采用串口转以太网模块使现有串口设备具备联网功能是一种低成本实用的解决方案。在使用之前,需要根据具体应用环境对串口转以太网模块的串口参数以及网络参数进行设置。对上位机与串口转以太网模块间的通信协议进行了详细阐述,采用UDP...采用串口转以太网模块使现有串口设备具备联网功能是一种低成本实用的解决方案。在使用之前,需要根据具体应用环境对串口转以太网模块的串口参数以及网络参数进行设置。对上位机与串口转以太网模块间的通信协议进行了详细阐述,采用UDP广播通信方式,由上位机通过网口对模块进行参数配置。在Visual Studio 2012下,用C#编程实现了一套配置软件。配置过程中,上位机和模块可以跨网段通信,避免需预知模块初始IP以及更改上位机IP地址的麻烦,使用更方便。展开更多
In this paper, a robust THP is proposed for broadcast channel in multi-user multi-input multi-output (MU-MIMO) system, in which the channel uncertainty caused by feedback delay and mobile speed is taken into account. ...In this paper, a robust THP is proposed for broadcast channel in multi-user multi-input multi-output (MU-MIMO) system, in which the channel uncertainty caused by feedback delay and mobile speed is taken into account. In order to acquire the imperfect channel state information at transmitter (CSIT), a dynamic CSIT model is introduced where the channel temporal and spatial correlations are considered. By utilizing the unchanged channel statistics and accurate outdated feedback channel information jointly, the imperfect CSIT is obtained as the channel estimate and error covariance. Based on the obtained imperfect CSIT, a Minimum Mean-Square Error (MMSE) Tomlinsion-Harashima precoding (THP) is designed and the closed-form solution is derived by the Lagrangian multiplier approach under total power constraint. Simulation results are provided to indicate the preferable performances of the robust THP. Performance analysis with respect to feedback delay and mobile speed is also given.展开更多
文摘采用串口转以太网模块使现有串口设备具备联网功能是一种低成本实用的解决方案。在使用之前,需要根据具体应用环境对串口转以太网模块的串口参数以及网络参数进行设置。对上位机与串口转以太网模块间的通信协议进行了详细阐述,采用UDP广播通信方式,由上位机通过网口对模块进行参数配置。在Visual Studio 2012下,用C#编程实现了一套配置软件。配置过程中,上位机和模块可以跨网段通信,避免需预知模块初始IP以及更改上位机IP地址的麻烦,使用更方便。
基金supported by National Basic Research Program of China (973 Program) (Grant No. 2007CB310604, 2009CB320401)National Natural Science Foundation of China (Grant No. 60772108, 60702048)
文摘In this paper, a robust THP is proposed for broadcast channel in multi-user multi-input multi-output (MU-MIMO) system, in which the channel uncertainty caused by feedback delay and mobile speed is taken into account. In order to acquire the imperfect channel state information at transmitter (CSIT), a dynamic CSIT model is introduced where the channel temporal and spatial correlations are considered. By utilizing the unchanged channel statistics and accurate outdated feedback channel information jointly, the imperfect CSIT is obtained as the channel estimate and error covariance. Based on the obtained imperfect CSIT, a Minimum Mean-Square Error (MMSE) Tomlinsion-Harashima precoding (THP) is designed and the closed-form solution is derived by the Lagrangian multiplier approach under total power constraint. Simulation results are provided to indicate the preferable performances of the robust THP. Performance analysis with respect to feedback delay and mobile speed is also given.
