CN107425900B - 一种vlc、noma系统最大最小公平波束成形优化方法 - Google Patents
一种vlc、noma系统最大最小公平波束成形优化方法 Download PDFInfo
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- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
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- H04B10/50—Transmitters
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- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
- H04B10/505—Laser transmitters using external modulation
- H04B10/5057—Laser transmitters using external modulation using a feedback signal generated by analysing the optical output
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- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
- H04B10/505—Laser transmitters using external modulation
- H04B10/5059—Laser transmitters using external modulation using a feed-forward signal generated by analysing the optical or electrical input
- H04B10/50595—Laser transmitters using external modulation using a feed-forward signal generated by analysing the optical or electrical input to control the modulator DC bias
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- H—ELECTRICITY
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
- H04B7/0621—Feedback content
- H04B7/0634—Antenna weights or vector/matrix coefficients
Abstract
Description
技术领域
本发明属于无线光通信技术领域,特别涉及一种VLC、NOMA系统最大最小公平波束成形优化方法。
背景技术
可见光通信(VLC)技术是一种公认的安全有效地高速室内通信方案,具有免费的独立于射频频谱的宽带频谱资源,无电磁干扰,保密性好,是一种“绿色的”通信技术。典型的VLC系统采用发光二极管(LED)作为发射端。
非正交多址(NOMA)技术作为潜在的可能应用于未来通信系统的一种多址接入技术,近年来得到了越来越多的关注。无论是在第5代移动通信系统(5G)还是在无线光通信领域,NOMA技术都得到了广泛研究。通过在发射端使用叠加编码(SC)技术和在接收端使用连续干扰抵消(SIC)技术,NOMA可以获得比传统正交多址(OMA)技术(如时分多址)更高的谱效率。
NOMA技术通过对功率的复用,可以同时服务于多个用户。具体说来就是发射信号在发射端通过SC被叠加在一起同时发射,用户通过SIC技术对相应信号进行检测,完成多址接入。由此可见,NOMA系统的性能主要取决于发射端叠加信号时分配给各个信号的权重。目前已有的NOMA优化研究,大多是针对单输入单输出(SISO)系统进行的,此时系统性能主要依赖于用户功率分配设计;而对多用户多输入单输出(MISO)系统来说,系统性能主要依赖于波束成形矩阵的设计。
发明内容
发明目的:针对现有技术中存在的问题,本发明提供一种通过优化发射波束成形矩阵,使用户的最小公平传输速率最大的VLC、NOMA系统最大最小公平波束成形优化方法。
技术方案:为解决上述技术问题,本发明提供一种VLC、NOMA系统最大最小公平波束成形优化方法,具体步骤如下:
进一步的,所述步骤一中建立优化模型的具体步骤如下:
其中Pl表示第l个LED的直流偏置,K表示用户总数,π和e分别表示圆周率和自然常数。
进一步的,所述步骤二中求解凸优化问题的具体步骤如下:
与现有技术相比,本发明的优点在于:
本发明通过优化发射波束成形矩阵,最大化最小用户传输速率,保证了最差用户的通信性能。相对于传统OMA方案,本发明所提出的优化算法能够获得更高的最大最小公平传输速率。
附图说明
图1为本发明的应用场景示意图;
图2为本发明的方法流程示意图;
图3为NOMA与OMA技术的最大最小公平传输速率随光功率变化的曲线图。
具体实施方式
下面结合附图和具体实施方式,进一步阐明本发明。
实施例1:
如图1所示,本发明的通信模型为多用户MISO室内可见光通信系统的下行链路。发射端由N个LED组成,接收端由光电二极管(PD)组成,房间内分布有K个用户。假设LED光源服从近朗伯辐射模型,视距信号的能量远大于反射信号,则第l个LED到第i个用户的直流信道增益即信道响应向量hi的第l个元素为:
其中,π为圆周率,m0为朗伯阶数,θ1/2为LED半角,dli为第l个LED与第i个用户的直达距离,φli为入射角,为辐照角,A为光电二极管(PD)的接收面积,RP为PD的响应度,T(φli)为光滤波器的增益,g(φli为聚光透镜的增益,β为聚光透镜的折射率,ΨFOV为PD的视场。不失一般性,假设||h1||2≤||h2||2≤…≤||hK||2。
非正交多址(NOMA)技术的原理是发射端将各用户的信号sj,j=1,2,…K叠加发射,波束成形后的发射信号记为x=w1s1+w2s2+…wKsK,其中信号sj满足[-1,1]的均匀分布,方差均为wj是波束成形矩阵W的第j列,用Pl表示第l个LED的直流偏置,为保证x的每个元素为正实数,则有如下不等式
其中,q为一个电子所带的电荷量,取常数q=1.6×10-19库仑;B为系统带宽;χamb为背景光电流;iamp为前置放大器的噪声电流密度。在该模型下,第i个用户的检测第j个发射符号sj的信干噪比,表示为:
本发明提供一种VLC、NOMA系统最大最小公平波束成形优化方法,通过优化发射波束成形矩阵W,最大化最小用户传输速率,优化模型如下:
实施例2:
进一步地,本发明提供一种VLC、NOMA系统最大最小公平波束成形优化方法,包括以下步骤得到优化问题的最优解:
为了验证本优化方法的性能,进行了仿真实验。仿真实验结果见图3,所涉及的参数如表1所示:
图3是NOMA和OMA技术的最大最小公平传输速率随光功率变化的曲线图,发射端、接收端器件参数如表1所示。用户数N=2时,用户坐标分别为(2.5m,2.5m),(0m,0m);用户数N=3时,用户坐标分别为(2.5m,2.5m),(0.5m,0.5m),(0m,0m);用户数N=4时,用户坐标分别为(2.5m,2.5m),(1.5m,1.5m),(0.5m,0.5m),(0m,0m);用户数N=5时,用户坐标分别为(2.5m,2.5m),(2m,2m),(1m,1m),(0.5m,0.5m),(0m,0m)。经计算,信道最好的用户坐标为(0m,0m),最差的用户坐标为(2.5m,2.5m)。由图可以看出,最大最小公平传输速率随着光功率的增加而增加。且随着光功率的增加,基于NOMA的系统性能较OMA的优势会越来越明显,光功率足够大时,NOMA的性能总会超过OMA。由图还可以得出,当最差、最好用户坐标保持不变时,NOMA相较于OMA的优势随着用户数的增加而减小,这是由各用户间的信道差距减小造成的。
以上所述仅为本发明的实施例子而已,并不用于限制本发明。凡在本发明的原则之内,所作的等同替换,均应包含在本发明的保护范围之内。本发明未作详细阐述的内容属于本专业领域技术人员公知的已有技术。
Claims (2)
1.一种VLC、NOMA系统最大最小公平波束成形优化方法,其特征在于,具体步骤如下:
所述步骤一中建立优化模型的具体步骤如下:
所述步骤二中求解凸优化问题的具体步骤如下:
1≤j≤i≤K
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Cooperative VLC Systems for Data Transmission and Environment Perception;Hongji Huang etc.;《2017 9th IEEE International Conference on Communication Software and Networks》;20170506;全文 * |
基于非正交多址接入的室内可见光通信系统;贾科军;《光学学报》;20170510;第37卷(第8期);全文 * |
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