Secure 2-User Gaussian Interference Channel with Limited Information Exchange at the Transmitters

This paper considers the interference-mitigation cooperation over a secure 2-user Gaussian Interference Channel with Limited Information Exchange at the Transmitters (GIC-LIET) over an infinite rate link between the two transmitters. The information exchange between the transmitters enables the precoding based on Block- Diagonalization and the privacy constrains the messages of one transmitter to be kept confidential for the other transmitter, as well as the other receiver. The privacy constraint is guaranteed by a wiretap coding. Based on the assumption of the infinite rate link between the two transmitters, we inject artificial noise at each of the two transmitters such that the received signal at the potential eavesdroppers (i.e., the other transmitter and receiver) is a degraded version of the signal received at the desired receiver. The secrecy rate region of the proposed GIC-LIET is derived and compared to two extreme cases: no information exchange at all and full information exchange at the transmitters. Numerical results prove that the secrecy rate region of the proposed scheme is in between the performance of the two competitors providing a good trade-off between the amount of information exchanged and the achievable secrecy rates.