Secret Wireless Communication with Public Feedback by Common Randomness

In this letter, we propose a feedback scheme to improve the secrecy rate of a wireless communication system which can help us to get a higher achievable secrecy rate than the traditional one-way communication scheme for Gaussian wiretap channel. It is shown that if the power of sending signal is large enough, positive secrecy rate can be achieved even when the eavesdropper's channel quality is better than the main channel. Closed-form solution of the achievable secrecy rate is derived.