Subcarrier allocation based on correlated equilibrium in multi-cell OFDMA systems

Zheng Jianchao, Cai Yueming, Wu, Wu Dan

Description

In uplink orthogonal frequency division multiple access (OFDMA) systems, efficient resource allocation can greatly improve system performance. In this article, taking throughput, inter-cell interference and complexity into account, we present a game-theoretical approach to perform distributed subcarrier allocation for multi-cell OFDMA systems with limited base station (BS) coordination. Firstly, we construct a multi-cell resource allocation game. Creatively, the subcarrier is viewed as a game player to choose the most satisfying user and the BS acts as a referee or a coordinator. Then, we introduce the correlated equilibrium which helps the non-cooperative players coordinate their strategies, hence, achieves better performance compared to Nash equilibrium. Particularly, we point out the condition under which the correlated equilibrium is Pareto efficient. Moreover, we propose a novel subcarrier allocation algorithm based on the no-regret procedure that guarantees convergence to correlated equilibrium, in which the BS coordinates the players’ strategies and provides only partial information exchange. Extensive simulation results are provided to demonstrate the effectiveness of the proposed algorithm.

Sujets

• Orthogonal Frecuency Division Multiple Access
• Correlated equilibrium

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 21
• Langue: English

Extrait

Zheng et al. EURASIP Journal on Wireless Communications and Networking 2012, 2012 :233 http://jwcn.eurasipjournals.com/content/2012/1/233

R E S E A R C H Open Access Subcarrier allocation based on correlated equilibrium in multi-cell OFDMA systems Jianchao Zheng * , Yueming Cai and Dan Wu

Abstract In uplink orthogonal frequency division multiple access (OFDMA) systems, efficient resource allocation can greatly improve system performance. In this article, taking throughput, inter-cell interference and complexity into account, we present a game-theoretical approach to perform distributed subcarrier allocation for multi-cell OFDMA systems with limited base station (BS) coordination. Firstly, we construct a multi-cell resource allocation game. Creatively, the subcarrier is viewed as a game player to choose the most satisfying user and the BS acts as a referee or a coordinator. Then, we introduce the correlated equilibrium which helps the non-cooperative players coordinate their strategies, hence, achieves better performance compared to Nash equilibrium. Particularly, we point out the condition under which the correlated equilibrium is Pareto efficient. Moreover, we propose a novel subcarrier allocation algorithm based on the no-regret procedure that guarantees convergence to correlated equilibrium, in which the BS coordinates the players’ strategies and provides only partial information exchange. Extensive simulation results are provided to demonstrate the effectiveness of the proposed algorithm. Keywords: OFDMA, Multi-cell, Inter-cell interference, Subcarrier allocation, Correlated equilibrium, Base station coordination

Introduction scheme, inter-cell interference is a major impairment that Orthogonal frequency division multiple access (OFDMA) limits the system throughput [3]. In multi-cell environ- has emerged as one of the most promising multiple access ment, one of the major issues to research is how to techniques for high data rate transmission over wireless maximize the performance by controlling the co-channel channels due to its ability to mitigate multipath fad- interference among the neighboring cells [4]. Interfer- ing and its efficient implementation using IFFT and FFT ence coordination can be fulfilled by allocating system blocks. The most recently proposed next generation wire- resources with interference awareness in terms of fre- less communication technologies, such as wireless wide quency, time, transmit power and space, etc. [5,6]. Due area network (WWAN) standards, 3GPP2 ultra mobile to limited and precious radio resources in cellular net- broadband (UMB), IEEE 802.20 mobile broadband wire- works, interference aware resource allocation is a chal- less access (MBWA), 3GPP LTE and worldwide interop- lenging problem and has received much attention from erability for microwave access (WiMAX) are all OFDMA both research and standardization communities in recent based [1]. years [5-9]. Moreover, because any change of resource In an OFDMA system, the spectrum is orthogonally allocation in a specific cell will affect the performance of divided into time-frequency resource blocks (RBs), which the nearby cells, joint resource allocation considering both increases flexibility in resource allocation, thereby allow- throughput and interference over a cluster of neighboring ing high spectral efficiency. Exploiting all RBs simultane- cells via BS coordination is a promising solution. ously in every cell to achieve universal frequency reuse Recently, BS coordination, where neighboring BSs con- becomes a key objective toward the deployment of 4G nected through high-speed wireline links only share chan- networks [2]. Focusing on the universal frequency reuse nel state information (CSI) and can jointly compute their transmit power and user scheduling, has been proposed *Correspondence: [e-mail] or t rference, Institute of Communications Engineering, PLA University of Science and as a maj echnique to mitigate co-channel inte Technology, Nanjing, China since it shifts the signal processing burden to the BSs © 2012 Zheng et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.