申威处理器硬件数据预取技术的实现

硬件数据预取技术可以有效提升处理器的访存性能,是申威处理器性能优化过程中亟需突破的一项技术。硬件开销和处理器架构的制约是硬件预取技术实现中的主要难点。借鉴学术界对硬件预取技术的研究成果和工业界的应用现状,紧密结合申威处理器的结构特点,研究了申威处理器硬件预取技术的实现方法。以流预取为例,在处理器核心面积增加0.97%的情况下,硬件预取技术的应用可以将目前申威处理器的整数性能平均提升5.17%,最高提升28.88%;浮点性能平均提升6.39%,最高提升30.11%。     

铁通公司FTTH发展与建设思考

本文从FTTH发展思路、应用场景、建设模式等方面进行阐述,并对铁通公司FTTH下一步发展提出4点建议。     

A dual-threshold up-down counter for GPS acquisition

In this work, the up-down counter detector for the acquisition of GPS signals is modified to use dual-thresholds for each trial. Closed form expressions for the mean and variance of the dwell time and the probabilities of detection and false alarm are derived. The new detector has a significantly smaller mean dwell time than the conventional single-threshold up-down counter and a lower dwell time variance when signals are weak. Further, the new detector has a low computational load, when compared to the optimal sequential probability ratio test (SPRT), whose main disadvantage is its computational complexity.     

Downlink multiple access schemes for transmitted reference pulse cluster UWB systems

Transmitted reference pulse cluster (TRPC) signaling was recently proposed for low data rate ultra‐wideband communications. Compared with the conventional transmitted reference (TR), TRPC has a more compact and uniform spacing for the reference and data pulses and therefore solves the implementation problem posed by the long delay line requirement in the conventional TR. In this paper, downlink multiple access issue is further investigated for TRPC systems. According to the TRPC signaling structure, both code division multiple access (CDMA) and time division multiple access (TDMA) methods are discussed. Theoretical analysis and simulation results show that TDMA outperforms CDMA in both bit error rate performance and throughput. Copyright © 2010 John Wiley & Sons, Ltd.     

The synthesis of novel fluorine-containing random polymer and application in modification of solid surfaces

The novel fluorine-containing random polymers, poly (2, 3, 4, 5, 6-pentafluorostyrene)-r-poly (4-vinyl benzocyclobutene) random copolymer was synthesized, which can effectively decrease the surface energy and provide a good corrosion protection for some metals. Additionally, textured silicon was fabricated by an optically assisted electrochemical etching process to study the effect of the random copolymer modification on the binary geometric structures of the solid surface. After modification the superhydrophobic property can easily be obtained, which show long-term stability and good superhydrophobicity in corrosive solutions over a wide pH range, including acidic and basic solutions.     

京津唐电力ATM数据网组网技术的研究与应用

从京津唐电力ATM数据网建设的背景出发，提出了京津唐电力ATM数据网的建网原则。结合电力调度、生产管理对通信网络的需求，重点论述了组网技术的选择、网络的结构设计、地址的规划、业务的实现方式和网络的安全。     

一类输电网损分摊方法的积分路径相关性简析

利用功率微增量进行求和是目前输电损耗分摊中的一类代表性方法。文中讨论了该类方法所存在的积分路径相关性问题,表明等步长划分积分区间本身即是一类特殊且并无明显理论依据的求和(积分)路径,至少到目前为止,尚无相关理论可以支持这类特解在理论体系上的恰当性。对该类方法而言,如何克服其所存在的求和路径相关性问题仍然是一个开放的、有待解决的问题。     

Ad Hoc网络技术研究进展

AdHoc网络现在是非常有吸引力的研究方向。本文介绍了Ad Hoc网络的定义、特点、体系结构、信道接入协议，最后分析了Ad Hoc网络面临的问题。希望本文能为进行AdHoc网络技术研究的人们提供一定的方便。     

Group-based user pairing for virtual MIMO in LTE

A user pairing method is proposed to improve the throughput gain of virtual multiple input multiple output (virtual MIMO) in 3G long-term evolution (LTE).The approach taken in this study separated the user pairing into four steps 1) the users are divided into two groups according to their signal-to-noise ratio (SNR), and different user pairing metrics are proposed for each group; 2) the scheduler chooses a user for transmitting by a given rule; 3) the scheduler searches the pairing candidate for the selected user in each group; 4) the scheduler chooses the final pairing user from the co-group and crossover-group candidates by using a marginal utility function, to balance fairness and efficiency.The method can improve the throughput of users with high SNR, and guarantee fairness for users with low SNR, so it can be used in 3G LTE systems.The article provides both theoretical analysis and simulation results to support the idea.     

Higher order spectral estimation for random fields

This paper is concerned with the nonparametric estimation of the higher order cumulant spectra of vector-valued stationary random fields onZ ^d by smoothing the periodograms, whereZ is the space of integers and the dimensiond1. We derive the asymptotic cumulant properties of the spectral estimates, and consider an application to multidimensional nonlinear systems identification. Numerical examples with simulated data are provided.