采样时钟偏差对OFDM系统性能的影响  

Effect of Sampling Clock Offsets on the Performance of OFDM System

作　　者：李平[1] 赵志辉[1] 张振仁[1] 

机构地区：[1]第二炮兵工程学院,陕西西安710025

出　　处：《信息与电子工程》2006年第6期431-435,共5页information and electronic engineering

摘　　要：针对采样时钟同步偏差对正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的影响,建立了数学模型,分别就采样定时偏差和采样频率偏差的影响进行详细分析;经过仿真,从星座图、误码率(Bit-Error-Rate,BER)及信噪比(Signal-to-Noise Ratio,SNR)损失等角度对采样频率偏差的影响做了揭示和验证。结果表明,采样频率偏差会引起信号幅度衰减和子载波间干扰(Inter-Carrier Interference,ICI),导致系统信噪比性能下降;这种影响与子载波位置有关,还会随着OFDM符号数的增多而加剧。This paper presents the effect of sampling clock offsets on the performance of OFDM system. The sample timing error and sampling frequency offset are analyzed respectively in detail by the digital model. In the simulation, constellation, Bit-Error-Rate （BER） and Signal-to-Noise Ratio （SNR） performance degradation are analyzed taking into account the effect of sampling frequency offset. It is shown that sampling frequency offset can lead to amplitude attenuation and Inter-Carrier Interference （ICI） due to the loss of orthogonality between the subcarriers. The SNR performance degrades with the increment of subcarriers indices and the number of OFDM symbols.

关 键 词：采样频率偏差 采样定时偏差 载波间干扰 OFDM 

分 类 号：TN919.3[电子电信—通信与信息系统]