Visual Basic中控制输入输出口的方法

Ｖｉｓｕａｌ Ｂａｓｉｃ（ＶＢ）以其强大的图形界面功能、可视化编程及方便的代码维护赢得了许多程序员的青睐，但ＶＢ却没有提供直接的Ｉ／Ｏ操作功能，为开发与硬件接口设备有关的系统程序的编制带来了一定的难度。文章详细论述了一种运用动态链接库ＤＬＬ对ＶＢ的功能进行扩展，实现Ｉ／Ｏ操作的办法，并给出了具体实例。

输入输出缓冲区的设置及工作原理

本文通过实例概要阐述了缓冲区的设置及工作原理。

三叉杆式万向联轴器的转角差值分析

建立三叉杆式等角速万向联轴器中各个构件坐标及坐标方程 ,导出不同坐标原点的坐标系之间坐标变换矩阵 ,从而推导出三叉杆式等角速万向联轴器的运动方程 ,计算了输入和输出转角间的关系。

触摸屏技术在16位单片机中的应用

分析了8096系列中的80196单片机在电力系统配电变压器智能检测终端设备中的人机交互界面接口应用问题,通过实例详细介绍了该类单片机与触摸屏芯片的软、硬件接口的应用技巧,分析了其工作特性,指出在应用中需注意的问题,并给出了触摸芯片的部分程序。

基于单片机的测温电路设计

本文以MCS-51单片机为主机模型,着重介绍了51单片机P1口的使用,并在此基础上阐述了单片机在监控中的应用,以及利用单片机实现的简单测温电路,使读者对单片机的输入输出口的控制作用有所了解。

Windows CE电池驱动采样算法的改进设计

首先介绍电池驱动的软硬件架构。该架构独立于具体的开发平台,可以方便地移植到各种平台上;重点讨论电池采样算法的改进,提出三折线段的放电曲线修正和拟合算法,并给出实现方案;结合Windows CE和三星公司S3C2443 CPU的特性,给出该架构的一种电池驱动程序的实现方案。该方案设计灵活、稳定可靠,已经应用到实际的嵌入式项目中,效果良好。

多核DSP Boot load代码加载方法研究

通过分析目前第三代移动通信WCDMA协议不断更新升级的现状,提出了一种基于IP的软升级多内核DSP代码的方法,以在硬件平台相同的情况下快速、方便的实现WCDMA协议版本软升级.并以德州仪器公司三内核DSPTCI6488为例,实现了EMAC(以太网口)及SRIO(串行快速输入输出口)混合加载方式.该方法为自动、远程可控的网络式代码加载方法.

Limited feedback SDMA schemes based on statistical CSI

This paper investigates the multi-beam selection algorithms for transmit correlation channels by using statistical channel state information （SCSI） and instantaneous channel state information. Unlike the conventional codebook-based transmission scheme, the proposed multi-beam selection with the single channel quality indicator （CQI） feedback （MBS- SCF） algorithm determines the preferred beam vector by exploiting the SCSI and only feeds back CQI at each timeslot. The performance of the MBS-SCF algorithm is nearly the same as that of the conventional scheme. In order to further improve the average sum rate, a novel multi-beam selection with the dual CQIs feedback （MBS-DCF） algorithm is proposed, which determines dual preferred statistical eigen- directions and feeds back dual CQIs at each timeslot. The theoretical analysis and simulation results demonstrate that the MBS-DCF algorithm can increase the multiuser diversity and multiplexing gain and exhibits a higher average sum rate.

Ordered successive noise projection cancellation algorithm for dual lattice-reduction-aided MIMO detection

A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme.

The Enlightment on Task-based Teaching Derived from Input Hypothesis

Aiming at gradually developing and perfecting the task-based teaching method, the essay, with enlightment from the Krashen＇s Input Hypothesis, discusses some issues about input, output, activities and teacher＇s role in this method.

An Efficient MMI SOI Splitter with Multimode Input/Output Waveguides

A 1×8 multimode interference power splitter with multimode input/output waveguides in SOI material is designed by the beam propagation method and fabricated by the inductive coupled plasma etching technology for use in fiber optics communication systems.The fabricated device exhibits low loss and good coupling uniformity.The excess loss is lower than 0 8dB,and the uniformity is 0 45dB at the wavelength of 1550nm.Moreover,the polarization dependent loss is lower than 0 7dB at 1550nm.The device size is only 2mm×10mm.

ADAPTIVE TRACKING CONTROL FOR A CLASS OF NONLINEAR COMPOSITE SYSTEMS *

In this paper, the problem of adaptive tracking control for a class of nonlinear large scale systems with unknown parameters entering linearly is discussed. Based on the theory of input output linearization of nonlinear systems, direct adaptive control schemes are presented to achieve bounded tracking. The proposed control schemes are robust with respect to the uncertainties in interconnection structure as well as subsystem dynamics. A numerical example is given to illustrate the efficiency of this method.

ROBUST STABILIZATING FOR A OLASS OF UNOERTAIN NONLINEAR INTEROONNECTED SYSTEMS USING VARIABLE STRUCTURE CONTROL

The robust stabilizating control problem for a class of uncertain nonlinear large-scale systems is discussed. Based on the theory of both input/output (I/O) linearization and decentralized variable structure control (VSC),two-level and decentralized variable structure control laws for this kind of systems are presented respectively,which achieve asymptotically stabilization despite the uncertainties and disturbances. At last,sirnulation of the disturbed two-pendulum system is given to illustrate the feasibility of proposed technique.

