光接收机作为室内可见光通信系统的重要组成部分,其接收角度的不同将会影响系统的性能。传统可见光通信系统采用的是垂直光接收机,其室内角落的信噪比(SNR)较低,信噪比峰-谷值较大。为了降低SNR峰-谷值,提高SNR在室内分布的均匀性,本文...光接收机作为室内可见光通信系统的重要组成部分,其接收角度的不同将会影响系统的性能。传统可见光通信系统采用的是垂直光接收机,其室内角落的信噪比(SNR)较低,信噪比峰-谷值较大。为了降低SNR峰-谷值,提高SNR在室内分布的均匀性,本文提出并设计了基于遗传算法的倾斜式光接收机。数值分析结果表明,采用倾斜式接收机的可见光通信系统,SNR的分布更加均匀。在12 W单个LED光源的系统中,SNR的峰-谷值改善了4.98 d B。在总功率为12 W的四个LED光源的系统中,SNR的峰-谷值改善了2.51 d B。由此可见,在可见光通信系统中,采用倾斜式光接收机可以改善系统的性能。展开更多
Based on the theory of multicarrier(MC) technique and the Rake receiver, a multicarrier DS-CDMA Rake system is proposed, where a data sequence multiplied by a spreading sequence modulates multiple carriers. The receiv...Based on the theory of multicarrier(MC) technique and the Rake receiver, a multicarrier DS-CDMA Rake system is proposed, where a data sequence multiplied by a spreading sequence modulates multiple carriers. The receiver provides a Rake for each subcarrier, and the outputs of the Rakes are combined by a maximal-ratio combiner. The average probability of error of the system is derived from an uncorrelated subcarrier and frequency-selective fading channel model. The system performances are evaluated over Rayleigh fading channel with an exponential multipath intensity profile(MIP) and with a rectangular MIP, respectively, when multipath interference is present. It is found that this kind of model has larger superiority in an exponential MIP than in a rectangular MIP.展开更多
文摘光接收机作为室内可见光通信系统的重要组成部分,其接收角度的不同将会影响系统的性能。传统可见光通信系统采用的是垂直光接收机,其室内角落的信噪比(SNR)较低,信噪比峰-谷值较大。为了降低SNR峰-谷值,提高SNR在室内分布的均匀性,本文提出并设计了基于遗传算法的倾斜式光接收机。数值分析结果表明,采用倾斜式接收机的可见光通信系统,SNR的分布更加均匀。在12 W单个LED光源的系统中,SNR的峰-谷值改善了4.98 d B。在总功率为12 W的四个LED光源的系统中,SNR的峰-谷值改善了2.51 d B。由此可见,在可见光通信系统中,采用倾斜式光接收机可以改善系统的性能。
基金Natural Science Key Projects from Education Department of Hubei Province(2004D002)
文摘Based on the theory of multicarrier(MC) technique and the Rake receiver, a multicarrier DS-CDMA Rake system is proposed, where a data sequence multiplied by a spreading sequence modulates multiple carriers. The receiver provides a Rake for each subcarrier, and the outputs of the Rakes are combined by a maximal-ratio combiner. The average probability of error of the system is derived from an uncorrelated subcarrier and frequency-selective fading channel model. The system performances are evaluated over Rayleigh fading channel with an exponential multipath intensity profile(MIP) and with a rectangular MIP, respectively, when multipath interference is present. It is found that this kind of model has larger superiority in an exponential MIP than in a rectangular MIP.
