Downlink Multi-Cell Radio Resource Management for Coordinated Base Stations

This paper addresses the design of joint multi-cell resource allocation and scheduling with coordination among neighboring base stations (BS). Considering N_s neighboring sectors, the solution that maximizes the sum-rate in the covered area is found for TDMA and TDMA/OFDMA access. The optimum solution exhibits low complexity as it presents the useful property that its computation admits a decomposition such that each BS is responsible for the selection of the users to be scheduled in its own sector. This result is proved analytically.

I. Introduction

In conventional cellular networks, frequency planning is usually considered to keep an acceptable signal-to-interference-plus-noise ratio (SINR) level, especially at cell boundaries. This approach, however, hampers the system spectral efficiency, particularly at low reuse rates. Depending on the allowed complexity and signaling overhead, multi-cell joint inter-cell radio resource allocation may bring significant gains. Intuitively, if users served from different BS experience a low level of interference, radio resources may be reused, thus increasing the system spectral efficiency. On the other side, if the served user experiences large interference, orthogonal transmissions with suitable power allocation are better.