Currently, the industry is using the MODBUS communication method, utilizing RS485 for the distributed equipment and network construction. This method has a rather good transmission and reception distance but has a disadvantage in that it is a half-duplex communication method that cannot simultaneously transmit and receive. Therefore, there is a great need for a full-duplex communication system that can simultaneously transmit and receive two-wire communications. Therefore, in this paper, we propose new communication hardware equipment that can implement a full-duplex communication method by communication signal level in order to overcome the disadvantage of communication speed when using a full-duplex communication method by time division method. The proposed communication hardware is a structure that can transmit and receive at the same time in such a way that two pieces of equipment communicating by two-wire communication can apply the outgoing signal to the same communication line and detect the received signal at the same time. Therefore, the receiving side can analyze the received signal based on the information on the current transmission signal. This signal can only be analyzed by the two communicating devices, indicating that communication security is very good.
On the Secrecy Capacity of a Full-Duplex Wirelessly Powered Communication System
