scholarly journals Interference-aware Coordinated Access Control for Heterogeneous Cellular D2D Communication Networks

2021 ◽  
Vol 10 (2) ◽  
pp. 1207-1215
Keyword(s):  
Access Control ◽  
Communication Networks ◽  
Base Stations ◽  
D2d Communication ◽  
System Capacity ◽  
System Throughput ◽  
Device User ◽  
User Throughput ◽  
Simulation Results ◽  
Device Deployment

Device-to-Device (D2D) communications is expected to be a key technology of the forthcoming mobile communication networks because of its benefits in terms of spectral efficiency, energy efficiency, and system capacity. To mitigate frequency collisions as well as reduce the effects of co-channel interference between user's connections, we propose an interference-aware coordinated access control (IaCAC) mechanism for heterogeneous cellular D2D communication networks with dense device deployment of user equipment (UEs). In the proposed network setting, we consider the co-existence of both macro base stations (MBSs) and smallcell base stations (SBSs). In the proposed IaCAC mechanism, MBSs and SBSs are coordinated to perform access control to their UEs while MBSs allocate bandwidth parts dynamically to SBSs based on the interference levels measured at SBSs. Besides, to reduce D2D-to-cellular interference, device user equipments (DUEs) can perform power control autonomously. Simulation results show that the proposed IaCAC can provide higher system throughput and user throughput than those achieved by the network-assisted device-decided scheme proposed in [21]. Moreover, simulation results also reveal that the proposed IaCAC also significantly improve SINR of MUE’s and SUE’s uplink connections.

scholarly journals Hybrid Precoding Design Using MMSE Baseband Precoder for mm-Wave Multi-User MIMO Systems

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3486-3490
Keyword(s):  
Communication Networks ◽  
Antenna Arrays ◽  
Mimo Systems ◽  
Minimum Mean Square Error ◽  
Path Loss ◽  
Cellular Systems ◽  
Base Stations ◽  
System Capacity ◽  
Achievable Rate ◽  
Hybrid Precoding

For future 5G wireless communication networks, millimeter-wave (mmWave) cellular systems is considered to be the key enabling technology because of its high data rates, low latency, high system capacity, and huge available bandwidths. However, multiuser networks in mmWave frequency bands encounter high path loss and interference, thus degrading the performance. Applying large antenna arrays at the base stations (BS) in order to achieve high beamforming gains with the help of precoding techniques is an efficient way of improving the performance of the system. Although multi-user beamforming can improve spectral efficiencies, full digital beamforming strategies used in the conventional microwave systems increase the hardware cost and consumes high power for large number of antennas in mmW systems. In this paper, a low-complexity multi-user hybrid precoding structure is proposed for mmWave multiple input multiple output (MIMO) channels utilizing Minimum Mean Square Error (MMSE) precoders at the BS with perfect channel knowledge. Simulations show that the achievable rate obtained by the proposed hybrid precoding scheme is very close to the single-user rate and also performs better compared to other hybrid precoding approaches.

scholarly journals Limited Comp Handover Algorithm For LTE-Advanced

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Cheng-Chung Lin ◽  
Kumbesan Sandrasegaran ◽  
Xinning Zhu ◽  
Zhuliang Xu
Keyword(s):  
Base Stations ◽  
System Capacity ◽  
System Throughput ◽  
System Delay ◽  
Coordinated Multipoint ◽  
Multiple Data ◽  
Lte Advanced ◽  
Hard Handover ◽  
Radio Resources ◽  
Handover Algorithm

Coordinated multipoint (CoMP) transmission and reception is the key technique in LTE-Advanced to improve the cell-edge throughput and/or system throughput. Joint processing (JP) in CoMP technology provides multiple data transmission points for each user among multiple cooperated radio base stations. Hard handover mechanism is adopted to be used in LTE-Advanced. Standard hard handover algorithm could not satisfy the concept of JP in CoMP in LTE-A due to the constraint of single connection for each user at any time. While the radio resources in the system are fixed, the more multiple data connections a user has, the more radio resources are used for the extra data connections, thus the lower capacity a system becomes. Therefore a new handover algorithm that not only supports JP in CoMP but also takes system capacity into consideration in LTE-A system is necessary. This paper proposes a new handover algorithm known as Limited CoMP Handover Algorithm to support JP in CoMP and overcome the system capacity issue. System performance of Limited CoMP Handover Algorithm is evaluated and compared with open literature handover algorithm via simulation in this paper. The simulation results show that Limited CoMP Handover Algorithm outperforms open literature handover algorithm by having shorter system delay and less system load whilst maintaining a higher system throughput in a high congested network.

