Feedback in the K-User Interference Channel
A traditional viewpoint on feedback capacity has been pessimistic over the past few decades. This is mainly due to Shannon's original result which shows that feedback provides no increase in capacity for discrete memory-less point-to-point channels. Although feedback can indeed increase the capacity of multiple access channels, the increase in capacity for the Gaussian case is bounded by 1 bit for all channel parameters. Contrary to the traditional belief on feedback capacity, recent results show that feedback is of fundamental importance when communicating over Interference Channels (ICs).