Dynamic resource allocation in OFDM systems: an overview of cross-layer optimization principles and techniques

Bohge, Mathias; Gross, James; Wolisz, Adam; Meyer, Max

doi:10.1109/mnet.2007.314539

Cited by 120 publications

(71 citation statements)

References 10 publications

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“…Several different strategies can be applied. Bit loading [28,32,15] refers to the case where the transmitter maximizes the sum data rate over all sub-carriers by varying the transmit power p n and modulation assignment r n per sub-carrier. It requires (as input) a maximum transmit power budget P max as well as a target bit error rate (BER) p max .…”

Section: Dynamic Single-user Ofdmmentioning

confidence: 99%

Enhancing IEEE 802.11a/n with dynamic single-user OFDM adaptation

Gross

Emmelmann

Punal

et al. 2009

Performance Evaluation

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Earlier paper have demonstrated that the achievable throughput of OFDM systems can benefit significantly from individual modulation/transmit power selection on a per sub-carrier basis according to the actual gain of individual sub-carriers (so called dynamic OFDM scheme). Usage of such approach requires, however, providing support for additional functionalities like: acquisition of the sub-carrier gains, signaling of the used modulation types between sender and receiver, etc. Therefore dynamic OFDM is actively pursued for future radio interfaces, rather than considered as extension of existing OFDM based standards. In this paper we introduce a proposal how the widely accepted IEEE 802.11a/g systems as well as the emerging IEEE 802.11n system might be extended to support the dynamic OFDM in a single-user (point-to-point) setting. The presented approach guarantees backward compatibility to legacy devices. We address these issues by presenting a) a set of protocol modifications required to incorporate dynamic OFDM in 802.11a/g/n; and b) a performance evaluation of the suggested extension (referred further on to as single-user 802.11 DYN mode). Although 802.11n already includes advanced MAC and PHY features, i.e., frame aggregation and MIMO transmissions, our performance evaluation demonstrates that a further improvement is achievable by incorporating dynamic OFDM.

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Section: Dynamic Single-user Ofdmmentioning

confidence: 99%

Enhancing IEEE 802.11a/n with dynamic single-user OFDM adaptation

Gross

Emmelmann

Punal

et al. 2009

Performance Evaluation

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“…Therefore, OFDMA is a promising technique for use in various systems and scenarios. While the application of OFDMA in single-cell settings is well understood (see References [1][2][3]), a key open issue with the application of orthogonal frequency division multiple access in mobile cellular systems is the control of co-channel interference. Especially terminals located at the cell border largely suffer from the power radiated by the During the last couple of years, soft frequency reuse (SFR) [4] has been established as a standard technique to control CCI in cellular OFDMA systems.…”

Section: Introductionmentioning

confidence: 99%

Optimal soft frequency reuse and dynamic sub‐carrier assignments in cellular OFDMA networks

Bohge

Gross

Wolisz

2010

Trans Emerging Tel Tech

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SUMMARYSoft frequency reuse (SFR) is a common technique for co-channel interference (CCI) mitigation in cellular OFDMA networks. The performance of such networks significantly depends on the configuration of the power profiles that implement the soft frequency reuse patterns. In this paper, we investigate the performance of static soft frequency reuse by comparing it against the optimal case, in which a central entity optimally distributes power among the users of the network. It is shown that there is a significant performance gap between both approaches, which needs to be filled by adaptive SFR mechanisms. Moreover, we show that the achievable gain of static SFR is small in a system that is able to optimally decide on terminal/sub-carrier assignments.

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“…In either case, the optimal resource allocation solutions are difficult to get due to high computational complexity. Instead, suboptimal solutions based on relaxation, problem splitting, or heuristic algorithms are proposed to reduce computational complexity (4). Such algorithms are often refereed to as loading algorithms.…”

Section: Introductionmentioning

confidence: 99%

Resource Management Framework for QoS Scheduling in IEEE 802.16 WiMAX Networks

HuaWang¹,

Dittmann²

2009

WIMAX New Developments

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IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays an important role in QoS provisioning for different types of services. In this chapter, we propose a downlink resource management framework for QoS scheduling in OFDMA based WiMAX systems. Our framework consists of a dynamic resource allocation (DRA) module and a connection admission control (CAC) module. A two-level hierarchical scheduler is developed for the DRA module, which can provide more organized service differentiation among different service classes, and a measurement-based connection admission control strategy is introduced for the CAC module. Through system-level simulation, it is shown that the proposed framework can work adaptively and efficiently to improve the system performance in terms of high spectral efficiency and low outage probability.

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Dynamic resource allocation in OFDM systems: an overview of cross-layer optimization principles and techniques

Cited by 120 publications

References 10 publications

Enhancing IEEE 802.11a/n with dynamic single-user OFDM adaptation

Enhancing IEEE 802.11a/n with dynamic single-user OFDM adaptation

Optimal soft frequency reuse and dynamic sub‐carrier assignments in cellular OFDMA networks

Resource Management Framework for QoS Scheduling in IEEE 802.16 WiMAX Networks

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