载波频率不一致且频谱严重交叠干扰下的盲自适应多用户检测试验研究

Experimental Research on Blind Adaptive Multiuser Detection Algorithm with Different Carrier Frequencies and Severe Overlapping Interference of Spectra

运动水声多用户通信时,干扰用户的载波频率很可能和期望用户的载波频率不再一致。针对运动水声多用户通信载波频率不一致时的多址干扰(MAI)问题,提出了适用于载波频率不一致下的盲自适应多用户检测(BAMUD)算法。利用虚拟用户技术,将期望用户的多途干扰(码间干扰)虚拟成MAI,即将水声多用户通信系统中的信道均衡环节和MAI抑制环节整合成一个环节,简化通信系统结构;利用卡尔曼滤波(KF) BAMUD(KF-BAMUD)算法的MAI抑制特性,即利用了KF在最小均方误差准则下的最优估计特性,抑制载波频率不一致下的虚拟MAI,有效估计出期望用户的传输数据,实现多用户通信。在渤海和渤海结冰期进行了载波频率不一致下的多用户通信试验,良好试验效果验证了所提算法的有效性。

The carrier frequencies of the interfering users may be inconsistent with those of the expected users when mobile multiuser underwater acoustic communications occur. A blind adaptive multiuser detection(BAMUD)algorithm for carrier frequency inconsistency is proposed for the multiple access interference (MAI) problem produced by inconsistent carrier frequencies in mobile multiuser underwater acoustic communications. The multi-path interference (inter-symbol interference) can be viewed as MAI using virtual user technology, that is, the channel equalization link and the MAI suppression link are combined into one link in the multiuser underwater acoustic communication system, simplifying the communication system structure. The MAI suppression characteristic of Kalman filter-based BAMUD(KF-BAMUD)algorithm, that is, the optimal estimation characteristic of KF under the minimum mean square error criterion, is used to suppress the virtual MAI with different carrier frequencies, the transmission data of the expected user is effectively estimated, thus realizing multiuser communication. A series of multi-user communication experiments under inconsistent carrier frequencies were conducted in Bohai Sea and during its ice period, and the good experimental results have verified the effectiveness of the proposed algorithm.