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.