摘要
相对于一般的通信系统而言,低轨卫星通信系统具有信号动态范围大,多普勒频移大且变化速度快,信道起伏剧烈等特点。首先分析了低轨卫星信道时变特征,提出了基于自由空间衰减与Corraza模型的全阶段静态信道模型,并采用C larke仿真模型及莱斯正弦和法对其误码率性能进行了仿真分析。在此基础上研究了基于隐马尔可夫模型的低轨卫星动态信道模型,仿真结果表明采用隐马尔可夫仿真模型比传统的波形级仿真运算量大大减小,且在性能方面接近。同时具有非常好的灵活性与扩展性。
LEO satellite communication system has the properties of larger power dynamic range, larger and faster changed doppler frequency shift and rapid fluctuation compared to ordinary communication system. The paper firstly analyzes the time -varying channel characteristics of LEO, proposes a full stage stationary channel model based on free space loss and Corraza model,and simulates the BER performance using the Clarke＇s model and Rice＇s sum of sinusoids. Then the hidden Markov model of LEO channel is studied. Simulation results show that the co/nplexity of computation will be decreased compared to traditionary waveform simulation but their performances are similar. This model also has very good flexibility and expansibility.
出处
《计算机仿真》
CSCD
2007年第1期319-322,共4页
Computer Simulation
基金
国防科工委十一五民用航天预研项目基金支持(c1320063102)
