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Wideband sensing-based cognitive radio with simultaneous wireless information and power transfer can be designed for efficient spectrum and energy usage. We investigate maxmin fairness energy-harvesting optimization problem in such a system by taking into account of the individual link fairness. In particular, we maximize the energy harvested by the worstcase link when the problem is subject to the...
We consider an Uplink License Assisted Access (LAA) system in which LTE systems compete transmission resources with WiFi systems. Before sending any signals, a listen-before-talk (LBT) process is mandated for LAA system: users are required to sense the environment and can only transmit if the channel is considered idle. To guarantee that all users are aligned for transmission, a designation period...
Spectrum Access System (SAS) is a three tier spectrum sharing framework proposed by the FCC. In this framework the aggregate interference of tier-3 General Authorised Access (GAA) users should be below a predetermined threshold anywhere within the tier-2 Priority Access Licensee (PAL) exclusion zone. GAA are expected to use a diverse range of Radio Access Technologies (RATs) with different levels...
Heterogeneous network (HetNet) has been widely accepted as a viable way to deal with the increasing traffic demand. However, the deployment of small cell base stations (SBSs) inevitably triggers a tremendous escalation of energy consumption. In this paper, we study the energy efficient HetNet deployment problem taking the disparities of the traffic load distribution into account. The optimization...
Capacity-coverage tradeoff balancing is a classical but critical problem for practical wireless multi- cell network optimization. Increasing the average capacity is often at the expense of decreasing the cell coverage and vice versa. It becomes more complex in massive multiple-input/multiple-output (MIMO) networks to balance the above two performance indicators since capacity is much highly improved...
To relieve the traffic burden and improve the system capacity, licensed-assisted access (LAA) has been becoming a promising technology to the supplementary utilization of the unlicensed spectrum. However, due to the densification of small base stations (SBSs) and the dynamic variety of the number of Wi-Fi nodes in the overlapping areas, the licensed channel interference and the unlicensed channel...
In this paper, we propose a sparse and low-rank optimization approach for network topology control in the partially connected fog radio access network (Fog-RAN). In this model, the sparsity of the modeling matrix represents the number of non-connected interference links, while the rank of the matrix models the achievable symmetric degrees-of-freedom (DoF) allocations. This model helps find the network...
In this paper, we propose an optimization framework for selecting an optimal downlink beamforming vector and an optimal uplink transmission power level in full-duplex small cell wireless networks. We study the case in which the full-duplex base station is equipped with multiple antennas and each half-duplex UE is equipped with a single antenna. To benefit from recent progresses in all-digital self-...
We investigate the overlay coding scheme as the capacity achieving multi user detection (MUD) technique, i.e., transmitting over non-orthogonal channels, in forward link in multi-beam satellite systems with dense frequency reuse. The classic overlay coding scheme, uses the strongest co- channel interference (CCI) as extra source of information. The data intended for the target user is shared between...
This paper considers low-complexity transmit beamforming schemes for signal-to-interference-plus- noise ratio (SINR) balancing problem in the Gaussian multiple-input single-output multi-receiver wiretap channel (MISO-MRWC). The formulated max-min-fair problem are shown to be non-convex. To overcome the computational complexity, we develop the leakage-based and zero forcing (ZF) based beamforming algorithms...
This paper proposes a novel Gain-Aware Uplink-Downlink(GAUD) jointly resource allocation scheme to maximize the Device-to-Device(D2D) throughput while guaranteeing Quality of Service (QoS) of cellular users. We formulate the global optimization problem as a mixed integer nonlinear programming problem and decompose it into three sub-problems. Firstly, a method of jointly uplink and downlink reuse mode...
Joint allocation of spectrum and user association is considered for a large cellular network. The objective is to optimize a network utility function such as average delay given traffic statistics collected over a slow timescale. A key challenge is scalability: given n access points (APs), there are O(2n) ways in which the APs can share the spectrum. The number of variables is reduced from O(2n) to...
Traffic aware precoder/decoder design in multi-cell multi-user multiple-input multiple-output systems is considered with the objective of weighted queue minimization, where the original non-convex optimization problem is solved via successive convex approximation. Centralized pilot reuse algorithms for mitigating the pilot contamination are investigated to reflect the traffic aware optimization objective...
The results of the aerodynamic optimization of wind-driven power-plant (WP) with a vertical axis of rotation, axially symmetric stator and special form rotor are presented. It is shown that WP using useful interference of the stator and the rotor, on the energy characteristics superior to the classical WP ceteris paribus. Prospect for WP development consists of variable geometry elements using, that...
In this article the cross-platform software and hardware solution for LTE key performance indicators optimization are developed. There are two important conflicting indicators are explained and optimized — LTE user's throughput and cell throughput versus different power control parameter settings such as nominal power per resource block and alpha for fractional power control. The results graphically...
Recently vehicle-to-vehicle (V2V) communication emerged as a key enabling technology to ensure traffic safety and other mission-critical applications. In this paper, a novel proximity and quality-of-service (QoS)-aware resource allocation for V2V communication is proposed. The proposed approach exploits the spatial-temporal aspects of vehicles in terms of their physical proximity and traffic demands,...
Energy efficiency (EE) is becoming one of the important criteria in wireless transmission design. This paper discusses the recently proposed energy-efficient transmit beamforming designs for multicell multiuser multiple-input single-output (MISO) systems, including maximizing overall network EE, sum weighted EE and fairness EE. Generally, the EE optimization problems are NP-hard nonconvex programs...
Device-to-Device (D2D) communications potentially allow users placed in a cell to establish direct connections among them using several connection modes. In this paper, we propose Multi-Path D2D (MPD2D), a mathematical optimisation framework that accounts for the availability of D2D modes under flow demand requirements. MPD2D selects the combination of cellular and D2D links that fits better for boosting...
This manuscript presents a comparative study between three Multiobjective Evolutionary Algorithms (NSGA-II, GDE3, and MOEA/D-DE) on Wireless Local Area Networks design. The considered problem consists on defining the positions, quantity, channels, and load balance of access points to be installed. Problem features such as equipment limitations, traffic demand, and minimum coverage level required are...
Efficient interference control is a prerequisite for realizing the possible capacity gains in large heterogeneous networks. An efficient way to do this is to mute some Base Station (BS) transmissions in some time frames to let other BSs serve their users. Two approaches for doing this is studied; a simple one similar to the schemes used in current mobile technologies and a more complex one with higher...
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