Secure communication in TDS-OFDM system using constellation rotation and noise insertion

Time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) is the key technology of Chinese digital television terrestrial broadcasting (DTTB) standard. However, the issue of security was not considered, and this limits its application in commercial or military scenarios where secure communication is very important. This paper proposes an encryption scheme based on pseudo random constellation rotation and weak artificial noise insertion, which jointly utilizes the pseudo random key and the irreversible property of wireless channel to guarantee the physical layer security of TDS-OFDM system. Simulation results show that the proposed security scheme can protect the system from eavesdroppers, while the legal receivers only suffer a negligible bit error rate (BER) performance loss compared with the conventional TDS-OFDM system without security.