变换域通信系统中的信道估计技术  

Channel Estimation Applied to Transform Domain Communication System

作　　者：王军[1] 李少谦[1] 龚树平[1] 韩川[1] 

机构地区：[1]电子科技大学通信抗干扰技术国家级重点实验室,成都610054

出　　处：《电子科技大学学报》2009年第1期40-42,96,共4页Journal of University of Electronic Science and Technology of China

基　　金：国家863计划(2007AA10Z209);国家自然科学基金(60496313;60702073);国家基础科研项目(A1420080150);国家973计划(2009CB320405)

摘　　要：针对基于OFDM的变换域通信系统在低信噪比时由于噪声的影响很难获得准确的信道估计问题,采用时域和离散傅里叶逆变换(IDFT)域级联降噪的方法降低导频信号的噪声来提高信道估计的准确性。时域利用慢衰落信道环境下信道系数变换缓慢的特点,提出了时间滑动平均、时间遗忘、时间平均与时间遗忘结合等几种降噪方法;IDFT变换域利用多径时延集中在整个时隙的前一段的特点降低噪声。仿真结果表明,该方法在慢衰落信道环境下是有效的。Aimed at the channel estimation of OFDM-based （orthogonal frequency division multiplex based） transform domain communication （TDCS） systems under low SNR scenarios, channel estimation techniques fou suppressing noise in time domain and/or transform domain are proposed. In time domain, the noise is mitigated through three schemes： time-sliding average, time-forgetting average, and their combination as the channel is slowly time-varying. To further reduce the influence of noise, the time-domain-based channel estimation methods are also combined with IDFT transform domain technique. Simulation results show the proposed channel estimation methods can achieve nearly the same performance as that of perfect channel estimation.

关 键 词：信道估计 OFDM 变换域通信系统 慢衰落信道 

分 类 号：TN92[电子电信—通信与信息系统]