共查询到17条相似文献，搜索用时 575 毫秒
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针对LTE无线通信系统上行链路,提出一种联合HII和OI的干扰协调方法.与以往提高整个网络吞吐量或小区边缘用户速率为目标的传统干扰协调方法不同,该方法从满足用户的实际通信质量要求出发,以提高用户满意度为目标,并首次联合使用了LTE R8标准定义的2个信息(高干扰指示HII和过载指示OI)进行频域协调和功率调整.仿真结果表明,该方法相比传统的干扰协调方法能明显提升用户满意度,具有较高的实用价值. 相似文献
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LTE系统能够提供更高的数据速率,然而小区边缘用户由于受到严重的小区间干扰以及较大的路径损耗,其吞吐量比小区中心用户差.对于相同的发射功率,小区边缘用户较低的吞吐量导致整个系统的能量效率较低.针对LTE 3扇区场景,提出一种基于LTE/WLAN的两跳中继网络架构,用于提高小区边缘用户的吞吐量,以及LTE系统的能量效率.理论分析和仿真结果表明,新型网络在用户吞吐量以及系统能量效率方面均有显著提升. 相似文献
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多用户MIMO-OFDM系统中基于迫零波束成型的自适应资源分配算法 总被引：2，自引：0，他引：2
针对多用户环境下的多天线正交频分复用下行系统,提出了2种有效的基于迫零波束成型的自适应资源分配算法.所提算法在保证每个用户的速率要求的情况下,通过自适应的功率、子载波和比特分配,最小化系统的发送功率.仿真结果表明,提出的2种次优的分配算法在满足用户的速率要求下能达到很好的系统性能. 相似文献
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近年来,无线蜂窝通信发展迅速导致频率资源日趋紧张,功率控制和动态信道分配是解决此瓶颈有效策略,但功率控制和动态信道分配的理论算法十分复杂,文献中多为仿真分析.本文对无线蜂窝通信系统中基于功率控制的动态信道分配进行深入研究,通过借用信道算法,分析同信道干扰,提出了干扰适应因子概念及其计算方法,可以简便可行地计算应用此算法下无线蜂窝系统容量;结果显示,此信道分配策略有效地提高了信道的利用率,算法简便,并大大降低了以往各种算法的复杂性.最后本文还进一步进行系统仿真,仿真结果和理论算法比较,符合程度良好,误差不超过8%. 相似文献
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近年来，无线蜂窝通信发展迅速导致频率资源日趋紧张，功率控制和动态信道分配是解决此瓶颈有效策略，但功率控制和动态信道分配的理论算法十分复杂，文献中多为仿真分析。本文对无线蜂窝通信系统中基于功率控制的动态信道分配进行深入研究，通过借用信道算法，分析同信道干扰，提出了干扰适应因子概念及其计算方法，可以简便可行地计算应用此算法下无线蜂窝系统容量；结果显示，此信道分配策略有效地提高了信道的利用率，算法简便，并大大降低了以往各种算法的复杂性。最后本文还进一步进行系统仿真，仿真结果和理论算法比较，符合程度良好，误差不超过8％。 相似文献
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《科技广场》2017,(12)
在多小区大规模多输入多输出(MIMO)系统中,针对各小区复用相同导频序列进行信道估计存在有导频污染问题,提出了一种大规模MIMO系统中联合最强用户冲突解决的最大似然(ML)信道估计算法。该方法联合最强用户冲突解决(SUCR)算法和循环前缀的最大似然信道估计算法,先在小区用最强用户冲突解决方案减轻用户之间的竞用相同导频的干扰,减少竞争导频的用户数,提高系统的成功接入用户数数量,然后再用循环前缀的最大似然的信道估计算法,对处理后的导频序列的信道进行信道估计,以获得较为准确的信道状态信息。仿真结果表明,提出的算法对比分析传统ML算法和MMSE算法能够得到更好的归一化均方误差和系统能量效率,并且可以较明显地减轻导频污染对信道估计的影响。 相似文献
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乘性噪声干扰下的船舶突发性故障检测挖掘方法 总被引：1，自引：0，他引：1
在船舶的突发性故障检测中,故障信号不但伴有很强的非线性,并且常伴随大量的随机噪声,乘性噪声会降低非线性故障数据之间的有效联系,淡化船舶可识别的突发特征.给船舶突发性故障检测带来较大困难.为解决此问题,提出一种基于小区域噪声消除的船舶突发故障检测挖掘算法,通过设计一种包含乘性噪声小区域内的故障确认对比方法,运用故障特征核作为船舶突发故障的标准,进行故障核距离的计算,排除乘性噪声的干扰,保证优化检测.实验表明,该方法能够较好地完成乘性噪声干扰环境下的故障检测,提高了船舶故障的检测效率. 相似文献
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《科技通报》2016,(3)
小区域重叠干扰下的通信滤波器通信信号由于受到外界环境的干扰通常极不稳定,传统噪声抑制方法只适用于平稳信号,无法实现复杂环境下通信滤波器噪声的抑制,提出一种基于自适应非线性滤波的小区重叠干扰下通信滤波器噪声抑制算法,对小区重叠干扰下的通信信号进行预增强处理,对得到的通信信号和既定阈值进行比较,判断是否需要进行噪声抑制,为小区重叠干扰下的通信滤波器噪声抑制提供有效依据。假设小区重叠干扰喜爱通信滤波器接收信号是同步的,给出采样结果。对滤波器的估计方差和条件方差进行计算,求出背景噪声和干扰剩余之和的方差,通过自适应改变非线性变换的非线性部分的变化曲线,实现小区域重叠干扰下的通信滤波器噪声抑制。仿真实验结果表明,所提方法具有很高的噪声抑制性能。 相似文献
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Graph-based recommendation approaches use a graph model to represent the relationships between users and items, and exploit the graph structure to make recommendations. Recent graph-based recommendation approaches focused on capturing users’ pairwise preferences and utilized a graph model to exploit the relationships between different entities in the graph. In this paper, we focus on the impact of pairwise preferences on the diversity of recommendations. We propose a novel graph-based ranking oriented recommendation algorithm that exploits both explicit and implicit feedback of users. The algorithm utilizes a user-preference-item tripartite graph model and modified resource allocation process to match the target user with users who share similar preferences, and make personalized recommendations. The principle of the additional preference layer is to capture users’ pairwise preferences, provide detailed information of users for further recommendations. Empirical analysis of four benchmark datasets demonstrated that our proposed algorithm performs better in most situations than other graph-based and ranking-oriented benchmark algorithms. 相似文献
