一种新型的双幅度定长脉冲间隔调制方式

针对数字脉冲间隔调制(DPIM)存在的问题和性能方面的不足,提出了一种新型的双幅度定长脉冲间隔调制(DAFDPIM)方式,对其调制结构进行了详细阐述,讨论了发射功率、带宽需求、传输容量和差错性能等问题,并与其他几种DPIM的改进方式进行了仿真对比。理论分析和仿真结果表明:这种新型的DAFDPIM方式能实现性能方面较好的平衡,并解决了DPIM符号长度不固定的问题,在无线光通信系统中具有一定的应用前景。     

高速率WDM系统光信噪比（OSNR）计算方法及软件实现

通过对光信噪比（OSNR）的理论分析,提出了OSNR的计算方法,并在此基础上开发出计算工具以快速仿真出WDM系统OSNR值,从而能够更加严谨地验证系统建设方案的合理性。     

两种WCDMA无线利用率浅析及高效小区判定方法

以网络极限承载能力为突破口,对两种无线资源利用率算法进行浅析,研究在网络极限能力下的实际运行效率,并将两种算法联合分析,通过两种建模,给出判定高效小区的初步方法。     

一种基于罚因子的DASH调度算法

随着移动互联网的普及,基于DASH的流媒体传输协议的应用越来越广泛。如何在带宽波动较大的移动互联网环境中保证用户实现流媒体的流畅点播,提高用户的体验度是DASH调度算法最主要研究的问题。以提高用户体验度为出发点,结合带宽和缓存深度两方面因素,对带宽预测模型的置信度进行评价。在高置信度情况下,大胆地对网络带宽估计模型的模型参量进行调整;在低置信度情况下,以保护缓冲区深度为目的,谨慎地对模型参量进行调整。这种调整势必会对QoE造成相应的影响,该影响作为"罚因子"反馈回模型置信度的评价,以获得模型参数的动态最优解,得到一种较好的DASH调度算法。     

面向TD-LTE的PTN接入网优化方案探讨

简要地介绍了某地市移动公司接入网的现状,分析了接入层不同的网络场景,针对TD-LTE对传输网的需求,提出了可行的PTN接入网的优化方案。     

HDI板高厚径比微盲孔跨层微导通孔技术开发

高厚径比微盲孔的HDI板制作通常需要很好的孔金属化能力保障其导通可靠性,但所需生产设备及其配套成本让不少厂商望而却步。本文所述高厚径比微盲孔跨层微导通孔（skip-μvia）技术,通过定位精度控制、激光钻孔参数调整以及制板流程优化等工艺的开发,能以更低的成本、更高的品质、更短的加工流程以及常规孔金属化设备实现高厚径比的微盲孔制造,从而降低了高厚径比微盲孔HDI板制造的难度。     

等离子设备加工高厚径比产品工艺研究

文章通过对孔壁平均去钻污量的数据分析,研究了厚径比与孔壁平均去钻污量的规律,初步界定了等离子去钻污加工高厚径比的能力。通过对等离子去钻污均匀性的控制,控制平均去钻污量,从而得到高厚径比产品稳定加工品质。     

Very facile fabrication of aligned organic nanowires based high-performance top-gate transistors on flexible,transparent substrate

Aligned single-crystalline organic nanowires (NWs) show promising applications in flexible and stretchable electronics, while the use of pre-existing aligned techniques and well-developed photolithography techniques are impeded by the large incompatibility with organic materials and flexible substrates. In this work, aligned copper phthalocyanine (CuPc) organic NWs were grown on flexible and transparent poly(dimethylsiloxane) (PDMS) substrate via a grating-assisted growth approach. Furthermore, a simple yet efficient etching-assisted transfer printing (ETP) method was used to achieve CuPc NW array-based flexible top-gate organic field-effect transistors (OFETs) with a high mobility up to 2.0 cm² V⁻¹ s⁻¹, a small operating voltage within ±10 V, a high on/off ratio >10⁴, and excellent bend stability with bending radius down to 3 mm. It is expected that the high-performance organic NW array-based top-gate OFETs with exceeding bend stability will have important applications in future flexible electronics.     

Achieving above 30% external quantum efficiency for inverted phosphorescence organic light-emitting diodes based on ultrathin emitting layer

High efficiency inverted phosphorescence organic light-emitting diodes (PhOLEDs) based on ultrathin undoped and doped emitting layer (EML) have been developed. Compared to conventional device, the inverted PhOLED with 0.5 nm undoped EML exhibits significantly larger external quantum efficiency (EQE), due to effective energy transfer from the excited host to the emitter. According to the atomic force microscopy image of EML, the 0.5 nm emitter sandwiched by two hosts can be considered as the emitter doped in two hosts. The inverted device with intentionally doped ultrathin EML (1.5 nm) exhibits the maximum EQE of 31.1%, which is attributed to optimized charge balance and preferred horizontal orientation of emitter. However, such inverted device has large efficiency roll-off at high brightness because of triplet–triplet annihilation process within the ultrathin EML. This can be improved by broadening the doped EML. The inverted device with 10.5 nm doped EML has about EQE of 20 % at 10,000 cd/m². It is expected that our inverted PhOLED will promote development of high efficiency active-matrix organic light-emitting diodes based on the n-type Indium Gallium Zinc Oxide thin film transistor.