搜索结果: 1-15 共查到“光信息技术 OFDM”相关记录70条 . 查询时间(0.05 秒)
自由空间光通信中相干OFDM系统性能分析
自由空间光通信 相干OFDM 误符号率 平均接收光功率
2015/11/6
结合正交频分复用（OFDM）技术和相干探测的优势，研究了相干OFDM自由空间光通信（FSO）系统的误码性能，考虑了OFDM映射方式以及映射阶数对系统误码性能的影响。在Gamma-Gamma大气湍流信道下，分别从平均信噪比和所需平均接受光功率的角度考虑了系统在弱、中和强湍流三种情况下的误码性能。在此基础上，推导了系统误符号率的闭合表达式。仿真结果表明，相干探测下OFDM FSO系统可以较好地克服大气...
色/频/空三维资源复用的室内可见光非直流偏置OFDM系统性能研究
室内可见光通信 光OFDM 空间调制 同色异谱调制
2015/11/5
提出一种新的室内可见光非直流偏置正交频分（Non-DC-Biased Orthogonal Frequency Division Multiplexing, NDC-OFDM）复用系统，该系统采用多个颜色LEDs作为光源，在保证高传输可靠性的同时可以维持环境光的稳定。将空间调制和同色异谱调制结合并应用到室内可见光OFDM通信系统中得到一种新的适用于室内可见光通信系统的NDC-OFDM传输方案，该方...
High-speed Fading-free Direct Detection for DoubleSideband OFDM Signal via Block-wise Phase Switching
High-speed Fading-free Direct Detection Double Sideband OFDM Signal Block-wise Phase Switching
2014/11/6
We employ phase switching of either main-carrier or subcarriers of two consecutive signal blocks for double-sideband fading-free direct-detection (DD). In so doing, 40-Gb/s DDOOFDM is successfully rec...
基于导频辅助法,对相干光正交频分复用系统中采样时钟频率偏差进行估计和补偿,并研究了导频的插入位置对该算法补偿效果的影响,通过对五种不同的导频插入位置进行分析和比较,得到最优导频插入位置.仿真结果表明:本文算法即使在较大的频率偏移情况下也有较好的补偿效果,并且采用该方法得到的光信噪比损耗不到1 dB,可以有效地降低系统成本;不同导频插入位置对算法的补偿效果会产生影响,在较小采样频率偏移范围内时,导频...
基于交叉复用技术的OFDM-WDM光传输系统的性能分析
OFDM 交叉复用 宰阅酝 光传输系统
2014/6/12
基于正交频分复用(OFDM)与波分复用(WDM)的基本原理,构建了一套基于OFDM技术的WDM传输系统的系统模型,并对其相关系统性能进行了理论分析。基于维纳相位噪声模型,文章对OFDM系统中相位噪声引起的公共相位误差和子载波间干扰进行了分析,在此基础上深入分析了基于交叉复用OFDM技术的OFDM子载波间干扰的消除方法,降低相位噪声对系统性能的影响。最后结合理论分析结果对系统模型的相关性能进行模拟计...
Channel Estimation Using Superimposed Training for Coherent Optical OFDM Systems
Channel Estimation Superimposed Training Optical OFDM Systems
2013/12/2
We demonstrate by simulation that the superimposed training based channel estimation scheme can achieve similar performance as compared with conventional schemes, without any loss in bandwidth. An ite...
基于OFDM-PON的媒质接入控制协议设计
光接入网 媒质接入控制协议 服务质量 动态带宽分配
2013/6/25
在以太网无源光网络帧结构的基础上,针对正交频分复用无源光网络的特点,提出了一种适用于正交频分复用无源光网络的媒质接入控制协议.对多点控制协议、控制消息的结构、业务优先级等进行了设计,提出了一种提供服务质量保障的特殊情况下区别用户服务等级的动态带宽分配算法.该算法引入两级调度的机制,将带宽资源的分配分为不同优先级业务的调度和同类型业务下不同等级的光网络单元调度.文章对提出协议的时延、丢包率、吞吐量等...
This investigation demonstrates the generation of OFDM-RoF signal using frequency doubling technique for the first time, to the author’s best knowledge. The 4-Gb/s OFDM signal using 16-QAM format modu...
Performance of Optical Fast-OFDM in MMF-Based Links
Fiber optics communications Modulation
2011/5/26
19.375Gb/s optical Fast-OFDM signals can be transmitted over 500m worst-case MMF DML-based links having 3-dB effective bandwidths of 150MHz.km. This performance is similar to that corresponding to a c...
31 Gbps RoF System Employing Adaptive Bit-Loading OFDM Modulation at 60 GHz
Optical Communications Modulation
2011/5/26
Record wireless data transmission of 31.4 Gbps within 7 GHz license-free band at 60 GHz is experimentally demonstrated using adaptive bit-loading OFDM modulation. Adaptive bit-loading OFDM also enable...
Impact of Intra-Channel Fiber Nonlinearity on Reduced- Guard-Interval CO-OFDM Transmission
Coherent communications Fiber optics communications Modulation
2011/5/26
Channel estimation for a reduced-guard-interval (RGI) CO-OFDM system shows a unique dependence on the training symbol design in the presence of intra-channel nonlinearities.Because smaller FFT sizes c...
Characterization and Monitoring of Laser Linewidths in Coherent Optical OFDM Systems
Fiber optics communications Modulation
2011/5/26
We demonstrate monitoring of digitally-generated laser linewidths for 107-Gb/s coherent optical OFDM systems. Unique characteristics of time-domain phase-error variance are exploited to extract laser ...
Integrated-optic demultiplexers for optical OFDM signals
Integrated optics devices Optical communications
2011/5/26
We review recent progress on our integrated-optic OFDM demultiplexers fabricated with silica PLC technology. We detail the configuration, operating principle, and characteristics of the demultiplexers...
Demonstration of Converged Bidirectional OFDM-m-QAM RoF and WDM-OFDM-PON Access Networks
Networks Optical communications
2011/5/26
We demonstrate a novel lightwave centralized hybrid bidirectional WDM-OFDM-PON and OFDM-m-QAM RoF network. The 11.29-Gb/s OFDM-16QAM wired DL, 5.65-Gb/s OFDM-QPSK wired UL and WiMAX downstream/upstrea...
Transmission of Multi-Band OFDM-UWB Signals along NG-FTTH Networks using Directly Modulated Lasers
Modulation Optical communications
2011/5/26
Transmission of multi-band OFDM-UWB signals along FTTH networks using directly modulated lasers is experimentally evaluated. Reach of 100 km of standard SMF is achieved with a BER below 10 -4 and an O...