A lower bound on feedback capacity of colored Gaussian relay channels

Relay channels aid in increasing the rate of communication possible from the source to the destination. However, in general, the capacity of a relay channel is still an open problem. In this work, we provide a lower bound for the capacity of the three-terminal relay channel with destination-source feedback in the presence of correlated noise using the recent results in [1] and employing linear processing at the relay node. We also extend our model to the one involving multiple relays in either series or parallel configuration. Simulation results show that significant improvements in the lower bound can be obtained via our formulation of the problem.