Advantage distillation over MIMO wiretap channels based on generalized extended orthogonal space-time block codes

The three-phase process of achieving secret sharing over a wiretap channel are, respectively, advantage distillation, information reconciliation, and privacy amplification. In this paper, we first generalize the extended orthogonal space time block codes (EO-STBCs). Then, based on the generalized EO-STBCs (GEO-STBCs) and the feedback bits from the legitimate receiver, we propose a new advantage distillation scheme for multiple-input multiple-output (MIMO) wiretap channels. Simulation results show that the bit error rate (BER) performance gain up to 4.2 dB is obtained by the legitimate receiver over the eavesdropper at the BER of 10-5. Moreover, it is shown that the feedback performance gain of the proposed advantage distillation scheme grows exponentially with signal-to-noise ratio (SNR).