基于最小二乘的同步多用户非周期长码直扩信号扩频序列估计
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摘要
针对低信噪比下同步多用户非周期长码直扩信号的扩频序列估计问题,提出了一种基于嵌套迭代最小二乘投影算法的扩频序列估计方法.首先,将同步多用户非周期长码直扩信号等效为含有缺失数据的相应的短码直扩信号.然后,利用最大似然估计理论对相应的短码直扩信号进行数学分析,构建扩频序列估计的数学模型.最后,利用一种嵌套迭代最小二乘投影算法来实现扩频序列的估计.研究表明,该算法在低信噪比(小于-10dB)情况下,对多用户(多达10路)扩频序列的估计有着良好的性能表现.
This paper studies the problem of estimation of the spread-spectrum sequence for low SNR synchronous multi-user long-code direct sequence spread spectrum(DSSS)signals.An estimation approach of spread-spectrum sequence based on a nested iterative least squares with projection(NILSP)algorithm is presented.First,The synchronous multi-user long-code DSSS signals is constructed as the shortcode ones with missing data.Then the mathematical analysis for the short-code ones with missing data is done based on the theory of maximum likelihood estimation(MLE)to establish a mathematical model of spread-spectrum sequence.After that,the spread-spectrum sequence is estimated by a NILSP algorithm.The theoretical analysis and simulations show that,the proposed algorithm always has a good performance for estimation of multi-users'(more than 10 users)spread-spectrum sequence in low-SNR(lower than-10 dB)scenarios,and under the same conditions,the longer the data size,the better the performance.
This paper studies the problem of estimation of the spread-spectrum sequence for low SNR synchronous multi-user long-code direct sequence spread spectrum(DSSS)signals.An estimation approach of spread-spectrum sequence based on a nested iterative least squares with projection(NILSP)algorithm is presented.First,The synchronous multi-user long-code DSSS signals is constructed as the shortcode ones with missing data.Then the mathematical analysis for the short-code ones with missing data is done based on the theory of maximum likelihood estimation(MLE)to establish a mathematical model of spread-spectrum sequence.After that,the spread-spectrum sequence is estimated by a NILSP algorithm.The theoretical analysis and simulations show that,the proposed algorithm always has a good performance for estimation of multi-users'(more than 10 users)spread-spectrum sequence in low-SNR(lower than-10 dB)scenarios,and under the same conditions,the longer the data size,the better the performance.
引文
[1]张天骐,张传武,林孝康.直扩信号伪码周期及序列的估计算法[J].系统工程与电子技术,2005,27(8):1365-1368.ZHANG T Q,ZHANG C W,LIN X K.Algorithms for period and sequence estimation of the PN code in DS-SS signals[J].Systems engineering and electronics,2005,27(8):1365-1368.(in Chinese)
[2]张天骐,周正中,林孝康,等.低信噪比长伪码直扩信号的盲估计方法[J].信号处理,2008,24(3):370-376.ZHANG T Q,ZHOU Z Z,LIN X K,et al.Approach to blind estimation of lower SNR long code DS signals[J].Signal processing,2008,24(3):370-376.(in Chinese)
[3]沈斌,王建新.基于奇异值分解的直扩信号伪码序列及信息序列盲估计方法[J].电子与信息学报,2014,36(9):2098-2103.SHEN B,WANG J X.Blind estimation of the PN sequence and information sequence of a DSSS signal based on SVD[J].Journal of electronics&information technology,2014,36(9):2098-2103.(in Chinese)
[4]ZHANG H G,MOU Q,L H S.A semidefinite relaxation approach to spreading sequence estimation for DS-SS signals[J].IEICE transactions on communications,2011,E94-B(11):3163-3167.
[5]周德强,陈卫东.基于Viterbi算法的扩频码与信息序列联合估计[J].飞行器测控学报,2014,33(5):441-447.ZHOU D Q,CHEN W D.Joint blind estimation of spreading code and information sequence based on Viterbi algorithm[J].Journal of spacecraft TT&C technology,2014,33(5):441-447.(in Chinese)
[6]马超,张立民,王建雄.基于子空间跟踪的长码直扩序列盲估计[J].计算机与数字工程,2014,292(42):223-226.MA C,ZHANG L M,WANG J X.Blind estimation of long code DSSS signal based on subspace tracking[J].Computer&digital engineering,2014,292(42):223-226.(in Chinese)
[7]CHENG H,LOU Z H,SUN G L.Non-supervised rule for direct sequence spread spectrum signal sequence acquisition[C]//2014Ninth International Conference on Broadband and Wireless Computing,Communication and Applications(BWCCA).IEEE,November 8-10,2014:151-154.
