一种改进的BPSK信噪比估计方法及其FPGA实现  

An improved SNR estimation for BPSK signals and its FPGA implementation

作　　者：刘源源[1] 江雪[1] 谢显中[1] 雷维嘉[1] 

机构地区：[1]重庆邮电大学个人通信研究所,重庆400065

出　　处：《重庆邮电大学学报（自然科学版）》2014年第5期630-635,共6页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家自然科学基金(61271259;61301123;61471076)~~

摘　　要：传统的二进制相移键控(binary phase shift keying,BPSK)信号的最大似然信噪比估计方法需要数据辅助,绝大多数只能在符号同步后进行估计,且不能有残余的载波相偏。针对此问题对该估计算法进行改进。利用二次方去除信号中的相位调制,不再需要数据辅助;对同相和正交通道分别进行处理,合并估计结果消除解调载波的相偏影响;直接对模/数(analog to digital,A/D)转换后样值进行分组估计,不需要进行符号同步。改进的信噪比估计算法复杂度低,是一种盲估计算法,可在符号同步前进行估计,且允许解调载波存在相差,具有很高的实用性。仿真表明,该算法在较低的信噪比下仍然有较高的估计精度,采用现场可编程逻辑门阵列(field programmable gatearray,FPGA)对改进算法进行了验证。Traditional maximum likelihood signal-to-noise ratio （SNR） estimation algorithms for BPSK signals require aided data, and a majority of them can only work after the symbol synchronization, where residual carrier phase deviation is not allowed. Aiming at that, an improved algorithm is proposed. We remove the data modulation by quadratic power without aided data, separately deal with the in-phase and orthogonal channels, and combine the estimate results to eliminate the influence of phase deviation. And symbol synchronization is not required when estimating samples of the A/D converter by grouping directly. The improved SNR estimation algorithm is blind, allowing the existence of phase deviation, with low complexity and high practicality. Simulation results show that it still has high estimation accuracy even at low SNR. Iinally, the realization scheme of the improved algorithm based on FPGA（field programmable gate array） is introduced.

关 键 词：最大似然准则 二进制相移键控(BPSK)信号 信噪比估计 相偏 现场可编程门阵列(FPGA) 

分 类 号：TN911.7[电子电信—通信与信息系统]