CAJ | 학술논문

针对低信噪比条件下直接序列扩频码分多址(DS-CDMA)信号扩频序列盲估计的难题,提出了一个能对同步和异步的短码调制DS-CDMA信号的扩频序列进行盲估计的新方法.该方法在分析接收信号特征结构及其相关矩阵结构的基础上,首先估计出接收信号中一个用户信号的功率、特征扩频序列的失步点及序列本身,再用已经估计出来的特征信息对相关矩阵进行缩减,以消除该用户对剩余用户信号估计的影响.依此方法,逐次迭代,最后完成对接收信号中所有用户信息的盲估计.所估计出用户信息的顺序与其功率大小密切相关,功率越大的用户,就越先被估计出来.理论分析和计算机仿真表明,该方法能够在低信噪比条件下较好地完成DS-CDMA扩频序列的盲估计.
침대저신조비조건하직접서렬확빈마분다지(DS-CDMA)신호확빈서렬맹고계적난제,제출료일개능대동보화이보적단마조제DS-CDMA신호적확빈서렬진행맹고계적신방법.해방법재분석접수신호특정결구급기상관구진결구적기출상,수선고계출접수신호중일개용호신호적공솔、특정확빈서렬적실보점급서렬본신,재용이경고계출래적특정신식대상관구진진행축감,이소제해용호대잉여용호신호고계적영향.의차방법,축차질대,최후완성대접수신호중소유용호신식적맹고계.소고계출용호신식적순서여기공솔대소밀절상관,공솔월대적용호,취월선피고계출래.이론분석화계산궤방진표명,해방법능구재저신조비조건하교호지완성DS-CDMA확빈서렬적맹고계.
According to the problem that the blind estimation of direct spread division multiple access (DS-CDMA) signals' spreading code was difficult to be obtained in low SNR,this paper proposed a new approach to blindly estimate the spreading code of short code DS-CDMA in synchronous and asynchronous conditions respectively.The approach bases the analysis to the received signals' feature structure and its correlation matrix's structure,then used the obtained estimations to deflate the correlation matrix,so could clear its influence to the estimation of the residual signals.Based on the approach,reduced the dimension of the signal subspace at each iteration so that the spreading code and desynchronizing point of the next user could be estimated reliably.At last,completed all the users' blind estimation.The order of a user signal being estimated is closely related to its power,i.e.the user which has the bigger power is earlier and easier to be estimated.Theoretical analysis and simulation results show that the proposed approach can effectively estimate the spreading code of DS-CDMA.