scholarly journals A QoS-based joint user association and resource allocation scheme in ultra-dense networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Zhiwei Si ◽  
Gang Chuai ◽  
Weidong Gao ◽  
Jinxi Zhang ◽  
Xiangyu Chen ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Power Allocation ◽  
System Capacity ◽  
System Throughput ◽  
User Association ◽  
Allocation Scheme ◽  
Dense Networks ◽  
Virtual Cell ◽  
Resource Allocation Scheme ◽  
Inter Cell Interference

AbstractUltra-dense networks (UDNs) have become an important architecture for the fifth generation (5G) networks. A large number of small base stations (SBSs) are deployed to provide high-speed and seamless connections for users in the network. However, the advantage of increasing the system capacity brought by the dense distribution of SBSs comes at the cost of severe inter-cell interference. Although the user-centric virtual cell method has been proposed to solve the interference problem, some challenges have been encountered in practical applications. For example, inter-cell interference still exists to a certain extent, and the cell load may be imbalance. Hence, under the virtual cell architecture, we propose a quality of service (QoS)-based joint user association and resource allocation scheme in UDNs. In order to mitigate the interference, balance cell load and improve the system throughput, a non-convex NP-hard problem is formulated. To effectively solve this problem, we decouple the formulated problem into three sub-problems: user association, physical resource block (PRB) allocation and power allocation. First, we consider the QoS requirements of user equipment (UE) and perform user association based on the PRB estimation method. Then, based on the overlapped virtual cells constructed, we propose a graph-based PRB allocation scheme for reducing virtual inter-cell interference. Moreover, we solve power allocation sub-problem by using the difference of concave (DC) programing method. The simulation results show that our proposed scheme is superior to other schemes in terms of user rates, cell load and system throughput.

Resource Allocation Scheme Based on Rate-Requirement for Device-to-Device Downlink Communications

2019 ◽  
Vol 33 (13) ◽  
pp. 1959040
Author(s):  
Xin Wang ◽  
Zhihong Qian ◽  
Xue Wang ◽  
Lan Huang
Keyword(s):  
Resource Allocation ◽  
Low Complexity ◽  
Superior Performance ◽  
System Throughput ◽  
Allocation Scheme ◽  
Resource Reallocation ◽  
Restricted Area ◽  
Device To Device ◽  
Resource Allocation Scheme ◽  
Rate Requirement

The rate-requirement of device-to-device (D2D) users is associated with the context information of velocity and data size of users to some extent. In this study, an efficient context-aware resource allocation scheme based on rate requirement (RARR) is proposed. This scheme consists of two allocation phases. In the rate-ensuring resource allocation phase, D2D pairs are allocated a certain amount of spectrum resource according to their rate requirement. In the allocation, the interference restricted area is limited to exclude cellular users that bring a negative capacity gain to the communication system. In the residual resource reallocation phase, surplus resources are assigned to D2D pairs according to the system fairness. Simulation results indicate that the proposed RARR scheme efficiently leads to superior performance in terms of system throughput and fairness and exhibits low complexity relative to traditional resource allocation.

Geometric Programming Based Resource Allocation for 5G High-Speed Mobile Networks

2017 ◽  
pp. 228-245
Author(s):  
Shaoyi Xu ◽  
Tianhang Fu
Keyword(s):  
Resource Allocation ◽  
Time Delay ◽  
Power Allocation ◽  
Mobile Networks ◽  
Mobile Communications ◽  
Geometric Programming ◽  
High Speed ◽  
Allocation Scheme ◽  
Delay Constraint ◽  
Resource Allocation Scheme

The high-speed railway (HSR) is a typical application case in 5G systems. Mobile relay stations (MRSs) which are mounted in a high-speed train (HST) is popular system architecture for high-speed mobile communications. However, sharing spectrums between the macro cell and the MRS cell, interference exists in this hybrid system. In this chapter, we investigate the downlink of a multi-cellular decode and forward (DF) relayed orthogonal frequency division multiple access (OFDMA) system and formulate the problem to maximize the system sum rate of all cells subject to a total power constraint and a new proposed time delay constraint. An effective resource allocation scheme combined by greedy sub-carriers allocation and geometric programming (GP) based power allocation algorithm is proposed to optimize subcarrier allocation and power allocation. Numerical experiments verify that the proposed resource allocation scheme outperforms the other traditional approaches and the necessity of introducing the time delay constraint.

