The Capacity of Known Interference Channel

In this paper, we investigate the capacity of a known interference channel, where a transmitter sends information to a receiver in the presence of a block-fading interference link, and the receiver knows the interference data but not the channel gain of the interference link. An upper bound and a lower bound for the capacity of this known interference channel are derived. Specifically, the capacity lower bound is achieved by a blind known interference cancellation (BKIC) scheme, which can remove the interference without the knowledge of the interference channel gain. We further show that the achievable lower bound of BKIC can approach the upper bound in high SNR regime. Our results show that the lack of the knowledge of the channel gain of the interfering link causes only a small fractional loss of degrees of freedom (capacity prelog).