CAJ | 학술논문

研究了一种水声异步多用户通信非集中式接收机系统,将码分多址和空时自适应滤波、多通道判决反馈均衡相结合,克服多用户系统中的多址干扰(MAI)以及水声信道多途效应引起的码间干扰(ISI),实现指定用户的正确接收.利用实测多通道浅海水声信道响应函数进行了三个用户的异步通信仿真,分别比较了空时滤波均衡与单通道直接解扩、空间分集合并均衡等接收算法的性能,显示了空时滤波均衡接收机在抑制多址干扰、码间干扰、正确区分不同用户等方面的优点.码分多址机制和空时滤波均衡结合使用的特点使系统适合于低速数据传输且水声信道变化较慢的场合.
연구료일충수성이보다용호통신비집중식접수궤계통,장마분다지화공시자괄응려파、다통도판결반궤균형상결합,극복다용호계통중적다지간우(MAI)이급수성신도다도효응인기적마간간우(ISI),실현지정용호적정학접수.이용실측다통도천해수성신도향응함수진행료삼개용호적이보통신방진,분별비교료공시려파균형여단통도직접해확、공간분집합병균형등접수산법적성능,현시료공시려파균형접수궤재억제다지간우、마간간우、정학구분불동용호등방면적우점.마분다지궤제화공시려파균형결합사용적특점사계통괄합우저속수거전수차수성신도변화교만적장합.
An underwater asynchronous multi-user communication decentralized receiver is studied.The receiver uses some techniques such as CDMA,space-time adaptive filtering and multi-channel decision-feedback equalization to overcome multi-access interference (MAI) existing in multi-user system and inter-symbol interference (ISI) caused by multi-path effect of underwater acoustic signals.The objectiveis to receive desired user signal correctly.The simulations of asynchronous underwater acoustic communication between three users are carried out by real shallow water multi-channel impulse response functions.The performance of space-time filtering and equalization receiver is compared respectively to single-channel dffect de-spreading receiver and space diversity equal gain combining and equalization.Results show the space-time filtering and equalization receiver having good performance in restraining ISI and MAI.In addition,the influence of pre-combining channel number on the system performance is studied.