改进的基于循环平稳分析的OFDM关键参数估计方法

提出了一种利用OFDM信号自相关特性和循环平稳特性进行多径信道下关键参数盲估计的算法.该算法首先利用OFDM信号的自相关特性估计信号的有效符号长度,接着利用多径信道下的OFDM信号具有二阶循环平稳特性来估计符号长度,并且在此过程中引入平均的思想,通过对信号的一组循环频率求均值的方法得到最终估计值.信号的二阶循环平稳特性使得该算法可抑制多径干扰,平均的处理方法提高了算法的抑制高斯噪声能力.计算机仿真结果表明:该算法在设定的多径信道下,当信噪比SNR=-2 dB时参数盲估计的正确率可以达到90%以上,在信噪比SNR=2 dB时正确率可以达到100%.

Improved Blind Estimation of OFDM Parameters Based on Cyclostationarity Analysis Method

This paper proposes a new algorithm for blind estimation of parameters of OFDM signals under multipath channel based on the autocorrelation properties and the cyclostationarity of OFDM signals.The autocorrelation of the OFDM signal is firstly applied to estimate the useful data period,then we introduce average idea when estimate symbol period based on the second-order cyclostationarity character of OFDM signals in multipath channel,and get more accurate OFDM symbol period by getting the average value of the cyclic frequencies,so the proposed algorithm has better performance.The simulation results show that the blind parameters estimation accuracy rate of this algorithm can reach more than 90% with SNR equals to-2 dB,as well as almost 100% when SNR equals to 2 dB.