非平稳信道衰落高效模拟方法及硬件实现

Efficient simulation method and hardware implement for no-stationary channel fading

针对由于收发端的高速移动导致信道衰落呈现的非平稳特性,提出了一种基于线性调频信号叠加的非平稳信道衰落产生方法,并推导了该方法所产生信道衰落的幅值分布、电平通过率和平均衰落持续时间等统计特性理论值。在此基础上,利用Xilinx FPGA(XC7K325TFFG900-2)硬件平台设计实现了一个非平稳信道衰落模拟器,该模拟器结合串行和时分复用的思想,大大降低了硬件资源消耗,单个非平稳信道衰落模拟单元仅占用芯片约2.16%的资源。硬件实测数据表明,该模拟器输出信道衰落的各项统计特性均与理论结果吻合,可用于实验室环境下对非平稳信道衰落的实时模拟复现。

Due to high-speed movements of the transmitter and receiver, the propagation channels have shown non-stationary characteristics. Based on the sum of linear-frequency-modulation signals( So LFM),a new generation method for non-stationary channel fading is proposed. Meanwhile,important statistical properties of our channel model,i. e. time-variant probability density function( PDF),time-variant level crossing rate( LCR) and time-variant average duration of the fades( ADF),are derived and analyzed. On this basis,the proposed channel model is realized on the Xilinx FPGA( XC7 K325 TFFG900-2) hardware platform. Using serial and time division multiplexing to reduce hardware resource consumption,a single module occupies only about 2. 16% of the resources of the chip. In addition,hardware measurements of statistical properties are also consistent well with the theoretical ones,which can be used for real-time simulation of non-stationary channel fading in laboratory environment.