Group Decoding with Static Clustering for Cloud Radio Access Networks

We consider a static clustering algorithm and the associated group decoding technology in the uplink cloud radio access networks (C-RAN), where the remote radio heads (RRHs) are connected to a common cloud processing (CP). In our work, the long-term average received signal strength is employed to design the static clustering, which is only updated as the user equipment (UE) location changes. Due to the C-RAN characteristics, each cluster is served by a data server which processes the decoding group in parallel and aims to achieve the maximal sum-rate per cluster. Simulation results illustrate that the proposed static clustering parallel group decoder (SC-PGD) always outperforms the random clustering algorithm and the static clustering without group decoding. In addition, increasing the group size leads to an increase in the sum-rate.

I. Introduction

With the rapid development of wireless communication and the surging mobile data traffic demands, the fifth generation (5G) mobile radio system is expected to construct a new wireless network architecture, achieving larger transmission capacity, lower transmission delay, and more energy efficiency [1]. To meet these demands, cloud radio access networks (C-RANs) are proposed by China Mobile [2], [3], which are promising to reduce the capital expenditure (CAPEX) and operational expenditure (OPEX) effectively, and thus provide a high transmission rate with more energy efficiency. For its “4C” characteristics, i.e., Clean, Centralized processing, Collaborative radio, and real-time Cloud radio access network, C-RAN attracts extensive attention in both academical and industrial areas. Different from the traditional cellular networks, C-RAN breaks the function of base stations (BSs) into two units, i.e., Remote radio heads (RRHs) and baseband units (BBUs). RRHs operate as a soft relay [4] by compressing and forwarding the received signals from the mobile user equipment (UE) to BBUs via fiber, which forms a virtual centralized BBU pool. The BBU often locates at a remote site such as a central office (CO), and thus the energy, real-estate and security costs can be reduced.