基于伪噪声序列的OFDM信道估计方法

OFDM Channel estimation based on pseudo-noise sequence

针对正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)的应用及需求,提出一种基于伪噪声(pseudo-noise)序列的OFDM系统模型,并针对其信道估计均衡需求,提出一种基于迭代的信道估计算法和低复杂度的频域均衡算法。最后在高斯白噪声信道、存在多普勒频移瑞利信道、双径延迟信道下,对误码率性能进行仿真和分析。结果表明,该方法适用于常见信道,误码率性能优于传统循环前缀(Cyclic Prefix,CP)OFDM,且通过迭代能够提高性能。以上研究结果可应用于OFDM数字电视地面广播工程。

A model of orthogonal frequency division multiplexing（OFDM） system based on the pseudo- noise sequence is designed in this paper. Meanwhile, an iterative algorithm for channel estimation and a frequency domain equalization algorithm of low com- plexity are proposed to satisfy the equalization demand in channel estimation of this model. Then simulations are carried out corre- sponding to a Gauss white noise channel, a Rayleigh channel with a Doppler frequency shift and a double path delay channel. And the bit error rates（BER） are calculated respectively. Analysis results indicate that the method applies to usual channels and has a superior BER over traditional cyclic prefix OFDM （CP-OFDM）. Moreover, its performance can be further improved though iteration. All findings mentioned above can be applied in OFDM digital television terrestrial broadcasting engineering.