The high frequency (HF) channel simulators with time-varying parameters based on the Watterson model are analyzed. The methods of simulating the HF channel with time-varying parameters are proposed. The linearly time-...The high frequency (HF) channel simulators with time-varying parameters based on the Watterson model are analyzed. The methods of simulating the HF channel with time-varying parameters are proposed. The linearly time-varying delay spread is introduced into the channel simulators to simulate the transition states between two channel modes of CCIR520-1. Two signals, including a 500 Hz and a 1 000 Hz bandwidth signal are respectively input into the standard Watterson HF channel model and the proposed channel model with time-varying parameters. Some simulation results prove that the proposed HF channel model with time-varying parameters can reflect the time-varying characteristics of frequency selected fading of HF channel.展开更多
Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communic...Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communication system is highly desired for achieving target-oriented beamforming and accommodating high-speed data service.However,an efficient solution to integrated sensing and light communication remains challenging.Here,we demonstrate an integrated system that concurrently accomplishes high-precision sensing and high-speed data transmission by spatio-temporal modulation of the illumination and computational reconstruction.We developed a compressive angular projection imaging scheme to achieve rapid three-dimensional localization with high resolution,and a jointly optimized waveform design ensures slight sacrifice in the transmission data rate on the integrated system.We experimentally demonstrated a resolving resolution of 1 mm in lateral and 4 cm in depth within 0.6 m×0.6 m×0.6 m volume over 2 m distance at the sensing speed of 39 Hz in both static and dynamic conditions.This capability enables adaptive beamforming,which significantly enhances the data rate by 184%to permit errorless transmission of high-throughput virtual reality videos.Our work offers a promising route for intelligent wireless light communication systems with spatial perception capability,presenting the possibility of cable-free,immersive virtual reality experiences.展开更多
A space-ground integrated network(SGIN)will be a future network for the heterogeneous convergence of space-and ground-based networks.The SGIN envisions satellites with the capability to adapt to various communication ...A space-ground integrated network(SGIN)will be a future network for the heterogeneous convergence of space-and ground-based networks.The SGIN envisions satellites with the capability to adapt to various communication protocols,enabling the convergence of diverse network systems.A crucial aspect of satellite payload in the SGIN is the recognition of satellite signal types and their modulation modes,which substantially enhances the processing of heterogeneous wireless signals at the baseband processing.A multitask learning(MTL)model-based convolutional neural network(CNN)architecture is proposed,which addresses the recognition problem.An MTL model-based CNN architecture is proposed,which addresses the recognition problem.This model is composed of 3 key components:A multi-input part that processes in-phase/quadrature(IQ)complex signals and power spectral density data,a set of shared part that facilitates the model’s efficiency and mitigate overfitting,and a multitask output part capable of concurrently recognizing signal types and modulation modes.Furthermore,we have developed a dataset that encompasses 5 satellite signal protocols,i.e.,signal type,and 6 modulation modes,derived from the digital video broadcasting(DVB)protocols and the tracking,telemetry,and command(TT&C)standards of the consultative committee for space data systems(CCSDS).This dataset also takes into account the impact of the additive white Gaussian noise(AWGN)channel and land mobile satellite(LMS)channel models.Simulation experiments validate the effectiveness of the proposed MTL model in accurately identifying various satellite signal protocols and modulation techniques.展开更多
文摘The high frequency (HF) channel simulators with time-varying parameters based on the Watterson model are analyzed. The methods of simulating the HF channel with time-varying parameters are proposed. The linearly time-varying delay spread is introduced into the channel simulators to simulate the transition states between two channel modes of CCIR520-1. Two signals, including a 500 Hz and a 1 000 Hz bandwidth signal are respectively input into the standard Watterson HF channel model and the proposed channel model with time-varying parameters. Some simulation results prove that the proposed HF channel model with time-varying parameters can reflect the time-varying characteristics of frequency selected fading of HF channel.
基金National Key Research and Development Program of China(2023YFB2804701)National Natural Science Foundation of China(62401156,61925104,62201157,62231018)。
文摘Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communication system is highly desired for achieving target-oriented beamforming and accommodating high-speed data service.However,an efficient solution to integrated sensing and light communication remains challenging.Here,we demonstrate an integrated system that concurrently accomplishes high-precision sensing and high-speed data transmission by spatio-temporal modulation of the illumination and computational reconstruction.We developed a compressive angular projection imaging scheme to achieve rapid three-dimensional localization with high resolution,and a jointly optimized waveform design ensures slight sacrifice in the transmission data rate on the integrated system.We experimentally demonstrated a resolving resolution of 1 mm in lateral and 4 cm in depth within 0.6 m×0.6 m×0.6 m volume over 2 m distance at the sensing speed of 39 Hz in both static and dynamic conditions.This capability enables adaptive beamforming,which significantly enhances the data rate by 184%to permit errorless transmission of high-throughput virtual reality videos.Our work offers a promising route for intelligent wireless light communication systems with spatial perception capability,presenting the possibility of cable-free,immersive virtual reality experiences.
基金supported by the National Key Research and Development Program(grant number 2021Y FB2900604)Young Elite Scientists Sponsorship Program by CAST(grant number 2022QNRC001).
文摘A space-ground integrated network(SGIN)will be a future network for the heterogeneous convergence of space-and ground-based networks.The SGIN envisions satellites with the capability to adapt to various communication protocols,enabling the convergence of diverse network systems.A crucial aspect of satellite payload in the SGIN is the recognition of satellite signal types and their modulation modes,which substantially enhances the processing of heterogeneous wireless signals at the baseband processing.A multitask learning(MTL)model-based convolutional neural network(CNN)architecture is proposed,which addresses the recognition problem.An MTL model-based CNN architecture is proposed,which addresses the recognition problem.This model is composed of 3 key components:A multi-input part that processes in-phase/quadrature(IQ)complex signals and power spectral density data,a set of shared part that facilitates the model’s efficiency and mitigate overfitting,and a multitask output part capable of concurrently recognizing signal types and modulation modes.Furthermore,we have developed a dataset that encompasses 5 satellite signal protocols,i.e.,signal type,and 6 modulation modes,derived from the digital video broadcasting(DVB)protocols and the tracking,telemetry,and command(TT&C)standards of the consultative committee for space data systems(CCSDS).This dataset also takes into account the impact of the additive white Gaussian noise(AWGN)channel and land mobile satellite(LMS)channel models.Simulation experiments validate the effectiveness of the proposed MTL model in accurately identifying various satellite signal protocols and modulation techniques.
