As wireless data applications over cellular networks become more widespread, the pressure to increase capacity will become even more intense. Capacity in the 800 and 900 MHz bands, where bandwidth is restricted, is al...As wireless data applications over cellular networks become more widespread, the pressure to increase capacity will become even more intense. Capacity in the 800 and 900 MHz bands, where bandwidth is restricted, is already becoming a limiting factor. This paper attempts to address how the application of smart antenna systems has brought about improvements in call quality and increased capacity through reduced Interference in Mobile Communication. The smart antenna may be in a variety of ways to improve the performance of a communications system. Perhaps most importantly is its capability to cancel co-channel interference. It helps in improving the system performance by increasing the channel capacity, spectrum efficiency, extending range coverage, speech quality, enabling tighter reuse of frequencies within a cellular network and economically, feasible increased signal gain, greater, reduced multipath reflection. It has been argued that Smart antennas and the Algorithms to control them are vital to a high-capacity communication system development.展开更多
针对传统压制式干扰仪对宽带长期演进(Long Term Evolution,LTE)信号干扰效果不理想,以及伪基站类干扰实现复杂的问题,基于通用软件无线电外设(Universal Software Radio Peripheral,USRP)设计并实现了一套LTE信号屏蔽系统。该系统利用...针对传统压制式干扰仪对宽带长期演进(Long Term Evolution,LTE)信号干扰效果不理想,以及伪基站类干扰实现复杂的问题,基于通用软件无线电外设(Universal Software Radio Peripheral,USRP)设计并实现了一套LTE信号屏蔽系统。该系统利用LTE系统中同物理层小区标识(Physical-layer Cell Identity,PCI)小区会产生严重同频干扰的特点,通过构建与屏蔽区域服务小区具有相同PCI的LTE小区,发射主同步信号(Primary Synchronization Signal,PSS)、辅同步信号(Second Synchronization Signal,SSS)、公共参考信号(Cell-specific Reference Signal,CRS)、广播信号和系统消息,使服务小区的信号与干扰加噪声比(Signal to Interference plus Noise Ratio,SINR)严重恶化,终端业务中断甚至掉线,从而达成屏蔽效果。该屏蔽系统包括扫频和信号接收单元、获取PCI单元、屏蔽信号生成单元以及屏蔽信号发送单元四个部分。实验测试表明,在天线增益不小于15 dBi、屏蔽区域所在公网服务小区的参考信号接收功率(Reference Signal Receiving Power,RSRP)不大于-63 dBm时,该设备能有效管控半径为10 m范围的LTE信号。展开更多
文摘As wireless data applications over cellular networks become more widespread, the pressure to increase capacity will become even more intense. Capacity in the 800 and 900 MHz bands, where bandwidth is restricted, is already becoming a limiting factor. This paper attempts to address how the application of smart antenna systems has brought about improvements in call quality and increased capacity through reduced Interference in Mobile Communication. The smart antenna may be in a variety of ways to improve the performance of a communications system. Perhaps most importantly is its capability to cancel co-channel interference. It helps in improving the system performance by increasing the channel capacity, spectrum efficiency, extending range coverage, speech quality, enabling tighter reuse of frequencies within a cellular network and economically, feasible increased signal gain, greater, reduced multipath reflection. It has been argued that Smart antennas and the Algorithms to control them are vital to a high-capacity communication system development.
文摘针对传统压制式干扰仪对宽带长期演进(Long Term Evolution,LTE)信号干扰效果不理想,以及伪基站类干扰实现复杂的问题,基于通用软件无线电外设(Universal Software Radio Peripheral,USRP)设计并实现了一套LTE信号屏蔽系统。该系统利用LTE系统中同物理层小区标识(Physical-layer Cell Identity,PCI)小区会产生严重同频干扰的特点,通过构建与屏蔽区域服务小区具有相同PCI的LTE小区,发射主同步信号(Primary Synchronization Signal,PSS)、辅同步信号(Second Synchronization Signal,SSS)、公共参考信号(Cell-specific Reference Signal,CRS)、广播信号和系统消息,使服务小区的信号与干扰加噪声比(Signal to Interference plus Noise Ratio,SINR)严重恶化,终端业务中断甚至掉线,从而达成屏蔽效果。该屏蔽系统包括扫频和信号接收单元、获取PCI单元、屏蔽信号生成单元以及屏蔽信号发送单元四个部分。实验测试表明,在天线增益不小于15 dBi、屏蔽区域所在公网服务小区的参考信号接收功率(Reference Signal Receiving Power,RSRP)不大于-63 dBm时,该设备能有效管控半径为10 m范围的LTE信号。
文摘提出了一种2.5维(2.5D)系统封装高速输入/输出(I/O)全链路的信号/电源完整性(Signal integrity/power integrity,SI/PI)协同仿真方法。首先通过电磁全波仿真分析SiP内部“芯片I/O引脚-有源转接板-印刷电路板(即封装基板)-封装体I/O引脚”这一主要高速信号链路及相应的转接板/印刷电路板电源分配网络(Power distribution network,PDN)的结构特征和电学特性,在此基础上分别搭建对应有源转接板和印刷电路板两种组装层级的“信号链路+PDN”模型,并分别进行SI/PI协同仿真,提取出反映信号链路/PDN耦合特性的模块化集总电路模型,从而在电路仿真器中以级联模型实现快速的SI/PI协同仿真。与全链路的全波仿真结果的对比表明,模块化后的协同仿真有很好的可信度,而且仿真时间与资源开销大幅缩减,效率明显提升。同时总结了去耦电容的大小与布局密度对PDN电源完整性的影响及对信号完整性的潜在影响,提出了去耦电容布局优化的建议。
