数字通信信号载波估计与干扰研究

发布时间：2018-05-16 04:34

本文选题：数字信号 + 载波估计　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：数字通信的快速发展,使得以数字信号为主体的通信系统被广泛应用。非合作通信作为研究的一个热点,受到越来越多的关注。信号参数估计与信号干扰作为其中重要的一部分,受到了高度的重视。本文以常用数字通信信号的载波估计及干扰为重点进行深入研究。本文首先介绍了数字通信信号的几种经典载波估计方法,并进行了相应的计算机仿真。其次针对OFDM信号的子载波估计作了具体的分析仿真,最后就音频干扰下的OFDM信号的干扰作干扰分析。具体工作如下:(1)对非线性载波估计、自相关载波估计和循环累积量这三种估计作分析,在证实其正确性的基础上,比较分析了各自的优缺点及适用性;(2)对OFDM信号的子载波估计进行研究。利用基于高阶循环累积量的子载波估计方法,对采用PSK或QAM调制的OFDM信号作子载波估计。通过计算机仿真在平坦衰落信道条件下和频率选择性衰落信道条件下,该方法的性能。由此有,在满足信噪比的条件下,基于高阶循环累积量的载波估计方法同样适用于频率选择性衰落信道;(3)对OFDM信号进行音频干扰。分析了音频干扰对最大似然同步算法进行定时同步和频偏估计时的影响。分别产生频率对准的音频干扰和频率没有对准的音频干扰,比较二者的干扰效果,由此可以得到干扰信号的频率范围取值。
[Abstract]:With the rapid development of digital communication, the communication system based on digital signal is widely used. As a research hotspot, non-cooperative communication has attracted more and more attention. As an important part of signal parameter estimation and signal interference, high attention has been paid to signal parameter estimation and signal interference. This paper focuses on carrier estimation and interference of common digital communication signals. In this paper, several classical carrier estimation methods for digital communication signal are introduced, and the corresponding computer simulation is carried out. Secondly, the subcarrier estimation of OFDM signal is analyzed and simulated. Finally, the interference of OFDM signal under audio interference is analyzed. The main work is as follows: 1) the nonlinear carrier estimation, the autocorrelation carrier estimation and the cyclic cumulant are analyzed, and their correctness is verified. The advantages, disadvantages and applicability of each method are compared and analyzed. (2) the subcarrier estimation of OFDM signal is studied. A subcarrier estimation method based on higher order cyclic cumulants is used to estimate the subcarriers of OFDM signals modulated by PSK or QAM. The performance of this method is simulated by computer under the condition of flat fading channel and frequency selective fading channel. Therefore, the carrier estimation method based on high order cyclic cumulant is also suitable for frequency selective fading channel / 3) to carry out audio interference to OFDM signal under the condition of satisfying SNR. The influence of audio interference on timing synchronization and frequency offset estimation of maximum likelihood synchronization algorithm is analyzed. The frequency range of the interference signal can be obtained by comparing the interference effect between the frequency aligned audio interference and the unaligned audio interference.
【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】：TN914.3

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