针对传统信道模型只对多径衰落进行统计建模的问题,将信道建模为包含多径及阴影衰落因素的复合模型,提出一种基于谐波叠加原理、易于硬件实现的时域相关复合衰落模拟方法. 推导了新方法输出衰落的幅值分布及相关性理论表达式,给出了仿真参数的计算方法. 基于Xilinx Virtex4 硬件平台的实测结果表明,该方法输出的信道衰落包络分布、多普勒功率谱及相关特性均与理论值吻合,可用于实验室模拟真实传播环境对无线信号的随机失真影响.
The traditional channel models usually consider the effects of multipath fading only. A new fading model including shadowing and multipath fading is established, and a novel generation method for this correlated composite fading is presented. The proposed method is based on the sum-of-sinusoids (SoS) theory that is easy to implement with hardware. Moreover, theoretical envelope distribution and correlation coefficient of output fading are derived. A method for calculating simulation parameters is given. Experiments on a Virtex4 FPGA hardware platform show that the envelope distribution, Doppler power spectrum and correlation characteristic agree well with the expected values, meaning that the proposed method can be used to simulate random distortion of wireless signals caused by real propagation environment in the lab.
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