【作者】 郝磊；

【导师】 肖丽萍；

【作者基本信息】 燕山大学 ， 通信与信息系统， 2010， 硕士

【摘要】 在无线移动信道中,实现高速率和高质量的通信服务,是无线通信的目标和要求。正交频分复用(OFDM)技术具有频谱利用率高、能够有效对抗频率选择性衰落的影响而日渐受到人们的普遍关注。而信道估计技术是实现OFDM可靠传输的关键技术之一,为了在接收端能够正确地解调出发端信息,需要从接收数据中将信道信息准确的估计出来,信道估计的精度将直接影响整个系统的性能。本文首先分析比较了基于导频类信道估计中的各种算法,在对基于m序列信道估计研究的基础上,从计算复杂度低,估计精度高的角度出发,给出了基于失配序列和序列偶的信道估计方法,并通过计算机仿真与m序列信道估计方法以及传统估计算法中的LS、DFT算法进行了比较。其次,在对判决反馈信道估计方法研究的基础上,针对传统判决反馈信道估计初始信道估计值不够精确的缺点,给出了m序列、失配序列分别与判决反馈相结合的信道估计方法,利用m序列、失配序列较为精确的估计性能作为初始估计值来进行判决反馈。通过MATLAB仿真,与判决反馈方法、失配序列信道估计方法、m序列信道估计的方法进行比较,仿真结果进一步验证了本文的可行性,并且总结了几种方法的优劣性及可能存在的问题,为进一步的研究提供了方向。更多还原

【Abstract】 In the wireless mobile channel, to realize high speed and high quality service is the target and requirement of wireless communications. Orthogonal Frequency Division Multiplexing has attracted much attention for its high spectrum efficiency and strong immunity to frequency selective fading availably. Nevertheless, channel estimation is one of the key technologies for reliable transmission in OFDM system. In order to correctly demodulate information from sending terminal, it is therefore needed to estimate channel information accurately from receiving data. The accuracy of channel estimation will directly affect the performance of the whole system.Firstly, this text analyzes some kinds of algorithms based on channel estimation using pilot symbols. Based on research of channel estimation applying m-sequence, using the mismatched sequence and sequence pairs channel estimation algorithm has been put forward in the circumstances of low complexity and higher accuracy. It compared with applying m-sequence and traditional algorithm by computer simulation.Secondly, based on decision feedback channel estimation, this text directed towards the shortcoming of inaccuracy on traditional decision feedback. It put forward new algorithm that uses mismatched sequence or m-sequence to combine decision feedback respectively. Using the mismatch sequence and m-sequence could accurately estimate performance as the initial estimate for decision feedback. It is compared with applying mismatch sequence channel estimation and m-sequence channel estimation and decision feedback channel estimation. The result of simulation by MATLAB verified the feasibility of the paper. It summarized disadvantage and advantage about seveval methods, and provided the direction of the further research aspects.更多还原