2 research outputs found
Joint Antenna Array Mode Selection and User Assignment for Full-Duplex MU-MISO Systems
This paper considers a full-duplex (FD) multiuser multiple-input
single-output system where a base station simultaneously serves both uplink
(UL) and downlink (DL) users on the same time-frequency resource. The crucial
barriers in implementing FD systems reside in the residual self-interference
and co-channel interference. To accelerate the use of FD radio in future
wireless networks, we aim at managing the network interference more effectively
by jointly designing the selection of half-array antenna modes (in the transmit
or receive mode) at the BS with time phases and user assignments. The first
problem of interest is to maximize the overall sum rate subject to
quality-of-service requirements, which is formulated as a highly non-concave
utility function followed by non-convex constraints. To address the design
problem, we propose an iterative low-complexity algorithm by developing new
inner approximations, and its convergence to a stationary point is guaranteed.
To provide more insights into the solution of the proposed design, a general
max-min rate optimization is further considered to maximize the minimum
per-user rate while satisfying a given ratio between UL and DL rates.
Furthermore, a robust algorithm is devised to verify that the proposed scheme
works well under channel uncertainty. Simulation results demonstrate that the
proposed algorithms exhibit fast convergence and substantially outperform
existing schemes.Comment: Accepted for publication in IEEE Transactions on Wireless
Communication
Max-Min Fairness User Scheduling and Power Allocation in Full-Duplex OFDMA Systems
In a full-duplex (FD) multi-user network, the system performance is not only
limited by the self-interference but also by the co-channel interference due to
the simultaneous uplink and downlink transmissions. Joint design of the
uplink/downlink transmission direction of users and the power allocation is
crucial for achieving high system performance in the FD multi-user network. In
this paper, we investigate the joint uplink/downlink transmission direction
assignment (TDA), user paring (UP) and power allocation problem for maximizing
the system max-min fairness (MMF) rate in a FD multi-user orthogonal frequency
division multiple access (OFDMA) system. The problem is formulated with a
two-time-scale structure where the TDA and the UP variables are for optimizing
a long-term MMF rate while the power allocation is for optimizing an
instantaneous MMF rate during each channel coherence interval. We show that the
studied joint MMF rate maximization problem is NP-hard in general. To obtain
high-quality suboptimal solutions, we propose efficient methods based on simple
relaxation and greedy rounding techniques. Simulation results are presented to
show that the proposed algorithms are effective and achieve higher MMF rates
than the existing heuristic methods.Comment: 15 pages, 8 figures, accepted by IEEE Trans. Wireless Commu