When CoMP is beneficial — And when it is not. Selective coordination from a spectral efficiency and a users' throughput perspective

Coordinated Multi-Point (CoMP) transmission schemes can provide large spectral efficiency gains in cellular networks. Because of the coordination among neighbor basestations, the planning interval for resource allocation with CoMP is longer than for uncoordinated local transmission modes. Especially for bursty data traffic, this planning interval might be too long to keep up with changes in offered load at small timescales. In this case, coordination gains might turn into losses when the coordinated resource allocation doesn't fit the system state anymore. To avoid these problems and to leverage the CoMP schemes' potential at higher layers, previous work has investigated traffic aware transmit mode selection schemes with the objective to maximize spectral efficiency. In this work, we do not focus on spectral efficiency, but on per-user throughput. We derive a suitable coordination threshold to improve throughput and evaluate it's impact on system performance.