Quality of Service Analysis and Queuing Performance Modeling of Orthogonal Frequency Division Multiple Access Based IEEE 802.16/WiMAX System

2012 ◽  
Vol 4 (3) ◽  
pp. 54-70
Author(s):  
Abdelali El Bouchti ◽  
Abdelkrim Haqiq ◽  
Said El Kafhali
Keyword(s):  
Quality Of Service ◽  
Poisson Process ◽  
Admission Control ◽  
Multiple Access ◽  
Performance Modeling ◽  
Base Station ◽  
Frequency Division ◽  
Packet Arrival ◽  
Subscriber Station

The authors present a problem of queuing theoretic performance modeling and analysis of Orthogonal Frequency Division Multiple Access (OFDMA) under broadband wireless networks. They consider a single-cell WiMAX environment in which the base station allocates sub channels to the subscriber stations in its coverage area. The sub channels allocated to a subscriber station are shared by multiple connections at that subscriber station. To ensure the Quality of Service (QoS) performances, a Connection Admission Control (CAC) mechanism is considered at a subscriber station. A queuing analytical framework for these admission control mechanisms is presented considering OFDMA-based transmission at the physical layer and based on the queuing model; both the connection-level and packet-level performances are studied and compared with their analogues in the case without CAC. The connection arrival is modeled by a Poisson process and the packet arrival for a connection by a Markov Modulated Poisson Process (MMPP). Several performance measures, namely connection blocking probability, average number of ongoing connections, average queue length, packet dropping probability, queue throughput and average packet delay, are then derived and quantified.

scholarly journals QoS-Oriented Dynamic Power Allocation in NOMA-based Wireless Caching Networks

2020 ◽  
Author(s):  
Yue Yin ◽  
Miao Liu ◽  
Guan Gui ◽  
Haris Gacanin ◽  
Fumiyuki Adachi
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Multiple Access ◽  
Base Station ◽  
System Efficiency ◽  
Allocation Strategy ◽  
Dynamic Power ◽  
Qos Requirement

<div>Non-orthogonal multiple access (NOMA) based</div><div>wireless caching network (WCN) is considered as one of the most</div><div>promising technologies for next-generation wireless communications</div><div>since it can significantly improve the spectral efficiency.</div><div>In this paper, we propose a quality of service (QoS)-oriented</div><div>dynamic power allocation strategy for NOMA-WCN. In content</div><div>stack phase, the base station sends multiple files to the content</div><div>servers by allocating different powers according to the different</div><div>QoS targets of files, for ensuring that all content servers can</div><div>successfully decode the two most popular files. In content deliver</div><div>phase, the content servers serve two users at the same time</div><div>by allocating the minimum power to the far user according</div><div>to the QoS requirement, and then all the remaining power is</div><div>allocated to the near user. Hence, the proposed power allocation</div><div>scheme is able to increase the hit probability and drop the outage</div><div>probability compared with conventional method. Simulation</div><div>results confirm that the proposed power allocation method can</div><div>significantly improve the caching hit probability and reduce the</div><div>user outage probability. It is also shown that this strategy can</div><div>reduce the user delay time, improve the system efficiency and</div><div>the capacity.</div>

scholarly journals QoS-Oriented Dynamic Power Allocation in NOMA-based Wireless Caching Networks

2020 ◽  
Author(s):  
Yue Yin ◽  
Miao Liu ◽  
Guan Gui ◽  
Haris Gacanin ◽  
Fumiyuki Adachi
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Spectral Efficiency ◽  
Multiple Access ◽  
Base Station ◽  
System Efficiency ◽  
Allocation Strategy ◽  
Dynamic Power ◽  
Qos Requirement

<div>Non-orthogonal multiple access (NOMA) based</div><div>wireless caching network (WCN) is considered as one of the most</div><div>promising technologies for next-generation wireless communications</div><div>since it can significantly improve the spectral efficiency.</div><div>In this paper, we propose a quality of service (QoS)-oriented</div><div>dynamic power allocation strategy for NOMA-WCN. In content</div><div>stack phase, the base station sends multiple files to the content</div><div>servers by allocating different powers according to the different</div><div>QoS targets of files, for ensuring that all content servers can</div><div>successfully decode the two most popular files. In content deliver</div><div>phase, the content servers serve two users at the same time</div><div>by allocating the minimum power to the far user according</div><div>to the QoS requirement, and then all the remaining power is</div><div>allocated to the near user. Hence, the proposed power allocation</div><div>scheme is able to increase the hit probability and drop the outage</div><div>probability compared with conventional method. Simulation</div><div>results confirm that the proposed power allocation method can</div><div>significantly improve the caching hit probability and reduce the</div><div>user outage probability. It is also shown that this strategy can</div><div>reduce the user delay time, improve the system efficiency and</div><div>the capacity.</div>

