Wireless Network Virtualization in Uplink Coordinated Multi-Cell MIMO Systems

We consider wireless network virtualization (WNV) in the uplink of a coordinated multi-cell system, where multiple service providers (SPs) operate in virtually isolated networks managed by an infrastructure provider (InP). The InP provides service isolation among the SPs by exploiting the spatial structure in MIMO communication. We jointly optimize the uplink receive beamforming at the base stations (BSs) and the transmit power of the SPs' subscribing users, by alternating between two subproblems that both admit efficient closed-form solutions. We then propose a distributed implementation that solves each subproblem among the BSs without the need for a central controller. We show that the distributed approach requires significantly less communication overhead compared with the centralized one, especially when the system is not overloaded. Our simulation results under typical wireless networking environments demonstrate that the proposed solution enables effective network virtualization, to support the independent operation of multiple SPs over multiple cells, without losing communication efficiency compared with non-virtualized network operation. Furthermore, it substantially outperforms traditional WNV based on strict resource separation, especially for systems with a large number of antennas or a large number of SPs.