A novel non-coherent BPSK modulation and demodulation scheme is proposed to remove both slow and fast fading completely. We formulate a compound function that reflects the different characteristics of both slow and fast fading and prove that the scheme can remove fading from the function completely. The scheme is reified by a simple architecture that can remove slow and fast phase shifts completely from the received signals. It is shown by using analytical model and numerical data that the proposed scheme outperforms other ones significantly under the presence of both slow and fast fading. The analytical results also show that the proposed scheme can work well even with a small sampling rate, resulting in a wireless device with low energy consumption.

This letter considers hiding messages into overt transmissions with a Full-Duplex receiver, which emits Artificial Noise to secure its transmission connection while a transmitter opportunistically sends a covert message to a covert user. The warden’s uncertainties of decoding the overt message and Artificial Noise received power are exploited to hide messages. Then, the covert throughput accompanied with the warden’s average detection error probability are determined. The results show that increasing the transmit power of Artificial Noise will improve the covert performance. The results also show that the covert performance is improved when the self-interference cancellation is improved at the Full-Duplex receiver or the warden is located close to the Full-Duplex receiver, indicating the positive impact of the overt performance on the covert performance.