摘要
为了分析信道估计和循环前缀对提高正交频分复用(OFDM)系统性能的具体作用。首先简要介绍了OFDM基本原理,然后在理想同步情况下,重点分析了循环前缀(CP)和信道估计算法对OFDM系统性能的影响。在给出OFDM系统模型的基础上,用MATLAB语言实现了整个系统的计算机仿真。最后给出在不同的信道条件下,循环前缀(CP)和信道估计算法对OFDM系统误码率影响的比较曲线。从仿真曲线可以看出:高斯信道下循环前缀的作用并不显著,因为这时没有信道时延,也就不会产生ISI;但是当存在多径瑞利信道的时候cp的作用就显得很重要;MMSE估计法明显优于LS估计法。得出理想结论。
In order to analyze the basic functions of Channel estimation and CP to improve the performance of the OFDM system, in this artiele, OFDM basic principle is briefly introduced, then, the influence of CP and different channel estimation on the system performance is emphatically analyzed in the condition of ideal synchronization. Besides, based on the given system model, the OFDM system is simulated. Finally, the BER curves of CP and channel estimation are given and compared. The curves of simulation show that： the benefit of （using） CP is not obvious in the situation of awgn channel due to the absence of time - delay, therefore the absence of ISI. However, the significance of CP seems to be greatly increased in the situation of multi -Rayleigh channel;the MMSE method （of estimation） obviously performs better than LS method. A satisfactory conclusion is got.
出处
《计算机仿真》
CSCD
2008年第8期287-290,共4页
Computer Simulation
关键词
正交频分复用
仿真
循环前缀
信道估计
Orthogonal frequency division multiplexing （OFDM）
Simulation
CP
Channel estimation
