移动通信衰落信道的建模与仿真

在分析移动通信信道的多普勒扩展、平坦衰落和频率选择性衰落的基础上,将有限个等频率间隔的随机相位谐波信号叠加,设计了移动通信系统的Rician信道确知仿真模型;通过选择不同滤波器结构和参数将高斯白噪声转化为多种有色高斯随机过程,设计了移动通信系统的Rician信道随机仿真模型.基于最小均方误差(MMSE)准则推导了任意信号功率谱条件下的信道模型参数,利用Matlab编程实现了移动通信衰落信道实验系统.仿真实验表明,提出的2种信道模型较好地反映了移动通信衰落信道的主要特征且实现简单,尤其是谐波数为8的确知仿真信道参数已经接近理论值,适用于多种移动通信系统的理论研究和信道仿真.

Modeling and emulation for mobile communications fading channel

Several characteristics of mobile communications channel, such as Doppler spread, flat fading and frequency-selective fading are analyzed in detail. The implementation of the deterministic model for Rician channel is proposed by combining finite harmonics with equal frequency interval and randomly distributed phases, while the implementation of the stochastic model for Rician channel is proposed by adjusting the filter configuration and parameters to transform the white Gaussian noise into colored Gaussian stochastic process. A minimum mean square error (MMSE) criterion is (employed) to figure out the model parameters based on random power spectrum. The experimental system for mobile communications fading channel is developed and simulated by Matlab. Simulation results show that the two proposed models achieve good performance and have lower complexity; (especially) the simulation results of the deterministic model are close to the theoretical parameters when the harmonic number is eight. The proposed models can be well applied to channel simulations and research.