• 제목/요약/키워드: Ofdma

Search Result 372, Processing Time 0.016 seconds

Joint Bandwidth Allocation and Path Selection Scheme for Uplink Transmission in IEEE 802.16j Networks with Cooperative Relays (협력 중계를 이용한 IEEE 802.16j 네트워크를 위한 상향 링크에서의 통합 대역 할당 및 경로 선택 기법)

  • Hwang, Ho-Young;Lee, Hyuk-Joon;Jeong, In-Gun;Jung, In-Sung;Roh, Bong-Soo;Park, Gui-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38C no.1
    • /
    • pp.64-77
    • /
    • 2013
  • In this paper, we propose a joint bandwidth allocation and path selection scheme for IEEE 802.16j networks in uplink with cooperative relaying, and we evaluate the performance of the proposed scheme by using OPNET based simulation in hilly terrain with heavy tree density. The proposed scheme maximizes the system throughput in uplink with cooperative relaying in IEEE 802.16j networks. Then, we transform the proposed scheme into multi-dimensional multiple choice knapsack problem (MMKP) based scheme. We also propose uplink throughput maximization scheme and MMKP based scheme without cooperative relaying. We show that the system throughput of the proposed MMKP based scheme is higher than that of link quality based scheme, and cooperative relaying provides higher system throughput than the conventional case without cooperative relaying in uplink.

Efficient Resource Allocation Schemes for Relay-based Cooperative Networks in 3GPP LTE-Advanced Systems (3GPP LTE-Advanced 시스템에서 릴레이 기반의 협력 네트워크를 위한 효율적인 자원할당 기법)

  • Kim, San-Hae;Yang, Mo-Chan;Lee, Je-Yeon;Shin, Yo-An
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.6A
    • /
    • pp.555-567
    • /
    • 2010
  • Unlike single-hop systems, multi-hop systems that use relay nodes assign a part of the overall resources to relay communications. If efficient resource allocation schemes are not adopted, this leads to a loss of resources. Moreover, because we may not be able to guarantee high-link performance due to the adjacent-cell interference in relay-based cellular systems, resource efficiency can be severely decreased. In this paper, we propose efficient resource allocation schemes for downlink relay-based networks in 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution)-Advanced systems. Unlike conventional schemes that have static resource regions for each data link, the proposed schemes dynamically allocate the resources of each link to resource blocks, by considering the channel state and the capacity of each link. We also propose resource overlapping schemes in which two different links overlap at the same resource region, so as to improve cell or user throughput performance. The proposed resource overlapping schemes do not require additional processes such as interference cancellation in users, thank to considering additional interference from resource overlapping in advance.