Cross-layer optimization for OFDM wireless networks-part I: theoretical framework

TLDR

This paper presents a theoretical framework for cross‑layer optimization in OFDM wireless networks. The authors use a utility function to link the physical and MAC layers, formulate a cross‑layer optimization problem maximizing average utility under adaptive resource allocation constraints, derive necessary and sufficient conditions for optimal subcarrier assignment and power allocation, and analyze convergence properties. Numerical results demonstrate a significant performance gain that increases with the number of active users.

Abstract

In this paper, we provide a theoretical framework for cross-layer optimization for orthogonal frequency division multiplexing (OFDM) wireless networks. The utility is used in our study to build a bridge between the physical layer and the media access control (MAC) layer and to balance the efficiency and fairness of wireless resource allocation. We formulate the cross-layer optimization problem as one that maximizes the average utility of all active users subject to certain conditions, which are determined by adaptive resource allocation schemes. We present necessary and sufficient conditions for utility-based optimal subcarrier assignment and power allocation and discuss the convergence properties of optimization. Numerical results demonstrate a significant performance gain for the cross-layer optimization and the gain increases with the number of active users in the networks.