Cross-Layer Scheduling for OFDMA-based Cognitive Radio Systems with Delay and Security Constraints

TL;DR

This paper develops an online resource allocation scheme for OFDMA-based cognitive radio networks that maximizes throughput while satisfying delay and security constraints, ensuring primary system stability.

Contribution

It introduces a novel stochastic optimization framework and an asymptotically optimal online scheme for joint flow control and radio resource allocation in CR networks.

Findings

The scheme achieves near-optimal throughput performance.

It maintains primary system stability under constraints.

Simulation results confirm the scheme's effectiveness.

Abstract

This paper considers the resource allocation problem in an Orthogonal Frequency Division Multiple Access (OFDMA) based cognitive radio (CR) network, where the CR base station adopts full overlay scheme to transmit both private and open information to multiple users with average delay and power constraints. A stochastic optimization problem is formulated to develop flow control and radio resource allocation in order to maximize the long-term system throughput of open and private information in CR system and ensure the stability of primary system. The corresponding optimal condition for employing full overlay is derived in the context of concurrent transmission of open and private information. An online resource allocation scheme is designed to adapt the transmission of open and private information based on monitoring the status of primary system as well as the channel and queue states in the CR network. The scheme is proven to be asymptotically optimal in solving the stochastic optimization problem without knowing any statistical information. Simulations are provided to verify the analytical results and efficiency of the scheme.