多径信道下数字信号调制识别的研究

在通信信号调制方式识别中,目前已有的方法大多是基于高斯白噪声干扰的通信环境.对于多径干扰强的环境下的调制识别难以实现以及识别率低的问题,首先提出基于改进的Liavas算法对信道阶数进行准确估计,在此基础上利用基于子空间的多信道盲辨识和盲均衡来克服多径信道带来的影响,然后对均衡结果进行高阶累积量计算,提取特征参数完成调制识别.与已有的算法相比,适用范围广,实用性强,所需先验知识少.仿真结果证实算法的有效性.

Research of Novel Method for Digital Modulation Identification in the Multi-path Channel

With regard to the recognition of modulation,most of the methods nowadays are set in the communication environment of Gaussian white noise interference.As for the problem of the difficulty in realizing the modulation recognition in the environment of strong multi-path interference and the low recognition rate,this paper first proposes to estimate the channel order accurately via/based on a refined Liavas algorithm.Based on that,the author then exploits the blind multi-channel identification and the blind equalization of the subspace to overcome the influence of the multi-path channel,conducts the high-order cumulant calculation towards the equilibrium result and extracts the characteristic parameters to finish the modulation recognition.Compared with the existing algorithms,the algorithm in this paper is applicable to a wider range.In addition,it is more practical and only needs less prior knowledge.Simulation results show the effectiveness of the algorithm.