连续相位调制信号的信噪比估计

针对连续相位调制（CPM）信号信噪比估计子空间分解算法运算量较大和最大似然估计（MLE）算法信噪比小于0dB时精确度差的问题，提出了一种精确度较高的快速算法。该算法是对常用的最大似然算法的改进，利用接收信号的统计和互相关特性，无需获得信号的初始相位，便可快速准确地估计出信号的信噪比。信噪比在-20dB～20dB之间时，估计误差小于1dB。MATLAB和FPGA仿真验证了该算法的有效性。

An estimation algorithm for the SNR of continuous phase modulation

Aiming at reducing the large amount of computation of Sub Space Decomposition（SSD） algorithm and improving the poor precision（when signal to noise ratio is below 0 dB） of the Maximum Likelihood Estimation（MLE） algorithm to estimate the signal to noise ratio of the Continuous Phase Modulation（CPM） signal, a new fast algorithm with higher accuracy is presented in this paper. This new algorithm is an improvement based on the frequently used MLE method. It takes the statistic and cross-correlation of the received signal into account, and can estimate the Signal to Noise Ratio fast and precisely without the initial phase. Error estimate is less than 1 dB when SNR is between -20 dB and 20 dB. A comprehensive deduction of the algorithm is included in this paper. Simulations by MATLAB and FPGA implementation show the validity of this algorithm.