为建立更高效的移动端对端(mobile to mobile)通信系统,针对城市狭窄街道多入多出系统(MIMO,multiple input multiple output)移动传播环境,在经典椭圆模型(EBSBM,ellipse based single bounce model)基础上引入等效散射点概念,提出了...
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为建立更高效的移动端对端(mobile to mobile)通信系统,针对城市狭窄街道多入多出系统(MIMO,multiple input multiple output)移动传播环境,在经典椭圆模型(EBSBM,ellipse based single bounce model)基础上引入等效散射点概念,提出了改进的多跳散射信道模型。此模型将多跳散射路径通过几何变换等效为单点椭圆散射路径,研究了模型的空时频统计特性,推导出发射角(AOD,angle of departure)、到达角(AOA,angle of arrival)及多普勒频移(Doppler shift)等随机参数的概率密度函数(PDF,probability density function)的解析表达式,并进一步分析天线圆形阵列(uniform circular array)分布下的MIMO信道空间相关性及信道容量。仿真实验与以往模型及数据对比验证了所提出模型的有效性。
Aimed at the problem of narrow tunability and low frequency microwave signal generated by the optical method,a novel approach to stabilizing the tunable photonic microwave generated by the multi-wavelength Brillouin f...
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Aimed at the problem of narrow tunability and low frequency microwave signal generated by the optical method,a novel approach to stabilizing the tunable photonic microwave generated by the multi-wavelength Brillouin fiber laser is proposed and is experimentally demonstrated.A singlelongitudinal-mode Brillouin fiber laser is designed,and by using the laser,a multi-wavelength Brillouin fiber laser with more than eleven orders of Stokes wave is *** wavelength spacing of the adjacent Stokes wave is 0.085 *** the Brillouin pump power is increased,the number of Stokes wave output can be further *** tunable microwave signals of 10.8 and 21.6 GHz are obtained by heterodyning the Rayleigh wave and Stokes wave of the multiwavelength Brillouin fiber *** the experiment,by tuning the pump wavelength and temperature of the gain fiber,microwave signals at different frequencies are *** tunable frequency range can be further expanded by using a temperature controller with a wider adjustment range,and the generated microwave signal exhibits high stability on frequency.
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