OFDM系统中信道有效阶数的估计

Channel Order Estimation for OFDM System

信道估计是无线通信的关键技术之一，知道信道长度可以提高信道估计的精度．本文针对基于OFDM调制技术的无线通信系统中LS信道估计算法时域结果的构成特点，结合无线信道冲激响应在时域为有限冲激响应的特点，提出对LS信道估计算法的时域结果进行能量检测，并进行逆向搜索以获得信道有效阶数估计的算法．同时从检测概率角度给出了检测门限．最后给出了计算机仿真结果．理论分析和计算机仿真表明此算法能够很好地得到信道有效阶数估计结果．

Channel estimation is one of the key technologies in wireless communication, the prior information of channel length can improve the accuracy channel estimation. In mobile communication system based on OFDM, this paper pays much attention to the character of LS algorithm＇s result in time-domain. At the same time, the character of Channel Impulse Response （CIR） in time-domain is taken into account. Then it is proposed to detect energy of CIR＇s tap in LS algorithm＇s result in time-domain and search the effective order of radio channel conversely. The detection threshold is given from point of probability theory. In the end, the simulation results are given. By theoretical analyses and computer simulation, it is indicated that this method shows good performance in estimating effective order of radio channel.