一种基于有限字符集特性的OFDM系统盲信道估计算法  

A novel finite alphabet based blind channel estimation algorithm for OFDM communications

作　　者：李玮[1] 程时昕[1] 

机构地区：[1]东南大学移动通信国家重点实验室,南京210096

出　　处：《高技术通讯》2007年第12期1216-1220,共5页Chinese High Technology Letters

基　　金：863计划重大项目(2002AA123031)资助

摘　　要：针对正交频分复用(OFDM)通信系统中传统的基于发送信号有限字符集特性的盲信道估计算法复杂度高、实用性低的问题进行了研究,提出了一种降低算法复杂度的改进的盲信道估计算法。通过将OFDM系统的频域接收信号模型等价分解成多个接收信号分组的方式,改进算法仅需搜索单个发送信号分组便可实现盲信道估计,其计算量大大降低。此外,改进算法还可以通过控制盲估计算法中分组的数目很好地实现系统性能和复杂度的折衷设计,实用性也更强。数值仿真结果表明,改进算法的最优估计方案与传统算法的性能完全相同,且其次优估计方案的性能随着比特信噪比的增加逐步逼近传统算法,分别在10和15dB处趋于一致。In order to reduce the complexity of the conventional blind channel estimation algorithm based on the finite alphabet property of the transmitted signals and enhance its feasibility, a complexity reduced algorithm is proposed in this paper. The conventional OFDM received signal model is decomposed into an equivalent mode with several received signal groups before doing blind finite alphabet search, and then a more flexible scheme based on the transformed model is presented. The improved algorithm only requires searching a part of the transmitted signals and as a result its calculations can be greatly reduced. Besides that, by setting the different number in the joint blind searching it also provides a better tradeoff between the system performance and its complexity. Through numerical simulations, the improved algorithm with the optimal performance performs as well as the conventional one, while its suboptimal tradeoff schemes can also approach the conventional one＇s performance as the Eb/N0 increases to 10 or 15 dB levels respectively.

关 键 词：正交频分复用(OFDM) 盲信道估计 有限字符集 

分 类 号：TN919.3[电子电信—通信与信息系统]