TY - JOUR
T1 - Degrees of Freedom of Full-Duplex Cellular Networks
T2 - Effect of Self-Interference
AU - Chae, Sung Ho
AU - Lee, Kisong
N1 - Publisher Copyright:
© 1972-2012 IEEE.
PY - 2017/10
Y1 - 2017/10
N2 - It was recently shown that full-duplex (FD) operation at a base station (BS) can provide up to twice as many degrees of freedom (DoF) as a conventional half-duplex (HD) cellular network in the absence of self-interference. In practice, however, self-interference in an FD BS may not be eliminated completely due to imperfect cancellation, and it is not yet known whether FD operation can improve the sum DoF of cellular networks in the presence of residual self-interference. In this paper, we provide a complete characterization of the sum DoF in an FD-BS cellular network with self-interference, where the rank of the self-interference matrix is arbitrary. Specifically, we propose a self-interference cancellation scheme that maximizes the sum DoF, and we prove its optimality by deriving the matching upper bound. Our results show that even in the presence of residual self-interference, an FD-BS network can still outperform a conventional HD-BS network, and furthermore, the sum DoF coincides with that of an FD-BS network with no self-interference under certain conditions. We also derive an achievable sum rate under ergodic phase fading, showing that not only a sum-DoF gain but also a sum-rate gain can be obtained over the entire signal-to-noise ratio range even if residual self-interference exists.
AB - It was recently shown that full-duplex (FD) operation at a base station (BS) can provide up to twice as many degrees of freedom (DoF) as a conventional half-duplex (HD) cellular network in the absence of self-interference. In practice, however, self-interference in an FD BS may not be eliminated completely due to imperfect cancellation, and it is not yet known whether FD operation can improve the sum DoF of cellular networks in the presence of residual self-interference. In this paper, we provide a complete characterization of the sum DoF in an FD-BS cellular network with self-interference, where the rank of the self-interference matrix is arbitrary. Specifically, we propose a self-interference cancellation scheme that maximizes the sum DoF, and we prove its optimality by deriving the matching upper bound. Our results show that even in the presence of residual self-interference, an FD-BS network can still outperform a conventional HD-BS network, and furthermore, the sum DoF coincides with that of an FD-BS network with no self-interference under certain conditions. We also derive an achievable sum rate under ergodic phase fading, showing that not only a sum-DoF gain but also a sum-rate gain can be obtained over the entire signal-to-noise ratio range even if residual self-interference exists.
KW - cellular network
KW - Degrees of freedom
KW - full duplex
KW - interference alignment
KW - multi-antenna technique
KW - self-interference
UR - http://www.scopus.com/inward/record.url?scp=85023761888&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2017.2719022
DO - 10.1109/TCOMM.2017.2719022
M3 - Article
AN - SCOPUS:85023761888
SN - 1558-0857
VL - 65
SP - 4507
EP - 4518
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 10
M1 - 7956187
ER -