  This work studies the uplink of a multi-tenant cloud radio access network
(C-RAN) system with spectrum pooling. In the system, each operator has a cloud
processor (CP) connected to a set of proprietary radio units (RUs) through
finite-capacity fronthaul links. The uplink spectrum is divided into private
and shared subbands, and all the user equipments (UEs) of the participating
operators can simultaneously transmit signals on the shared subband. To
mitigate inter-operator interference on the shared subband, the CPs of the
participating operators can exchange compressed uplink baseband signals on
finite-capacity backhaul links. This work tackles the problem of jointly
optimizing bandwidth allocation, transmit power control and fronthaul
compression strategies. In the optimization, we impose that the inter-operator
privacy loss be limited by a given threshold value. An iterative algorithm is
proposed to find a suboptimal solution based on the matrix fractional
programming approach. Numerical results validate the advantages of the proposed
optimized spectrum pooling scheme.
