Nonlinear Distortion Suppression of Cooperative Jamming System for Secure Wireless Communication

Future wireless communication is expected to incorporate billions of wireless smart devices on the premise of secure communication. In presence of some illegitimate eavesdroppers, cooperative jamming (CJ) is considered as an effective approach, which enables confidential communication with assistance of the CJ signals from cooperative transmitters. The legitimate receiver, however, inevitably suffers from such undesired CJ at the same time. Moreover, as transmit power increases to efficiently interfere with eavesdroppers, the nonlinear distortion is introduced to CJ due to inherent nonlinearity of the power amplifier (PA). In this paper, a novel digital CJ cancellation scheme is proposed to tackle the CJ nonlinearity at legitimate receiver. By developing a nonlinear model to capture the overall nonlinearities, the accurate estimates for CJ are reconstructed from the reference data, thus CJ can be effectively suppressed. Furthermore, experiments are performed on a self-designed testbed that demonstrate the effectiveness of the proposed CJ cancellation architecture.