该种宽带波形接收处理,提出了一种查表式、免解扰的直接解扩方法,利用含扰码序列的本地解扩矩阵对数据解扩。在逐符号方法因均衡器不收敛... 某短波协议定义了最新的宽带短波波形,其中零号波形采用了Walsh正交扩频加扰的复杂调制方式。针对该种宽带波形接收处理,提出了一种查表式、免解扰的直接解扩方法,利用含扰码序列的本地解扩矩阵对数据解扩。在逐符号方法因均衡器不收敛导致解扩结果可信度较低时新方法的结果仍保持较高可信度。参考该协议条件,对6 kHz、12 kHz和48 kHz三种带宽零号波形处理进行仿真,所提方法与协议描述相比有明显的性能增益。 展开更多
关键词 宽带短波(WBHF)波形 Walsh正交频调制 直接解扩
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Power-line Modem over the Low Voltage Grid Using Direct Sequence Spread Spectrum Techniques
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作者 A. Mahgoub H. Abdeel-Baky E. El-Badawy 《Journal of Energy and Power Engineering》 2011年第6期562-568,共7页
Power-line networks are designed to deliver electricity. They reach most of the domiciles and other buildings nowadays, so most of the people have access to it. On the other hand the backbone for the communications ne... Power-line networks are designed to deliver electricity. They reach most of the domiciles and other buildings nowadays, so most of the people have access to it. On the other hand the backbone for the communications networks is not available in all countries especially the developing ones. A high cost and changing the design for the networks may be needed to construct this backbone. If data can be transmitted over the power-line networks, a recognized cost and time save can be achieved. In Egypt, the infrastructure is not always available for constructing a communications network backbone due to the already designed buildings before the need for these backbones. In this paper, we overcome this problem by designing a reliable Power-line Modem that operates safely on the low voltage grid. The modem is based on the Direct Sequence Spread Spectrum technique. It uses the mains zero crossing as an efficient way for the synchronization between the transmitter and the receiver. The Modem takes into account the problems of the Power-line including noise, attenuation and impedance dismatching. 展开更多
关键词 Power-line modem DS/SS micro-controller (firmware) low voltage grid.
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