The polarization-enabled digital self-interference cancellation scheme for the full duplex communication

In this paper, we propose a polarization-enabled digital self-interference cancellation (PDC) scheme for the full duplex communication. This scheme provides a new degree of freedom, polarization domain, to increase the distinction between desired signal and self-interference and solve the problem caused by insufficient reference information in time-frequency domains in baseband. The proposed PDC scheme uses oblique projection along the desired signal space to the interference space to cancel self-interference in the local receiver. Furthermore, additive white Gaussian noise can be reduced partly, which is an extra gain of the proposed scheme. Theoretical analysis and simulation results verify that the cancellation performance of the PDC scheme has the lower bound of 3dB when polarization states of self-interference and desired signal are orthogonal. And the PDC scheme has robust cancellation performance when dissimilarity coefficient of used polarization states is greater than 0.5 even if the reference information is insufficient.