基于先验信息的M-APSK信号迭代信噪比估计

Iterative SNR Estimation Algorithm for M-APSK Signal Based on A Priori Information

该文提出了一种适合多进制振幅移相键控信号信噪比估计的迭代算法。给定先验信息的条件下,由经过平坦衰落的多进制振幅移相键控信号的概率分布出发,对其对数期望求导得到信噪比参数和数据的关系,引入数据可信度更新信噪比参数,从而获得相应的迭代算法。与已有的矩方法相比,该文提出的基于先验信息迭代算法在迭代四次,互信息大于0.4以上时性能优于已有非数据辅助算法,而无先验信息下的五次迭代时中高信噪比下优于矩方法。

This paper proposes an iterative Signal-to-Noise Ratio （SNR） estimation algorithm suited to Multiple Amplitude Phase Shift Keying （M-APSK） signal based on a priori information. Given a priori, the M-PASK signal has the determinate probability distribution with flat-fading, and its logarithmic expection is differentiated to yield the relation between the SNR parameters and the data. Reliability metric is introduced to updata the parameters, then the iterative algorithm is put forward correspondingly. Compared with the foregone Memont Methods （MM）, simulation results show that the new algorithm using a prior has better performance when the intrinsic information is larger than 0.4 with 4 iterations, while that without a prior only better in middle and hign SNR with 5 iterations used.