基于叠加训练序列的OFDM系统信道估计算法研究_毕业设计论文.doc

毕业设计论文
基于叠加训练序列的OFDM系统信道估计算法的研究
摘要:在OFDM系统中,为了能达到系统需要的解码要求,必须要进行准确的信道估计。本文首先介绍了OFDM系统基本原理,着重研究了OFDM信道估计技术。论文主要研究一种基于叠加训练序列的OFDM系统信道估计方法。由于这种估计方法具有计算复杂度低,而且最主要的特点是该方法不占用系统额外的时隙,把导频序列直接叠加在信息序列上,因而可以节省系统的频谱资源。论文首先对基于叠加训练序列的OFDM系统信道估计算法进行了仿真分析,并比较了在不同值情况下的性能,从而存在一个最优的值取得最好的估计性能。最后,论文对三种不同的信道估计算法进行了仿真分析,比较了三种不同的信道估计算法的误码率和均方误差,从而对三者的性能进行分析得出,基于叠加训练序列的信道估计方法可能会更加广泛的用于生产和生活中。
关键词:正交频分复用,信道估计,训练序列,多径衰落,多普勒频移。
Abstract: In OFDM system, it is necessary for achieving good decode performance to estimate accurately channel characteristic parameters;accordingly,the dissertation focuses on the channel estimation method design for OFDM dissertation introduce the basic principles of mainly investigate the channel estimation technology in OFDM a estimation method based on implicit training in OFDM was studied on the frequency selective estimation method has a plexity,and most of all avoiding the need for additional time slots for training because the training sequence is actually arithmetically added to the information data. And on this basis, the selections of the appropriate sequences were of superposition. Finally, the paper three different channel estimation algorithms in analysis parison of three different channel estimation algorithm error rate and MSE, and thus analyze the performance of the three superimposed training based channel estimation method may be more widely used in the production and life.
Key words:OFDM(Orthogonal Frequency Division Multiplexing),Channel Estimation,Training Sequence,Multi-path Fading,Doppler Frequency Shift.
目录
目录 3
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OFDM技术的发展、应用及其优势 4
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国内外研究现状综述 7
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2. OFDM的基本原理及其信道估计算法 12
OFDM的基本原理 12
OFDM的发展及现状 12
OFDM系统的基本原理 13
OFDM系统的基本模型 14
OFDM系统的关键技术 16
OFDM的信道估计方法 18
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(Pilot—Symbol-Aided Modulation,PSAM)信道估计 19