随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G...随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G NR NTN和DVB-S2X/RCS2两种主流卫星通信体制,总结出卫通终端的功能性能指标,并结合机载环境下的需求,分析了典型卫通终端协议模块的架构和指标。最后,研究总结了基于5G NR和DVB标准的测试指标及方法,以提高测试效能,并实现产品的实时自检应用。展开更多
针对多进制部分响应串行级联CPM信号解调算法复杂度过高的问题,提出一种基于n Sn OEE分解的低复杂度算法。在传统的SISO迭代译码结构基础上,该算法首先利用n Sn OEE分解,简化匹配滤波器组,然后修正SISO算法分支度量的计算,得到迭代运算...针对多进制部分响应串行级联CPM信号解调算法复杂度过高的问题,提出一种基于n Sn OEE分解的低复杂度算法。在传统的SISO迭代译码结构基础上,该算法首先利用n Sn OEE分解,简化匹配滤波器组,然后修正SISO算法分支度量的计算,得到迭代运算所需的充分的统计软信息,最终实现串行级联CPM信号解调复杂度的降低。针对DVB-RCS2协议信号进行仿真实验,证明该算法能在性能损失较小的情况下大大降低解调复杂度。展开更多
Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without re...Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without real-time requirements.In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS.These solutions become critical when satellite systems are utilized,since resources are limited,network latency is huge and bandwidth costs are high.Using satellite capacity for cloud-computing bulk traffic,keeping acceptable performance of interactive applications,is very important and can limit the connectivity costs.This goal can be achieved installing in the Set Top Box(STB) a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud computing traffic.This aim is typically reached using a specific QoS architecture,adding functional blocks at network or lower layers.We propose to manage such a process at transport layer only.The endpoint proxy implements a new transport protocol called TCP Noordwijk+,introducing a flow control differentiation capability.The proxy includes TPCN+ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of friendliness.The outcomes of Ns-2simulations confirm applicability and good performance of the proposed solution.展开更多
文摘随着卫星通信技术的迅速发展,卫星互联网已成为现代通信的重要组成部分。机载卫星通信终端及其核心组件的性能直接决定了通信系统的效率与可靠性。目前,这些关键组件的研发主要由国外企业垄断,限制了技术的发展并且成本高昂。通过对比5G NR NTN和DVB-S2X/RCS2两种主流卫星通信体制,总结出卫通终端的功能性能指标,并结合机载环境下的需求,分析了典型卫通终端协议模块的架构和指标。最后,研究总结了基于5G NR和DVB标准的测试指标及方法,以提高测试效能,并实现产品的实时自检应用。
文摘针对多进制部分响应串行级联CPM信号解调算法复杂度过高的问题,提出一种基于n Sn OEE分解的低复杂度算法。在传统的SISO迭代译码结构基础上,该算法首先利用n Sn OEE分解,简化匹配滤波器组,然后修正SISO算法分支度量的计算,得到迭代运算所需的充分的统计软信息,最终实现串行级联CPM信号解调复杂度的降低。针对DVB-RCS2协议信号进行仿真实验,证明该算法能在性能损失较小的情况下大大降低解调复杂度。
文摘Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without real-time requirements.In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS.These solutions become critical when satellite systems are utilized,since resources are limited,network latency is huge and bandwidth costs are high.Using satellite capacity for cloud-computing bulk traffic,keeping acceptable performance of interactive applications,is very important and can limit the connectivity costs.This goal can be achieved installing in the Set Top Box(STB) a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud computing traffic.This aim is typically reached using a specific QoS architecture,adding functional blocks at network or lower layers.We propose to manage such a process at transport layer only.The endpoint proxy implements a new transport protocol called TCP Noordwijk+,introducing a flow control differentiation capability.The proxy includes TPCN+ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of friendliness.The outcomes of Ns-2simulations confirm applicability and good performance of the proposed solution.
