Correlation-Based Cooperative Opportunistic Beamforming in Cellular Systems

In this paper, we consider a cooperative opportunistic beamforming scheme that can mitigate other cell interference (OCI) in downlink cellular environments. By exploiting the spatial channel correlation of adjacent cells, a random beam is cooperatively generated to statistically avoid the OCI from adjacent cells. Selecting its user for the proposed random beam in an opportunistic manner, the proposed scheme can simultaneously achieve both the multi-user diversity (MUD) gain and OCI avoidance gain. Finally, the performance of the proposed scheme is verified by computer simulation. The simulation results show that the proposed scheme can noticeably improve the spectral efficiency and the outage probability of users near the cell boundary compared to conventional opportunistic beamforming scheme. Keywords-Cooperative transmission; opportunistic beamforming; other-cell interference (OCI); spatial channel correlation