低信噪比条件下正弦信号幅度盲估计

Blind amplitude estimation of sinusoid at low signal to noise ration

研究了电子侦察信号处理中正弦信号幅度盲估计问题。提出了一种基于相关累加及线性回归的正弦信号幅度盲估计算法。先对接收到的信号进行频率估计,建立参考信号,将接收信号与参考信号相关后变换到基带并作累加,后将相关累加曲线进行最小二乘线性回归,以回归得到的直线斜率值作为信号幅度的估计值。仿真结果表明,当信噪比大于-3 dB时,方法的估计均方根误差小于1.1倍克拉美罗限,可在低信噪比条件下,实现正弦信号幅度的盲估计。

Amplitude estimation of the sinusoid signals contaminated by noises in the electronic reconnaissance is researched in this article. A new blind amplitude estimator of sinusoid is proposed based on correlation and linear regression. The received sig- nals are transformed to baseband by the reference signals constructed by the estimation of the frequency. Consequently, the gradi- ent of the linear regression of correlation and accumulation curve between the received signals and the referenced ones is regard- ed as the amplitude estimator. Computer simulation results show that the root-mean-square error of the estimator is less than 1.1 times CRLB when the signal to noise ratio is greater than - 3 dB and the proposed estimating method is an efficient blind estima- tion for the amplitude of the sinusoid on the condition of low signal to noise ratio.