Data service oriented networking analysis of TD-LTE system

The development of mobile internet and internet of things brings the vigorous developing data service, which increases need of bandwidth sharply. Operators strive to develop the data service oriented LTE(long term evolution)technology, especially TD-LTE (time division-LTE) technology adopting the spectral asymmetric. This paper analyzed details of TD-LTE system networking, and studied the feasibility of TD-LTE and TD-SCDMA(TD-synchronous code division multiple access) system with the same spectrum. At last, the paper provided suggestions on networking of TD-LTE system.

A Re-Configurable Dual-Mode Delay-Aware Scheduling and Resource Allocation for LTE System

Long Term Evolution( LTE) has been proposed as an advanced wireless radio access technology to provide higher peak data rates and better spectral utilization efficiency,but the classical scheduling and resource allocation algorithms cannot optimally enhance the system performance due to high computational complexity. In this paper,a re-configurable dual mode delay-aware( CDD) scheduling and resource allocation algorithm is proposed to achieve the joint consideration of scheduling pattern,scheduling priority and quantity of scheduled data. In this study,dual-mode scheduling mechanism is associated with three configurable parameters and the CDD algorithm is involved to guarantee queuing delay with low loss of resource utilization and fairness.The computational cost of the scheduling and resource allocation algorithm is significantly reduced by efficiently utilizing Qo S Class Identifier( QCI) and Channel Quality Indicator( CQI) defined by LTE standards. The simulation results based on different application scenarios also represent the computation cost and complexity of scheduling algorithm along with the improved system throughput.

Energy-Saving Technology in Indoor LTE System with DTX Based on CQI

In LTE (Long Term Evolution) system, CQI (Channel Quality Indication) is a technical method to realize adaptive modulation and coding. The dispatcher of BS (base station) would allocate resource blocks to users dynamically based on CQI of uplink and downlink channels, which is necessary in the process of uplink and downlink transmission [1]. When the CQI level of the channel is high, the energy efficiency is high. On the contrary, when the CQI level of the channel is low, the energy efficiency is low. However, if signals are not transmitted until the quality of the channel is good, energy loss may be lowered in the expense of group delay. That is to say, we take CQI into account on the basis of the technology of DTX [2] [3] (Discontinuous Transmission). According to the result of simulation, the energy consumption can be reduced by using our proposed scheme. Particularly, the energy-saving effect is significant when the load is low.

Improved Method of Contention-Based Random Access in LTE System

Random access is the necessary process to establish the wireless link between the user equipment （UE） and network. The performance of the random access directly affects the performance of the network. In this work, we propose a method on the basis of the existing alternatives. In this method, we estimate the system load in advance to adjust the number of terminals. An access threshold is set to control the number of terminals which want to access the base station at an acceptable level. At the same time, we havean improvement on the existing power climbing strategy. We suppose that the power ramping is not always necessary for the re-access. And the selection ofpower ramping steps is studied in this paper. Simulations based on MATLAB are employed to evaluate the effectiveness of the proposed solution and to make comparisons with existing alternatives.

Hierarchical power control for OFDM based LTE system

Abstract3GPP LTE has approved uplink intra-cell power control and defined overload indicator(OI)for uplink inter-cell power control to mitigate the inter-cell interference(ICI),respectively.In this paper,we propose a hierarchical power control(HPC)scheme where intra-cell and inter-cell power controls interact with each other.The inter-cell power control command is generated by radio resource management(RRM)entity according to the ICI-load model together with the current ICI and served load information.This ICI-load model is proposed as a guideline for coordination among cells to enable the system to approach its system specific interference over thermal noise(IoT)work area.Simulation results show that for HPC scheme,the system's IoT is well controlled to fit its pre-defined work area and the power efficiency is improved significantly.Our proposed scheme is also robust to different settings of its inter-cell power control period.

Throughput Evaluation of Downlink Multiuser-MIMO OFDM-LTE System

Recently, the mobile communication industry is moving rapidly towards long-term evolution (LTE) systems. LTE aims to provide improved service quality over 3G systems in terms of throughput, spectral efficiency, latency, and peak data rate, and MIMO technique is one of the key enablers of the LTE system for achieving these diverse goals. Among several operational modes of MIMO, multiuser MIMO (MU-MIMO) in which the base station transmits multiple streams to multiple users, has received much attention as a way for achieving improvement in performance. In this paper we present a Multiuser MIMO-OFDM-based simulator that includes the main physical layer functionalities and calculate the throughput of LTE Frequency Division Duplex (FDD) and Time Division Duplex (TDD) systems. The simulator has been used to evaluate the performance of the 3GPP Long-Term Evolution (LTE) technology.