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《Information processing & management》2023,60(2):103175
Task assignment, the core problem of Spatial Crowdsourcing (SC), is often modeled as an optimization problem with multiple constraints, and the quality and efficiency of its solution determines how well the SC system works. Fairness is a critical aspect of task assignment that affects worker participation and satisfaction. Although the existing studies on SC have noticed the fairness problem, they mainly focus on fairness at the individual level rather than at the group level. However, differences among groups in certain attributes (e.g. race, gender, age) can easily lead to discrimination in task assignment, which triggers ethical issues and even deteriorates the quality of the SC system. Therefore, we study the problem of task assignment with group fairness for SC. According to the principle of fair budget allocation, we define a well-designed constraint that can be considered in the task assignment problem of SC systems, resulting in assignment with group fairness. We mainly consider the task assignment problem in a common One-to-One SC system (O2-SC), and our goal is to maximize the quality of the task assignment while satisfying group fairness and other constraints such as budget and spatial constraints. Specifically, we first give the formal definition of task assignment with group fairness constraint for O2-SC. Then, we prove that it is essentially an NP-hard combinatorial optimization problem. Next, we provide a novel fast algorithm with theoretical guarantees to solve it. Finally, we conduct extensive experiments using both synthetic and real datasets. The experimental results show that the proposed constraint can significantly improve the group fairness level of algorithms, even for a completely random algorithm. The results also show that our algorithm can efficiently and effectively complete the task assignment of SC systems while ensuring group fairness. 相似文献
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Broadband power line communication (BPLC) is a promising solution to satisfy the growing data rate demands for broadband indoor communication networks. However, the BPLC transmission power spectral density (PSD) is restricted in the very high frequency (VHF) band to avoid harmful interference to the existing wireless services. In this paper, a new hybrid system is proposed utilizing BPLC and cognitive radio over TV white space (TVWS) to enhance the system capacity over BPLC in VHF, forming a VHF TVWS BPLC multiple-input multiple-output (MIMO) system. An iterative precoding algorithm is proposed to satisfy the interference limit at the TV primary user (PU) receiver (Rx) and enhance the ergodic capacity. Moreover, a power allocation algorithm is developed for the MIMO system to achieve the maximum ergodic capacity subject to the average total power constraint and limit of interference to TV PU. Simulation results demonstrate the significant enhancement in the achieved capacity by our proposed system in the VHF band compared to both previous cognitive and hybrid BPLC systems. 相似文献
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作为新一代宽带业务的国际标准(4G时代),LTE网络采用了许多新技术。它采用扁平化网络构架的方式进行设计,包括一些聚合多载波、异构网络、中继、多点发送、MIMO和先进的抗干扰管理等技术。这些技术极大地提高了小区边缘用户的一些性能,使小区的信息传输速率和系统容量得以增加。 相似文献