基于衰落信道传输的OFDM信号的信道估计

下一代移动无线通信系统的目标是实现无所不在的、高质量的、高速率的移动多媒体传输.但是为了实现这一目标,面临许多技术挑战.例如,移动无线通信信道面临的是十分恶劣的衰落特性,无线信道通常具有频率选择性而且是时变的,而且多径衰落信道其信道转移函数无论在时域还是频域都呈现出非均匀性.因此要在这样的传播条件下保持可以接受的传输质量,就必须采用各种技术措施来抵消衰落的不利影响.本文简要介绍了在衰落信道中传输OFDM信号的信道估计方法和算法,以及进行的仿真,通过仿真得出基于块插入型的有无反馈器的BER特性和基于梳插入型的低通滤波的BER特性.

Channel Estimation of OFDM Signal Transmission Based on Fading Channel

The next-generation wireless personal communication systems are expected to provide ubiquitous,high-quality,and high-rate mobile multimedia transmission.However,to achieve this objective various technical challenges must be overcome.For example,the deployment of broadband wireless access systems would require a transmission technique which can mitigate the detrimental effects of the inter-symbol interference(ISI) caused by the multipath fading channels.The methods of channel estimatioin based on both block type and comb type are studied in this paper.The channel estimation based on block type pilot is assigned to a particular OFDM block,which is sent periodically in timedomain.