MathWorks推出用于MATLAB的LTE System Toolbox

MathWorks推出了全新的LTESystemToolbox，为LTE和LTE—Advanced无线通信系统和设备提供了与标准兼容的仿真、验证和分析功能。此工具箱是MATLAB和CommunicationsSystemToolbox的扩展，目标用户针对需要设计或验证无线设备是否符合LTE标准的工程师。

Design of OFDM Transceiver for LTE System—A Survey

LTE (Long Term Evolution) is the latest technology in wireless communication. It is being used because of its peak data rate and spectral efficiency. LTE uses OFDMA (Orthogonal Frequency Division Multiple Access) technology for radio transmission and reception in downlink. OFDM is a multicarrier modulation and multiplexing technique to improve data rate, spectral efficiency and minimize the problem of fading and ISI (Inter Symbol Interference). Many transceivers design have been designed for OFDM system to minimize error and maximize throughput of the information being transmitted and received at the system. The purpose of this article is to present a survey of the published literature which deals with various OFDM transceiver design, focusing on the merits and demerits of the corresponding OFDM transceiver design.

Planning and Profit Sharing in Overlay WiFi and LTE Systems toward 5G Networks

With the increasing demand for data traffic and with the massive foreseen deployment of the Internet of Things (IoT), higher data rates and capacity are required in mobile networks. While Heterogeneous Networks (HetNets) are under study toward 5G technology, Wireless Fidelity (WiFi) Access Points (APs) are considered a potential layer within those multiple Radio Access Technologies (RATs). For this purpose, we have proposed in this paper a novel WiFi dimensioning method, to offload data traffic from Long Term Evolution (LTE) to WiFi, by transferring the LTE energy consuming heavy users, to the WiFi network. First, we have calculated the remaining available capacity of the WiFi network based on the estimated load of each WiFi physical channel using the overlapping characteristic of the channels. Then, we were able through this dimensioning method, to calculate the minimum needed number of WiFi APs that ensure the same or better throughput for the LTE transferred users. By this method, we have ensured additional capacity in the LTE network with minimum investment cost in the WiFi network. Finally, we have estimated the profit sharing between LTE and WiFi by considering data bundles subscription revenues and the infrastructure capital and operational costs. We have calculated for each network the profit share using a coalition game theory Shapley value that pinpoints the benefit of the cooperation using the proposed dimensioning method.

MathWorks推出用于MATLAB的LTE System Toolbox

MathWorks推出了全新的LTE System Toolbox，为LTE和LTE—Advanced无线通信系统和设备提供了与标准兼容的仿真、验证和分析功能。此工具箱是MATLAB和Communications System Toolbox的扩展，目标用户针对需要设计或验证无线设备是否符合LTE标准的工程师。

采用LTE Cat.1通信的物联网高精度高度计设计

为解决传统的基于物联网的远程测量技术中存在的测量精度与传感器成本无法兼顾、数据更新实时性不好、通信成本过高的问题,提出一种传感器数据采集方案,利用软件算法实现了高精度。同时,采用LTE Cat 1为数据通信方式,将数据传输到远程云服务器及终端。将方案运用到远程海拔高度测量中,经过严谨的计算和测试验证,测量的绝对误差小于5 m,相对误差低于0.5%,数据传输的稳定性高,实时性可以控制到1 s之内,同时兼顾了通信的成本,在数据上传频率达到1次/s的情况下,数据流量可以控制在600 KB/h,满足系统的高精度、低成本、高实时性和稳定性要求。

LTE汽车单片机通信网络优化与安全性设计

随着汽车技术的不断进步,汽车单片机通信网络在实现智能出行中扮演着关键角色。在这一趋势中,LTE技术作为一项先进的通信技术,其在提高汽车通信性能和网络安全性方面的潜力不可忽视。本文对LTE技术在汽车通信中的优化与安全性设计进行了深入研究,旨在为实现更高效、可靠、安全的汽车通信网络提供理论支持。

轨道交通LTE系统等保接入方案及实现

根据西安地铁14号线研究对承载信号业务的LTE系统增加3级等级保护的具体方案及步骤,针对14号线线路特点提出2个可行的等级保护接入方案,并通过网络架构及性能评估比较,选择最优的等保接入方案,确保网络传输的安全稳定。同时通过等保系统相关接口配置、注意事项等描述,详细阐述涉及行车安全的LTE系统在增加等级保护过程中的重要步骤,确保网络安全,为轨道交通信号系统的行车指挥和列车运行控制提供重要保证,为后续轨道交通等保接入提供可参考价值。

