Contract-Based Interference Coordination in Heterogeneous Cloud Radio Access Networks

TL;DR

This paper introduces a contract-based interference coordination framework for H-CRANs that effectively mitigates inter-tier interference, enhances data rates, and adapts to different CSI availability scenarios.

Contribution

It proposes a novel contract-based approach for inter-tier interference management in H-CRANs, including optimal contract design under perfect and partial CSI conditions.

Findings

Significant increase in transmission data rates compared to baselines

Effective mitigation of inter-tier interference in H-CRANs

Framework adaptable to practical CSI estimation scenarios

Abstract

Heterogeneous cloud radio access networks (HCRANs) are potential solutions to improve both spectral and energy efficiencies by embedding cloud computing into heterogeneous networks (HetNets). The interference among remote radio heads (RRHs) can be suppressed with centralized cooperative processing in the base band unit (BBU) pool, while the intertier interference between RRHs and macro base stations (MBSs) is still challenging in H-CRANs. In this paper, to mitigate this inter-tier interference, a contract-based interference coordination framework is proposed, where three scheduling schemes are involved, and the downlink transmission interval is divided into three phases accordingly. The core idea of the proposed framework is that the BBU pool covering all RRHs is selected as the principal that would offer a contract to the MBS, and the MBS as the agent decides whether to accept the contract or not according to an individual rational constraint. An optimal contract design that maximizes the rate-based utility is derived when perfect channel state information (CSI) is acquired at both principal and agent. Furthermore, contract optimization under the situation where only the partial CSI can be obtained from practical channel estimation is addressed as well. Monte Carlo simulations are provided to confirm the analysis, and simulation results show that the proposed framework can significantly increase the transmission data rates over baselines, thus demonstrating the effectiveness of the proposed contract-based solution.