153 research outputs found
Nearly Optimal Resource Allocation for Downlink OFDMA in 2-D Cellular Networks
In this paper, we propose a resource allocation algorithm for the downlink of
sectorized two-dimensional (2-D) OFDMA cellular networks assuming statistical
Channel State Information (CSI) and fractional frequency reuse. The proposed
algorithm can be implemented in a distributed fashion without the need to any
central controlling units. Its performance is analyzed assuming fast fading
Rayleigh channels and Gaussian distributed multicell interference. We show that
the transmit power of this simple algorithm tends, as the number of users grows
to infinity, to the same limit as the minimal power required to satisfy all
users' rate requirements i.e., the proposed resource allocation algorithm is
asymptotically optimal. As a byproduct of this asymptotic analysis, we
characterize a relevant value of the reuse factor that only depends on an
average state of the network.Comment: submitted to IEEE Transactions on Wireless Communication
Energy minimization based Resource Scheduling for Strict Delay Constrained Wireless Communications
This paper investigates the energy consumption minimization
for resource scheduling in a wireless communication.
We propose to take into account a strict delay constraint for each
queued packet rather than an average delay constraint, in addition
to a buffer overflow constraint. The associated optimization
problem can be modeled as Constraint Markov Decision Problem
where the actions are the number of packets sent on the known
channel at each slot. The optimal random policy is exhibited
through the resolution of standard linear programming. We show
the gain in energy is substantial compared to naive policy
Egalisation aveugle au second ordre pour des signaux à bande limitée : Connaisssance a priori sur le filtre
La plupart des algorithmes d'égalisation aveugle au second ordre basés sur le suréchantillonnage du signal reçu a des performances médiocres quand le signal reçu a une bande passante réduite. Or, le filtre à identifier provient de l'effet conjugué d'un filtre de mise en forme (connu) et d'un canal de propagation (inconnu). Nous analysons, ici, les conséquences de cette connaissance partielle du filtre dans le cadre de la méthode sous-espace introduite par Moulines et al
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