Study of Power Control in CDMA System on the basis of optimization Technique

2017 ◽  
Vol 7 (8) ◽  
pp. 126
Author(s):  
. Geetanjli
Keyword(s):  
Power Control ◽  
Multiple Access ◽  
Optimization Technique ◽  
System Optimization ◽  
Base Station ◽  
Particle Swarm Algorithm ◽  
Cdma System ◽  
Frequency Division ◽  
Cdma Systems ◽  
Time Division

The power control in CDMA systems, grant numerous users to share resources of the system uniformly between each other, leading to expand capacity. With convenient power control, capacity of CDMA system is immense in contrast of frequency division multiple access (FDMA) and time division multiple access (TDMA). If power control is not achieved numerous problems such as the near-far effect will start to monopolize and consequently will reduce the capacity of the CDMA system. However, when the power control in CDMA systems is implemented, it allows numerous users to share resources of the system uniformly between themselves, leading to increased capacity For power control in CDMA system optimization algorithms i.e. genetic algorithm & particle swarm algorithm can be used which regulate a convenient power vector. These power vector or power levels are dogged at the base station and announce to mobile units to alter their transmitting power in accordance to these levels. The performances of the algorithms are inspected through both analysis and computer simulations, and compared with well-known algorithms from the literature.

scholarly journals A Hybrid Approach to Call Admission Control in 5G Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammed Al-Maitah ◽  
Olena O. Semenova ◽  
Andriy O. Semenov ◽  
Pavel I. Kulakov ◽  
Volodymyr Yu. Kucheruk
Keyword(s):  
Artificial Intelligence ◽  
Quality Of Service ◽  
Admission Control ◽  
Mobile Communications ◽  
Communication Systems ◽  
Call Admission Control ◽  
Hybrid Approach ◽  
5G Networks ◽  
Call Admission

Artificial intelligence is employed for solving complex scientific, technical, and practical problems. Such artificial intelligence techniques as neural networks, fuzzy systems, and genetic and evolutionary algorithms are widely used for communication systems management, optimization, and prediction. Artificial intelligence approach provides optimized results in a challenging task of call admission control, handover, routing, and traffic prediction in cellular networks. 5G mobile communications are designed as heterogeneous networks, whose important requirement is accommodating great numbers of users and the quality of service satisfaction. Call admission control plays a significant role in providing the desired quality of service. An effective call admission control algorithm is needed for optimizing the cellular network system. Many call admission control schemes have been proposed. The paper proposes a methodology for developing a genetic neurofuzzy controller for call admission in 5G networks. Performance of the proposed admission control is evaluated through computer simulation.

scholarly journals Joint power allocation and subcarrier assignment for device to device in 5G time division duplex networks

2018 ◽  
Vol 14 (11) ◽  
pp. 155014771881109 ◽  
Author(s):  
Pan Zhao ◽  
Lei Feng ◽  
Peng Yu ◽  
Wenjing Li ◽  
Xuesong Qiu
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Base Station ◽  
Joint Power ◽  
Time Division Duplex ◽  
Device To Device ◽  
Minlp Problem ◽  
Device To Device Communication ◽  
Time Division

The explosive demands for mobile broadband service bring a major challenge to 5G wireless networks. Device-to-device communication, adopting side links for user-direct communication, is regarded as a main technical source for offloading large volume of mobile traffic from cellular base station. This article investigates the joint power and subcarrier allocation scheme for device-to-device communication in 5G time division duplex systems. In time division duplex system, instead of utilizing an exclusive portion of the precious cellular spectrum, device-to-device pairs reuse the subcarriers occupied by cellular users, thus producing harmful interference to cellular users in both uplink and downlink communication, and strongly limiting the spectrum efficiency of the system. To this end, we focus on the maximization of device-to-device throughput while guaranteeing both uplink and downlink channel quality of service of cellular users as well as device-to-device pairs. The problem is formulated as a mixed integer non-linear programming (MINLP) problem. To make it tractable, we separate the original MINLP problem into two sub problems: power allocation and sub-carrier reusing. The former is to develop optimal power allocation for each device-to-device pair and each cellular user, with the constraints of maximum power and quality of service. It is solved by geometric programming technique in convex optimization method. The latter is derived as a one-to-many matching problem for scheduling multiple subcarriers occupied by cellulars to device-to-device pairs. It is solved by Hungarian method. Simulation results show that the proposed scheme significantly improves system capacity of the device-to-device underlay network, with quality of service of both device-to-device users and cellular users guaranteed.

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