• Title, Summary, Keyword: 자원할당 multiple access scheme

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A Simple Resource Allocation Scheme for Throughput Enhancement in Relay Based OFDMA Cellular Systems (릴레이 기반의 OFDMA 시스템에서 전송량 증대를 위한 간략화 된 자원 할당 방법)

  • Oh, Eun-Sung;Ju, Hyung-Sik;Han, Seung-Youp;Hong, Dae-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.9
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    • pp.24-30
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    • 2009
  • This paper presents a simple resource allocation scheme for throughput enhancement in relay based orthogonal frequency division multiple access (OFDMA) cellular systems. The resource allocation schemes, which are based on the optimization problem, have high computational complexity. That is why a searching process is required on the overall allocable resources. Since these schemes should be performed in real time, we propose a simple resource allocation scheme which has very low computational complexity. Firstly, we formulate the optimization problem and draw observations for throughput maximization. Based on observations, we propose a three step allocation scheme that separates the allocable resources into three (i.e. relay, frequency and time). By doing so, the computational complexity can be reduced. Simulation results show that the proposed scheme has near-optimum performance in spite of its low computational complexity.

Multimedia Ad Hoc Wireless LAMs with Distributed Channel Allocation Based on OFDM-CDMA (OFDM-CDMA에 기반을 둔 분산 채널 할당 구조를 갖는 멀티미디어 Ad Hoc 무선 LAM에 관한 연구)

  • Yang, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.5
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    • pp.965-972
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    • 2005
  • We propose a new resource management scheme, Distributed Channel Allocation Protocol (DCAP), for multimedia Ad Hoc Wireless LANs (AWLANS). This scheme implements a Qualify-of-Service (QoS) providing distributed resource management on the Orthogonal Frequency Division Multiplexing-Code Division Multiple Access (OFDM-CDMA) channel architecture. According to the performance evaluation results for MPEG traffic sources, DCAP can be a good choice of resource management scheme for AWLANs supporting multimedia services on the Broadband Wireless Access(BWA)-type physical layer.

Optimization and Performance Analysis of Partial Multiplexing (부분 다중화의 성능 분석 및 최적화)

  • Kim, Seong Hwan;Ban, Tae Won;Jung, Bang Chul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.7
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    • pp.1589-1596
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    • 2013
  • Recently, spectral efficiency or reliability is required to be improved in the scenario of multiple access. In this paper, we consider a scenario where two source nodes access one destination node. Different with conventional multiple access studies, in our research, a part of the allocated resource is shared by two source nodes and this scheme is called partial multiplexing. Let $R_s$ denote the ratio of the amount of the shared resource to that of the resource allocated to each user. We analyze and optimize the performance of the partial multiplexing in term of $R_s$. We show that the optimal $R_s$ to maximize the throughput is 1 or 0 based on approximated bit error rate (BER). In addition, if we set a constraint on frame error rate (FER), $R_s$ can have a value between 0 and 1. We also find the approximated $R_s$ to meet the constraint as a closed form. Partial multiplexing can be a novel multiple access scheme.

User Pairing and Resource Allocation for DFTS-OFDMA Uplink Systems Using Virtual MIMO (가상 여러입력 여러출력을 적용한 DFTS-OFDMA 상향 링크 시스템에서의 사용자 쌍 선택 및 자원 할당)

  • Shin, Dong Ryul;Wang, Jinsoo;Kim, Yun Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.5
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    • pp.443-450
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    • 2013
  • We consider user pairing and resource allocation for the uplink of cellular systems employing virtual multiple input multiple output (MIMO). As a multiple access scheme, discrete Fourier transform spread orthogonal frequency division multiple access (DFTS-OFDMA) is adopted for more flexible resource allocation than single carrier (SC)-OFDMA adopted in the Long Term Evolution (LTE) system. We formulate the optimization problems of user pairing and resource allocation to maximize the throughput of the DFTS-OFDMA system under different constraints. The DFTS-OFDMA allowing non-contiguous subcarrier allocation and redundant user assignment provides a better throughput than the SC-FDMA at lower complexity in finding the optimal solution but at the cost of the increased control information indicating the allocated resources.

A Study on QoS Mapping Scheme for DAMA-based MF-TDMA Satellite Network (요구할당 기반 MF-TDMA 위성통신망에서 QoS 맵핑 기술에 관한 연구)

  • Kim, Moon;Cho, Byeong Gak
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.743-745
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    • 2012
  • 본 논문에서는 DAMA (Demand Assigned Multiple Access) 방식의 MF-TDMA ((Multi Frequency-Time Division Multiple Access) 시스템을 사용하는 위성통신망에서 QoS (Quality of Service) 성능의 보장 및 향상을 위한 효율적인 QoS 맵핑 기술을 제안한다. 제안하는 QoS 맵핑 기술은 트래픽의 패킷 우선순위와 함께 송수신 가입자 우선순위 및 위성통신망의 링크상태에 따라 트래픽의 QoS 우선순위를 결정한다. 따라서, 효과적인 트래픽 우선순위의 차별화를 통해 트래픽의 자원할당 및 전송의 QoS 성능을 향상시킬 수 있다.

