Secure channel estimation method in TDD OFDM systems

Physical layer security in wireless communication deals mainly with unauthorized users, eavesdroppers, and/or jammers. It is crucial for wireless network due to its broadcast nature and the channel state information (CSI) is easily acquired by unauthorized receivers. Thus, eavesdroppers can easily obtain information by utilizing the estimated CSI. In this paper, we propose a secure channel estimation method which includes two components, i.e., the designs of pilot signals and estimator for time division duplex orthogonal frequency division multiplexing systems. According to analyses, the CSI can be estimated successfully at the authorized receiver. Eavesdroppers cannot obtain the CSI even if they are close to the transmitter or the authorized receiver.