摘要
针对短波信道衰落特征复杂,难以在仿真中较为真实的重现这一问题,提出了一种基于NS2和VOACAP联合仿真的短波信道模拟方法。采用Walnut Street模型作为基础,将短波信道衰落划分为慢衰落、中等时间尺度的衰落和快衰落。在实现短波信道衰落模型时,按需在C++中调用VOACAP计算慢衰落,使用对数正态分布模拟中等时间尺度的衰落,使用瑞利分布来模拟快衰落。仿真结果表明,此模型能够较好地反映短波信道的衰落特点,不同频率的衰落随时间的变化与理论和经验相符,可以作为短波网络仿真的物理层信道模型;同时,所采取的联合仿真方法避免了事先计算链路衰落的繁琐性,更加适合于大规模的短波网络仿真。
In consideration of the complicated fading characteristics of high frequency （HF） channel and the difficulty of reappearing in simulation, a combined method of NS2 （ Network Simulation 2 ） and VOACAP （Voice of America Coverage Analysis Program） is proposed to simulate HF channel. Based on Walnut Street Model, the HF channel fading is divided into slow fading, mid-time scale fading and fast fading. In the fading model of HF propagation model, VOACAP is called in C ＋ ＋ to calculated slow fading on need, medium time scale fading is treated as log-normal distribution and fast fading is treated as Rayleigh distri- bution. The simulation results show that, this model can reveal the fading characteristics of HF channel, and the change of frequencies＇ fading with time of day is consistent with that of theory and experience. So this model may serve as the base of physical layer in HF network simulation. Meanwhile, the joint simula- tion method used in this paper avoids the complexity of calculation of channel fading before simulation, so it＇s more suitable for large scale HF network simulation.
出处
《电讯技术》
北大核心
2014年第1期102-108,共7页
Telecommunication Engineering
基金
全军军事学研究生资助课题(2012JY003-584)~~