scholarly journals Enhanced ABSF Algorithm with a Relay Function in LTE Heterogeneous Networks

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1343
Author(s):  
Lehung Nguyen ◽  
Sungoh Kwon
Keyword(s):  
User Satisfaction ◽  
Base Stations ◽  
System Throughput ◽  
Intercell Interference ◽  
Scheduling Policy ◽  
The Third ◽  
Term Evolution ◽  
Simulation Results ◽  
Almost Blank Subframe

In this study, we enhance the almost blank subframe (ABSF) algorithm in a Long Term Evolution (LTE) heterogeneous network (HetNet) by providing a relay function. The ABSF is a technique proposed by the Third Generation Partnership Project to reduce interference in a HetNet. Despite the fact that the ABSF effectively mitigates intercell interference, it has two major disadvantages. First, the ABSF algorithm alters the scheduling policy of macro base stations. Second, it degrades the capacity of users served by femto base stations. Our proposed enhanced algorithm applies a relay function to assist victim macro user equipment (VMUE), and it reduces the side effects caused by the ABSF algorithm. Taking resource allocation and power control into account, the relay function assists VMUE in such a way that interference with other users is minimized. Via simulation results, the proposed algorithm exhibits improvements of 18% and 8% for system throughput and user satisfaction, respectively, in comparison with the conventional ABSF.

scholarly journals Resource Allocation in Millimeter-Wave Device-to-Device Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Filbert Onkundi Ombongi ◽  
Heywood Ouma Absaloms ◽  
Philip Langat Kibet
Keyword(s):  
Resource Allocation ◽  
Millimeter Wave ◽  
Base Stations ◽  
D2d Communication ◽  
System Capacity ◽  
Fourth Generation ◽  
Live Streaming ◽  
Data Traffic ◽  
Research Issues ◽  
Device To Device

Recently, the mobile wireless communication has seen explosive growth in data traffic which might not be supported by the current Fourth Generation (4G) networks. The Fifth Generation (5G) networks will overcome this challenge by exploiting a higher spectrum available in millimeter-wave (mmwave) band to improve network throughput. The integration of the millimeter-wave communication with device-to-device communication can be an enabling 5G scheme in providing bandwidth-intensive proximity-based services such as video sharing, live streaming of data, and socially aware networking. Furthermore, the current cellular network traffic can also be offloaded by the D2D user devices thereby reducing loading at Base Stations (BSs), which would then increase the system capacity. However, the mmwave D2D communication is associated with numerous challenges, which include signal blockages, user mobility, high-computational complexity resource allocation algorithms, and increase in interuser interference for dense D2D user scenario. The paper presents review of existing channel and power allocation approaches and mathematical resource optimization solution techniques. In addition, the paper discusses the challenges hindering the realization of an effective allocation scheme in mmwave D2D communication and gives open research issues for further study.

scholarly journals D2D Assisted Cellular Networks in Licensed and Unlicensed Spectrum: Matching-Iteration-Based Joint User Access and Resource Allocation

Algorithms ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 80
Author(s):  
Qiuqi Han ◽  
Guangyuan Zheng ◽  
Chen Xu
Keyword(s):  
Resource Allocation ◽  
Cellular Networks ◽  
System Capacity ◽  
System Throughput ◽  
Unlicensed Spectrum ◽  
Resource Allocation Algorithm ◽  
User Access ◽  
Limited Spectrum

Device-to-Device (D2D) communications, which enable direct communication between nearby user devices over the licensed spectrum, have been considered a key technique to improve spectral efficiency and system throughput in cellular networks (CNs). However, the limited spectrum resources cannot be sufficient to support more cellular users (CUs) and D2D users to meet the growth of the traffic data in future wireless networks. Therefore, Long-Term Evolution-Unlicensed (LTE-U) and D2D-Unlicensed (D2D-U) technologies have been proposed to further enhance system capacity by extending the CUs and D2D users on the unlicensed spectrum for communications. In this paper, we consider an LTE network where the CUs and D2D users are allowed to share the unlicensed spectrum with Wi-Fi users. To maximize the sum rate of all users while guaranteeing each user’s quality of service (QoS), we jointly consider user access and resource allocation. To tackle the formulated problem, we propose a matching-iteration-based joint user access and resource allocation algorithm. Simulation results show that the proposed algorithm can significantly improve system throughput compared to the other benchmark algorithms.

