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针对传输损耗条件下空间复用(SM)和Alamouti空时分组码的盲识别问题,提出一种单接收天线下的基于循环平稳检测的盲识别算法。首先通过理论推导,证明Alamouti空时分组码具有循环频率的特性;然后,求取接收信号的四阶循环累积量来观察循环频率;最后使用循环平稳检测的方法,构造检测不同空时分组码循环频率的假设检验,从而对2种码的接收信号进行区分。该方法可在单接收天线下进行,蒙特卡洛仿真结果表明,该算法不需要预先知道信道信息、调制方式、载波相位和时间偏移,不需要精确知道载波频偏,识别效果较好。 相似文献
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基于Alamouti提出的BPSK调制下空时分组码在Rayleigh衰落信道中的简单分集方案。推导出多发射和多接收天线系统中正交空时分组码在Rician衰落信道的BPSK调制下的比特差错率的最小距离球界,并推广到在高阶调制下衰落信道中系统符号差错率的性能。仿真分析和比较了空时分组码的多天线系统中发射和接收天线分集增益,以及信道相关参数的变化对系统误比特性能的影响。 相似文献
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基于坐标交织正交设计(CIOD)的空时编码,提出了一种新型的4发射天线空间调制(SM)方案。与传统的空间调制技术相比,该方案不仅利用天线序号携带信息,提高了无线通信系统的频带利用率,而且通过空时编码可获得较大的分集增益。接收端采用条件最大似然(ML)算法,大大降低了译码复杂度。在独立和相关信道情况下对所提方案、传统空间调制及空时分组码(STBC)的误比特(BER)性能进行了仿真,结果表明,所提方案的性能优于传统的空时分组码和空间调制。 相似文献
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基于VBLAST-OFDM系统中传统QR分解算法,将最大似然和并行干扰消除的思想引入QR分解算法中,提出了对QR分解算法的改进方法,克服了传统QR分解算法检测性能差的缺点,运用QR分解从最后两层信号开始,等效为2收2发的MIMO系统。用最优算法检测判决后,回代到原QR分解算法检测余下层信号;或者依次并行消除已判决信号的影响,再进行下个等效MIMO系统的判决,直至所有信号检测完毕。仿真结果表明,本文改进的QR分解检测算法比传统的QR算法和迫零算法在误码性能上得到改善。 相似文献
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《Parallel Computing》2014,40(5-6):70-85
QR factorization is a computational kernel of scientific computing. How can the latest computer be used to accelerate this task? We investigate this topic by proposing a dense QR factorization algorithm with adaptive block sizes on a hybrid system that contains a central processing unit (CPU) and a graphic processing unit (GPU). To maximize the use of CPU and GPU, we develop an adaptive scheme that chooses block size at each iteration. The decision is based on statistical surrogate models of performance and an online monitor, which avoids unexpected occasional performance drops. We modify the highly optimized CPU–GPU based QR factorization in MAGMA to implement the proposed schemes. Numerical results suggest that our approaches are efficient and can lead to near-optimal block sizes. The proposed algorithm can be extended to other one-sided factorizations, such as LU and Cholesky factorizations. 相似文献
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《Parallel Computing》1997,23(13):2075-2093
This paper studies the parallel solution of large-scale sparse linear least squares problems on distributed-memory multiprocessors. The key components required for solving a sparse linear least squares problem are sparse QR factorization and sparse triangular solution. A block-oriented parallel algorithm for sparse QR factorization has already been described in the literature. In this paper, new block-oriented parallel algorithms for sparse triangular solution are proposed. The arithmetic and communication complexities of the new algorithms applied to regular grid problems are analyzed. The proposed parallel sparse triangular solution algorithms together with the block-oriented parallel sparse QR factorization algorithm result in a highly efficient approach to the parallel solution of sparse linear least squares problems. Performance results obtained on an IBM Scalable POWERparallel system SP2 are presented. The largest least squares problem solved has over two million rows and more than a quarter million columns. The execution speed for the numerical factorization of this problem achieves over 3.7 gigaflops per second on an IBM SP2 machine with 128 processors. 相似文献
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In this paper, a new algorithm for neuro-fuzzy identification of multivariable discrete-time nonlinear dynamic systems, more specifically applied to consequent parameters estimation of the neuro-fuzzy inference system, is proposed based on a decomposed form as a set of coupled multiple input and single output (MISO) Takagi-Sugeno (TS) neuro-fuzzy networks. An on-line scheme is formulated for modeling a nonlinear autoregressive with exogenous input (NARX) recurrent neuro-fuzzy structure from input-output samples of a multivariable nonlinear dynamic system in a noisy environment. The adaptive weighted instrumental variable (WIV) algorithm by QR factorization based on the numerically robust orthogonal Householder transformation is developed to modify the consequent parameters of the TS multivariable neuro-fuzzy network 相似文献
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提出了一种VBLAST-OFDM系统中的平行干扰消除QR分解检测算法,称为P-ICQR算法。该算法首先对最先检测层信号做出假设,分成多个平行分支,在每个分支上依次干扰消除已检测信号的影响,运用QR分解判决余下层信号而只保留分集增益最高的最后检测层判决信号,最后用部分最大似然法对平行分支选取最优解作为最终检测结果,有效提高了系统的检测性能。仿真结果表明,提出的P-ICQR算法比传统的平行算法、循环迭代QR分解算法、QR算法、迫零算法的误码性能都要好。 相似文献
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We consider three algorithms for solving linear least squares problems based upon the modified Huang algorithm (MHA) in the ABS class for linear systems recently introduced by Abaffy, Broyden and Spedicato. The first algorithm uses an explicit QR factorization of the coefficient matrixA computed by applying MHA to the matrixA T . The second and the third algorithm is based upon two representations of the Moore-Penrose pseudoinverse constructed with the use of MHA. The three algorithms are tested on a large set of problems and compared with the NAG code using QR factorization with Householder rotations. The comparison shows that the algorithms based on MHA are generally more accurate. 相似文献
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对广义行(列)对称矩阵的QR分解和性质进行了研究,给出了广义行(列)对称矩阵的QR分解的公式和快速算法,它们可有效减少广义行(列)对称矩阵的QR分解的计算量与存储量,并且不会丧失数值精度。同时讨论了系统参数估计,推广和丰富了两文(邹红星,王殿军,戴琼海,等.行(或列)对称矩阵的QR分解.中国科学:A辑,2002,32(9):842-849;蔺小林,蒋耀林.酉对称矩阵的QR分解及其算法.计算机学报,2005,28(5):817-822)的研究内容,拓宽了实际应用领域的范围, 并修正了后者的错误。 相似文献
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iSAM: Incremental Smoothing and Mapping 总被引:3,自引:0,他引:3
《Robotics, IEEE Transactions on》2008,24(6):1365-1378
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在频域均衡系统中,基于预编码的子空间盲信道估计算法可以有效地对信道进行估计。针对多天线单载波循环前缀系统,提出了一种基于预编码的盲信道估计算法。该算法通过分离出连续两个接收符号块的互相关矩阵所包含的信道信息实现信道盲估计。仿真结果表明,该算法具有较低的计算复杂度以及对信道阶数过估计有很好的鲁棒性,并且该算法利用较少的数据块个数就得到了一个可靠的信道估计值。 相似文献