Geometric Programming Based Resource Allocation for 5G High-Speed Mobile Networks

2021 ◽  
pp. 811-828
Author(s):  
Shaoyi Xu ◽  
Tianhang Fu
Keyword(s):  
Resource Allocation ◽  
Time Delay ◽  
Power Allocation ◽  
Mobile Networks ◽  
Mobile Communications ◽  
Geometric Programming ◽  
High Speed ◽  
Allocation Scheme ◽  
Delay Constraint ◽  
Resource Allocation Scheme

The high-speed railway (HSR) is a typical application case in 5G systems. Mobile relay stations (MRSs) which are mounted in a high-speed train (HST) is popular system architecture for high-speed mobile communications. However, sharing spectrums between the macro cell and the MRS cell, interference exists in this hybrid system. In this chapter, we investigate the downlink of a multi-cellular decode and forward (DF) relayed orthogonal frequency division multiple access (OFDMA) system and formulate the problem to maximize the system sum rate of all cells subject to a total power constraint and a new proposed time delay constraint. An effective resource allocation scheme combined by greedy sub-carriers allocation and geometric programming (GP) based power allocation algorithm is proposed to optimize subcarrier allocation and power allocation. Numerical experiments verify that the proposed resource allocation scheme outperforms the other traditional approaches and the necessity of introducing the time delay constraint.

scholarly journals Joint User Association and Energy Offloading in Downlink Heterogeneous Cellular Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Rui Li ◽  
Ning Cao ◽  
Minghe Mao ◽  
Yunfei Chen ◽  
Yifan Hu
Keyword(s):  
Power Allocation ◽  
Cellular Networks ◽  
Communication Systems ◽  
System Throughput ◽  
User Association ◽  
Heterogeneous Cellular Networks ◽  
Macro Cell ◽  
System Resource ◽  
Resource Allocation Scheme

As a key technology in Long-Term Evolution-Advanced (LTE-A) mobile communication systems, heterogeneous cellular networks (HCNs) add low-power nodes to offload the traffic from macro cell and therefore improve system throughput performance. In this paper, we investigate a joint user association and resource allocation scheme for orthogonal frequency division multiple access- (OFDMA-) based downlink HCNs for maximizing the energy efficiency and optimizing the system resource. The algorithm is formulated as a nonconvex optimization, with dynamic circuit consumption, limited transmit power, and quality-of-service (QoS) constraints. As a nonlinear fractional problem, an iteration-based algorithm is proposed to decompose the problem into two subproblems, that is, user association and power allocation. For each iteration, we alternatively solve the two subproblems and obtain the optimal user association and power allocation strategies. Numerical results illustrate that the proposed iteration-based algorithm outperforms existing algorithms.

scholarly journals A Robust Cooperative Spectrum Sensing-Assisted Multiuser Resource Allocation Scheme

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Du ◽  
Daoxing Guo ◽  
Bangning Zhang ◽  
Yunxia Su
Keyword(s):  
Resource Allocation ◽  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
System Throughput ◽  
Allocation Scheme ◽  
Spectrum Access ◽  
Primary User Emulation Attack ◽  
Resource Allocation Scheme

