【作者】 金华峰；

【导师】 孙献璞；

【作者基本信息】 西安电子科技大学 ， 通信与信息系统， 2007， 硕士

【摘要】 正交频分复用(OFDM)由于其良好的抗多径时延扩展性能和高效的频谱特性越来越受到人们的关注。OFDM系统对时偏和频偏十分敏感,容易引起载波间干扰。因此,在OFDM通信系统中,进行精确的时频偏移估计和补偿显得极为重要,同步问题已成为OFDM系统研究的主要内容。本文重点阐述了系统同步问题,并提出了一种新的基于单个训练符号的OFDM系统的时频同步算法。该算法在传统基于单个训练符号同步算法的基础上,通过对训练符号的重新设计,以一种新的方式引入伪随机序列加权因子,从而极大地提高了OFDM时频估计的精度,提高了同步的性能。仿真结果进一步证明了该算法的适用性。更多还原

【Abstract】 Orthogonal Frequency Division Multiplex (OFDM) is a kind of efficientmodulation mode. Due to its good ability in coping with multi-path fading and optimumspectrum efficiency, OFDM is widely used in wideband wireless communication.OFDM system is sensitive to symbol timing and carrier frequency offset very muchso that it is probably to produce inter-carrier-interference. Therefore precise timing andfrequency offset estimation and compensation is very important in OFDMcommunication system. Synchronization becomes one of major research topics in thisdomain.The synchronization is discussed particularly and a novel timing and frequencysynchronization algorithm requiring only one training symbol is proposed in this paperfor orthogonal frequency division multiplexing (OFDM) systems. Based on the analysisof conventional methods, the proposed algorithm redesigns a modified training symbolwhich is weighted by the pseudo-noise (PN) sequence in a new manner. This algorithmcan improve the synchronization performance greatly. The simulation results show thatthe proposed algorithm not only possesses better timing synchronization performancethan the conventional method, but also ensures higher accuracy of frequencysynchronization estimation even in the multi-path fading channel.更多还原