一种MIMO-OFDM系统天线和子载波分配算法

在多输入多输出-正交频分复用(MIMO-OFDM)系统中,根据信道状况自适应地分配天线与子载波是使信道容量达到最大的关键技术。提出一种基于拥挤模型的差分进化算法,即拥挤差分进化算法(Crowding Differential Evolution Algorithm,CDE)用于解决MIMO-OFDM系统的自适应天线和子载波联合分配问题,利用该算法参数少、寻优能力强以及收敛速度快的特点,可快速确定最佳的天线和子载波联合分配方案,实现信道容量最大。     

多用户分布式MIMO-OFDM系统中天线与子载波分配算法研究

本文针对多用户分布式MIMO-OFDM系统中的资源联合分配问题,提出了一种基于端口选择的天线与子载波分配算法。该算法依据计算复杂度容限设定用户通信静态端口数,以此为每个用户选取信道状况最好的通信端口进行通信,进而通过天线端口与下属用户的相互配合,并行地完成天线与子载波的分配。仿真结果表明,该算法在系统天线数大于用户数的情况下容量性能优于MASA算法,且其端口并行处理机制可以有效提高资源分配效率。     

一种多用户天线组选择辅助的MIMO-OFDM新型子载波分配算法

提出了一种适应多用户MIMO-OFDM下行传输的新型子载波分配算法.该算法根据各个用户的信道特征,将空间维多用户天线组选择手段引入频率维的子载波组分配算法中,从而在不明显降低系统整体性能的前提下大大降低发射端计算复杂度,使之更适用于实时信道传输环境.仿真结果表明,该算法在计算复杂度大幅减小的情况下仍能保证系统性能无明显损失.     

基于容量最大化的多用户MIMO-OFDM子载波分配算法

针对多用户MIMO-OFDM通信网络,提出了一种基于系统和容量最大化的子载波分配算法。通过对MIMO-OFDM系统和容量公式进行分析,提取出子载波分配的判决参数,再利用匈牙利算法对子载波进行分配,同时分析了分配后系统平均容量的统计特性。为了兼顾公平,又提出了传输速率最小的用户传输速率最大化的子载波分配算法。仿真结果表明,所提容量最大化算法能使系统和容量达到全局最大值,且具有较低的复杂度。     

基于多用户MIMO-OFDM系统的自适应子载波和比特分配算法

文章通过建立系统模型和仿真，详细介绍了一种基于多用户多人多出正交频分复用（MIMO—OFDM）系统的自适应传输算法。在保证各个用户速率和误码率要求的前提下，该算法根据不同用户的信道信息来自适应分配子载波和比特，从而使系统需要的发送功率达到最小。     

多用户MIMO-OFDM系统中的子信道与功率分配算法研究

针对多用户MIMO-OFDM系统下行链路,分析了通过遍历搜索来使容量最大化的最优子信道与功率分配算法,在此基础上提出了低复杂度的次优多用户子信道与功率分配算法,即MSPA算法。为了最大限度地保证用户之间的公平性,进一步提出了考虑每个用户速率要求的MSPA-RoU算法。仿真结果表明：本文提出的MSPA算法在复杂度可接受的情况下所获得的容量增益与最优算法十分接近,并且远远大于在MIMO环境下仅对子载波进行分配的算法;MSPA-RoU算法在考虑用户速率要求时仍能获得可观的容量增益。     

一种部分信道响应环境中的多用户MIMO-OFDM自适应子载波分配优化算法

该文提出一种在部分信道响应环境中利用各个用户的信道反馈信息自适应调整多用户子载波分配的优化算法,该算法考虑到实际环境中反馈信息延迟和误差引起的部分信道响应情况,结合各用户的反馈信道信息和动态子载波组分配技术,可实现有效降低自适应子载波分配运算量同时又不明显弱化系统性能的目的。仿真结果表明,该算法可改善部分信道响应带来的负面影响,同时也使子载波分配算法获得较大的简化。     

