Chapter 9 (METIS Book) Multi-node Coordination
Performance in a wireless network strongly depends on user position in the cell, with users in the cell border typically experiencing much lower throughputs than those nearer to the transmitting base station. This is mainly due to the presence of inter cell interference, generated by concurrent transmissions in other cells. Inter cell interference is particularly relevant for modern wide area wireless communication systems like UMTS or LTE, where the frequency reuse factor is one or very close to one. In such a scenario the system is primarily interference limited, and performance cannot be improved by simply increasing the transmitted power, since not only the useful signal strength would be improved, but also the signal of interfering cells would be boosted. As a consequence, alternative techniques are necessary that target specifically inter cell interference and allow a more even user experience throughout the whole network, reducing the gap between cell edge and average throughput.