A rate adaptive multi-band ultra-wideband (UWB) system based on the quadrature fractal modulation (QFM) scheme was proposed.Exploring the use of homogeneous signals as modulating waveforms in UWB system,the signal wit...A rate adaptive multi-band ultra-wideband (UWB) system based on the quadrature fractal modulation (QFM) scheme was proposed.Exploring the use of homogeneous signals as modulating waveforms in UWB system,the signal within each 528MHz sub-band was divided into 8 different frequency bandwidths using wavelets transform and these data sequences to be transmitted were embedded into homogeneous waveforms.It is found that the use of homogeneous signals in such UWB system is quite feasible,leadings to a novel multi-rate diversity strategy.Within each 528MHz sub-band,the UWB-QFM system can provide much higher data rates than that of the UWB orthogonal frequency division multiplexing (OFDM) system.Simulation results also show that the bit error rate (BER) performance of the UWB-QFM system achieves a greatly improvement over existing UWB-OFDM system.Due to the fractal properties of the homogeneous signals,these data sequences to be transmitted can be recovered using arbitrarily short receiver signal.展开更多
在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法...在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法,普遍存在着误码率及损失值偏高的问题。为了弥补上述难题,文中提出一种基于多层感知机(Multilayer Perceptron,MLP)的索引调制检测算法,即MLP-IM算法。该算法采用融合两个连接层与一个输出层的架构设计,通过挑选的激活函数实现对OFDM索引调制系统中数据比特的精准还原。首先将OFDM索引调制系统的基础理论巧妙应用于数据的预处理阶段,随后利用仿真数据集对MLP神经网络模型进行全面而深入的离线训练,确保模型的稳健性与准确性。在检测阶段,通过MLP-IM检测算法实现了对OFDM索引调制系统的高效检测。仿真结果表明,所提出的MLP-IM算法在误码率控制和损失值两个方面的性能表现与最大似然检测算法相媲美,甚至在某些场景下超越了现有DNN-IM算法的性能,其性能改善幅度在0.2~6 dB的区间内。展开更多
阐述了低压电力线载波通信技术研究的主要方向,概括了国内外学者在阻抗特征、信号衰减特性、噪声特性、信道模型等方面的研究成果和相应解决策略。针对电力线通信的调制解调技术和组网技术等方面进行了分析。其中,调制解调技术主要包括...阐述了低压电力线载波通信技术研究的主要方向,概括了国内外学者在阻抗特征、信号衰减特性、噪声特性、信道模型等方面的研究成果和相应解决策略。针对电力线通信的调制解调技术和组网技术等方面进行了分析。其中,调制解调技术主要包括当前热点研究的正交频分复用(orthogonal frequency division multiplexing,OFDM)相关技术以及跳频调制/解调技术,组网技术则主要分析考虑网络有效性和服务需求的蚁群优化路由算法。对国内外电力线标准的最新研究工作进行了总结。最后,结合低压电力线载波通信技术现状和发展要求,对低压电力线载波通信的技术研究方向和发展潜力进行了展望和探讨。展开更多
基金National Natural Science Fund of China(60372097), Beijing Municipal Natural Science Fund(4052021),University IT Research Center Project(INHA UWB-ITRC)Korea, KDDI R&D Labs Co-Project, Japan.
文摘A rate adaptive multi-band ultra-wideband (UWB) system based on the quadrature fractal modulation (QFM) scheme was proposed.Exploring the use of homogeneous signals as modulating waveforms in UWB system,the signal within each 528MHz sub-band was divided into 8 different frequency bandwidths using wavelets transform and these data sequences to be transmitted were embedded into homogeneous waveforms.It is found that the use of homogeneous signals in such UWB system is quite feasible,leadings to a novel multi-rate diversity strategy.Within each 528MHz sub-band,the UWB-QFM system can provide much higher data rates than that of the UWB orthogonal frequency division multiplexing (OFDM) system.Simulation results also show that the bit error rate (BER) performance of the UWB-QFM system achieves a greatly improvement over existing UWB-OFDM system.Due to the fractal properties of the homogeneous signals,these data sequences to be transmitted can be recovered using arbitrarily short receiver signal.
文摘在探讨正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统的优化中,一个显著挑战在于其信号检测性能的相对不足。同时,针对基于深度神经网络的索引调制(Deep Neural Network Based Index Modulation,DNN-IM)检测算法,普遍存在着误码率及损失值偏高的问题。为了弥补上述难题,文中提出一种基于多层感知机(Multilayer Perceptron,MLP)的索引调制检测算法,即MLP-IM算法。该算法采用融合两个连接层与一个输出层的架构设计,通过挑选的激活函数实现对OFDM索引调制系统中数据比特的精准还原。首先将OFDM索引调制系统的基础理论巧妙应用于数据的预处理阶段,随后利用仿真数据集对MLP神经网络模型进行全面而深入的离线训练,确保模型的稳健性与准确性。在检测阶段,通过MLP-IM检测算法实现了对OFDM索引调制系统的高效检测。仿真结果表明,所提出的MLP-IM算法在误码率控制和损失值两个方面的性能表现与最大似然检测算法相媲美,甚至在某些场景下超越了现有DNN-IM算法的性能,其性能改善幅度在0.2~6 dB的区间内。
文摘阐述了低压电力线载波通信技术研究的主要方向,概括了国内外学者在阻抗特征、信号衰减特性、噪声特性、信道模型等方面的研究成果和相应解决策略。针对电力线通信的调制解调技术和组网技术等方面进行了分析。其中,调制解调技术主要包括当前热点研究的正交频分复用(orthogonal frequency division multiplexing,OFDM)相关技术以及跳频调制/解调技术,组网技术则主要分析考虑网络有效性和服务需求的蚁群优化路由算法。对国内外电力线标准的最新研究工作进行了总结。最后,结合低压电力线载波通信技术现状和发展要求,对低压电力线载波通信的技术研究方向和发展潜力进行了展望和探讨。
