941 research outputs found
Resource allocation in OFDMA networks with half-duplex and imperfect full-duplex users
Recent studies indicate the feasibility of in-band fullduplex (FD) wireless
communications, where a wireless radio transmits and receives simultaneously in
the same band. Due to its potential to increase the capacity, analyzing the
performance of a cellular network that contains full-duplex devices is crucial.
In this paper, we consider maximizing the weighted sum-rate of downlink and
uplink of a single cell OFDMA network which consists of an imperfect FD
base-station (BS) and a mixture of half-duplex and imperfect full-duplex mobile
users. To this end, the joint problem of sub-channel assignment and power
allocation is investigated and a two-step solution is proposed. A heuristic
algorithm to allocate each sub-channel to a pair of downlink and uplink users
with polynomial complexity is presented. The power allocation problem is
convexified based on the difference of two concave functions approach, for
which an iterative solution is obtained. Simulation results demonstrate that
when all the users and the BS are perfect FD nodes the network throughput could
be doubled, Otherwise, the performance improvement is limited by the inter-node
interference and the self-interference. We also investigate the effect of the
self-interference cancellation capability and the percentage of FD users on the
network performance in both indoor and outdoor scenarios.Comment: 6 pages, 8 figures, Accepted in IEEE International Conference on
Communication (ICC), Malaysia, 201
On the Benefits of Network-Level Cooperation in Millimeter-Wave Communications
Relaying techniques for millimeter-wave wireless networks represent a
powerful solution for improving the transmission performance. In this work, we
quantify the benefits in terms of delay and throughput for a random-access
multi-user millimeter-wave wireless network, assisted by a full-duplex network
cooperative relay. The relay is equipped with a queue for which we analyze the
performance characteristics (e.g., arrival rate, service rate, average size,
and stability condition). Moreover, we study two possible transmission schemes:
fully directional and broadcast. In the former, the source nodes transmit a
packet either to the relay or to the destination by using narrow beams,
whereas, in the latter, the nodes transmit to both the destination and the
relay in the same timeslot by using a wider beam, but with lower beamforming
gain. In our analysis, we also take into account the beam alignment phase that
occurs every time a transmitter node changes the destination node. We show how
the beam alignment duration, as well as position and number of transmitting
nodes, significantly affect the network performance. Moreover, we illustrate
the optimal transmission scheme (i.e., broadcast or fully directional) for
several system parameters and show that a fully directional transmission is not
always beneficial, but, in some scenarios, broadcasting and relaying can
improve the performance in terms of throughput and delay.Comment: arXiv admin note: text overlap with arXiv:1804.0945
Transmission Capacity of Full-Duplex MIMO Ad-Hoc Network with Limited Self-Interference Cancellation
In this paper, we propose a joint transceiver beamforming design to
simultaneously mitigate self-interference (SI) and partial inter-node
interference for full-duplex multiple-input and multiple-output ad-hoc network,
and then derive the transmission capacity upper bound (TC-UB) for the
corresponding network. Condition on a specified transceiver antenna's
configuration, we allow the SI effect to be cancelled at transmitter side, and
offer an additional degree-of-freedom at receiver side for more inter-node
interference cancellation. In addition, due to the proposed beamforming design
and imperfect SI channel estimation, the conventional method to obtain the
TC-UB is not applicable. This motivates us to exploit the dominating interferer
region plus Newton-Raphson method to iteratively formulate the TC-UB. The
results show that the derived TC-UB is quite close to the actual one especially
when the number of receive-antenna is small. Moreover, our proposed beamforming
design outperforms the existing beamforming strategies, and FD mode works
better than HD mode in low signal-to-noise ratio region.Comment: 7 pages, 4 figures, accepted by Globecom 201
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