The design of secure wireless communication suffers a great challenge for openness of wireless channel and the broadcast nature of radio signals.The security problem introduced by wireless channel may be solved adequately by wireless channel itself.The space redundancy is often used in existing physical-layer security method to enhance security.So the concept of

mean square error is proposed in the paper

which is used to introduce redundancy for pre-coding weight.The concrete analysis and corresponding formal derivations are also given in the paper.Based on these

a novel physical-layer encryption method is proposed according to short-term reciprocity

rapid Decorrelation of wireless channel.Simulation results sho

w that the proposed method guarantees wireless transmission in the authorized receiver and reduces the probability of interception.