摘要
在平坦衰落假设基础上,分析了QPSK信号通过移动卫星信道的非线性性能。在仿真模型中,除了考虑上、下行信道的加性高斯白噪声,还考虑了多径效应、阴影衰落以及引起AM AM和AM PM转换的TWT(travelwavetube)非线性效应。利用matlab的Simulink仿真工具,分析了TWT放大器不同输入回退值和升余弦滤波器不同滚降因子对系统性能的影响。仿真结果表明,TWT放大器的工作点应接近饱和点,升余弦滤波器的滚降因子应选择在0.4～0.6。
The performance of QPSK signal transmitted through nonlinear mobile satellite channel is analyzed based on presumed frequency non-selective fading. In the simulation model, the multipath effect and shadowing and the nonlinearity of TWT that exhibits AM-AM and AM-PM conversion, are considered together with AWGN in both uplink and downlink. On Simulink platform, the effects of input back-off (IBO) and square root raise cosine (SRRC) roll-off factor are analyzed. The simulation results show that the optimum operating point of TWT is close to saturation and the optimum value of SRRC roll-off factor is about 0.4-0.6.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2005年第5期774-776,共3页
Systems Engineering and Electronics
基金
国家自然科学基金资助课题(60372013)
关键词
移动卫星通信
非线性
输入回退值
滚降因子
mobile satellite communication
nonlinearity
input back-off
roll-off factor
