Robust Beamforming and Power Allocation for Secure Communication in Systems With Imperfect Channel and Hardware Impairments

Abstract

In practice, hardware impairments (HIs) of communication systems are inevitable. In addition, perfect channel state information (CSI) is difficult to get due to channel estimation errors. In this letter, we design the power allocation strategy (PAS) at transmitters to optimize the worst-case secrecy rate for the wireless communication system with both norm-bounded channel uncertainty and HIs. The proposed problem is non-convex and difficult to solve. To solve this thorny problem, we use S-procedure, conservative approximation (CA), robust beamforming, and sequential convex approximation (SCA) to effectively convert the non-convex problem into a series of convex problems that are easy to solve. The numerical results demonstrate that the proposed PAS and robust beamforming method can offset the performance loss caused by HIs to a large extent.