衰落性AWGN 信道的OFDM 性能保护间隔的优化(英)

阐述了OFDM系统的基本原理及保护间隔（GI）对系统的影响.首先就保护间隔（GI）参数在接收机干扰问题上起到的作用进行了讨论.然后计算了保护间隔参数的最佳值，结果表明它们对最大延迟有很强的依赖性.同时对多径衰落和加性高斯白噪声同时存在的QPSK调制情况进行了仿真，从而分别得出了GI、信噪比（SNR）、最大传播延迟和副载波数量与误码率的关系.

Guard Period Optimization of OFDM Performance over Fading and AWGN Channels(English)

In this paper, the principals of Orthogonal Frequency Division Multiplexing (OFDM) system was described and the effect of the Guard Interval (GI) on the system performance was studied. The role of the GI period to solve the problem of interferences that occur at the receiver was discussed. The optimum values of the GI parameter are determined, which were shown to have strong dependence on the maximum delay. A series of simulations have been carried out on Quadrature Phase Shift Keying (QPSK) modulation scheme over multi-path fading and Add White Gaussian Noise (AWGN). The relationship between Bit Error Rate (BER) performance and GI, Signal to Noise Ratio (SNR) , the maximum delay spread and number of Sub-carrier was studied.