[8]李军伟,张天骐,朱洪波,等.基于聚类的多进制扩频伪码序列盲估计方法[J].科学技术与工程,2014,14(2):32-36.LI J W,ZHANG T Q,ZHU H B,et al.Clustering based blind estimation of PN sequences in mary spread spectrum system[J].Science technology and engineering,2014,14(2):32-36.(in Chinese)
[9]汤辉.直扩信号参数估计的盲源分离方法研究[D].[D].武汉:华中科技大学,2012.TANG H.Parameters estimation of DSSS signals based on blind source separation[D].Wuhan:Huazhong University of Science&Technology,2012.(in Chinese)
[10]张天骐,林孝康,周正中.基于神经网络的低信噪比直扩信号扩频码的盲估计方法[J].电路与系统学报,2007,12(2):118-123.ZHANG T Q,LIN X K,ZHOU Z Z.A neural network approach to blind-estimation of PN spreading sequence in lower SNR DS/SS signals[J].Journal of circuits and systems,2007,12(2):118-123.(in Chinese)
[11]赵知劲,顾骁炜,沈雷,等.非周期长码直扩信号的伪随机码盲估计[J].通信学报,2015,36(5):1-8.ZHAO Z J,GU X W,SHEN L,et al.Blind estimation of pseudo-random codes in non-periodic long code direct-sequence spread-spectrum signals[J].Journal on communications,2015,36(5):1-8.(in Chinese)
[12]赵知劲,李淼,吴金沂.长码直扩信号扩频序列估计[J].杭州电子科技大学学报,2015,35(2):1-4.ZHAO Z J,LI M,WU J Y.The spread spectrum code estimation of long-code DSSS signal[J].Journal of Hangzhou Dianzi University(Natural Sciences),2015,35(2):1-4.(in Chinese)
[13]张花国,魏平.同步多用户长码直扩信号的盲解扩[J].电子与信息学报,2011,33(7):1748-1751.ZHANG H G,WEI P.Blind despreading of synchronous multi-user long-code DS-SS signals[J].Journal of electronics&information technology,2011,33(7):1748-1751.(in Chinese)
[14]张花国,魏平.未知频偏下直扩信号的扩频序列估计[J].电子科技大学学报,2013,42(1):44-47.ZHANG H G,WEI P.Spreading sequence estimation of direct sequence spread spectrum signals with unknown carrier offset[J].Journal of University of Electronic Science and Technology of China,2013,42(1):44-47.(in Chinese)
[15]徐海源,王丰华,黄知涛,等.长码直扩信号的符号速率盲估计方法[J].国防科技大学学报,2007,29(6):44-48.XU H Y,WANG F H,HUANG Z T,et al.Blind estimation of the Symbol rate of a long code DSSS signal[J].Journal of National University of Defense Technology,2007,29(6):44-48.(in Chinese)
[16]TALWAR S,VIBERG M,PAULRAJ A.Blind separation of synchronous co-channel digital signals using an antenna array.I.algorithms[J].IEEE transactions on signal processing,1996,44(5):1184-1197
[17]TALWAR S,PAULRAJ A.Blind separation of synchronous co-channel digital signals using an antenna array.II.Performance analysis[J].IEEE transactions on signal processing,1997,45(3):706-718.
[2]张天骐,周正中,林孝康,等.低信噪比长伪码直扩信号的盲估计方法[J].信号处理,2008,24(3):370-376.ZHANG T Q,ZHOU Z Z,LIN X K,et al.Approach to blind estimation of lower SNR long code DS signals[J].Signal processing,2008,24(3):370-376.(in Chinese)
[3]沈斌,王建新.基于奇异值分解的直扩信号伪码序列及信息序列盲估计方法[J].电子与信息学报,2014,36(9):2098-2103.SHEN B,WANG J X.Blind estimation of the PN sequence and information sequence of a DSSS signal based on SVD[J].Journal of electronics&information technology,2014,36(9):2098-2103.(in Chinese)
[4]ZHANG H G,MOU Q,L H S.A semidefinite relaxation approach to spreading sequence estimation for DS-SS signals[J].IEICE transactions on communications,2011,E94-B(11):3163-3167.
