【作者】 滕鹏伟；

【导师】 汪一鸣；

【作者基本信息】 苏州大学 ， 通信与信息系统， 2006， 硕士

【摘要】 超宽带(UWB)以其隐蔽性好、传输速率高、抗多径和窄带干扰能力强等优点,在短距多址高速无线通信中良好的应用前景而引起广泛研究。本文以UWB通信系统为背景,主要研究UWB系统室内密集多径信道的信道估计方法,以及基于TURBO原则的迭代信道估计的接收机结构。本文首先介绍TURBO码的编码解码结构和纠错性能,分析TURBO原则的概念,软件实现TURBO码的编码和解码。研究了TURBO码作为信道编码在UWB系统中的应用。随后针对UWB系统室内密集离散多径信道,根据RAKE分集接收技术对信道参数的要求,提出一种基于训练比特的UWB信道估计方法。最后结合TURBO原则,重点提出无训练比特的迭代信道估计方法和接收机结构。该估计方法充分利用了译码器软输出中包含的数据的先验信息。仿真结果表明,两种信道估计方法都能够有效估计信道参数,而无训练比特的迭代信道估计方法在跟踪信道参数变化方面的性能更优越。更多还原

【Abstract】 Ultra-wideband (UWB) communication has been the subject of extensive research in recent years due to its unique capabilities and potential applications, particularly in short-range multiple access wireless communications.The subject of this thesis is the channel estimation technology and receivers based on TURBO principle in UWB. In order to utilize the resoluble ability of signals and improve resistant ability to multipath fading, the Rake receiver is a good option. But proper Rake operation requires information about the delays and attenuations of the channel paths which is difficult to obtain. In the recent years, excellent forward error correction capability of turbo codes has been exploited which can lead to highly power and bandwidth efficient in wireless communication systems. Combining two technologies together may produce a new scheme. Firstly, this thesis investigates the application of turbo codes as channel code in UWB, and then introduces TURBO principle. Aiming at UWB indoor multipath channel, we propose a channel estimation algorithm with training bits. Finally, we propose an iterative channel estimation algorithm based on TURBO principle. This method fully utilizes the soft outputs of channel coder, and regards it as prior information. The simulation results show that two algorithms can efficiently estimate channel parameters, but the late method has better performance than the former when channel is time-variant.Finally, there are conclusion and prospect.更多还原