一种基于匹配滤波的空时分组码译码方法

空时分组码译码采用直接法构造判决统计量。两副发射天线、一副接收天线的空时分组码系统的判决统计量还有另外一种构造方法——匹配滤波法。将匹配滤波法进一步推广到多维空时分组码系统,给出了匹配滤波器的构造方法,并在SPW平台上对这种方法进行了仿真。分析和仿真结果表明:提出的增强匹配滤波法易于实现,适用于多维空时分组码系统,其误码性能与直接法相同。     

基于子空间法的空时分组码系统信道盲估计

结合多信道子空间理论,结合空时分组码的正交特性,提出了新的盲信道估计算法。首先,根据空时分组码结构特点,将原编码矩阵分解,并将接收矩阵合理地构造,把原信道矩阵重新构造成新的重构信道矩阵。然后求出重构信道矩阵的噪声子空间,之后利用信号子空间与噪声子空间正交特性,构造出信道矩阵作为变量的线性方程组,因而可以得到信道矩阵的闭式解。对三种典型的空时分组码进行仿真验证,仿真结果表明本算法的有效性。     

Differential modulation based on space-time block codes

A differential modulation scheme using space-time block codes is put forward. Compared with other schemes, our scheme has lower computational complexity and has a simpler decoder. In the case of three or four transmitter antennas, our scheme has a higher rate a higher coding gain and a lower bit error rate for a given rate. Then we made simulations for space-time block codes as well as group codes in the case of two, three, four and five transmit antennas. The simulations prove that using two transmit antennas, one receive antenna and code rate of 4 bits/s/Hz, the differential STBC method outperform the differential group codes method by 4 dB. Useing three, four and five transmit antennas, one receive antenna, and code rate of 3 bits/s/Hz are adopted, the differential STBC method outperform the differential group codes method by 5 dB, 6. 5 dB and 7 dB, respectively. In other words, the differential modulation scheme based on space-time block code is better than the corresponding differential modulation     

基于JADE与特征提取的正交/非正交空时分组码盲识别

针对非协作多输入多输出通信系统中正交空时分组码(orthogonal space-time block codes, OSTBC)与非正交空时分组码(non-orthogonal space-time block code, NOSTBC)的盲识别问题,提出结合特征值矩阵联合近似对角化(joint approximate diagonalization of eigenvalue matrix, JADE)与特征提取的盲识别方法。首先将接收信号转换为盲源分离问题中的线性瞬时混合模型,然后利用JADE算法估计出该模型的虚拟信道矩阵,根据该信道矩阵的相关矩阵为数量矩阵的特点,从相关矩阵中提取特征参数,利用此特征参数识别OSTBC与NOSTBC。仿真结果表明,在较低信噪比以及不同的调制模式下,所提方法均可有效识别出OSTBC与NOSTBC。     

Constructions of unitary space-time codes with full diversity

The problem of constructing unitary space-time codes with high diversity product has been studied in many prior works. Recently, constructions of parametric fully diverse unitary space-time codes for prime number antennas system have been introduced. In this paper, the authors propose new construction methods based on these constructions. And fully diverse codes of any number antennas are obtained from these constructions. Unitary space-time codes from present constructions are found to have better error performance than many best known ones.     

多接收天线下空时分组码解码算法的研究

针对时变瑞利衰落信道,提出多接收天线下两种新的空时分组码解码算法。由于多普勒频移和载频偏移,引起信道的时间选择性衰落,信道时间选择性衰落引起发送天线间互干扰(intertransmit antennas interfer-ence,ITAI)。所提方案中信道用一阶自回归模型建立,在多接收天线时,通过分集增益合并(diversity advantagecombiner,DAC)后,采用约束置零或cholesky分解的方法移除发送天线间互干扰。最后针对不同变化系数的衰落信道给出计算机仿真结果,结果表明提出的方案表现出了更好的性能。     

Efficient spread space-time block coding scheme in multiple antenna systems

1 .INTRODUCTIONRecently ,an intense interest has focused on wire-less systems that can provide good quality and highdata rate .Space-ti me coding is an i mportant tech-nique that can i mprove system performance at fa-ding environments by obtaining diversity gains andcoding gains in multiple antenna systems .To make multiple antenna system practical ,methods that can obtain diversity gains with mod-erate complexity and provide acceptable bit errorrate ( BER) performance are investigated i…     

基于协方差拟合准则的降维空时自适应处理方法

最优空时自适应处理方法由于计算量大且需要大量的训练样本来估计杂波协方差矩阵而无法满足实际应用,针对此问题,本文提出一种基于协方差拟合准则的降维空时自适应处理方法.该方法首先对每个阵元收到的回波信号进行时域滤波,然后通过协方差拟合准则构造了在高斯信源下与最大似然估计器渐近等价的优化问题,同时我们将协方差拟合优化问题转换为...     

