行业要闻

未来TD-LTE将与FDD-LTE平分天下近日,工信部副部长奚国华在我国台湾省参加移动互联网研讨会时表示,第四代移动通讯技术TD-LTE未来将与欧美主导的4G技术(FDD-LTE)平分天下,台湾芯片、终端供应链将扮演关键角色,两岸下一步将签订合作备忘录。     

FDDLTE与TD-LTE基站邻频杂散辐射的研究

随着LTE技术的初步商用,FDDLTE和TD-LTE基站邻频共存的情况很可能出现,这两种LTE基站间将会产生邻频干扰。基站发射机输出的信号通常为大功率信号,基站发射信号有可能会在有用频带之外产生较大的杂散辐射。杂散辐射对异系统的影响在这两种基站工作频段相邻时更为严重,本文正是基于这种场景对两种LTE基站之间邻频共存的杂...     

Design of an active fault tolerant control system for a simulated industrial steam turbine

An active fault tolerant control (FTC) scheme is proposed in this paper to accommodate for an industrial steam turbine faults based on integration of a data-driven fault detection and diagnosis (FDD) module and an adaptive generalized predictive control (GPC) approach. The FDD module uses a fusion-based methodology to incorporate a multi-attribute feature via a support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) classifiers. In the GPC formulation, an adaptive configuration of its internal model has been devised to capture the faulty model for the set of internal steam turbine faults. To handle the most challenging faults, however, the GPC control configuration is modified via its weighting factors to demand for satisfactory control recovery with less vigorous control actions. The proposed FTC scheme is hence able to systematically maintain early FDD with efficient fault accommodation against faults jeopardizing the steam turbine availability. Extensive simulation tests are conducted to explore the effectiveness of the proposed FTC performances in response to different categories of steam turbine fault scenarios.     

TD-SCDMA与LTE系统的比较

本文着重分析TTD—SCDMA与LTE的网络结构、帧结构、多址接入技术以及调制技术,使我们能够对比分析,深刻了解到TD—SCDMA与LTE的不同点。     

跨频共站升级LTE FDD网络天线下倾角优化策略分析

在800MHz频段现有CDMA网络共站升级2.1GHz频段LTE FDD网络。以密集市区站间距500m场景为例,首先分析2.1GHz频段天线下倾角对LTE FDD网络覆盖性能和容量性能的影响,给出相应的最优天线下倾角配置原则;然后通过与800MHz频段网络最优天线下倾角进行比较,给出跨频共站升级方案天线下倾角的优化策略。跨频共站升级LTE FDD网络方案天线下倾角优化策略的研究,可为4G网络的升级与部署提供可靠的参考数据。     

巧用RACK接收增强CDMA FDD覆盖

首先对RACK接收的性能进行了分析,接着分别介绍了增强CDMAFDD上行覆盖和下行覆盖的解决方案,最后总结了CDMAFDD覆盖增强方案的应用场景。     

TD-LTE/FDD LTE融合浅析

文章从LTE网络发展现状出发,预测了LTE发展趋势,并分析了双模LTE基站的可行性,为运营商LTE网络建设提供了一种新的思路。     

个人移动通信频谱需求分析

分析了移动通信市场发展的特点,通过预测远期移动用户及业务状况.使用ITU-RM.1390计算方法估算了移动通信2G、3G混合组网阶段对频谱资源的需求情况,并分析了3G独立组网后频谱资源估算方法.     

自适应调制技术在衰落信道中的应用

该文论述了智能传输中的关键技术——自适应调制技术的应用,结合当前的背景给出了FDD和TDD方式下基站和移动台采用自适应调制的原理框图,并在文章的最后分析了一般调制方式与自适应方式的仿真结果。     

Identification and Damage Detection in Structures Subjected to Base Excitation

This paper presents an experimental study of different algorithms for the health monitoring of frame structures subjected to base excitation (e.g. earthquake ground motion). These algorithms use only the acceleration time histories of the input and of the response output and are tested for the identification of the dynamic characteristics of the structure (natural frequencies and damping ratios) and for detecting and quantifying any possible structural damage that occurs in the frame. Three algorithms were considered: (1) a frequency domain decomposition algorithm, (2) a time domain Eigensystem Realization Algorithm together with Observer Kalman Identification algorithm, and (3) a subsequent physical parameter identification algorithm (MLK). Through extensive experimental testing of a four-story steel frame model on a uniaxial shake table, the performance of the various methods as well as the inherent complications of physical instrumentation and testing are explored.