Multiuser subcarrier allocation for QoS provision in the OFDMA systems

Pietrzyk, Sławomir; Janssen, G. C. A. M.

doi:10.1109/vetecf.2002.1040769

Cited by 82 publications

(44 citation statements)

References 4 publications

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“…Such approach is motivated by a simple observation that users with good channels require less transmit power, thus causes less CCI and therefore have higher chances for admission. Various options of this routine have been described in many papers, including [5], [4] and [3]. An alternative strategy is to use the optimal Hungarian algorithm or to improve the greedy assignment by swapping subcarriers between users as in [5], [3].…”

Section: Step 2: Subcarrier To User Allocationmentioning

confidence: 99%

“…Various options of this routine have been described in many papers, including [5], [4] and [3]. An alternative strategy is to use the optimal Hungarian algorithm or to improve the greedy assignment by swapping subcarriers between users as in [5], [3]. These methods, however, are not considered here due to their increased computational complexity.…”

Section: Step 2: Subcarrier To User Allocationmentioning

confidence: 99%

“…-Single-cell systems, [3], [4], [5]. These papers present various interesting resource allocation algorithms for OFDMA but they do not consider CCI.…”

Section: Introductionmentioning

confidence: 99%

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Performance Evaluation of Bit Loading, Subcarrier Allocation, and Power Control Algorithms for Cellular OFDMA Systems

Pietrzyk

Janssen

2004

Personal Wireless Communications

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Abstract.We consider the problem of radio resource allocation for QoS support in the downlink of a cellular OFDMA system. The major impairments present are co-channel interference (CCI) and frequency selective fading. The allocation problem involves assignment of base stations, subcarriers and bits, as well as power control, for multiple users. We evaluate the performance of a three-stage, low-complexity, heuristic algorithm, which allows to distribute radio resources among multiple users according to theirs individual QoS requirements, while at the same time maintaining the QoS of already established links in all co-channel cells. The evaluation includes checking system operation for various conditions described by different: a) delay spread, b) data rate required by a single user and c) path loss. It is shown that the proposed method is superior in terms of offered traffic and blocking probability to classical method based on FDMA with power control. Also, the performance of our scheme increases in highly frequency selective environment, disastrous for classical fixed schemes, since our method benefits from multiuser diversity.

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Section: Step 2: Subcarrier To User Allocationmentioning

confidence: 99%

Section: Step 2: Subcarrier To User Allocationmentioning

confidence: 99%

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Performance Evaluation of Bit Loading, Subcarrier Allocation, and Power Control Algorithms for Cellular OFDMA Systems

Pietrzyk

Janssen

2004

Personal Wireless Communications

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“…However, while achieving significant gain, this algorithm might not reach the optimal solution (in terms of achieving the total maximum channel gain for users). The Hungarian method [9] and sort-swap algorithm [10] are introduced and extended to solve this allocation problem as an assignment problem in maximizing total channel gain and achieve an optimal solution. However, simulation results show that the DSA algorithm in [3] achieves perceived channel gains within a fraction of a decibel of the optimal solution [11].…”

Section: Introductionmentioning

confidence: 99%

An Investigation of Dynamic Subcarrier Allocation in MIMO–OFDMA Systems

Peng

Armour

McGeehan

2007

IEEE Trans. Veh. Technol.

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Abstract-In this paper, orthogonal frequency-division multiple-access (OFDMA) systems with dynamic deterministic (as opposed to pseudorandom) allocation of subcarriers to users to exploit multiuser diversity are investigated. Previously published work on dynamic multiuser subcarrrier allocation for OFDMA systems with single-input-single-output (SISO) channels are surveyed. A near-optimal low-complexity algorithm for SISO systems, which is structurally similar to the algorithm by Rhee and Cioffi, is extended to the case of multiple-input-multiple-output (MIMO) systems in this paper. The optimality and adaptability of this algorithm are analyzed by formulating an assignment problem and comparing with one optimal and two extended suboptimal strategies proposed based on previous work. Consideration of a MIMO channel creates further issues for the subcarrier-allocation process. In particular, methods whereby an appropriate subcarrier allocation may be exploited to minimize the effects of correlation in MIMO channels are of considerable interest. Several novel variants of the algorithm (referred to as "schemes") are proposed and evaluated for MIMO systems employing both space-time block coding (STBC) and spatial multiplexing (SM) in both uncorrelated and correlated fading channels. Simulation results identify the most suitable schemes for both STBC and SM and, in particular, show that substantial improvements in performance (in terms of bit-error rate) in correlated channels can be achieved by means of suitable subcarrier allocation. In uncorrelated channels, the best scheme can offer approximately 7-dB gain over the conventional MIMO channel; in highly correlated channels, even more substantial improvements (> 11-dB gain for STBC, > 20-dB gain for SM) in performance can also be achieved, demonstrating the ability of a well-designed subcarrier-allocation scheme to mitigate the debilitating effects of correlation on MIMO systems. Allocation-mapping matrix element for user k and subcarrier n. c k,n Allocation-mapping matrix element for a user or its duplication k and subcarrier n. Index Terms-Multiple

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“…More specifically, using a simple but efficient uniform SSCH (USSCH) pattern, the SSCH/SDMA-OFDM system is capable of achieving a high frequency diversity, and hence exhibits a high robustness to MUI. In the literature, substantial research efforts have been invested in designing subcarrier allocation algorithms for singleinput-single-output (SISO) OFDM systems, which are subject to various design constraints, such as requiring the minimal overall transmit power [14][15][16][17][18][19], achieving the maximum capacity [19][20][21] or complying with specific quality-of-service (QoS) criteria [22], etc. A subcarrier and bit allocation algorithm designed for minimising the overall transmit power for a MIMO-OFDM systems was proposed in [23].…”

Section: Introductionmentioning

confidence: 99%

Multiuser MIMO-OFDM systems using subcarrier hopping

Jiang

Hanzo

2006

IEE Proc., Commun.

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Recently space division multiple access (SDMA) assisted multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems invoking multiuser detection (MUD) techniques have attracted substantial research interest, which is capable of exploiting both transmitter multiplexing gain and receiver diversity gain. A new scheme referred to here as slowsubcarrierhopping (SSCH) assisted multiuser SDMA-OFDM, is proposed. It is shown that, with the aid of the so-called uniform SSCH (USSCH) pattern, the multiuser interference (MUI) experienced by the high-throughput SDMA-OFDM system can be effectively suppressed, resulting in a significant performance improvement. In the investigations conducted, the proposed USSCH-aided SDMA-OFDM system was capable of outperforming a range of SDMA-OFDM systems considered, including the conventional SDMA-OFDM system dispensing with the employment of frequency-hopping techniques. For example, at an E b /N 0 value of 12 dB, the proposed USSCH/SDMA-OFDM system reduced the bit error ratio (BER) by about three orders of magnitude, in comparison to the conventional SDMA-OFDM system, while maintaining a similar computational complexity.

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Multiuser subcarrier allocation for QoS provision in the OFDMA systems

Cited by 82 publications

References 4 publications

Performance Evaluation of Bit Loading, Subcarrier Allocation, and Power Control Algorithms for Cellular OFDMA Systems

Performance Evaluation of Bit Loading, Subcarrier Allocation, and Power Control Algorithms for Cellular OFDMA Systems

An Investigation of Dynamic Subcarrier Allocation in MIMO–OFDMA Systems

Multiuser MIMO-OFDM systems using subcarrier hopping

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