This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of tho...This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of those strategies on the fabricated silicon force-balance MEMS accelerometer. The mathematical model presented is implemented in VHDL- AMS and SIMULINK TM,respectively. The simulation results from the two approaches are compared and show a slight difference. Using VHDL-AMS is flexible,reusable,and more accurate. But there is not a mature solver developed for the language and this approach takes more time, while the simulation model can be easily built and quickly evaluated using SIMULINK.展开更多
---Double data rate synchronous dynamic random access memory （DDR3） has become one of the most mainstream applications in current server and computer systems. In order to quickly set up a system-level signal integri...---Double data rate synchronous dynamic random access memory （DDR3） has become one of the most mainstream applications in current server and computer systems. In order to quickly set up a system-level signal integrity （SI） simulation flow for the DDR3 interface, two system-level SI simulation methodologies, which are board-level S-parameter extraction in the frequency-domain and system-level simulation assumptions in the time domain, are introduced in this paper. By comparing the flow of Speed2000 and PowerSI/Hspice, PowerSI is chosen for the printed circuit board （PCB） board-level S-parameter extraction, while Tektronix oscilloscope （TDS7404） is used for the DDR3 waveform measurement. The lab measurement shows good agreement between simulation and measurement. The study shows that the combination of PowerSI and Hspice is recommended for quick system-level DDR3 SI simulation.展开更多
针对电力无线通信在应用中存在的问题,为更好地服务智能电网和开展分时长期演进(time division long term evolution,TD-LTE)技术在电力通信等领域的应用研究,建立了TD-LTE电力无线专网仿真平台。从链路级仿真和系统级仿真两个方面对电...针对电力无线通信在应用中存在的问题,为更好地服务智能电网和开展分时长期演进(time division long term evolution,TD-LTE)技术在电力通信等领域的应用研究,建立了TD-LTE电力无线专网仿真平台。从链路级仿真和系统级仿真两个方面对电力无线专网的性能进行仿真,并分析了无线参数对无线专网性能的影响。该仿真平台的建立为电力终端通信接入网的统一建设和LTE电力无线专网的应用提供技术支撑,也为后期的网络规划奠定了理论基础。展开更多
LTE-A(long term evolution advanced)通信系统采用正交频分复用(OFDM)为其物理层核心技术以获得抗频率选择性衰落和高频谱利用率等优点。接收端需要对多径信道动态估计和跟踪以满足相干解调,准确而简单的信道估计算法可以提高数据传输...LTE-A(long term evolution advanced)通信系统采用正交频分复用(OFDM)为其物理层核心技术以获得抗频率选择性衰落和高频谱利用率等优点。接收端需要对多径信道动态估计和跟踪以满足相干解调,准确而简单的信道估计算法可以提高数据传输速率和降低用户设备的功耗。对LTE-A中基于导频的下行信道估计算法进行研究,提出了一种使用神经网络的信道估计算法。该算法考虑了下行传输链路的信道频率选择性,利用接收到的导频信号动态跟踪信道的变化特征,然后根据得到的信道信息对接收数据进行相干解调。仿真结果表明,与最小二乘(LS)、最小均方误差(MMSE)等传统方法相比较,该信道估计算法在均方误差(MSE)、误符号率(SER)和计算复杂度方面具有更好的性能,并且能保证LTE-A系统吞吐量需求。展开更多
主要研究基于LTE(long term evolution)系统开展巨量机器类通信业务的性能.介绍了机器类通信的业务特点,并以北京近郊区的抄表类业务为例,分析了现有LTE系统开展机器类巨量用户通信时存在的问题.从理论上分析得到了随机接入资源和调度...主要研究基于LTE(long term evolution)系统开展巨量机器类通信业务的性能.介绍了机器类通信的业务特点,并以北京近郊区的抄表类业务为例,分析了现有LTE系统开展机器类巨量用户通信时存在的问题.从理论上分析得到了随机接入资源和调度资源受限是制约终端接入数量的主要因素.本文搭建了符合3GPP标准的系统级仿真平台,仿真了不同用户数和不同下行控制信道资源对系统吞吐量、时延、接入碰撞概率等的影响,仿真结果验证了理论分析的正确性.展开更多
根据3GPP对4G无线通信系统性能提出的要求,通过系统建模,设计并搭建了LTE-Advanced无线通信系统仿真平台.该仿真平台主要包括地理拓扑、Wrap-around,大/小尺度衰落,干扰计算,自适应调制编码,HARQ,分组调度等功能模块.在仿真平台的建模...根据3GPP对4G无线通信系统性能提出的要求,通过系统建模,设计并搭建了LTE-Advanced无线通信系统仿真平台.该仿真平台主要包括地理拓扑、Wrap-around,大/小尺度衰落,干扰计算,自适应调制编码,HARQ,分组调度等功能模块.在仿真平台的建模过程中,应用了蒙特卡洛思想,对系统性能进行多次随机独立采样,统计采样结果作为有效数据.在VISUAL STUDIO 2008环境下搭建了LTE-Ad-vanced系统级仿真平台,并通过比较轮询算法和正比公平算法评估了仿真平台的性能,仿真结果表明,该系统级仿真平台达到了3GPP对系统设计的要求,为LTE-Advanced的标准化工作奠定了基础.展开更多
文摘This paper presents two approaches for system-level simulation of force-balance accelerometers. The derivation of the system-level model is elaborated and simulation results are obtained from the implementation of those strategies on the fabricated silicon force-balance MEMS accelerometer. The mathematical model presented is implemented in VHDL- AMS and SIMULINK TM,respectively. The simulation results from the two approaches are compared and show a slight difference. Using VHDL-AMS is flexible,reusable,and more accurate. But there is not a mature solver developed for the language and this approach takes more time, while the simulation model can be easily built and quickly evaluated using SIMULINK.
