Interference alignment with rate splitting in a three-user interference channel with a cognitive transmitter

This paper proposes a new strategy combining interference alignment (IA) and rate splitting for a three user interference channel with a cognitive transmitter. Although a half of available dimensions are sacrificed to align interference signals from other users in conventional IA, the proposed scheme recycles the sacrificed dimensions with the help of a cognitive transmitter. The achievable rate region and generalized degrees of freedom are derived. Compared with conventional IA, the proposed scheme improves achievable rate and generalized degrees of freedom.