scholarly journals A Comparative Analysis of Wi-Fi Offloading and Cooperation in Small-Cell Network

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1493
Author(s):  
Ayesha Ayub ◽  
Sobia Jangsher ◽  
M. Majid Butt ◽  
Abdur Rahman Maud ◽  
Farrukh A. Bhatti
Keyword(s):  
Small Cell ◽  
Base Stations ◽  
Small Cells ◽  
Effective Capacity ◽  
Rate Enhancement ◽  
Cell Network ◽  
Small Cell Network ◽  
User Throughput ◽  
Average User ◽  
Cell Cooperation

Small cells deliver cost-effective capacity and coverage enhancement in a cellular network. In this work, we present the interplay of two technologies, namely Wi-Fi offloading and small-cell cooperation that help in achieving this goal. Both these technologies are also being considered for 5G and B5G (Beyond 5G). We simultaneously consider Wi-Fi offloading and small-cell cooperation to maximize average user throughput in the small-cell network. We propose two heuristic methods, namely Sequential Cooperative Rate Enhancement (SCRE) and Sequential Offloading Rate Enhancement (SORE) to demonstrate cooperation and Wi-Fi offloading, respectively. SCRE is based on cooperative communication in which a user data rate requirement is satisfied through association with multiple small-cell base stations (SBSs). However, SORE is based on Wi-Fi offloading, in which users are offloaded to the nearest Wi-Fi Access Point and use its leftover capacity when they are unable to satisfy their rate constraint from a single SBS. Moreover, we propose an algorithm to switch between the two schemes (cooperation and Wi-Fi offloading) to ensure maximum average user throughput in the network. This is called the Switching between Cooperation and Offloading (SCO) algorithm and it switches depending upon the network conditions. We analyze these algorithms under varying requirements of rate threshold, number of resource blocks and user density in the network. The results indicate that SCRE is more beneficial for a sparse network where it also delivers relatively higher average data rates to cell-edge users. On the other hand, SORE is more advantageous in a dense network provided sufficient leftover Wi-Fi capacity is available and more users are present in the Wi-Fi coverage area.

Reconfigurable Antenna Beamforming in Device to Device Communication

2015 ◽  
Vol 740 ◽  
pp. 819-822
Author(s):  
Qing Shen ◽  
Tian Tian Guo ◽  
Yao Zhi Du
Keyword(s):  
Communication System ◽  
Signal Transmission ◽  
Cellular Communication ◽  
D2d Communication ◽  
System Capacity ◽  
Reconfigurable Antenna ◽  
Device To Device ◽  
Device To Device Communication

Device-to-Device (D2D) communication allows user devices in proximity to directly communicate with each other through reusing resources in cellular communication system. D2D improves the system capacity while it also raises some challenges on interference. This paper adopts reconfigurable antenna in D2D communication generating directional signal transmission between D2D pairs which mitigates the interference to other users. The simulations show that such scheme improve the system capacity compared to the traditional one.

scholarly journals Latency optimization for D2D-enabled parallel mobile edge computing in cellular networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Yan Cai ◽  
Liang Ran ◽  
Jun Zhang ◽  
Hongbo Zhu
Keyword(s):  
Cellular Networks ◽  
Optimal Solution ◽  
Vital Role ◽  
Base Stations ◽  
Low Latency ◽  
Mobile Edge Computing ◽  
System Delay ◽  
Simulation Results ◽  
And Task ◽  
Parallel Communication

AbstractEdge offloading, including offloading to edge base stations (BS) via cellular links and to idle mobile users (MUs) via device-to-device (D2D) links, has played a vital role in achieving ultra-low latency characteristics in 5G wireless networks. This paper studies an offloading method of parallel communication and computation to minimize the delay in multi-user systems. Three different scenarios are explored, i.e., full offloading, partial offloading, and D2D-enabled partial offloading. In the full offloading scenario, we find a serving order for the MUs. Then, we jointly optimize the serving order and task segment in the partial offloading scenario. For the D2D-enabled partial offloading scenario, we decompose the problem into two subproblems and then find the sub-optimal solution based on the results of the two subproblems. Finally, the simulation results demonstrate that the offloading method of parallel communication and computing can significantly reduce the system delay, and the D2D-enabled partial offloading can further reduce the latency.

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