非高斯噪声环境下PSK信号的参数估计方法研究

发布时间：2018-05-27 01:08

本文选题：参数估计 + Alpha稳定分布　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：近年来,随着通信环境的日趋复杂,基于高斯白噪声环境的数字信号处理方法在实际通信环境下存在很多弊端。实际通信系统中的噪声往往具有显著的尖峰脉冲特性,且通常以Alpha稳定分布模型进行建模。PSK信号凭借其较强的抗干扰能力,广泛应用于高、中速数据传输。研究非高斯Alpha稳定分布噪声下PSK信号的参数估计可以为信号的解调、识别、恢复等后续工作提供依据,是非合作通信信号处理过程中必不可少的环节。因此,本文对Alpha稳定分布噪声下的PSK信号的部分参数进行估计,所取得的主要研究成果如下:1.针对Alpha稳定分布噪声下PSK信号的载频估计方法在低信噪比条件下性能较差的问题,提出了一种基于循环共变谱的PSK信号载频估计新方法。该方法通过构建信号的循环共变函数,推导出了其循环共变谱,并通过谱截面特征的提取以及该特征与载频之间的特定关系,实现非高斯Alpha稳定分布噪声下PSK信号的载频估计。此外,本文还从理论上分析了Alpha稳定分布噪声下的PSK信号载波频率估计的克拉美罗界(CRLB)。仿真结果表明,在Alpha稳定分布噪声下,该方法的估计性能在低信噪比下较好。2.针对Alpha稳定分布噪声下PSK信号的码元速率估计困难的问题,提出了一种基于分数低阶离散域累加平均的PSK信号码元速率估计新方法。该方法首先对离散时域点及其累加值进行分数低阶运算,然后构建分数阶离散域累加平均时域图,则相位跳变的位置点会出现峰值特性,再通过搜索并计算任意相邻峰值谱线的时间距离,确定最小时间距离,从而得出PSK信号的码元速率。此外,本文还从理论上分析了Alpha稳定分布噪声下PSK信号的码元速率估计的克拉美罗界。仿真结果表明,在Alpha稳定分布噪声下,该方法的估计性能较好且计算复杂度较低。
[Abstract]:In recent years, with the increasing complexity of communication environment, the digital signal processing method based on Gao Si white noise environment has many drawbacks in the actual communication environment. The noise in practical communication system often has the characteristic of sharp spike pulse, and the model of Alpha stable distribution model is usually used to model .PSK signal, because of its strong anti-jamming ability, it is widely used in high and medium speed data transmission. The parameter estimation of PSK signal under non-Gao Si Alpha stable distributed noise can provide basis for signal demodulation, identification, recovery and so on. It is an essential link in the process of non-cooperative communication signal processing. Therefore, this paper estimates some parameters of PSK signal under Alpha stable distributed noise, and the main research results are as follows: 1. A novel carrier frequency estimation method for PSK signals based on cyclic covariant spectrum is proposed to solve the problem that the carrier frequency estimation method of PSK signals with stable distribution of Alpha noise is of poor performance under low SNR. By constructing the cyclic covariant function of the signal, the cyclic covariant spectrum of the signal is derived, and the carrier frequency estimation of the PSK signal under the non-Gao Si Alpha stable distribution noise is realized by extracting the spectral cross-section feature and the specific relationship between the characteristic and the carrier frequency. In addition, in this paper, the Clemero bound for the carrier frequency estimation of PSK signals under the stable distributed noise of Alpha is analyzed theoretically. The simulation results show that the estimation performance of this method is good at low SNR under the condition of Alpha stable distribution noise. Aiming at the difficulty of estimating the symbol rate of PSK signals under the stable distributed noise of Alpha, a new method for estimating the rate of PSK number elements based on the accumulative average of fractional low order discrete domain is proposed. In this method, the discrete time domain points and their accumulative values are first performed fractional low order operations, and then the fractional discrete domain accumulative mean time domain maps are constructed, and the peak value of the position points of the phase jump will appear. Then the minimum time distance is determined by searching and calculating the time distance of any adjacent peak line, and the symbol rate of PSK signal is obtained. In addition, this paper theoretically analyzes the Clemero bound for the estimation of the symbol rate of PSK signals under the stable distribution of Alpha noise. The simulation results show that the proposed method has better estimation performance and lower computational complexity under the stable distribution of Alpha noise.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.23

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