Enhancing the Network Sum-Rate without Sharing Channel State Information between Base Stations

We consider the downlink of a cellular wireless network where the base stations are equipped with multiple transmit antennas and operate in the same frequency band. Each base station serves one user per orthogonal frequency-division multiplexing (OFDM) sub-carrier by means of spatial precoding. Due to temporal scheduling, the active users change rapidly in time and consequently, intercell interference becomes non-stationary limiting the achievable network sum-rate. Under the assumption of perfect channel knowledge at each base station, we optimize both precoding and scheduling in order to maximize the achievable network sum-rate. The solution, however, unveils that both precoding and scheduling can be performed locally at each base station without the need for CSI to be exchanged between base stations if they are solely based on average channel measurements.