非平稳信道衰落FPGA实时模拟方法

A Real-time FPGA-based Emulation Method 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,并对输出信道衰落的幅值分布和平均增益进行了详细分析,据此设计了基于FPGA硬件平台的非平稳信道衰落模拟器,实测结果表明,该模拟器输出信道衰落分布、自相关函数和多普勒功率谱等均与理论结果非常吻合,可应用于针对非平稳散射环境下的下一代无线通信系统性能测试和验证。

Due to high-speed movements of the transmitter and receiver, propagation channels have shown non-stationary characteristics. In this paper, based on the sum of linear-frequency-modulation signals （SoLFM） method, a new generation method for non-stationary channel fading is proposed. Meanwhile, theorical expresssious of statistical properties, i. e. , time-variant probability density function （PDF） and the average gain of channel are derived and analyzed. On this basis, the proposed method is implemented on a Xilinx FPGA hardware platform. The time-variant PDF, autocorrelation function （ACF） and Doppler power spectrum （DPSD） of the emulator are also measured. Hardware measurements have shown that the output statistical properties are consistent well with the theoretical ones, which can be used for real-time simulation of non-stationary channel fading in laboratory environment.