Cognitive radio (CR), which is proposed as a solution for spectrum scarcity, imposes some threats to the network. One severe attack to cognitive radio network is the primary user emulation attack (PUEA), in which an attacker may transmit its signal with high power or mimic specific features of the primary user’s signal to prevent secondary users from accessing the licensed spectrum. In this paper, we study a subcarrier and power allocation problem for orthogonal frequency division multiple access-(OFDMA-) based CR systems in the presence of PUEA. To maximize the system throughput while keeping the interference introduced to the primary user (PU) below given thresholds with a certain probability, a joint design of a robust cooperative spectrum sensing and a resource allocation scheme is proposed. In the proposed scheme, the inaccurate classification of PU signals and PUEA signals provided by robust cooperative spectrum sensing is utilized by resource scheduling module. To further exploit the underutilized spectrum bands, we also evaluate the performance of the proposed scheme in the hybrid overlay/underlay spectrum access mechanism. Numerical results demonstrate the effectiveness of the proposed scheme compared to conventional scheme regardless of the number of SUs or the kind of spectrum access mechanism being used.

scholarly journals Joint Resource Allocation Scheme for Device-To-Device Communication under a Cellular Network

2015 ◽  
Vol 15 (6) ◽  
pp. 91-102
Author(s):  
Chenwei Feng ◽  
Pingbo Chen ◽  
Zewang Zhang
Keyword(s):  
Resource Allocation ◽  
Utility Function ◽  
Cellular Network ◽  
Optimization Theory ◽  
D2d Communication ◽  
System Throughput ◽  
Allocation Scheme ◽  
Joint Resource Allocation ◽  
Device To Device ◽  
Resource Allocation Scheme

Abstract Device-To-Device (D2D) communication is a new technology that allows the mobile terminals to directly communicate with each other by sharing the resources of the cellular network under the control of a cellular system. D2D communication was introduced into the cellular network in order to improve the efficiency of resource utilization and increase the system throughput. However, there exist interferences between D2D links and cellular links due to the resource reuse. In order to efficiently limit the cases of interference, a joint resource allocation scheme for D2D communication under a cellular network is proposed. The scheme, based on the user’s Quality of Service (QoS), defines a new utility function to balance the increasing system throughput and the interference in the cellular users D2D communication. The optimal D2D transmitting power is obtained through optimizing the utility function by using the convex optimization theory. The simulation shows that the scheme can fulfill the user’s QoS requirements efficiently, improve the system throughput and the reliability of the resources as well.

scholarly journals Hybrid OFDMA Resource Allocation Scheme for Ensuring Required Level of Proportional Fairness

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Ming Sun ◽  
Kangle Zhai ◽  
Wei Cao ◽  
Ying Wang ◽  
Yaoqun Xu
Keyword(s):  
Resource Allocation ◽  
Power Allocation ◽  
Complexity Analysis ◽  
Proportional Fairness ◽  
Subcarrier Allocation ◽  
Allocation Scheme ◽  
Greedy Method ◽  
Hungarian Algorithm ◽  
Data Rates ◽  
Resource Allocation Scheme

The new-generation wireless communication networks are envisioned to offer higher sum data rates along with the required level of fairness. Previous works tend to suffer from a decayed performance as subcarriers become relatively insufficient in allocation to users. To maximize the sum data rates and ensure the required level of proportional fairness, this paper presents a hybrid OFDMA resource allocation scheme which uses Hungarian algorithm combined with a greedy method for subcarrier allocation and uses bee colony optimization for power allocation. The proposed subcarrier allocation scheme can make full use of advantages of both globally optimal Hungarian algorithm in enhancing sum data rates and locally optimal greedy method in maintaining a reasonable fairness level and can make Hungarian algorithm work in a searching mode for further improvement of sum data rates and fairness. The proposed power allocation scheme can converge to the required level of proportional fairness but with higher sum data rates if the subcarrier allocation does not achieve the required fairness. Simulation results show that the proposed scheme can obtain the required level of proportional fairness but with higher sum data rates even if subcarriers are relatively insufficient in allocation to users. Complexity analysis shows the proposed method has moderate complexity.

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