Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel wi...Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel width without loss of speech quality remains a crucial problem in speech coding theory. A new full-duplex digital speech communication system based on the Vocoder of AMBE-1000(TM) and microcontroller ATMEL 89C51 is introduced. It shows higher voice quality than current mobile phone system with only a quarter of channel width needed for the latter. The prospective areas in which the system can be applied include satellite communication, IP Phone, virtual meeting and the most important, defence industry.展开更多
针对齿轮箱智能运维技术中面临的旋转元件动态运行状态难以直接实时测量的难题,构建了一种基于无线携能通信(simultaneous wireless power and information transfer, SWPIT)的旋转元件状态传感系统。设计了系统电路拓扑结构,通过理论...针对齿轮箱智能运维技术中面临的旋转元件动态运行状态难以直接实时测量的难题,构建了一种基于无线携能通信(simultaneous wireless power and information transfer, SWPIT)的旋转元件状态传感系统。设计了系统电路拓扑结构,通过理论计算分析了齿轮箱内部金属元件对传感系统电路参数的影响规律,并使用有限元方法探究了金属齿轮对传感系统中线圈参数的影响,获得了各线圈在系统中的最佳安装位置;此外,设计了传感系统的电能传输、全双工通信电路的实现方案,并开展了齿轮箱内部元件状态采集实验。本系统为旋转设备内部元件运行状态的监测奠定了技术基础。展开更多
提出一种蜂窝网络中全双工蜂窝用户协作D2D(device to device)通信机制,全双工蜂窝用户采用功率域叠加支持上行传输和D2D通信并发,为无直传链路的D2D用户对协作中继;分析了系统的可达速率域,提出了一种基于最大-最小可达速率的功率分配...提出一种蜂窝网络中全双工蜂窝用户协作D2D(device to device)通信机制,全双工蜂窝用户采用功率域叠加支持上行传输和D2D通信并发,为无直传链路的D2D用户对协作中继;分析了系统的可达速率域,提出了一种基于最大-最小可达速率的功率分配算法。仿真分析表明,随着自干扰消除性能的提升,系统的可达速率域扩大,全双工协作D2D通信的可达速率域显著大于半双工协作D2D通信,且蜂窝上行链路和协作D2D链路间存在可达速率折中;功率分配算法能根据信道状态动态调整蜂窝用户的发射功率和功率分配因子,功率效率高,且随着最大发射功率的增加,蜂窝上行链路和协作D2D链路的可达速率趋同,能满足最大-最小准则,兼顾蜂窝上行链路和协作D2D链路间的公平性。展开更多
文摘Since Pulse Code Modulation emerged in 1937, digitized speech has experienced rapid development due to its outstanding voice quality, reliability, robustness and security in communication. But how to reduce channel width without loss of speech quality remains a crucial problem in speech coding theory. A new full-duplex digital speech communication system based on the Vocoder of AMBE-1000(TM) and microcontroller ATMEL 89C51 is introduced. It shows higher voice quality than current mobile phone system with only a quarter of channel width needed for the latter. The prospective areas in which the system can be applied include satellite communication, IP Phone, virtual meeting and the most important, defence industry.
文摘针对齿轮箱智能运维技术中面临的旋转元件动态运行状态难以直接实时测量的难题,构建了一种基于无线携能通信(simultaneous wireless power and information transfer, SWPIT)的旋转元件状态传感系统。设计了系统电路拓扑结构,通过理论计算分析了齿轮箱内部金属元件对传感系统电路参数的影响规律,并使用有限元方法探究了金属齿轮对传感系统中线圈参数的影响,获得了各线圈在系统中的最佳安装位置;此外,设计了传感系统的电能传输、全双工通信电路的实现方案,并开展了齿轮箱内部元件状态采集实验。本系统为旋转设备内部元件运行状态的监测奠定了技术基础。
文摘提出一种蜂窝网络中全双工蜂窝用户协作D2D(device to device)通信机制,全双工蜂窝用户采用功率域叠加支持上行传输和D2D通信并发,为无直传链路的D2D用户对协作中继;分析了系统的可达速率域,提出了一种基于最大-最小可达速率的功率分配算法。仿真分析表明,随着自干扰消除性能的提升,系统的可达速率域扩大,全双工协作D2D通信的可达速率域显著大于半双工协作D2D通信,且蜂窝上行链路和协作D2D链路间存在可达速率折中;功率分配算法能根据信道状态动态调整蜂窝用户的发射功率和功率分配因子,功率效率高,且随着最大发射功率的增加,蜂窝上行链路和协作D2D链路的可达速率趋同,能满足最大-最小准则,兼顾蜂窝上行链路和协作D2D链路间的公平性。
