Secure transmission using MIMO precoding

In this paper, we propose an MIMO precoding and postcoding transceiver to achieve data secrecy at the physical layer. When full channel state information (CSI) of the legitimate receiver is known to the transmitter, the proposed precoder can simultaneously maximize to receive signal-to-noise ratio (SNR) and attain secrecy. When only partial CSI is available, a modified Lloyd algorithm is proposed to construct codebooks for quantizing the precoder. As will be explained in this paper, the use of the proposed codebooks does not affect the secrecy of the proposed system. In addition, we propose a low-complexity postcoder to compensate the SNR loss when full CSI is not available. Furthermore, the performance of the proposed system is analyzed from the view points of both recovery rate and secrecy. Based on the analyzed results, we show how to achieve full recovery rate and perfect secrecy for the proposed system. Finally, simulation results corroborate the theoretical results, and show that the proposed system enjoys different advantages when different recovery algorithms are used.