基于正弦波叠加的短波信道仿真方法

在短波信道建模中,通常采用对高斯白噪声滤波来仿真多普勒扩展效应,这些模型的时域相关值与理论值相差较大.为克服这些缺点,提出了一种基于正弦波叠加的方法来实现短波信道中特定多普勒谱的Rayleigh衰落因子.推导了由Lorentzian型多普勒谱得到正弦波的频率和加权系数的四种不同方法的计算式.采用时域相关值的均方误差作为性能评价函数,计算机仿真结果表明模型在时域相关上与理论值非常接近.

HF Channel Modeling by Sum of Sinusoids

In HF channel modeling, doppler spread effects are usually simulated by filtering white Gaussian noise. The signal correlation in time domain deviates far from the theoretical value. In order to improve the simulation performance, a method based on sum of sinusoids to implement Rayleigh faders with special doppler spectrum is presented. According to the Lorentzian doppler spectrum, the weighted coefficients and the frequencies of the sinusoids are derived in four different modes. The mean square error of the signal correlation in time domain is introduced as the performance evaluation function. The simulation results show that the method can approximate the Rayleigh stochastic processes very closely.