Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the ...Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna number.However,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered.We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual coupling.Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system.展开更多
6G wireless technologies involve dense device deployment,utilize large-scale antenna arrays,and operate in the millimeter-wave and terahertz bands.This will shift the challenges of communication and sensing from the f...6G wireless technologies involve dense device deployment,utilize large-scale antenna arrays,and operate in the millimeter-wave and terahertz bands.This will shift the challenges of communication and sensing from the far field to the radiative near field,where traditional models and algorithms may incur errors or even become obsolete due to mismatch.Therefore,there is an urgent need to discuss localization and communication issues in the near-field region.The near-field assumption allows us to capture more information in electromagnetic signals,unlocking new possibilities for improving communication quality and localization accuracy.It can be anticipated that research on the near-field will play an increasingly important role in 6G and future wireless networks.展开更多
基金supported in part by National Key Research and Develop⁃ment Program of China under Grant No.2020YFB1807600.
文摘Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna number.However,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered.We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual coupling.Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system.
文摘6G wireless technologies involve dense device deployment,utilize large-scale antenna arrays,and operate in the millimeter-wave and terahertz bands.This will shift the challenges of communication and sensing from the far field to the radiative near field,where traditional models and algorithms may incur errors or even become obsolete due to mismatch.Therefore,there is an urgent need to discuss localization and communication issues in the near-field region.The near-field assumption allows us to capture more information in electromagnetic signals,unlocking new possibilities for improving communication quality and localization accuracy.It can be anticipated that research on the near-field will play an increasingly important role in 6G and future wireless networks.