基于空时二维结构的低旁瓣宽带波束形成

在分析空时自适应处理结构的基础上,提出了一种工程上易于实现的低旁瓣波束形成算法.虚拟了不同幅度、不同频点、不同方位角的干扰源,使得空时二维方向图的主瓣指向期望信号来波方向的同时,在其他方向上形成低旁瓣,达到抑制干扰和噪声的目的.由于此算法权值是已知系数矩阵与当前时刻期望信号的空时二雏导向矢量的乘积,计算量简单,避免了传统线性约束算法中多次矩阵求逆的复杂运算,既保证了抗干扰性能又便于工程实现.     

自适应调制STBC-MC-CDMA系统仿真分析

分别将G2、G3和H3三种空时分组码（STBC）与MC-CDMA结合构成STBC-MC-CDMA系统,并在上述系统中应用自适应调制技术。通过仿真研究了在瑞利衰落信道条件下,采用G2、G3和H3三种空时分组码的自适应调制STBC-MC-CDMA系统的误符号率性能,并对三种方案下的系统误符号率性能进行了比较。仿真结果表明,在相同信道条件下,编码速率为1/2的G3系统误符号率性能最好,全速编码G2系统误符号率性能最差,编码速率为3/4的H3系统的误符号率则介于二者的之间。

Abstract：

G2 ,G 3 ,H 3 three space-time block codes （STBC） were combined with MC-CDMA respectively to form STBC- MC-CDMA wireless communication systems.Then,adaptive modulation techniques were applied to the three systems.The symbol error rates （SER） of the three STBC-MC-CDMA systems were simulated and compared under Rayleigh fading channel.Simulation results show that under the same channel conditions,the SER performance of G 3 system with 1/2 coding rate is best among the three systems,the full-speed coding rate G 2 system performs worst,and the SER performance of H 3 system with 3/4 coding rate is between G 2 and G 3 system.     

基于深度学习的多STBC盲识别算法

针对空时分组码(space-time block code, STBC)识别中多种编码类型难区分的问题, 提出了一种基于卷积神经网络的STBC盲识别算法。该算法首先将接收信号采用自相关函数的频域预处理, 输入到卷积神经网络中对信号特征进行提取, 全连接层对特征进行映射, 实现对6种STBC类型的识别。仿真实验结果表明, 在无信道和噪声等先验信息的条件下, 所提算法能够有效区分3种相似度高的STBC3码, 且将STBC可识别的编码类型由目前的4种扩充到6种, 识别准确率能达到96%。该方法的复杂度较低, 不需要利用大量样本数据, 实时性高, 具有较好的工程应用价值。     

Optimal MMSE successive interference cancellation in group-wise STBC MIMO systems

1.INTRODUCTIONInformationtheoryshowsthat a multiple-input multi-ple-output(MI MO)communication systemcan effi-ciently increase system capacity in rich scatteringwireless channel environment without additional pow-er and frequency spectrumrequirement as traditionaltechniques need[1,2].Transmission schemes based onMI MO typically fall into two categories:data ratemaxi mization schemes and diversity maxi mumschemes.The representative of the first category isBell laboratories layered space…     

空时分层结构码分多址系统的上行多用户检测

针对目前已提出的空时编码结构大多只研究单用户检测这一现状,研究了频率选择性信道下多输入多输出(MIMO)的多用户结构,并提出了一种采用V BLAST空时编码结构码分多址系统的多用户检测算法。基于发射符号的旋转不变特性和奇异值分解,得到了矢量信道冲激响应(VCIR)的盲估计,进而提出了上行信号的多用户检测器。该方法在满足系统对多用户检测性能期望的同时,还能很容易地对算法复杂度进行有效控制。仿真结果表明了该方法的有效性。     

