一种可用于莱斯衰落信道的信噪比估计算法

An SNR estimation algorithm for Rician fading channel

针对莱斯衰落信道条件下,常规非数据辅助信噪比估计算法复杂度高、适用调制类型单一等问题,提出了一种信噪比估计算法.在建立系统等效模型的基础上,推导出信噪比与接收信号期望和方差的关系表达式.由于在莱斯衰落信道下,该表达式无解析解,故提出用多项式拟合法得到一定范围内的信噪比近似解.仿真和对比分析实验表明,提出的信噪比估计算法不需要使用训练序列,不仅对低阶和高阶多种调制方式具有普适性,而且当信道莱斯因子K=10 d B且信噪比为5~25 d B时,归一化估计偏差均小于0.2,计算时间复杂度与M2M4算法相当,适合一般工程应用需要.

Aimed at the problems in Rician fading channel,i. e. general Non-Data-Aided signal-tonoise ratio（ SNR） estimation algorithms were very complex and usually suitable for a certain modulation pattern. This paper proposed an SNR estimation algorithm. On the basis of establishing equivalent system model,the relationship expression of SNR,expectation and variance of received signals were deduced. Under the conditions of the Rician fading channel,the deduced expression had no analytic solutions,thus using the polynomial fitting method to obtain approximate solutions of SNR during a certain range. Simulations and comparison experiments showthat,the algorithm does not need any training sequence and is universal for both lower and higher order modulations. If the channel Rician factor K = 10 d B and the SNR is between 5 and 25 d B,the normalization bias is lower than 0. 2,the computational complexity is comparable with M2M4 algorithm,thus satisfying requirements of general engineering application.