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Multiuser Resource Allocation Scheme Considering Link Layer Effective Capacity in OFDMA Systems (직교 주파수 분할 다원 접속 시스템에서 실효 링크 계층 용량을 고려한 다중 사용자 자원 할당 기법)

  • Sung Si-Hwan;Yoo Myung-Sik;Shin Yo-An;Lee Won-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6B
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    • pp.508-516
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    • 2006
  • The explosive growth of wireless network users and the existence of various wireless services have demanded high rate throughput as well as user's QoS guarantees. Towards this, this paper proposes QoS-oriented subcarrier allocation scheme considering the QoS provisioning of multiple users, which is major requirement for wireless network design point of view. This paper introduces joint RR/K&H combined with M-LWDF(Modified Largest Weighted Delay First) scheme throughout observing statistical channel behavior and real time queuing analysis for appropriate resource allocation tightly connected to multiuser scheduling. Accordingly, the system throughput can be enhanced, and the QoS demanded for delay sensitive services can be satisfied. Furthermore, the proposed scheme is applied for OFDMA(Orthogonal Frequency Division Multiple Access) systems to allocate sub-carriers in optimal way. The simulation results verify plausible performances of proposed resource allocation scheme via showing superior effective capacity under time-varying physical-layer channel behaviors.

Interference Avoidance Resource Allocation for Device-to-Device Communication Based on Graph-Coloring (단말 간 직접 통신을 위한 그래프-컬러링 기반 간섭 회피 자원 할당 방법)

  • Lee, Changhee;Oh, Sung-Min;Park, Ae-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.12
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    • pp.729-738
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    • 2014
  • In this paper, we propose interference avoidance resource allocation scheme based on graph-coloring algorithm to introduce performance gain using spatial reuse in D2D (Device-to-Device) system. By assigning multiple D2D pairs to a single D2D resource, interference from neighboring D2D pairs is inevitable, which leads to performance degradation. Therefore, we first introduce the feedback information and the method considering the amount of information that can be practically provided by a D2D pair. Then, we propose how to construct a graph, which is corresponding to the D2D system, using the feedback information and adopt a graph-coloring algorithm to efficiently avoid interference. Simulation results show that the proposed resource allocation scheme outperforms traditional resource allocation schemes in both overall sum rate and spectral efficiency of D2D system while reducing the outage probability. Moreover, the outage probability, which indicates a failure rate of D2D communication, can be reduced by adopting the proposed scheme.

A QoS Based Multiple Access Scheme for the Wireless ATM Services (무선 ATM 서비스를 위한 QoS 기준 다중 접속 방법)

  • Yae, Byung-Ho;Lee, Sung-Chang
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.6
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    • pp.36-45
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    • 1998
  • This paper discusses multiple access control aspects for a wireless extension of high-speed asynchronous transfer mode(ATM) networks. One challenging requirement is that mobile systems convey of diverse types of information including voice, computer data, facsimile, and video data that have different quality of service constraints. Basically, a centralized control scheme for a coordinated multiple access is required in order to efficiently accommodate multimedia traffic on wireless links. The proposed scheme dynamically scheduling the mobile terminal, which has data to transfer according to the service, types at base station. In this scheme, the scheduling algorithm is performed on the basis of traffic descriptors and QoS parameters, which required in the connection set up phase. As a consequence, the transmission scheduling is very flexible and can account for the different traffic rate and delay constraints that emerge from voice and data integration. The simulation result shows that the proposed scheme has better performance over other scheduling algorithms.

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Resource Allocation Information Sorting Algorithm Variable Selection Scheme for MF-TDMA DAMA Satellite Communication System (MF-TDMA DAMA 위성통신 시스템에서의 자원할당정보 정렬 알고리즘 가변 선택기법 연구)

  • Park, Nam Hyoung;Han, Joo-Hee;Han, Ki Moon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.1-7
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    • 2020
  • In modern society, as technology has advanced and human life area has expanded, there has been an increasing demand for high-quality voice and video communications services without restrictions on time and place. In response to this demand, satellite communications systems that provide a wide range of communications and that offer multiple access are evolving day by day. In satellite communications systems such as Digital Video Broadcasting - Return Channel Via Satellite (DVB-RCS) and Warfighter Information Network-Tactical (WIN-T), the multi-frequency time division multiple access (MF-TDMA) demand assigned multiple access (DAMA) scheme is used for efficient resource allocation. In this scheme, since the satellite terminals periodically request resources from the network controller, and the network controller dynamically allocates resources, it is necessary to arrange resource allocation information from time to time. Shortening of the alignment time is a more important factor in a satellite communications system in which a long transmission delay occurs due to long-distance transmission and reception. In this paper, we propose a sorting algorithm variable-selection scheme that shortens the sorting time by cross-selecting the sorting algorithm based on a threshold value, while setting the number of frames in the MF-TDMA DAMA satellite communications system as the threshold value.

Distributed Resource Allocation in Multimedia Ad Hoc Local Area Networks Based on OFDM-CDMA (OFDM-CDMA 기반 멀티미디어 무선 Ad Hoc LAN에서의 분산적 자원 할당 방식)

  • Yang, Hyun-ho;Jeon, Hee-jeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.7
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    • pp.1250-1256
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    • 2001
  • A resource management scheme for ad hoc wireless local area networks (AWLAN's) is presented. This scheme combines distributed resource management scheme and orthogonal frequency division multiplexing-code division multiple access(OFDM-CDMA) technique to support multimedia services with QoS guarantees. The performance evaluation has done in terms of blocking rates and QoS loss probability.

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