基于局部三角变换的OFDM系统  

OFDM System Based on Local Trigonometric Transform

作　　者：孟洪涛[1] 陈迪荣[1] 刘红英[1] 

机构地区：[1]北京航空航天大学理学院,北京100191

出　　处：《航空学报》2009年第6期1126-1130,共5页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(10571010)

摘　　要：正交频分复用(OFDM)调制技术由于具有良好的抗多径干扰能力和高效的频谱利用率,在许多数字传输系统中被广泛应用,成为当今卫星通信研究的热点。本文提出了基于局部三角变换(LTT)的OFDM系统模型,该系统带外频率谱密度下降快,并能保持相邻的OFDM符号的正交性。给出了用离散余弦变换(DCT)实现的快速算法及复杂度,并考查了最优基的选取。仿真和分析结果表明:该系统误码率比基于快速傅里叶变换(FFT)的系统更小,能更好地适应高速传输带来的大多普勒频移,更有效地利用带宽,为接收端对高速数据的解调提供很好的保证。The orthogonal frequency division multiplexing （OFDM） modulation technique is widely used in digital transmission systems because of its good performance in withstanding multi-path disturbances and its efficient use of frequency bandwidths. In this article, an OFDM system based on local trigonometric transform （LTT） is proposed in which the spectral density out of the bandwidths decreases rapidly and the adjacent symbols of OFDM remain orthnormal. The fast algorithm based on discrete cosine transform （DCT） and its complexity are obtained and the selection of the best basis is discussed. Theoretical analysis and computer simulation results show that the biterror and anti-Doppler-frequency-offset capability of the proposed method outperform the conventional fast Fourier transform （FFT）-based system. It can effectively utilize the frequency resources and greatly improve system performance.

关 键 词：正交频分复用 局部三角变换 最优基 谱分析 多普勒效应 

分 类 号：TN914.51[电子电信—通信与信息系统]