Cooperative Jamming Cancellation Under Nonlinearity and Imperfect Time-Frequency Alignments for Physical-Layer Security

Cooperative jamming (CJ) is considered as one of the crucial means in physical-layer security (PLS) for defending against eavesdropping. With the aid of the CJ signal from a friendly jammer, the eavesdropper's channel quality will be intentionally degraded. Unfortunately, the CJ signal also propagates into the legitimate receiver (RX) as the jamming-interference (JI), which should be estimated, rebuilt, and cancelled accordingly. In this paper, we first model the JI after considering practical imperfections existed in the transmit-receive link that incorporates the power amplifier nonlinearity, the carrier frequency offset, and imperfect time-frequency alignments. Then, we formulate an advanced time-frequency misalignments tolerant memory polynomial (TFMT-MP) model to rebuild and cancel the received JI in the legitimate RX. Numerical simulations show that the proposed solution provides the excellent JI cancellation performance and exhibits the strong tolerance of imperfect time-frequency alignments, over the existing MP model solution.