3rd International ICST Workshop on Resource Allocation in Wireless Networks

Research Article

Wardrop Equilibrium for CDMA Systems

  • @INPROCEEDINGS{10.1109/WIOPT.2007.4480091,
        author={Nicolas Bonneau and Merouane  Debbah and Eitan Altman and Are  Hjorungnes},
        title={Wardrop Equilibrium for CDMA Systems},
        proceedings={3rd International ICST Workshop on Resource Allocation in Wireless Networks},
        publisher={IEEE},
        proceedings_a={RAWNET},
        year={2008},
        month={3},
        keywords={Base stations  Channel state information  Downlink  Fading  Frequency  Game theory  Matched filters  Multiaccess communication  Nash equilibrium  Performance analysis},
        doi={10.1109/WIOPT.2007.4480091}
    }
    
  • Nicolas Bonneau
    Merouane Debbah
    Eitan Altman
    Are Hjorungnes
    Year: 2008
    Wardrop Equilibrium for CDMA Systems
    RAWNET
    IEEE
    DOI: 10.1109/WIOPT.2007.4480091
Nicolas Bonneau1,*, Merouane Debbah2,*, Eitan Altman3,*, Are Hjorungnes4,*
  • 1: MAESTRO, INRIA Sophia Antipolis, 2004 Route des Lucioles, B.P. 93, 06902 Sophia Antipolis, France
  • 2: Mobile Communications Group, Institut Eurecom, 2229 Route des Cretes, B.P. 193, 06904 Sophia Antipolis, France
  • 3: MAESTRO, INRIA Sophia Antipolis, 2004 Route des Lucioles, B.P. 93, 06902 Sophia Antipolis, Franc
  • 4: UniK-University Graduate Center, University of Oslo, Instituttveien 25, P. 0. Box 70, N-2027 Kjeller, Norway
*Contact email: nicolas.bonneau@sophia.inria.fr, merouane.debbah@eurecom.fr, eitan.altman@sophia.inria.fr, arehj@unik.no

Abstract

In this contribution, the performance of an uplink CDMA system is analyzed in the context of frequency selective fading channels. Using game theoretic tools, a useful framework is provided in order to determine the optimal power allocation when users know only their own channel (while perfect channel state information is assumed at the base station). We consider the realistic case of frequency selective channels. This scenario illustrates the case of decentralized schemes and aims at reducing the downlink signaling overhead. Various receivers are considered, namely the Matched filter, the MMSE filter and the optimum filter. The goal of this paper is to derive simple expressions for the non-cooperative Nash equilibrium as the number of mobiles becomes large. To that end we combine two asymptotic methodologies. The first is asymptotic random matrix theory which allows us to obtain explicit expressions for the impact of all other mobiles on any given tagged mobile. The second is the theory of non-atomic games along with the Wardrop equilibrium concept which allows us to compute good approximations of the Nash equilibrium as the number of mobiles grow.