Robust resource allocation and clustering formulation for multicast C-RAN with impaired CSI

Abstract

In this paper, we study the robust design of downlink multicast Cloud Radio Access Network (C-RAN), equipped with wireless backhaul. Due to feedback delays, channel estimation or quantization errors, etc., only impaired Channel State Information (CSI) might be available at the Central Processor (CP). In order to achieve a power-efficient system, we aim to minimize the network power cost while guarantee the Quality of Service (QoS) for all delivered contents, under several practical constraints of C-RAN. Despite the uncertainties introduced by the impaired CSI, we propose an algorithm, yielding a robust backhaul resource and power allocation mechanism. Moreover, the clustering formulation for Radio Units, as well as the robust multicast beamforming vectors, can also be derived. Numerical results demonstrate the effectiveness of such robust design in counteracting the channel uncertainties, and confirm the robustness in fulfilling the network constraints.