Low complexity iterative differential decoding algorithm for multiband UWB communication systems

Due to not requiring channel state information （CSI） at both the transmitter and the receiver, noncoherent ultra-wideband （UWB） incurs a performance penalty of approximately 3 dB in the required signal to noise ratio （SNR） compared to the coherent case. To overcome the gap, an effective differential encoding and decoding scheme for multiband UWB systems is proposed. The proposed scheme employs the parallel concatenation of two recursive differential unitary space-frequency encoders at the transmitter. At the receiver, two component decoders iteratively decode information bits by interchanging soft metric values between each other. To reduce the computation complexity, a decoding algorithm which only uses transition probability to calculate the log likelihood ratios （LLRs） for the decoded bits is given. Simulation results show that the proposed scheme can dramatically outperform the conventional differential and even coherent detection at high SNR with a few iterations.

NON-UNIFORM LINEAR ARRAY CONFIGURATION FOR MIMO RADAR

Array configuration of multiple-input multiple-output （MIMO） radar with non-uniform linear array （NLA） is proposed. Unlike a standard phased-array radar where NLA is used to generate thinner beam patterns, in MIMO radar the property of NLA is exploited to get more distinct virtual array elements so as to improve pa- rameter identifiability, which means the maximum number of targets that can be uniquely identified by the radar. A class of NLA called minimum redundancy linear array （MRLA） is employed and a new method to construct large MRLAs is descrihed. The numerical results verify that compared to uniform linear array （ULA） MIMO radars, NLA MIMO radars can retain the same parameter identifiability with fewer physical antennas and achieve larger aperture length and lower Cramer-Rao bound with the same number of the physical antennas.

Uplink capacity analysis of single-user SA-MIMO system

A novel framework of which combines smart antennas multiple antenna systems, （SA） with multiple-input multiple-output （MIMO） at the receiver, is proposed. The uplink SA-MIMO system is investigated. The joint optimization problem corresponding to the uplink capacity of the single-user SA-MIMO system is deduced. Then the closedform expression of the capacity is obtained in the case of equal power allocation and the same direction-of-arrivals （DOAs） from different transmit antennas at the same antenna array, and an upper bound of the capacity is also given in the case of different DOAs at the same antenna array. After that, for the general case, a suboptimal method for the capacity optimization problem is presented. Some numerical results are also given to compare the capacities of conventional MIMO and SA-MIMO systems and show that the proposed method is viable.

MIMO系统中的迭代分组MAP检测算法

该文提出了在分组MAP检测器内部进行干扰信息更新和检测信息迭代反馈的检测算法。在MIMO系统基本的分组MAP检测算法基础上,利用先检测分组产生的后验信息替代先验信息提高干扰信号的估计精确度,进一步可以使用迭代反馈的方法在检测器内部进行反馈检测分组的后验信息,从而提高了检测信号的分集度。仿真结果表明在未编码系统中改进的分组检测方法能够显著地提高系统误码率性能,在编码系统中能够加快整个系统的收敛。

Polynomial rooting based frequency offset estimation for MIMO OFDM systems

Based on the frequency domain training sequences, the polynomial-based carrier frequency offset （CFO） estimation in multiple-input multiple-output （ MIMO ） orthogonal frequency division multiplexing （ OFDM ） systems is extensively investigated. By designing the training sequences to meet certain conditions and exploiting the Hermitian and real symmetric properties of the corresponding matrices, it is found that the roots of the polynomials corresponding to the cost functions are pairwise and that both meger CFO and fractional CFO can be estimated by the direct polynomial rooting approach. By analyzing the polynomials corresponding to the cost functions and their derivatives, it is shown that they have a common polynomial factor and the former can be expressed in a quadratic form of the common polynomial factor. Analytical results further reveal that the derivative polynomial rooting approach is equivalent to the direct one in estimation at the same signal-to-noise ratio（SNR） value and that the latter is superior to the former in complexity. Simulation results agree well with analytical results.

PLC在袋式除尘器中的应用

本文通过对陶瓷行业喷雾干燥塔的烟气除尘系统的工作特点进行深入分析,设计并制造了一个实用的控制系统,其功能完整、结构简化,并对该控制系统的成功经验进行总结。

Downlink cooperative beamforming for MIMO cellular systems

In downlink cellular multiple users in multiple cells systems using beams, the should cooperate to generate beams to improve the spectrum efficiency. A mathematical model for the multi-cell multi-user downlink transmission is established, and the gradients of the variables including beamfonning filters, receiving filters and transmitting power are calculated. Then, a gradient-project-based cooperative beamforming scheme is proposed in which each user iteratively adjusts bearnforming variables in the direction of the gradients and projects onto feasible spaces. The information exchange protocol needed to support the scheme is also described. Simulation results show that the proposed scheme can achieve an average spectral efficiency of about 5 bit/（ s · Hz · cell）. The results show that cooperative beamforming can improve the spectrum efficiency of the cellular systems.