6,444 research outputs found
In-Band Full-Duplex Communications for Cellular Networks with Partial Uplink/Downlink Overlap
In-band full-duplex (FD) communications have been optimistically promoted to
improve the spectrum utilization in cellular networks. However, the explicit
impact of spatial interference, imposed by FD communications, on uplink and
downlink transmissions has been overlooked in the literature. This paper
presents an extensive study of the explicit effect of FD communications on the
uplink and downlink performances. For the sake of rigorous analysis, we develop
a tractable framework based on stochastic geometry toolset. The developed model
accounts for uplink truncated channel inversion power control in FD cellular
networks. The study shows that FD communications improve the downlink
throughput at the expense of significant degradation in the uplink throughput.
Therefore, we propose a novel fine-grained duplexing scheme, denoted as
-duplex scheme, which allows a partial overlap between uplink and
downlink frequency bands. To this end, we show that the amount of the overlap
can be optimized via adjusting to achieve a certain design objective.Comment: To be presented in IEEE Globecom 201
Opportunistic Scheduling for Full-Duplex Uplink-Downlink Networks
We study opportunistic scheduling and the sum capacity of cellular networks
with a full-duplex multi-antenna base station and a large number of
single-antenna half-duplex users. Simultaneous uplink and downlink over the
same band results in uplink-to-downlink interference, degrading performance. We
present a simple opportunistic joint uplink-downlink scheduling algorithm that
exploits multiuser diversity and treats interference as noise. We show that in
homogeneous networks, our algorithm achieves the same sum capacity as what
would have been achieved if there was no uplink-to-downlink interference,
asymptotically in the number of users. The algorithm does not require
interference CSI at the base station or uplink users. It is also shown that for
a simple class of heterogeneous networks without sufficient channel diversity,
it is not possible to achieve the corresponding interference-free system
capacity. We discuss the potential for using device-to-device side-channels to
overcome this limitation in heterogeneous networks.Comment: 10 pages, 2 figures, to appear at IEEE International Symposium on
Information Theory (ISIT) '1
Limits on the Capacity of In-Band Full Duplex Communication in Uplink Cellular Networks
Simultaneous co-channel transmission and reception, denoted as in-band full
duplex (FD) communication, has been promoted as an attractive solution to
improve the spectral efficiency of cellular networks. However, in addition to
the self-interference problem, cross-mode interference (i.e., between uplink
and downlink) imposes a major obstacle for the deployment of FD communication
in cellular networks. More specifically, the downlink to uplink interference
represents the performance bottleneck for FD operation due to the uplink
limited transmission power and venerable operation when compared to the
downlink counterpart. While the positive impact of FD communication to the
downlink performance has been proved in the literature, its effect on the
uplink transmission has been neglected. This paper focuses on the effect of
downlink interference on the uplink transmission in FD cellular networks in
order to see whether FD communication is beneficial for the uplink transmission
or not, and if yes for which type of network. To quantify the expected
performance gains, we derive a closed form expression of the maximum achievable
uplink capacity in FD cellular networks. In contrast to the downlink capacity
which always improves with FD communication, our results show that the uplink
performance may improve or degrade depending on the associated network
parameters. Particularly, we show that the intensity of base stations (BSs) has
a more prominent effect on the uplink performance than their transmission
power
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