一种低复杂度信道模拟器的设计

Design of a Low Complexity Channel Simulator

针对TD-LTE射频一致性测试系统专项的需求及通用信道模拟器设计周期长、复杂度高的现状,研究了影响无线信道特性的路径损耗、阴影衰落、多径多普勒效应和高斯白噪声等因素,并相应提出了一种新的计算正余弦函数方法和高斯白噪声产生方法。通过信道理论建模、Matlab链路搭建进行模型优化分析以及基于Xilinx公司Virtex-6芯片的模型FPGA实现,得到了一种简单有效的信道模拟器。实验表明,用TD-LTE基带信号作为激励,该信道冲激响应与Matlab理论值误差在2‰之内,且模型不涉及SCM、WINNER等模型天线方向图、多链路等高复杂度模块,说明该信道模拟器具有简便性和可靠性。

According to the requirement of TD-LTE Radio Frequency（RF） Conformance Test System and the actuality of long designing circle and high complexity of general channel simulator, this paper studies the characteristics of the path loss, muhipath and Doppler effect and Gauss white noise （GWN） and other factors of the wireless channel, and proposes a new method to calculate the sine and cosine functions and a new method to produce GWN. Then through the channel theory modeling, Matlab link building, and FPGA implementation based on Virtex-6 chip of Xilinx Company, a simple and effective channel simulator is ob- tained. The experiment results show that with the TD-LTE baseband signal as excitation, the error between the channel impulse response and the theoretical value is lower than 2‰, and the model optimizes the high complexity modules of antenna pattern and multi-link of Spatial Channel Model（SCM） , WINNER and oth- er models, which verifies the simplicity and reliability of the channel simulator.