B 3G移动通信系统可提供高达100Mbit/s的速度,MIMO-OFDM作为B 3G的核心技术,同步问题一直是该系统的关键问题.介绍了正交频分复用技术(OFDM),多输入多输出系统(MIMO)技术的原理,分析MIMO-OFDM系统中存在的同步问题,总结MIMO-OFDM系统的...B 3G移动通信系统可提供高达100Mbit/s的速度,MIMO-OFDM作为B 3G的核心技术,同步问题一直是该系统的关键问题.介绍了正交频分复用技术(OFDM),多输入多输出系统(MIMO)技术的原理,分析MIMO-OFDM系统中存在的同步问题,总结MIMO-OFDM系统的同步方法.展开更多
Automatic gain control（AGC） has an important role in multi-input multi-output-orthogonal frequency-division multiplexing （MIMO-FDM） system, especially, when receiving antennas are distributed. In recent years, muc...Automatic gain control（AGC） has an important role in multi-input multi-output-orthogonal frequency-division multiplexing （MIMO-FDM） system, especially, when receiving antennas are distributed. In recent years, much work has been done on efficiency and simplification of AGC, but few of them are aiming at multiple antennas. This article, on the assumption of ideal AGC for single receiving antenna, analyzes feasible AGC methods for MIMO system from a new aspect, then brings forward three applicable AGC methods： separate automatic gain control, joint automatic gain control, and partly-joint automatic gain control （PJ-AGC）. After simulation, when parameters are properly set, PJ-AGC has the best performance and can be applied to B3G MIMO-OFDM system.展开更多
The paper thinks that China should begin studying B3G as early as possible,participate in the establishment of international standards and draft its own set of standards especially.It briefs the four development trend...The paper thinks that China should begin studying B3G as early as possible,participate in the establishment of international standards and draft its own set of standards especially.It briefs the four development trends of contemporary infocommunications based on four related laws and the development of mobile communications.It discusses the development goal of B3G in China and points out that among the B3G related technologies,the effective spectrum and coverage technologies as well as pure IP architecture should be studied in strength.展开更多
LTE（Long Term Evolution，长期演进）项目是3G的演进，LTE并非人们普遍误解的4G技术，而是3G与4G技术之间的一个过渡，是3.9G的全球标准，采用OFDM和MIMO作为其无线网络演进的唯一标准，改进并增强了3G的空中接入技术，这种以OFDM／F...LTE（Long Term Evolution，长期演进）项目是3G的演进，LTE并非人们普遍误解的4G技术，而是3G与4G技术之间的一个过渡，是3.9G的全球标准，采用OFDM和MIMO作为其无线网络演进的唯一标准，改进并增强了3G的空中接入技术，这种以OFDM／FDMA为核心的技术可以被看作“准4G”技术，该技术改善了小区边缘用户的性能，提高小区容量和降低系统延迟。在本文中重点介绍了LTE的背景和关键技术。展开更多
文摘Automatic gain control（AGC） has an important role in multi-input multi-output-orthogonal frequency-division multiplexing （MIMO-FDM） system, especially, when receiving antennas are distributed. In recent years, much work has been done on efficiency and simplification of AGC, but few of them are aiming at multiple antennas. This article, on the assumption of ideal AGC for single receiving antenna, analyzes feasible AGC methods for MIMO system from a new aspect, then brings forward three applicable AGC methods： separate automatic gain control, joint automatic gain control, and partly-joint automatic gain control （PJ-AGC）. After simulation, when parameters are properly set, PJ-AGC has the best performance and can be applied to B3G MIMO-OFDM system.
文摘The paper thinks that China should begin studying B3G as early as possible,participate in the establishment of international standards and draft its own set of standards especially.It briefs the four development trends of contemporary infocommunications based on four related laws and the development of mobile communications.It discusses the development goal of B3G in China and points out that among the B3G related technologies,the effective spectrum and coverage technologies as well as pure IP architecture should be studied in strength.
文摘LTE（Long Term Evolution，长期演进）项目是3G的演进，LTE并非人们普遍误解的4G技术，而是3G与4G技术之间的一个过渡，是3.9G的全球标准，采用OFDM和MIMO作为其无线网络演进的唯一标准，改进并增强了3G的空中接入技术，这种以OFDM／FDMA为核心的技术可以被看作“准4G”技术，该技术改善了小区边缘用户的性能，提高小区容量和降低系统延迟。在本文中重点介绍了LTE的背景和关键技术。
