Multi-Cell Coordinated Power Control with Adjacent Cell Cooperative Transmission Considering Actual Environment

To further increase the spectrum efficiency of cellular mobile communication systems, it is important to control co-channel interference among cells. To control co-channel interference and improve spectrum efficiency over the whole cell, we proposed QoS-guaranteed multi-cell coordinated transmit power control, which limits the communication of some users and fully guarantees the QoS for the remaining users. On the other hand, as one of the techniques for improving the cell-edge performance, we have studied adjacent base station cooperative transmission in which simultaneously transmits signals from both own base station and adjacent base station to the cell-edge mobile terminal. In order to increase not only cell capacity but also cell edge capacity at the same time, we proposed a generalized scheme that combines the adjacent base station cooperative transmission with the QoS-guaranteed multi-cell coordinated transmit power control. Our previous analysis assumed an ideal condition in that each mobile terminal could measure the received power of each base station accurately. In practice, however, the mobile terminal cannot measure the received power especially from far base stations because the received power is lower than the noise power. Applying our proposed technology to actual systems, it demands method that can estimate the received power. This paper proposes such a method; its impact on overall performance is clarified by computer simulation.