• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.35-43
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• 2014

A data allocation technique is essential to improve the performance of data broadcast systems. This paper explores the issues for allocating data items on broadcast channels in the environment where multiple-data queries are submitted, and proposes a new data allocation scheme named DAMA. The proposed scheme employs the strategy that the broadcast frequency of each data is determined by the moving average of its access probability. DAMA could enhance the performance of query response time since it is capable of controlling the influence of access probability properly according to the query size. Simulation is performed to evaluate the performance of the proposed scheme. The simulation results show that the performance of DAMA is superior to other schemes in terms of the average response time.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.577-582
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• 2012

If the mobile station requests the channel allocation in mobile networks, switching center is assigned a channel to mobile station that belong to each base station. Channel allocation schemes is a fixed channel allocation, dynamic channel allocation and a hybrid approach that combines the two forms. To assign a frequency well to use resources efficiently to provide quality service to our customers. In this paper, we proposed method to assign frequencies to minimize interference between channels and to minimizes the number of searching time. The proposed method by the genetic algorithm to improve accuracy and efficiency of the verification steps and reproduction stages were used. In addition, the proposed method by comparing with other methods showed that proposed method is better through the simulations.

• ETRI Journal
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• v.37 no.3
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• pp.471-479
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• 2015

Traditional designs of cognitive radio (CR) focus on maximizing system throughput. In this paper, we study the joint overlay and underlay power allocation problem for orthogonal frequency-division multiple access-based CR. Instead of maximizing system throughput, we aim to maximize system energy efficiency (EE), measured by a "bit per Joule" metric, while maintaining the minimal rate requirement of a given CR system, under the total power constraint of a secondary user and interference constraints of primary users. The formulated energy-efficient power allocation (EEPA) problem is nonconvex; to make it solvable, we first transform the original problem into a convex optimization problem via fractional programming, and then the Lagrange dual decomposition method is used to solve the equivalent convex optimization problem. Finally, an optimal EEPA allocation scheme is proposed. Numerical results show that the proposed method can achieve better EE performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.9-15
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• 2017

In this paper, we propose a resource allocation scheme for high-power user equipment (HPUE) in public safety communication environments. The use of HPUE is being considered to increase the throughput and communication range of a UE in the disaster area where normal communication links are not available. However, HPUE may cause higher interference to UE's in adjacent cells that are allocated to the same radio resources. Therefore, it is necessary to deal with the potential interference through frequency planning and resource allocation. The performance of the proposed resource allocation scheme is evaluated through simulations in 3GPP public safety communication scenarios.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.650-657
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• 2011

This paper proposes a novel bit allocation algorithm for H.264 scalable extension(SE) based on a human visual system (HVS) to improve the coding efficiency. The proposed algorithm is consist of two stages: visual weighting model and visual weighting-based bit allocation algorithm. In the first stage, the visual weighting for each macroblock (MB) is analyzed according to the region of interests. Then the adaptation of the visual weighting into the bit allocation routine for each quality layer is performed for improving the visual quality. In the simulation results, it is observed that the proposed scheme can improve the subjective and objective video quality in the same bit rate, compared to the previous scalable video coding in H.264.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2240-2254
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• 2021

We investigate the channel allocation problem in an ultra-dense device-to-device (D2D) enabled cellular network in underlaying mode where multiple D2D users are forced to share the same channel. Two kinds of low complexity solutions, which just require partial channel state information (CSI) exchange, are devised to resolve the combinatorial optimization problem with the quality of service (QoS) guaranteeing. We begin by sorting the cellular users equipment (CUEs) links in sequence in a matric of interference tolerance for ensuring the SINR requirement. Moreover, the interference quota of CUEs is regarded as one kind of communication resource. Multiple D2D candidates compete for the interference quota to establish spectrum sharing links. Then base station calculates the occupation of interference quota by D2D users with partial CSI such as the interference channel gain of D2D users and the channel gain of D2D themselves, and carries out the channel allocation by setting different access priorities distribution. In this paper, we proposed two novel fast matching algorithms utilize partial information rather than global CSI exchanging, which reduce the computation complexity. Numerical results reveal that, our proposed algorithms achieve outstanding performance than the contrast algorithms including Hungarian algorithm in terms of throughput, fairness and access rate. Specifically, the performance of our proposed channel allocation algorithm is more superior in ultra-dense D2D scenarios.

• ETRI Journal
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• v.45 no.1
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• pp.45-59
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• 2023

In this paper, to optimize the average delay and power allocation (PA) for system users, we propose a resource scheduling scheme for wireless networks based on Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) according to the first fifth-generation standards. For delay minimization, we solve a throughput maximization problem that considers CPOFDM systems with carrier aggregation (CA). Regarding PA, we consider an approach that involves maximizing goodput using an effective signal-to-noise ratio. An algorithm for jointly solving delay minimization through computation of required user rates and optimizing the power allocated to users is proposed to compose the resource allocation approach. In wireless network simulations, we consider a scenario with the following capabilities: CA, 256-Quadrature Amplitude Modulation, millimeter waves above 6 GHz, and a radio frame structure with 120 KHz spacing between the subcarriers. The performance of the proposed resource allocation algorithm is evaluated and compared with those of other algorithms from the literature using computational simulations in terms of various Quality of Service parameters, such as the throughput, delay, fairness index, and loss rate.

• Journal of Convergence Society for SMB
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• v.4 no.1
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• pp.1-6
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• 2014

PB/MC-CDMA is an efficient system which divides the whole frequency band into several blocks, unlike a conventional MC-CDMA system. We propose an efficient resource allocation scheme in Multi-Block PB/MC-CDMA (Partial Block Multi-Carrier Code Division Multiple Access). This system aims to improve frequency efficiency and maximize the total throughput while satisfying predefined threshold over various channel conditions. Through computer simulations, we confirm that the performance of the proposed system is more effective in terms of throughput.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1357-1372
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• 2017

Energy harvesting techniques, particularly radio frequency energy harvesting (RF-EH) techniques, which are known to provide feasible solutions to enhance the performance of energy constrained wireless communication systems, have gained increasing attention. In this paper, we consider a wireless-powered cooperative communication network (WPCCN) for transferring energy in the downlink and forwarding signals in the uplink. The objective is to maximize the average transmission rate of the system, subject to the total network power constraint. We formulate such a problem as a form of wireless energy transmission based on resource allocation that searches for the joint subcarrier pairing and the time and power allocation, and this can be solved by using a dual approach. Simulation results show that the proposed joint optimal scheme can efficiently improve system performance with an increase in the number of subcarriers and relays.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.4
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• pp.436-442
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• 2006

It is important matter that inflect well allocated frequency resource in cellular network and is still more serious element in environment that provide multimedia services. Also, that do that make job scheduling how base station system or terminal according to this service request is important constituent that evaluate performance of whole system. channel allocation according to service kind causes big effect to whole system when hand off gets up in cellular network. This paper describes model and algorithm that increase two elements that is frequency allocation and job scheduling that consider multimedia service traffic special quality by emphasis that do mapping present in CDMA cellular system.