基金supported by the National Natural Science Foundation of China under Grant No.61161001
文摘---Double data rate synchronous dynamic random access memory （DDR3） has become one of the most mainstream applications in current server and computer systems. In order to quickly set up a system-level signal integrity （SI） simulation flow for the DDR3 interface, two system-level SI simulation methodologies, which are board-level S-parameter extraction in the frequency-domain and system-level simulation assumptions in the time domain, are introduced in this paper. By comparing the flow of Speed2000 and PowerSI/Hspice, PowerSI is chosen for the printed circuit board （PCB） board-level S-parameter extraction, while Tektronix oscilloscope （TDS7404） is used for the DDR3 waveform measurement. The lab measurement shows good agreement between simulation and measurement. The study shows that the combination of PowerSI and Hspice is recommended for quick system-level DDR3 SI simulation.
文摘针对电力无线通信在应用中存在的问题,为更好地服务智能电网和开展分时长期演进(time division long term evolution,TD-LTE)技术在电力通信等领域的应用研究,建立了TD-LTE电力无线专网仿真平台。从链路级仿真和系统级仿真两个方面对电力无线专网的性能进行仿真,并分析了无线参数对无线专网性能的影响。该仿真平台的建立为电力终端通信接入网的统一建设和LTE电力无线专网的应用提供技术支撑,也为后期的网络规划奠定了理论基础。
文摘LTE-A(long term evolution advanced)通信系统采用正交频分复用(OFDM)为其物理层核心技术以获得抗频率选择性衰落和高频谱利用率等优点。接收端需要对多径信道动态估计和跟踪以满足相干解调,准确而简单的信道估计算法可以提高数据传输速率和降低用户设备的功耗。对LTE-A中基于导频的下行信道估计算法进行研究,提出了一种使用神经网络的信道估计算法。该算法考虑了下行传输链路的信道频率选择性,利用接收到的导频信号动态跟踪信道的变化特征,然后根据得到的信道信息对接收数据进行相干解调。仿真结果表明,与最小二乘(LS)、最小均方误差(MMSE)等传统方法相比较,该信道估计算法在均方误差(MSE)、误符号率(SER)和计算复杂度方面具有更好的性能,并且能保证LTE-A系统吞吐量需求。
文摘主要研究基于LTE(long term evolution)系统开展巨量机器类通信业务的性能.介绍了机器类通信的业务特点,并以北京近郊区的抄表类业务为例,分析了现有LTE系统开展机器类巨量用户通信时存在的问题.从理论上分析得到了随机接入资源和调度资源受限是制约终端接入数量的主要因素.本文搭建了符合3GPP标准的系统级仿真平台,仿真了不同用户数和不同下行控制信道资源对系统吞吐量、时延、接入碰撞概率等的影响,仿真结果验证了理论分析的正确性.
文摘根据3GPP对4G无线通信系统性能提出的要求,通过系统建模,设计并搭建了LTE-Advanced无线通信系统仿真平台.该仿真平台主要包括地理拓扑、Wrap-around,大/小尺度衰落,干扰计算,自适应调制编码,HARQ,分组调度等功能模块.在仿真平台的建模过程中,应用了蒙特卡洛思想,对系统性能进行多次随机独立采样,统计采样结果作为有效数据.在VISUAL STUDIO 2008环境下搭建了LTE-Ad-vanced系统级仿真平台,并通过比较轮询算法和正比公平算法评估了仿真平台的性能,仿真结果表明,该系统级仿真平台达到了3GPP对系统设计的要求,为LTE-Advanced的标准化工作奠定了基础.
