Cloud Radio Access meets Heterogeneous Small Cell Networks: A Cognitive Hierarchy Perspective

TL;DR

This paper introduces a hierarchical game-theoretic approach for distributed power allocation in coexisting cloud radio access and heterogeneous small cell networks, significantly improving total network throughput.

Contribution

It proposes a novel cognitive hierarchy framework for power control in CRAN and heterogeneous networks, reducing interference and enhancing performance over traditional Nash equilibrium methods.

Findings

Cognitive hierarchy approach doubles the total network rate compared to Nash equilibrium.

Hierarchical design effectively reduces interference from high-powered to low-powered base stations.

Simulation results demonstrate substantial performance gains in multi-tier network scenarios.

Abstract

In this paper, the problem of distributed power allocation is considered for the downlink of a cloud radio access network (CRAN) that is coexisting with a heterogeneous network. In this multi-tier system, the heterogeneous network base stations (BSs) as well as the CRAN remote radio heads seek to choose their optimal power to maximize their users' rates. The problem is formulated as a noncooperative game in which the players are the CRAN's cloud and the BSs. Given the difference of capabilities between the CRAN and the various BSs, the game is cast within the framework of cognitive hierarchy theory. In this framework, players are organized in a hierarchy in such a way that a player can choose its strategy while considering players of only similar or lower hierarchies. Using such a hierarchical design, one can reduce the interference caused by the CRAN and high-powered base stations on low-powered BSs. For this game, the properties of the Nash equilibrium and the cognitive hierarchy equilibrium are analyzed. Simulation results show that the proposed cognitive hierarchy model yields significant performance gains, in terms of the total rate, reaching up to twice the rate achieved by a classical noncooperative game's Nash equilibrium.