多用户MIMO-OFDM系统中一种子载波分配算法

介绍了多用户MIMO-OFDM系统中的Hungarian子载波分配算法,然后针对其计算复杂度过高的缺陷,提出一种局部最优的子载波分配算法,并与Hungarian子载波分配算法进行仿真比较。结果表明,该算法使系统总数据速率仅下降1．7％,而其计算复杂度却大幅减小,提高了资源分配的效率,符合高速无线系统资源实时分配的要求。     

一种低复杂度MIMO-OFDMA系统的自适应子载波分配算法

本篇论文提出一种多用户多输入多输出正交频分复用系统(MIMO-OFDMA)下行链路具有信道变化实时性的动态子载波分配算法.文中采用奇异置分解,将每个子载波的MIMO衰落信道分解为独立的并行子信道,利用子信道通对各子载波容量的求解推导出本文算法.此次优的算法在满足各个用户数据速率和BER要求的同时,能减小发射功率.仿真结果也证明了这一点.     

基于子载波配对的多用户协作中继系统资源分配算法

针对多用户协作中继系统中的功率最小化问题,提出了一种基于联合子载波配对及分配的资源分配算法。首先根据不同用户的目标速率要求及平均信道增益进行子载波数目的分配;然后以信道条件最佳为准则,提出了一种联合子载波配对及分配的多用户迭代算法,以实现对每个用户的中继链路和直传链路分别进行子载波配对及虚拟配对;最后利用注水算法对子载波进行功率分配,从而保证各用户以最小功率进行传输。仿真结果表明,该算法在满足用户目标速率的情况下,能够进行有效的子载波配对及分配,从而最小化系统的发射功率。     

A Subcarrier Allocation Algorithm for Efficiently Reducing Power in Multiuser OFDM Systems

Resource allocation in multiuser OFDM systems is a complex nonlinear optimization problem. In order to avoid direct solution, based on the analytical results of the problem of minimizing the total transmit power, a two-step subcarrier allocation algorithm is presented. The algorithm reduces the total transmit power by reducing the achievable minimum transmit power value required by each user. Subcarriers are allocated in the algorithm according to the data rate required by users and the channel characteristics. The required number of subcarriers allocated to users does not need to be known in advance. The allocation process consists of two steps: basic subcarrier allocation and residual subcarrier allocation. Numerical results demonstrate that the proposed algorithm can reduce the total transmit power effectively. Handong Gong was born in 1974. He received the B.S. degree in auto control and the M.S. degree in physical electronic, and the Ph.D. degree in communication and information system from South China University of Technology in 1996, 2002 and 2006 respectively. He is now a lecturer in Shenzhen Institute of Information Technology. His main research interest include OFDM signal process, linearization technique for amplifier and mobile communication technologies. Wu Ye was born in 1938. Now he is a professor and Ph. D. advisor at South China University of Technology. His research interests include queuing theory and its application in communication networks, mobile communication technologies and video process. Suili Feng was born in 1955. Now he is a professor and doctor supervisor at South China University of Technology. His research interests include theory and technology of communication network, key technologies of mobile communication and embedded system. Hui Song was born in 1980. She received doctor’s degree from South China University of Technology in communication and information system in 2005. Now she is a lecturer in South China Normal University. Her research interests include signal process, flow control and optimization.     

