一种快速时变衰落信道估计方法研究

Research on a method of fast time-varying fading channel estimation

由于现代无线通信系统对快速移动通信服务的要求越来越高,传统的信道估计方法在快速时变信道环境下的估计性能下降幅度很大。文章提出了一种快速时变信道环境下的信道估计方法,在发射端发射2个调频率相反的LFM信号,在接收端在峰值搜索的过程中结合谱校正技术搜索信号幅度谱的峰值和对应点的坐标,实现谱峰值的超分辨率估计,利用分数阶傅里叶变换的时移和频移性质,根据发射端信号的峰值点与收端信号的峰值点之间的差值,估计出信道的时延和频移,并给出信道的衰落幅度和初始相位的估计方法。仿真结果表明,该方法较传统信道估计方法的估计精度有较大的提升且实时性高。

As demand from modern wireless communication system for rapid mobile service is higher and higher, the estimation performance of traditional channel estimation methods under the environment of fast time-varying channel estimation has a great drop. This paper prop oses a fast channel estimation method under the time-varying channel environment by sending two LFM signals with opposite frequency modulation. The method combines spectrum correction technology during the process of peak searching at the receiving end and then get signal amplitude spectrum peak and the coordinates of corresponding points, realizing the super resolution estimation of spectrum peak.By the performances of fractional Fourier transform time shift and frequency shift, and the difference of the peaks of the transmitted signal and receiving si gnal in value, the method can estimate the channel delay and frequency shift and can also get the decline of channel amplitude and initial phase. Simulation results show that proposed method has higher estimation accuracy and better real-time performance estimation precision, which has greater promotion compared with the traditional channel estimation methods.