基于SPW的差分空时分组码的仿真实现

近年来，差分空时码受到广泛关注。这是由于当接收端没有信道状态信息时，差分空时码仍然可以获得良好的性能。在介绍了差分空时分组码编译码原理的基础上，将差分空时分组码封装为SPW中的自定义模块，然后在SPW中对差分空时分组码在瑞利平坦衰落信道下的性能进行了仿真，并与相同信道条件下具有理想信道估计的空时分组码的性能进行了比较。仿真和分析结论表明了差分空时码的优越性。     

基于四天线的并行空时分组编码方案

空时编码是一种结合信道编码和分集技术的新型的编码和信号处理方法,可以不需增加带宽而大幅度的提高无线通信系统的信道容量和传输速率,从而提供远高于传统单天线系统的频带利用率,空时分组码以其译码的简单性获得人们的广泛关注。为提高空时分组码的码元速率,在现有的空时分组编码方案的基础上,结合并行传输策略,提出了基于四天线的并行空时分组编码方案。与传统的空时分组编码方案相比,该方案能够在保证误码性能的同时提高码元速率,从而进一步提高了系统的性能。仿真结果验证了所提出的编码方案所具有的良好性能。     

准正交空时分组码的自适应正交化设计

为了能够在满足空时分组码完全分集的同时尽可能的降低译码复杂度,提出了准正交空时分组码的自适应正交化设计方案。在准正交空时分组码的编码结构上添加自适应系数,根据当前信道状态信息计算得到自适应系数的具体数值,使得传输数据符号之间相互正交,彼此没有干扰,从而实现完全分集,并且可以采用复杂度低的单符号译码方法恢复数据。仿真结果表明,准正交空时分组码自适应正交化设计方案的误码率性能明显好于利用星座旋转获得完全分集的准正交空时分组码方案,并且,只需要采用有限反馈的方法就能够实现近似理想反馈的误码率性能。

Abstract：

Adaptive orthogonalization design for quasi-orthogonal space-time block codes was proposed to achieve full diversity and decrease decoding complexity.Known of channel state information,adaptive parameter could be calculated and input symbols could be coded in the designed structure.With the particular space-time codes structure,symbols on different antenna were orthogonal to each others and received symbols could be single-symbol decoded.Simulation results show that the adaptive scheme has obvious advantage compared with constellation rotation scheme.Limited feedback scheme is feasible and has almost the same optimal performance as the ideal full feedback scheme.     

多用户条件下利用信道信息结合发送分集的空时编码

给出了多用户条件下利用扩频结合空时编码传输信号的系统模型,然后利用多用户与基站之间的信道冗余,通过提出的天线优选模型对信道进行选择,经优选后的系统,从整体上提高了误码率性能。理论分析和仿真结果表明,该方法具有较好的性能和较强的实用性。     

Novel time-frequency differential space-time modulation for multi-antenna OFDM systems

1.INTRODUCTIONRecently,there has been considerable interest in thewireless communication system with multiple trans-mit and receive antennas[1,2].So far,most researchon space-ti me modulation has assumed that accuratechannel esti mations are available at the receivers.Differential space-ti me(DST)modulationschemes were proposed to achieve diversity gainswithout channel state information(CSI)[3].DSTmodulation schemes allowfor slowly changing chan-nels that have to remaininvariant within…     

机载雷达三维空时自适应相关域降维算法

由于利用了俯仰维的自适应能力,三维空时自适应处理(three-dimensional space-time adaptive processing, 3D-STAP)能够获得比传统二维空时自适应处理(2D-STAP)更好的性能,但同时在运算量和采样数目的要求都将急剧增大。为了克服这个问题,提出了一种基于相关域的机载雷达三维空时自适应降维算法,即利用空时相关矩阵的子矩阵,将最优空时处理的二次代价函数转化为两个二次代价函数,并迭代求解这两个二次代价函数的两个低维权向量,所提算法能够明显降低计算复杂度和样本数目要求。基于仿真和实测数据的实验验证了算法的有效性。     

基于线性分散码的放大前传协作分集研究

线性分散码空时协作分集系统与传统的正交分组空时码协作分集系统相比,前者的性能在高速率情况下要好于后者.提出了两种基于线性分散码的放大前传协作分集方案.两种方案的主要区别在于中继端的噪声是在线性分散码编码之前还是之后引入的.首先通过理论推导证明了两种方案的误码率性能相同,然后对两种方案的特点进行了分析,指出一种方案较另外一种方案相比,具有较低的中继端和协议复杂度,但是在协作的信息传输第一阶段的速率较低.最后通过蒙特·卡罗仿真验证了理论上的推导.