Cyclic interference neutralization on the 2 × 2 × 2 full-duplex two-way relay-interference channel

A two-way relay-interference channel describes a system of four communicating transceivers with two interjacent parallel relays arranged in a bidirectional 2 × 2 × 2 relay-interference network. Two pairs of transceivers are each communicating bidirectionally with the aid of both relays. All transceivers and relays are assumed to operate in full-duplex mode. Since Interference Neutralization is known as a promising method to achieve the cut-set upper bounds on the data rates of the unidirectional relay-interference channel, we investigate a Cyclic Interference Neutralization scheme on the corresponding bidirectional relay-interference channel w.r.t. a conceptual channel model based on a polynomial ring. We show that, if the channel matrix satisfies a certain set of symmetry conditions, a total number of 4 degrees of freedom is asymptotically achievable.