Blind Equalization Using Coordinate Mapping for 4-PAM and 16-QAM Signals

It is well known that the famous Constant modulus algorithm （CMA） presents a large steady-state Mean square error （MSE） for nonconstant modulus sig- nals. In this paper a coordinate mapping approach for a 4-PAM nonconstant modulus signal is described which can change the signal to an Offset QPSK （OQPSK） constant modulus signal. And a new algorithm based on this ap- proach is proposed which is also suitable for a 16-QAM signal. For the 4-PAM and 16-QAM nonconstant modulus signals the proposed algorithm can achieve a zero steady- state MSE in a noiseless environment but CMA cannot, Theoretical analysis and simulations results demonstrate the high performance of the proposed algorithm.     

Dynamic Self‐Repair Architectures for Defective Through‐silicon Vias

Three‐dimensional integration technology results in area savings, platform power savings, and an increase in performance. Through‐silicon via (TSV) assembly and manufacturing processes can potentially introduce defects. This may result in increases in manufacturing and test costs and will cause a yield problem. To improve the yield, spare TSVs can be included to repair defective TSVs. This paper proposes a new built‐in self‐test feature to identify defective TSV channels. For defective TSVs, this paper also introduces dynamic self‐repair architectures using code‐based and hardware‐mapping based repair.     

(Semi-)blind channel estimation for space time block coded system with transmit diversity

This paper deals with a blind channel estimation method for space-time coded block transmission system. By concatenating the real part and imaginary part of the received signal to form an elongated vector, we derive an equivalent input–output system model. Then channel state information (CSI) is blindly estimated using subspace method, utilizing only the redundancy inherent in space-time block coding (STBC) and cyclic prefix (CP). The estimation ambiguity, which is common to all blind methods, is analyzed in detail and we prove that there only exist four scalar indeterminacies. Three effective methods to eliminate the ambiguities are also proposed. Compared with other blind channel estimation methods for space time systems, this method needs neither redundant precoding nor oversampling, and thus has higher data rate. Besides, this method is robust to channel order overestimation, which is effectively demonstrated by numerical simulations. This work was supported by NSFC (60496310, 60672093), NSFJS(BK2005061) and BK2005061.     

氧化铝陶瓷基板过孔的新型激光打孔工艺

陶瓷基板激光打孔一固有缺点即孔周围会形成大量不规则堆溅物。提出一种直接在凝胶注模成型陶瓷素坯上激光打孔的新工艺。Nd:YAG激光在氧化铝上打孔的研究表明,该方法能大大减少堆溅物的形成,从而得到分布致密、形状规则的微孔。     

基于拓扑分析的多层通道布线算法

本文提出了一种基于拓扑分析的多层通道布线算法。算法把整个布线过程分成拓扑分层和物理布线两个部分。拓扑分层利用线段交叠图及模拟退火算法解决线段分层及通孔最少化问题，物理布线过程引入虚拟走线道解决交叉问题，再利用轮廓线跟踪的方法来决定最终确定各线段的布线位置。算法还解决了多层布线分层的管脚约束问题和相邻约束问题。实验结果表明，这是一种有效的方法。     

An exact, linear solution to the problem of imaging through turbulence

We show how, in principle, to solve the ‘blind deconvolution' problem. This is in the context of the problem of imaging through atmospheric turbulence. The approach is digital but not iterative, and requires as input data but two short-exposure intensity images, without the need for reference point sources. By taking the Fourier transform of each image and dividing, a set of linear equations is generated whose unknowns are sampled values of the two random point spread functions that degraded the images. An oversampling by 50% in Fourier space equalizes the number of unknowns and independent equations. With some prior knowledge of spread function support, and in the absence of added noise of image detection, the inverted equations give exact solutions. The two observed images are then inverse filtered to reconstruct the object.     

光纤接续和配线产品与测试仪器的使用

介绍光缆施工过程中使用的各种接续产品和相关的设备,包括光纤配线柜、光纤熔接机和OT-DR等,就使用经验和技巧提出个人的看法.     

Comparison of laser-wavelength operation for drilling of via holes in AlGaN/GaN HEMTs on SiC substrates

By using a frequency-tripled Nd:YVO₄ laser source (355 nm) for drilling through-wafer via holes in SiC substrates, we can reduce the surface contamination and achieve better smoothness inside the via holes compared to use of the more common 1064-nm Nd:YVO₄ laser. The sheet and contact resistance of AlGaN/GaN HEMT layers grown on SiC substrates were similar after formation of vias by 355-nm laser drilling to those of the undrilled reference sample. By sharp contrast, 1064-nm laser drilling produces significant redeposition of ablated material around the via and degrades the electrical properties of the HEMT layers.     

遗传优化神经网络的水声信道盲均衡

不需要训练序列的盲均衡技术可以有效地节省水声通信带宽，消除码间干扰，提高水声通信效率和质量。以前馈神经网络（FNN）作为盲均衡器，既适用于最小相位信道，也适用于非最小相位信道，包括非线性信道，但是前馈神经网络在实际的应用中其网络拓扑结构的选取和初始权重的确定缺乏理论依据，且其训练主要依靠BP算法，存在收敛速度慢、容易陷入局部极值及“过学习”的问题。为此，本文提出了一种遗传优化神经网络的水声信道盲均衡算法（GA—BP），对前馈神经网络拓扑结构和网络权重同时优化，有效地克服了传统前馈神经网络盲均衡的缺陷，提高了前馈神经网络盲均衡的泛化性能并加强了跟踪时变信道的能力和对信道突变的适应能力。水池试验结果证明了文中提出的遗传优化神经网络水声信道盲均衡算法的有效性，与直接前馈神经网络盲均衡相比较，均衡性能明显得到了提高。