痰热清注射液辅助支气管肺泡灌洗对重症肺炎患者血清sCD163、Presepsin、LTE4水平的影响

目的探究痰热清注射液辅助支气管肺泡灌洗对重症肺炎患者血清可溶性CD163(sCD163)、可溶性白细胞分化抗原14(Presepsin)、尿白三烯E4(LTE4)水平的影响。方法选取重症肺炎患者180例,随机法分为参考组与研究组,各90例。参考组予以支气管肺泡灌洗治疗,研究组在参考组的基础上增用痰热清注射液治疗。对比两组疗效,各项症状消失时间,血清sCD163、Presepsin、LTE4水平,血气指标。结果研究组总有效率高于参考组,差异有统计学意义(P<0.05)。研究组各项症状消失时间均短于参考组,差异均有统计学意义(P<0.05)。治疗后两组血清sCD163、Presepsin、LTE4水平均低于治疗前,且研究组上述各项指标水平均低于参考组,差异均有统计学意义(P<0.05);两组各项血气指标较治疗前均明显改善,且研究组改善优于参考组,差异均有统计学意义(P<0.05)。结论痰热清注射液辅助支气管肺泡灌洗治疗重症肺炎患者的效果较佳,且能降低血清sCD163、Presepsin、LTE4水平,改善血气指标水平。

LTE与WLAN技术在轨道交通PIS系统中的应用对比

随着城市交通的不断发展,轨道交通PIS系统在提供实时乘客信息和确保交通系统的高效运行方面变得愈发重要。文中比较了LTE和WLAN两种通信技术在轨道交通PIS系统中的应用。通过性能、可靠性、成本、适用性等方面的比较,揭示了两种技术各自的优势和不足。研究结果有助于决策者选择适当的通信技术,以满足PIS系统的需求,提高系统性能。

浅析LTE移动通信网络优化

随着当前我国移动通信网络的发展,群众对于网络信息发展的服务质量也有着越来越严格的标准和需求,在当前人们生活节奏逐渐提升的基础上,人们的时间观念得到显著发展,尤其是对列车安全性和准点性要求不断提升。移动通信网络发展的初级阶段,对网络服务质量进行提升主要展现在覆盖上,从而借助有效的方式对网络规模进行扩大。时代的发展大大推动了当前网络的进步,社会众多领域也实现了信息化建设和发展。所以,只有对LTE移动通信网络技术进行深入研究和优化,才能有效促进LTE网络的稳定发展,为列车的安全性发展奠定良好基础。针对这种情况,本文就将以LTE的概念作为基本出发点,详细研究移动网络中出现问题的主要原因,从而提出更合理的解决方案和应对策略,希望这项研究工作的开展对于LTE移动网络的优化能提出更为有效的指导和帮助作用,保障列车安全正点运行。

LTE技术在城市轨道交通信号系统的设计及应用

随着国家经济水平的快速发展,城镇化建设进程持续加快。城市轨道交通工具作为经济发展的重要组成部分,除了基本的通勤功能外,人们对乘坐过程中的多媒体多样性服务提出了更高的需求。为了防止外界因素对地铁运输过程中信号传输稳定性的影响,研究者开始将LTE技术引入信号框架设计中,对提高乘客的舒适性及列车运行安全性具有十分重要的意义。鉴于此,本文首先介绍了LTE技术的概念,其次分析了基于LTE技术的车-地无线系统架构设计,然后阐述了基于LTE技术的信号系统设计方案,最后对LTE技术在轨道交通信号设计中的未来发展提出了一定建议。以期为LTE技术在轨道交通信号系统中的应用提供一定的借鉴意义。

LTE无线通信技术与物联网技术的结合应用

随着科技的不断发展,人们对信息服务的需求越来越高。在无线通信技术方面,长期演进(Long Term Evolution,LTE)被广泛应用于移动通信领域,因其高速、高质量的数据传输能力而备受青睐。物联网技术的出现和发展为各行各业带来了巨大的机遇和挑战。将LTE无线通信技术与物联网技术相结合,可以进一步提高用户的信息服务体验,为后续发展提供坚实的基础。

电力系统中的LTE无线网络规划设计的研究

本文重点介绍电力LTE无线网络的规划设计、网络参数配置与覆盖性能分析,并通过仿真实验来验证无线网络规划设计的可行性。仿真结果表明:利用LTE 230MHz技术对电力系统中的无线通信网络进行优化,大幅提高了电力系统中无线网络的性能、覆盖范围与容量,为电力系统的长期稳定可靠运行提供了有力的技术支持,同时也为LTE无线网络规划设计提供一定借鉴与参考。

LTE-M车地无线通信系统中的自适应调制编码技术

城市轨道交通车地综合通信(LTEM)系统在通信环境、业务需求等方面与公共无线通信系统有较大的差异。传统的调制编码技术已无法满足系统性能要求。文章针对LTE-M应用场景的特殊性,提出了一种AMC技术的优化方案。经过测试证明,该方案解决了由于信号质量变化太快以及信号频繁抖动所带来的调制编码等级不准确问题,保证了在切换过程中的丢包率以及时延,大大提高了切换过程中的性能指标。