Full‐duplex OFDMA multi‐user cellular systems: resource allocation and user pairing

This study investigates a joint resource allocation (channel selection (CS) and power allocation (PA)) problem with multiple channels, users, constraints, and uncertainties in the underwater acoustic communication networks (UACNs). A hierarchical joint resource allocation model is formulated considering different user requirements. This model aims to minimize the maximum outage probability of lower users while satisfying the outage requirements of upper users. This study presents a robust distributed power allocation (RDPA) algorithm to solve complex PA problems with nonconvex mixed integers and uncertainties in UACNs. The residual energy of nodes is considered in the proposed RDPA algorithm to balance their energy, thereby extending the working time of the entire network. The proposed robust CS algorithm considers the actual and potential interferences of all neighboring nodes to decrease the interferences of nodes and the entire network, thereby reducing the outage probability of the network. Simulation results are presented to demonstrate the effectiveness of the proposed algorithm. INTRODUCTIONWith the increasing exploitation of marine resources, the research on underwater communication technology has recently attracted increasing attention. 1,2 Underwater acoustic communication networks (UACNs) can facilitate a wide range of civil and military applications, including mine reconnaissance, disaster prediction, coastline protection, and target tracking. 3,4 UACNs face larger connatural challenges than radio communication networks. 5 These challenges include the following. (1) Narrow bandwidth: the underwater acoustic transmission bandwidth is usually less than 100 kbps, 6 which decreases with the increase in communication distance. (2) Limited energy: acoustic modems are battery-powered, and changing or recharging batteries is difficult in the underwater environment. As a result, the working time of the nodes in UACNs is short. (3) Multiple uncertainties: the underwater acoustic channel is one of the most complex channel affected by various environmental factors, such as temperature, salinity, and aquatic organism. Therefore, a resource allocation approach that can achieve high resource utilization rate, long working time, and strong robustness is a key technology in improving the quality of service (QoS) of complex UACNs.

Section: Robust Joint Cs and Pa Problem Formulationmentioning

confidence: 99%

“…Resource allocation issues have been extensively studied in radio frequency (RF). The studies 7,8 considered the joint channel selection (CS) and power allocation (PA) problem in RF as a resource optimization problem and solved it based on traditional optimization schemes. However, traditional optimization schemes cannot be applied in a distributed manner.…”

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confidence: 99%

Robust joint resource allocation algorithm for hierarchical underwater acoustic communication networks based on outage probability minimization

Zhao

Han

et al. 2021

“…Recently, many studies have implemented the FD communication systems using combined SI suppression techniques such as passive suppression, analog suppression, and digital suppression, and thus, SI can be attenuated to detect the intended signal. () The feasibility of FD extensively creates new design opportunities for theories and applications of FD wireless communications, such as FD relay() and FD base station (BS) …”

Section: Introductionmentioning

confidence: 99%

“…Full‐duplex (FD) wireless communications simultaneously operate over the same frequency channel, which have the potential to double spectrum efficiency. () Full‐duplex communications contrast with half‐duplex (HD) communications, which are time‐division, frequency‐division, or code‐division for transmitting and receiving. In the past decades, the main obstacle of implementing the FD transceiver has been the large self‐interference (SI) leaking from the local transmitter because of the closeness of the transmitter and receiver chains.…”

Section: Introductionmentioning

confidence: 99%

“…[5][6][7][8][9] The feasibility of FD extensively creates new design opportunities for theories and applications of FD wireless communications, such as FD relay 10-12 and FD base station (BS). 3 Since the SI suppression techniques are too complex for mobile users compared with the BS to implement in the near future, we focus on studying a network comprising the HD mobile users and the FD BSs. Considering an FD network shown in Figure 1, two HD mobile users communicate with an FD BS that supports 1 uplink and 1 downlink traffic at the same time on the same frequency.…”

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confidence: 99%

See 1 more Smart Citation

An interuser interference suppression approach in full‐duplex wireless communications

Zhang

et al. 2018

Considering that a full‐duplex network is composed of a full‐duplex base station (BS) and 2 half‐duplex users, one user transmits on the uplink channel and the other receives through the downlink channel on the same frequency. The uplink user will generate interuser interference (IUI) on the downlink user through the interference channel. In this paper, we propose a novel IUI suppression scheme when the BS knows the full channel state information. The main idea of this scheme is to retransmit the weighted uplink signal as soon as it has been received by the BS. For the narrowband case, we first assess the performance of the proposed scheme through simulation with residual self‐interference at the BS. Specially, we derive the closed‐form expression of the optimum weighted coefficient when self‐interference is perfectly canceled at the BS and then discuss the performance of the proposed IUI suppression scheme in practical considerations. Furthermore, the proposed IUI suppression scheme can be extended to the broadband case using a time‐domain weighted filter. Simulation results show the advantage over existing IUI suppression schemes.

Joint subchannel assignment and power control in OFDMA in‐band full‐duplex heterogeneous networks

Rajabi

Rasti

Pedram

et al. 2020

Among the emerging technologies for the fifth‐generation (5G) cellular networks, in‐band full‐duplex (FD) wireless communication and heterogeneous networks (HetNets) are two promising technologies, which can significantly improve the network capacity. Due to self‐interference (SI) and multiple sources of intercell interference, base station (BS)‐BS interference and user equipment (UE)‐UE interference in FD HetNets, interference management is a significant and challenging issue in such a network. To this end, in this article, we study the joint subchannel assignment and power control problem in the OFDMA FD HetNet. The joint subchannel assignment and power control problem in this network is formulated as an optimization problem to maximize the uplink and downlink sum throughput of the femtocell user equipments (FUEs) taking into account the maximum interference constraint imposed on the macrocell user equipments (MUEs) and the minimum throughput constraint of FUEs. Since the formulated problem is a nonconvex and intractable mixed integer nonlinear programming (MINLP) problem, we invoke variable change and linear approximation to reformulate and convert the problem into a tractable mixed‐integer linear programming (MILP) problem. Numerical results show that the optimal solution of the new MILP problem is very close to the optimal objective value of the original MINLP problem. The results also demonstrate that in an OFDMA FD HetNet, when all the UEs and the BSs are FD, approximately 50% improvement in the network throughputcan be achieved compared with a half‐duplex HetNet.