In recent years , with the development of communication technologies , digital protection devices are also improved . in this paper , the communications that are used in digital protection device and the protocol they followed are studied . as a kind of field bus technology , can ( control area network ) is applied to the communications of double mcu , which has higher reliability and strong transmission ability 同以往的通信技术相比, can信号传输采用短帧结构,每帧的有效字节数为8个,因而传输时间短,受干扰的概率低,当节点严重错误时,具有自动关闭的功能,以切断该节点与总线的联系,使总线上的其他节点和通信不受影响,具有较强的抗干扰能力。
The thesis originally shows a new second - frame structure , which is made up of the synchronization codes , time mark codes and pseudo - random codes , also brings out the spread spectrum method for the synchronization codes and time mark codes and the analysis of the correlation and security of the pieces of the pseudo - random codes in the satellite signal 本文设计出了“前导码?时间标记码?伪随机码”的信号秒帧结构,提出了前导码和时间标记码的gold码扩频方案,以及伪随机码的生成方案,在此基础上分析了伪码的相关性和安全性。
And considering the practical adaptive modulation , when the value of pilot symbol message length is more than twenty symbol message length , map channel estimation is obviously superior to ml channel estimation . facing the qam constellation controllable adaptive modulation system , we go deep into the models , frame architecture , the constellation select for star qam and square qam , architecture implementation and so on . we elaborate on the slice decision of the square qam 针对qam星座可调的自适应调制系统,深入研究了系统的模型、帧结构、星型qam星座和方型qam星座的选择、实现的结构等,分析了方型星座下的判决门限,并给出了判决门限的仿真结果。
The synchronization of frequency hopping method referenced the jtrs radio system of usa military , and designed a synchronization method used in our radio include creating the frequency hopping map and the base band frame architecture in frequency hopping mode . the paper also analyzed the synchronization capability on theory . it has been proved correct on theory by showing the false probability , capture probability and the synchronization time 对跳频图案的产生和跳频的帧结构,本文不仅从理论上分析了同步性能,给出了虚警概率和检测概率,估算了同步的捕获时间,证明均能满足系统指标要求,而且通过与合作单位进行的整机联调和实测证实了该方案的可行性。
Following , after dicussing and comparing adventage and disadvantage of flow control protocols concerning data - link - layer , go - back - n arq is presented and used as method of flow control concerning data - link - layer . and then , the problems on time delay , frame length , window size , frame format and so on are studied deeply 本文在对比分析了几种流量控制协议的优缺点基础上,选择了以滑动窗口作为数据链路层的流量控制机制。详细地研究了时延、帧长、窗口大小和帧结构等问题以及滑动窗口实现的策略。