LTE uplink scheduling algorithms: Performance and challenges

Safa, Haïdar; Tohme, Kamal

doi:10.1109/ictel.2012.6221230

Cited by 50 publications

(45 citation statements)

References 4 publications

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“…Different system performance measures for SC-FDMA scheduling and subcarrier allocation are presented in Lee et al (2009), Wong et al (2009), Ahmad and Assaad (2011), and Safa and Tohme (2012). Maximizing the sum utility, known as the proportional fair criterion, in the time and frequency domain, is presented in Lee et al (2009), where some sub-algorithms for assigned UEs are also proposed.…”

Section: Related Workmentioning

confidence: 99%

“…In Ahmad and Assaad (2011), the authors transformed the BIP problem in Wong et al (2009) into a canonical dual problem, and based on this approach, they developed a polynomial-time complexity, but suboptimal, algorithm to solve the power minimization problem in SC-FDMA uplink. The problem of minimizing the number of allocated subcarriers meeting the given demand, is considered in Safa and Tohme (2012), as a measure for the performance of the existing greedy-based heuristic algorithms. Comparatively, the problem of minimizing power efficiency has been much less studied.…”

Section: Related Workmentioning

confidence: 99%

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Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation

et al. 2015

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We study resource allocation in cellular systems and consider the problem of finding a power efficient scheduling in an uplink single carrier frequency division multiple access system (SC-FDMA). Due to the discrete nature of this problem and its computational difficulty, particularly in a real-time setting, the use of suboptimal algorithms is common practice. We aim at an effective way of gauging the performance of suboptimal algorithms by finding tight bounds on the global optimum.Toward this end, we first provide a basic integer linear programming formulation. Then we propose a significantly stronger column-oriented formulation and a corresponding column generation method, as well as an enhanced column generation scheme. The latter extends the first scheme through the inclusion of a stabilization technique, an approximate column generation principle, and a tailored heuristic that is embedded in the column generation scheme to find high-quality though not necessarily global optimal solutions.The computational evaluation demonstrates that compared with a poor performance by the integer linear programming formulation, the column generation method can produce near-optimal schedules that enable a sharp bounding interval. The enhanced column generation method significantly sharpens the bounding interval. Hence the column generation approach serves well for the purpose of benchmarking results for large-scale instances.

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Section: Related Workmentioning

confidence: 99%

Section: Related Workmentioning

confidence: 99%

Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation

et al. 2015

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“…The consecutive-channel allocation problems in LFDMA are more challenging than IFDMA. Some works have been devoted for addressing the problems [46,47,48]. Global optimal solutions for these problems in LFDMA may not be achievable in practice due to the heavy computational overhead.…”

Section: Utility Optimization In Sc-fdma Systemsmentioning

confidence: 99%

From Orthogonal to Non-orthogonal Multiple Access: Energy- and Spectrum-Efficient Resource Allocation

Lei¹

2016

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The rapid pace of innovations in information and communication technology (ICT) industry over the past decade has greatly improved people's mobile communication experience. This, in turn, has escalated exponential growth in the number of connected mobile devices and data traffic volume in wireless networks. Researchers and network service providers have faced many challenges in providing seamless, ubiquitous, reliable, and high-speed data service to mobile users. Mathematical optimization, as a powerful tool, plays an important role in addressing such challenging issues.This dissertation addresses several radio resource allocation problems in 4G and 5G mobile communication systems, in order to improve network performance in terms of throughput, energy, or fairness. Mathematical optimization is applied as the main approach to analyze and solve the problems. Theoretical analysis and algorithmic solutions are derived. Numerical results are obtained to validate our theoretical findings and demonstrate the algorithms' ability of attaining optimal or near-optimal solutions.Five research papers are included in the dissertation. In Paper I, we study a set of optimization problems of consecutive-channel allocation in single carrier-frequency division multiple access (SC-FDMA) systems. We provide a unified algorithmic framework to optimize the channel allocation and improve system performance. The next three papers are devoted to studying energy-saving problems in orthogonal frequency division multiple access (OFDMA) systems. In Paper II, we investigate a problem of jointly minimizing energy consumption at both transmitter and receiver sides. An energy-efficient scheduling algorithm is developed to provide optimality bounds and near-optimal solutions. Next in Paper III, we derive fundamental properties for energy minimization in load-coupled OFDMA networks. Our analytical results iii suggest that the maximal use of time-frequency resources can lead to the lowest network energy consumption. An iterative power adjustment algorithm is developed to obtain the optimal power solution with guaranteed convergence. In Paper IV, we study an energy minimization problem from the perspective of scheduling activation and deactivation of base station transmissions. We provide mathematical formulations and theoretical insights. For problem solution, a column generation approach, as well as a bounding scheme are developed. Finally, towards to 5G communication systems, joint power and channel allocation in nonorthogonal multiple access (NOMA) is investigated in Paper V in which an algorithmic solution is proposed to improve system throughput and fairness. iv Populärvetenskaplig SammanfattningDen snabba utvecklingen inom informations-och kommunikations teknikområdet har avsevärt förbättrat människors upplevelser av mobilkommunikation. Detta i sin tur har lett till en exponentiellökning av antalet anslutna mobila enheter och mängden datatrafik i mobila nätverk. Forskare och nätverksoperatörer har stått inför många utmaningar för att ...

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“…As mobile users typically employ battery-powered handsets, it is of significance to consider minimum sum power, subject to meeting specified uplink demand target. Another problem amounts to minimizing the number of allocated channels required to meet given demand target [15]. This problem setting is relevant to making as much resource available as possible for elastic traffic, while guaranteeing the rates for real-time applications.…”

Section: Introductionmentioning

confidence: 99%

“…Besides maximizing the sum utility, other performance measures have been considered [15], [17]. As mobile users typically employ battery-powered handsets, it is of significance to consider minimum sum power, subject to meeting specified uplink demand target.…”

Section: Introductionmentioning

confidence: 99%

A Unified Graph Labeling Algorithm for Consecutive-Block Channel Allocation in SC-FDMA

Lei

Yuan

et al. 2013

IEEE Trans. Wireless Commun.

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Abstract-Optimal channel allocation is a key performance engineering aspect in single-carrier frequency-division multiple access (SC-FDMA). In SC-FDMA with localized channel assignment, the channels of each user must form a consecutive block. Subject to this constraint, various performance objectives, such as maximum utility, minimum power, and minimum number of channels, have been studied. We present a unified graph labeling algorithm for these problems, based on the structural insight that SC-FDMA channel allocation can be modeled as finding an optimal path in an acyclic graph. By this insight, our algorithm applies the concept of labeling and label domination that represent non-trivial extensions of finding a shortest or longest path. The key parameter in trading performance versus computation is the number of labels kept per node. Increasing the number ultimately enables global optimality. The algorithm's approach is further justified by its global optimality guarantee with strong polynomial-time complexity for two specific scenarios, where the input is user-invariant and channel-invariant, respectively. For the general case, we provide numerical results demonstrating the algorithm's ability of attaining near-optimal solutions.

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LTE uplink scheduling algorithms: Performance and challenges

Cited by 50 publications

References 4 publications

Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation

Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation

From Orthogonal to Non-orthogonal Multiple Access: Energy- and Spectrum-Efficient Resource Allocation

A Unified Graph Labeling Algorithm for Consecutive-Block Channel Allocation in SC-FDMA

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