TY - JOUR
T1 - Electromagnetic Effective Degree of Freedom of an MIMO System in Free Space
AU - Yuan, Shuai S.A.
AU - He, Zi
AU - Chen, Xiaoming
AU - Huang, Chongwen
AU - Sha, Wei E.I.
N1 - Publisher Copyright:
© 2002-2011 IEEE.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - Effective degree of freedom (EDOF) of a multiple-input-multiple-output (MIMO) system represents its equivalent number of independent single-input-single-output (SISO) systems, which directly characterizes the communication performance. Traditional EDOF only considers single polarization, where the full polarized components degrade into two independent transverse components under the far-field approximation. However, the traditional model is not applicable to complex scenarios especially for the near-field region. Based on an electromagnetic (EM) channel model built from the dyadic Green's function, we first calculate the EM EDOF to estimate the performance of an arbitrary MIMO system with full polarizations in free space. Then, we clarify the relations between the limit of EDOF and the optimal number of sources/receivers. Finally, potential benefits of near-field MIMO communications are demonstrated with the EM EDOF, in which the contribution of the longitudinally polarized source is taken into account. This letter establishes a fundamental EM framework for MIMO wireless communications.
AB - Effective degree of freedom (EDOF) of a multiple-input-multiple-output (MIMO) system represents its equivalent number of independent single-input-single-output (SISO) systems, which directly characterizes the communication performance. Traditional EDOF only considers single polarization, where the full polarized components degrade into two independent transverse components under the far-field approximation. However, the traditional model is not applicable to complex scenarios especially for the near-field region. Based on an electromagnetic (EM) channel model built from the dyadic Green's function, we first calculate the EM EDOF to estimate the performance of an arbitrary MIMO system with full polarizations in free space. Then, we clarify the relations between the limit of EDOF and the optimal number of sources/receivers. Finally, potential benefits of near-field MIMO communications are demonstrated with the EM EDOF, in which the contribution of the longitudinally polarized source is taken into account. This letter establishes a fundamental EM framework for MIMO wireless communications.
KW - Dyadic Green's function
KW - effective degree of freedom (EDOF)
KW - multiple-input-multiple-output (MIMO)
KW - near-field communications
UR - https://www.scopus.com/pages/publications/85126304696
U2 - 10.1109/LAWP.2021.3135018
DO - 10.1109/LAWP.2021.3135018
M3 - 文章
AN - SCOPUS:85126304696
SN - 1536-1225
VL - 21
SP - 446
EP - 450
JO - IEEE Antennas and Wireless Propagation Letters
JF - IEEE Antennas and Wireless Propagation Letters
IS - 3
ER -