基于子带处理的MPSK符号速率估计  

Subband Processing Based Symbol Rate Estimation Method For MPSK Signals

作　　者：罗胜恩[1] 苑小华[1] 罗来源[1] 

机构地区：[1]西南电子电信技术研究所,四川成都610041

出　　处：《信号处理》2011年第2期304-308,共5页Journal of Signal Processing

摘　　要：本文针对未知频点短波MPSK信号研究宽带接收条件下的符号速率估计问题。由于宽带数据包括大量窄带信号,一般需利用分析滤波器组进行信道化处理,当信号频点未知且随机分布时,上述处理易造成信号频段被划分到相邻的若干个子信道中,从而产生存在频谱失真的子带信号。本文首先建立MPSK子带信号模型,通过理论分析指出可将信号频谱失真视为码元成型函数的改变,在此基础上提出一种新的基于子带信号复包络的波特率估计算法,并进行估计无偏性证明,最后给出不同频谱损失度及信噪比(SNR)下的参数估计性能仿真分析。仿真表明采用30%频谱损失的子带信号进行符号速率估计,在加性高斯白噪声(AWGN)背景下SNR提高4dB即可达到无失真情况下的估计精度,同时在CCIR短波中等信道条件下SNR提高约3dB即可达到AWGN背景下的参数估计精度。理论分析及仿真表明该方法可有效可靠应对频谱失真信号的符号速率估计问题。This paper is focusing on the MPSK signal＇ s symbol rate estimation problem under wideband receiving situation.As the wideband data comprises lots of separated narrowband signals,channelization using analysis filterbanks is needed.When the carrier frequency is unknown and have random distribution,the MPSK signal may be divided into several subband signals.This paper is aimed to discuss the symbol-rate estimation problem using the spectrum-distorted subband signal.The model of MPSK subband signal is proposed firstly.The spectrum distortion can be considered as the transition of shape function after theoretical analysis.Then a new symbol rate estimation method is presented based on the complex envelope of the subband signal.The estimation is unbiased which is proven by the deduction of the estimation expectation.The influence of the frequency domain coverage percentage and SNR are analyzed with the computer simulation at last.When 30%of the signal spectrum is damaged,the SNR should be 4dB higher in order to achieve the same estimation accuracy under no spectrum damage circumstance.Under the CCIR-Moderate HF channel environment,the SNR should be approximately 3dB higher to achieve the same performance under Additive White Gauss Noise（AWGN） circumstance.The efficiency and credibility of the method are testified by the theoretical deduction and simulations.

关 键 词：子带信号 MPSK 波特率估计 宽带处理 

分 类 号：TN911[电子电信—通信与信息系统]