Subcarrier and Power Allocation for the Downlink of Multiuser OFDM Transmission

In this paper, a new algorithm for subcarrier and power allocation for the downlink of multiuser OFDM transmission is presented. The proposed algorithm is more stable and it offers a lower complexity and better performance than previous existing algorithms. Khalid El Baamrani was born in Ouarzazate, Morocco in 1976. He received the License degree (equiv. B.A.) in electronic engineering from the University of Cadi Ayyad, Marrakech, Morocco, in 1998, the D.E.S.A. (equiv. M.A) in electrical engineering from the University of CadiAyyad, Marrakech, Morocco, in 2000, the certificate in engineering of the data-processing networks and telecommunications from the national institute of posts and telecommunications, Rabat, Morocco in 2002 and the Ph.D. degree at University of Cadi Ayyad, Marrakech, Morocco in 2005. His research interests include multicarrier modulation, communication theory, multiuser information theory, OFDM and DSL systems. Victor P. Gil Jiménez received the B. Eng. in Telecommunications with honors from University of Alcalá in 1998 and the M. Eng. in Telecommunications and the PhD. degree both from the University Carlos III de Madrid in 2001 and 2005, respectively. He is with the Department of Signal Theory and Communications at the University Carlos III de Madrid as an Assistant Professor. He worked at the Spanish Antarctica Base in 1999 as Communications Staff. He visited University of Leeds and Chalmers Technical University in 2003 and 2004 respectively. His research interests include multicarrier communications and signal processing for wireless systems. Ana Garcia Armada received the Telecommunication Engineer degree and the Ph.D in Electrical Engineering both from the Polytechnic University of Madrid (Spain) in 1994 and 1998, respectively. She is currently working as an Associate Professor at the University Carlos III de Madrid, where she has occupied several management positions. She has participated in several national and international research projects, most of them related to OFDM. She is coauthor of four books on wireless communications and signal processing. She has published 13 papers in international journals and more than 40 papers in conferences. She has contributed to international organizations such as ITU and ETSI. She has performed research stays in ESA-ESTEC, Kansas University, Stanford University and Bell Labs. Her research interests are simulation of communication systems, multicarrier and MIMO techniques.     

一种改进的MIMO-OFDM系统注水功率分配算法

鉴于目前MIMO—OFDM系统中大多数比特功率分配算法需要多次迭代,复杂度较高,及系统比特分配离散性的特点,本文结合贪婪功率分配算法逐步优化的思想,提出了修正的二次注水功率比特分配算法。该算法首先利用注水功率分配方案得到连续速率最优的功率分配,接着针对实际数据速率量化的误差对不同特征模式下的功率进行微调,实验证明改进后的算法有效提高了系统的总体传输速率。     

多用户OFDM系统中改进的动态子载波与功率分配算法

提出了一种对于多用户OFDM（Orthogonal Frequency Division Multiple）系统改进的动态子载波和功率分配算法.算法采用分步的思想对系统资源进行动态分配,在已知系统总功率和用户最小速率请求的条件下,使系统总的比特速率最大,资源得到了有效利用.此算法简单易于理解,复杂度较低,仿真结果表明,其性能接近于联合的分配算法.     

多用户OFDM系统中子载波比特分配算法

针对多用户OFDM系统中的功率优化问题,提出了一种新的子载波、比特分配算法。利用匈牙利算法对子载波进行初始分配,然后根据信道的状态信息为每个子载波动态地分配比特,最后对分配的结果作进一步调整,直到发射总功率不再减小为止。仿真结果表明,调整后的结果比原有方法有所改善,在满足传输速率和误码率要求的条件下,有效地降低了系统发射总功率。     

基于多用户MIMO-OFDM系统的子信道和功率分配算法

在多用户MIMO-OFDM系统中，当总功率受限时，为了使整个系统的数据传输速率最大．已有的最优算法的计算十分复杂，这里采用了一种次最优算法。在发射端，基于已知信道状态信息。应用奇异值分解将MIMO信道转化为并行的子信道，并将表征信道增益的信道特征值用于子信道自适应调制优化设计中。在自适应过程中．用到了子信道和功率联合分配算法。仿真结果表明，这种算法能使系统的性能明显提高。     

一种低复杂度的OFDM子载波分配算法

针对认知无线电中基于OFDM子载波分配ACG算法的计算复杂度高的这一缺点,提出了一种能降低计算复杂度的OFDM子载波分配算法。新的分配算法是通过运用设定方差门限值的方法把一些信道状态变化不大的连续子载波结合成子信道,从而将原来针对每个子载波的分配转变为针对子信道的分配,以此来降低频谱资源的分配次数。仿真分析表明,新的分配算法以牺牲少量频谱效益的代价,较之原有算法,明显地降低了计算复杂度。