点对多点(Point-to-Multipoint,P2MP)光收发机,使不同位置的多个低速光收发机同时与集中或分布在网络中心局的几个高速光收发机通信,为5G-Advanced网络提供了一种高效的解决方案。针对基于级联快速傅里叶逆变换(Inverse Fast Fourier Tr...点对多点(Point-to-Multipoint,P2MP)光收发机,使不同位置的多个低速光收发机同时与集中或分布在网络中心局的几个高速光收发机通信,为5G-Advanced网络提供了一种高效的解决方案。针对基于级联快速傅里叶逆变换(Inverse Fast Fourier Transform,IFFT)/傅里叶变换(Fast Fourier Transform,FFT)多信道聚合/解聚合技术,深入研究了P2MP光收发机在上行强度调制直接检测(Intensity Modulation and Direct Detection,IMDD)无源光网络(Passive Optical Network,PON)中的可扩展性。仿真结果表明:每个光网络单元(Optical Network Unit,ONU)可以自适应地改变其聚合的信道数目,而不会明显降低系统传输容量和ONU发射功率动态范围;ONU数目的增加也可以通过略微降低传输容量和ONU发射功率动态范围来有效实现。因此,该P2MP光收发机为PON提供了良好的可扩展性。展开更多
Considering the influence of more random atmospheric turbulence, worse pointing errors and highly dynamic link on the transmission performance of mobile multiple-input multiple-output （MIMO） free space optics （FSO...Considering the influence of more random atmospheric turbulence, worse pointing errors and highly dynamic link on the transmission performance of mobile multiple-input multiple-output （MIMO） free space optics （FSO） communica- tion systems, this paper establishes a channel model for the mobile platform. Based on the combination of Alamouti space-time code and time hopping ultra-wide band （TH-UWB） communications, a novel repetition space-time coding （RSTC） method for mobile 2x2 free-space optical communications with pulse position modulation （PPM） is devel- oped. In particular, two decoding methods of equal gain combining （EGC） maximum likelihood detection （MLD） and correlation matrix detection （CMD） are derived. When a quasi-static fading and weak turbulence channel model are considered, simulation results show that whether the channel state information （CSI） is known or not, the coding sys- tem demonstrates more significant performance of the symbol error rate （SER） than the uncoding. In other words, transmitting diversity can be achieved while conveying the information only through the time delays of the modulated signals transmitted from different antennas. CMD has almost the same effect of signal combining with maximal ratio combining （MRC）. However, when the channel correlation increases, SER performance of the coding 2×2 system de- grades significantly.展开更多
文摘点对多点(Point-to-Multipoint,P2MP)光收发机,使不同位置的多个低速光收发机同时与集中或分布在网络中心局的几个高速光收发机通信,为5G-Advanced网络提供了一种高效的解决方案。针对基于级联快速傅里叶逆变换(Inverse Fast Fourier Transform,IFFT)/傅里叶变换(Fast Fourier Transform,FFT)多信道聚合/解聚合技术,深入研究了P2MP光收发机在上行强度调制直接检测(Intensity Modulation and Direct Detection,IMDD)无源光网络(Passive Optical Network,PON)中的可扩展性。仿真结果表明:每个光网络单元(Optical Network Unit,ONU)可以自适应地改变其聚合的信道数目,而不会明显降低系统传输容量和ONU发射功率动态范围;ONU数目的增加也可以通过略微降低传输容量和ONU发射功率动态范围来有效实现。因此,该P2MP光收发机为PON提供了良好的可扩展性。
基金supported by the National Natural Science Foundation of China(No.61205106)
文摘Considering the influence of more random atmospheric turbulence, worse pointing errors and highly dynamic link on the transmission performance of mobile multiple-input multiple-output （MIMO） free space optics （FSO） communica- tion systems, this paper establishes a channel model for the mobile platform. Based on the combination of Alamouti space-time code and time hopping ultra-wide band （TH-UWB） communications, a novel repetition space-time coding （RSTC） method for mobile 2x2 free-space optical communications with pulse position modulation （PPM） is devel- oped. In particular, two decoding methods of equal gain combining （EGC） maximum likelihood detection （MLD） and correlation matrix detection （CMD） are derived. When a quasi-static fading and weak turbulence channel model are considered, simulation results show that whether the channel state information （CSI） is known or not, the coding sys- tem demonstrates more significant performance of the symbol error rate （SER） than the uncoding. In other words, transmitting diversity can be achieved while conveying the information only through the time delays of the modulated signals transmitted from different antennas. CMD has almost the same effect of signal combining with maximal ratio combining （MRC）. However, when the channel correlation increases, SER performance of the coding 2×2 system de- grades significantly.
