在通用移动通信系统(Universal Mobile Telecommunications System,UMTS)异构网络中,理论分析了宏基站对微微(Pico)小区边缘用户的下行干扰问题。在传统空白帧(ABS)方法的基础上,提出了一种干扰避免策略,其主要思想是通过联合时域ABS策...在通用移动通信系统(Universal Mobile Telecommunications System,UMTS)异构网络中,理论分析了宏基站对微微(Pico)小区边缘用户的下行干扰问题。在传统空白帧(ABS)方法的基础上,提出了一种干扰避免策略,其主要思想是通过联合时域ABS策略和空域基于码本限制的策略提高传统ABS策略的系统性能,即在ABS子帧上,宏基站并不是完全不发送数据,而是采用码本受限的预编码进行传输。限制的码本可以根据宏小区自身的负载动态进行更改,并通过广播传递给低功率节点(Low Power Node,LPN),LPN根据得到的信息进行边缘用户的调度。仿真结果表明,提出的方法在最差5%用户吞吐率比ABS方法略有下降的情况下,使用户平均吞吐量得到了提升。展开更多
The control system of an autonomous underwater vehicle (AUV) is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation ...The control system of an autonomous underwater vehicle (AUV) is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation is done to test the feasibility of the control system. The neural network idea and the structure of PID controller are referred to design the adaptive PID controller. An intelligent integral is introduced to improve control precision. Compaed with traditional PID con- trollers, the adaptive PID controller has simple structure, good online adjusting ability, fast convergence and good robustness. The simulation experiments also show that the adaptive PID control system has high precision and fine antijamming ability.展开更多
文摘在通用移动通信系统(Universal Mobile Telecommunications System,UMTS)异构网络中,理论分析了宏基站对微微(Pico)小区边缘用户的下行干扰问题。在传统空白帧(ABS)方法的基础上,提出了一种干扰避免策略,其主要思想是通过联合时域ABS策略和空域基于码本限制的策略提高传统ABS策略的系统性能,即在ABS子帧上,宏基站并不是完全不发送数据,而是采用码本受限的预编码进行传输。限制的码本可以根据宏小区自身的负载动态进行更改,并通过广播传递给低功率节点(Low Power Node,LPN),LPN根据得到的信息进行边缘用户的调度。仿真结果表明,提出的方法在最差5%用户吞吐率比ABS方法略有下降的情况下,使用户平均吞吐量得到了提升。
文摘The control system of an autonomous underwater vehicle (AUV) is introduced. According to control requirements of the AUV, a simple but practical adaptive PID control method is designed The semi-physical simulation is done to test the feasibility of the control system. The neural network idea and the structure of PID controller are referred to design the adaptive PID controller. An intelligent integral is introduced to improve control precision. Compaed with traditional PID con- trollers, the adaptive PID controller has simple structure, good online adjusting ability, fast convergence and good robustness. The simulation experiments also show that the adaptive PID control system has high precision and fine antijamming ability.