OFDM系统中一种改进的信噪比估计算法

摘要

在OFDM系统,SNR承担着监控信号质量的责任.主要研究了基于LMMSE信道估计的信噪比估计.针对现有算法的复杂度高,信噪比估计有偏的问题,提出了一种改进的修正算法.该方法通过无偏的噪声估计以及前后OFDM符号之间的迭代来实现快速收敛,并且直接利用LMMSE信道估计过程的系数来计算修正因子,计算复杂度低.经仿真表明,所提方法在高SNR时估计精度可提高2dB,误码率也有0.3dB的提升.%In OFDM systems,The SNR serves as a standard measure of signal quality.In this paper,we researched the SNR estimation based LMMSE channel estimation.In order to deal with the shortcomings of high complexity and biased SNR for traditional method,we present a new modified SNR estimation which is unbiased,and iteration throw last OFDM and this OFDM symbols can get good performance.The simulation shows estimation accuracy of the proposed method is improved about 2dB in high SNR,and also can promote the BER 0.3dB.