LTE终端接收机射频吞吐量测试方法研究

阐述了LTE终端射频一致性测试标准3GPPTS36．521—1中终端接收机特性的吞吐量测试原理和方法,研究了相关的物理层吞吐量判决准则和原理,并对物理层吞吐量判决表的生成做了详细介绍。     

LTE系统中Turbo译码的改进算法

LTE系统对可靠通信提出了更高的要求,这在一定程度上依赖于信道编码的性能。针对LTE系统中的Turbo译码算法进行了研究,在Max-Log-MAP和Log-MAP算法的基础上提出了一种改进算法。理论分析和仿真结果表明,这种改进算法的性能有进一步提升,并且更加易于硬件实现,具有较低的复杂度。     

反馈时延下LTE链路自适应算法性能研究

介绍了一种LTE系统的快速链路自适应算法,算法基于瞬时信道信息计算预编码矩阵指示、秩指示和信道质量指示3种反馈信息。当前对快速链路自适应算法的研究大部分都假设无反馈时延,因此研究了反馈时延对算法性能的影响,针对发射分集和闭环空间复用两种传输模式在低速和较高速场景下进行了算法性能评估。     

Group-based user pairing for virtual MIMO in LTE

A user pairing method is proposed to improve the throughput gain of virtual multiple input multiple output (virtual MIMO) in 3G long-term evolution (LTE).The approach taken in this study separated the user pairing into four steps 1) the users are divided into two groups according to their signal-to-noise ratio (SNR), and different user pairing metrics are proposed for each group; 2) the scheduler chooses a user for transmitting by a given rule; 3) the scheduler searches the pairing candidate for the selected user in each group; 4) the scheduler chooses the final pairing user from the co-group and crossover-group candidates by using a marginal utility function, to balance fairness and efficiency.The method can improve the throughput of users with high SNR, and guarantee fairness for users with low SNR, so it can be used in 3G LTE systems.The article provides both theoretical analysis and simulation results to support the idea.     

加速发展中的LTE

据全球移动设备供应商协会（GSA）近日发布的报告显示：迄今为止,全球已有70个国家的180家运营商对LTE进行投资,而在去年8月底这个数字仅为46个国家、101家运营商。在上述180家运营商中,52个国家的128家运营商承诺部署LTE商用网。另外18个国家的52家运营商作出了＂预承诺＂。现已开通LTE商用业务的有17家运营商,它们分别位于奥地利、丹麦、爱沙尼亚、芬兰、德国、香港、日本、挪威、波兰、瑞典、美国和乌兹别克斯坦。与此同时,全球已有35家设备供应商提供大约100款LTE终端设备。     

广东联通LTE承载技术分析及选择探讨

首先简要介绍了LTE／EPC网络,然后分析、比较了现有各种传送网络技术,最后对LTE阶段核心网及基站回传的承载技术选择提出了建议。     

利用LTE的RRU不同射频端口进行分裂使用的方法

随着经济、社会的发展,移动通信业务需求逐步多元化,对LTE 4G网络的覆盖、容量产生的较大的压力。对LTE网络建设投资随着5G技术逐渐清晰而减少,为保证LTE用户的使用感知,需要充分利用现有的网络资源。文章研究利用LTE基站设备的一些特性,采用RRU设备分裂的能力,增加网络容量、提高设备利用效率。同时,也提出一点其它场景的应用方案,全市的建设过程中推广使用。     

Energy-saving scheduling for LTE multicast services

In the Long Term Evolution （LTE） downlink multicast scheduling, Base Station （BS） usually allocates transmit power equally among all Resource Blocks （RBs）, it may cause the waste of transmit power. To avoid it, this paper put forward a new algorithm for LTE multicast downlink scheduling called the Energy-saving based Inter-group Proportional Fair （EIPF）. The basic idea of EIPF is to calculate an appropriate transmitting power for each group according to its data rate respectively, and then follow the inter-group proportional fair principle to allocate RBs among multicast groups. The results of EIPF simulation show that the proposed algorithm not only can reduce the transmit power of BS effectively but also improve the utilization rate of energy.     

Scheduling Constraints and Interference Graph Properties for Graph-based Interference Coordination in Cellular OFDMA Networks

The currently emerging 802.16e (WiMAX) and 3GPP Long Term Evolution (LTE) cellular systems are based on Orthogonal Frequency Division Multiple Access (OFDMA). OFDMA suffers from heavy inter-cell interference if neighboring base stations use the same frequency range. One approach to solve this issue is the application of beamforming antennas in combination with interference coordination (IFCO) mechanisms between base stations. In this paper, we trace the problem of IFCO back to the graph coloring problem and investigate the achievable resource utilization of the interference coordinated system. We develop a heuristic that allows the combination of arbitrary scheduling algorithms with the IFCO mechanism. This allows an efficient utilization of the radio system’s frequency resources while still obeying scheduling constraints, such as Quality of Service requirements. Finally, we study the tradeoff between fairness and the total system throughput.

连接状态下LTE接入系统内的移动性管理

3GPPLTE是基于OFDM和MIMO技术并针对当前3G系统的长期演进计划,对3G系统的网络结构和无线接入技术进行了较大的改进。文章详细分析了连接状态下LTE接入系统内的移动性管理,将双播技术作为一种保证数据无损的机制引入到LTE中,并与现在应用于LTE中的数据转发技术进行了比较性研究。