太阳能无线传感器网络节点传输功率策略优化

针对配备太阳能采集设备的无线传感器网络节点,以如何合理使用采集到的能量使得时间期限内点对点传输的数据量最大为优化目的,结合必要的约束条件（能量获取电池只有有限的能量存储能力以及能量因果关系）,建立了数据传输的能量通道优化模型,通过能量通道策略优化算法得到了最优传输功率策略。与当前普遍使用的能量即到即用方法进行了性能对比,仿真发现系统累积传输了更多的数据量,性能提升明显。在此基础上,考虑了实际太阳能获取量与预测值的偏差,提出了改进的能量通道算法,使得其更加适应于实际场景中。     

辐射诊断用的光纤传输系统

光纤频带宽、线径细、抗电磁干扰、抗腐蚀。近年来它在高能粒子物理、聚变研究、核爆和核动力学诊断等不利环境中的应用,引起了人们极大的关注。本文将扼要介绍采用光纤传输的快脉冲辐射诊断系统,并以核爆诊断为例说明这类系统的特点及与以往同轴电缆传输系统相比的优越性。     

微波光子晶体的实验研究

制造了工作于微波波段的三角形光子晶体,并测量了光子晶体的透射谱和存在缺陷时的光子晶体的透射谱。在此基础上,研究了它的缺陷模,并讨论了光子晶体的潜在应用     

Improvements in Carrier-to-Noise-Ratio (CNR) of Lightwave Amplitude Modulated Vestigial-Sideband (AM-VSB) Transmission Systems by the Use of Optical Isolators

In lightwave community antena television (CATV) systems as well as other optical fiber communication networks, a transmitted optical signal is known to be degraded by an intensity noise produced within the fiber due to the interference between the signal and doubly reflected light. We report on the improvements to the signal degradation due to the double Rayleigh backscattering by inserting optical isolators in the trunk lines of the systems. A carrier-to-noise ratio (CNR) has been calculated as a function of the number and the insertion loss of the isolators. The calculated results indicate that there is an optimum number of isolators, and if the insertion loss is less than 0.3 dB, the CNR degradation can be restored by more than 60%. To test the calculated results, we conducted experiments for the specific case of employing one isolator, and obtained good agreements between the two.     

空间光通信指令传输的抗干扰设计

设计一种用归零码及多重相关解调技术的传输方案，并给了所需的几种抗干扰单元电路，最后结合实验说明了此方案可提高不良环境下传输数据的置信率。     

Cd_(0.96)Zn_(0.04)S/Cd_(0.97)Mn_(0.03)S/Cd_(0.96)Zn_(0.04)S多层纳米线中s-d交换作用的研究

以氧化铝纳米孔为模板,采用直流电化学沉积的方法制备了Cd_(0.96)Zn_(0.04)S/Cd_(0.97)Mn_(0.03)S/Cd_(0.96)Zn_(0.04)S量子阱纳米线阵列,并系统研究了该纳米线阵列在不同温度和不同磁场下的电学输运特性.随着外磁场的变化,样品表现出共振传输特性.通过量子阱理论对实验现象进行了分析,直接得到了稀磁层Cd_(0.97)Mn_(0.03)S中s-d交换作用常数N_0α的定量结果.研究发现该交换作用常数随温度具有e~(-1/T)的变化趋势.     

Spectral analysis of the UFBG-based acousto optical modulator in V–I transmission matrix formalism

In this study, the V-I transmission matrix formalism （V-I method） is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating （FBG）-based acousto--opfic modulators （UFBG-AOM）. The simulation results demon- strate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave （AW） have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V-I method is 4 × （2M-l） in addition/subtraction, 8 × （2M - 1） in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix （TM） method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix （TM） method, the V-I method is faster and less complex.     

微波器件微放电阈值计算的蒙特卡罗方法研究

为了精准快速地计算微波器件中微放电效应的阈值,在传统蒙特卡罗方法的基础上,提出了三种不同的蒙特卡罗方法,分别对二次电子的初始能量、出射角度和初始相位等参数进行随机,结合四阶龙格-库塔法和Furman模型计算电子的运动轨迹和单次碰撞产生的二次电子发射系数,然后应用不同的方法计算有效二次电子发射系数作为微放电效应的判据.以平板传输线TEM模式为研究对象,采用四种不同的蒙特卡罗方法计算微放电阈值,并与统计模型结果进行对比.结果表明单电子-多碰撞蒙特卡罗方法误差最小,而且稳定性最好.     

基于PXI总线高速数据传输卡的设计 

为了实现数据采集存储设备产生的高速、大容量地数据能够快速、可靠、远距离地实时传输,提出了以PXI系统为平台,采用单一周期和线性突发模式相结合的总线访问方式,以PCI9054作为“桥接”芯片,高速FPGA为微控制器,结合LVDS及高速光纤传输技术的总体方案设计;经实践测试,传输数据正确可靠,实现了177 Mbps长距离通信速率。     

A new coding scheme of QC-LDPC codes for optical transmission systems

Based on Galois Field (GF(q)) multiplicative group, a new coding scheme for Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) codes is proposed, and the new coding scheme has some advantages such as the simpler construction, the easier implementation encoding, the lower complexity of the encoding and decoding, the more flexible adjustment of the code length as well as the code rate and so forth. Under the condition of considering the characteristics of optical transmission systems, an irregular QC-LDPC (3843,3603) code to be suitable for optical transmission systems is constructed by applying the proposed new coding scheme. The simulation result shows that the net coding gain (NCG) of the irregular QC-LDPC (3843,3603) code is respectively improved 2.14 dB, 1.19 dB, 0.24 dB and 0.14 dB more than those of the classic RS (255,239) code in ITU-T G.975, the LDPC (32640,30592) code in ITU-T G.975.1, the regular SCG-LDPC (3969,3720) code constructed by the Systematically Constructed Gallager (SCG) coding scheme and the regular QC-LDPC (4221,3956) code at the bit error rate (BER) of 10-8. Furthermore, all the five codes have the same code rate of 93.7%. Therefore, the irregular QC-LDPC (3843,3603) code constructed by the proposed new coding scheme has the more excellent error-correction performance and can be better suitable for optical transmission systems.