[5]周德强,陈卫东.基于Viterbi算法的扩频码与信息序列联合估计[J].飞行器测控学报,2014,33(5):441-447.ZHOU D Q,CHEN W D.Joint blind estimation of spreading code and information sequence based on Viterbi algorithm[J].Journal of spacecraft TT&C technology,2014,33(5):441-447.(in Chinese)
[6]马超,张立民,王建雄.基于子空间跟踪的长码直扩序列盲估计[J].计算机与数字工程,2014,292(42):223-226.MA C,ZHANG L M,WANG J X.Blind estimation of long code DSSS signal based on subspace tracking[J].Computer&digital engineering,2014,292(42):223-226.(in Chinese)
[7]CHENG H,LOU Z H,SUN G L.Non-supervised rule for direct sequence spread spectrum signal sequence acquisition[C]//2014Ninth International Conference on Broadband and Wireless Computing,Communication and Applications(BWCCA).IEEE,November 8-10,2014:151-154.
[8]李军伟,张天骐,朱洪波,等.基于聚类的多进制扩频伪码序列盲估计方法[J].科学技术与工程,2014,14(2):32-36.LI J W,ZHANG T Q,ZHU H B,et al.Clustering based blind estimation of PN sequences in mary spread spectrum system[J].Science technology and engineering,2014,14(2):32-36.(in Chinese)
[9]汤辉.直扩信号参数估计的盲源分离方法研究[D].[D].武汉:华中科技大学,2012.TANG H.Parameters estimation of DSSS signals based on blind source separation[D].Wuhan:Huazhong University of Science&Technology,2012.(in Chinese)
[10]张天骐,林孝康,周正中.基于神经网络的低信噪比直扩信号扩频码的盲估计方法[J].电路与系统学报,2007,12(2):118-123.ZHANG T Q,LIN X K,ZHOU Z Z.A neural network approach to blind-estimation of PN spreading sequence in lower SNR DS/SS signals[J].Journal of circuits and systems,2007,12(2):118-123.(in Chinese)
[11]赵知劲,顾骁炜,沈雷,等.非周期长码直扩信号的伪随机码盲估计[J].通信学报,2015,36(5):1-8.ZHAO Z J,GU X W,SHEN L,et al.Blind estimation of pseudo-random codes in non-periodic long code direct-sequence spread-spectrum signals[J].Journal on communications,2015,36(5):1-8.(in Chinese)
[12]赵知劲,李淼,吴金沂.长码直扩信号扩频序列估计[J].杭州电子科技大学学报,2015,35(2):1-4.ZHAO Z J,LI M,WU J Y.The spread spectrum code estimation of long-code DSSS signal[J].Journal of Hangzhou Dianzi University(Natural Sciences),2015,35(2):1-4.(in Chinese)
[13]张花国,魏平.同步多用户长码直扩信号的盲解扩[J].电子与信息学报,2011,33(7):1748-1751.ZHANG H G,WEI P.Blind despreading of synchronous multi-user long-code DS-SS signals[J].Journal of electronics&information technology,2011,33(7):1748-1751.(in Chinese)
[14]张花国,魏平.未知频偏下直扩信号的扩频序列估计[J].电子科技大学学报,2013,42(1):44-47.ZHANG H G,WEI P.Spreading sequence estimation of direct sequence spread spectrum signals with unknown carrier offset[J].Journal of University of Electronic Science and Technology of China,2013,42(1):44-47.(in Chinese)
[15]徐海源,王丰华,黄知涛,等.长码直扩信号的符号速率盲估计方法[J].国防科技大学学报,2007,29(6):44-48.XU H Y,WANG F H,HUANG Z T,et al.Blind estimation of the Symbol rate of a long code DSSS signal[J].Journal of National University of Defense Technology,2007,29(6):44-48.(in Chinese)
[16]TALWAR S,VIBERG M,PAULRAJ A.Blind separation of synchronous co-channel digital signals using an antenna array.I.algorithms[J].IEEE transactions on signal processing,1996,44(5):1184-1197
[17]TALWAR S,PAULRAJ A.Blind separation of synchronous co-channel digital signals using an antenna array.II.Performance analysis[J].IEEE transactions on signal processing,1997,45(3):706-718.