基于FRFT_LFM信道探测的TDCS系统衰落信道抑制技术

利用分数傅里叶变换(FRFT)对线性调频信号(LFM)检测的优势,提出一种基于FRFT_LFM的变换域通信系统(TDCS)衰落信道探测技术;该技术利用FRFT算法对预先发射的LFM信号进行检测,以估计信道的衰落特征,并采用预均衡的方法对TDCS系统基函数幅度谱函数进行预修正,以提高TDCS系统对信道衰落特性的抑制能力.理论分析和仿真结果证明,FRFT_LFM技术可有效探测信道的衰落特性,基于预均衡的TDCS系统的信道衰落特征抑制性能明显提升.

Fading channel suppression of TDCS system based on FRFT_LFM channel detection

Using the superiority of fractional Fourier transform（FRFT） to detect linear frequency modulated signal （LFM）, the fading channel detection technology of transform domain communication system（TDCS） is proposed based on FRFT_LFM. The technology makes use of FRFT algorithm to test pre-launched LFM signals so as to estimate the channel fading characteristics, and uses the pre-equalization approach to pre-amend the basis function amplitude spectrum of TDCS system in order to improve the ability of TDCS system about restraining fading channel characteristics. Theoretical analysis and simulation results show that FRFT_LFM technology can detect the channel fading characteristics effectively and the suppression performance of TDCS about restraining fading channel characteristics has improved evidently.