摘要
正交频分多址(OFDMA)技术具有高的频谱利用率，大的用户容量，并能有效地抵抗多径衰落，成为第四代移动通信系统中的关键技术之一。本文阐述了OFDMA系统的基本原理，给出了基站与用户端站上的收发信机的总体设计，并针对该系统中的同步技术，指出了载波频偏、采样钟偏移和符号定时偏差对该系统的影响，深入研究了基于多相滤波器组的载波频偏和定时偏差的估计算法，针对该系统中的信道估计技术，深入研究了基于导频符号的信道估计方法，从而提出了一系列的同步与信道估计的改进措施和新算法，本文还简要讨论了OFDMA系统中的子载波、比特与功率的最佳分配算法，最后结合MATLAB仿真对这些算法的有效性和可行性进行了全面地分析与比较。
With high spectrum efficiency, large capacity and immunity for multipath fading, orthogonal frequency division multiplexing access (OFDMA) technique is one of key skills in the fourth generation of mobile communication. In this paper, we discuss the basic principle of OFDMA system, and propose a whole design of transceivers both in BS and in user terminal end. In the system synchronization aspect, we point out the effects of the carrier frequency offset, sampling offset, and symbol timing offset to the system, and investigate the estimation algorithms of carrier frequency offset and timing offset based on polyphase filter banks. In the channel estimation aspect, we investigate the algorithms based on pilot symbol. Accordingly, we propose a series of amendments and new algorithms for synchronization and channel estimation. We also discuss the optimal subcarrier, bit and power allocation algorithm in brief. Finally, we analysis and compare the effectivity and feasibility of these algorithms with Matlab software simulation.
引文
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