Secrecy Rate Analysis for the Cooperative Communications.

Due to the character of low cost and easily to implemented, the cooperative communication is the future tendency. Three fundamental mode, Amplify-and-Forward (AF) mode, Decode-and-Forward (DF) mode and Compress and Forward (CF) mode are employed to the system. In the cooperative system, relays function to transmit the delivered signal to the destination. Each node in the system could play as the source station, the relay and the destination station. Currently, the issue of privacy and security are seriously requested in the communication. There could be the eavesdroppers pre-tend as the relay to steal the message. Hence, the secrecy protection becomes important. In the higher layer, the encryption scheme is applied to protect the message. However, it is difficult for those devices with low computing resources, the example of IoT (Internet of Things). With Shannon Theory, a secure communication could be supported with a positive secrecy rate. Hence, secure cooperative communication could be possible if there exist a positive secrecy rate between the two ends in the transmissions. Base on the secrecy rate analysis, the maximum secrecy rate is the initial step toward a secure communication. In the cooperative system, the delivered signal could be transmitted via relays. Hence, the path from the source to the destination could be a huge combination. With the exhaustive method to find the optimal secrecy rate could be realized. Hence, in this work, the numerical experiment, the AF and DF mode cooperative mode is adopted.