CAJ | 학술논문

本文针对高斯窃听信道模型下的物理层安全问题，提出一种基于删余Polar码的、拥有编码比特的可信度计算的物理层安全编码方案。方案考虑到信道噪声对译码结果的影响，通过Bhattacharyya参数评估各信息比特的恢复差错概率，并将这恢复差错概率应用于编码比特的可信度计算。理论证明所提出的方案可使窃听者保持较高误码率，同时合法用户在高于自身信噪比门限时保证较低误码率。数值仿真结果表明所提出的安全编码方案能够有效地减小安全间隙。当窃听信道质量比合法信道质量稍差时窃听者误码率能迅速逼近0．5，而合法信道的误码率能够降到10－5以下，大大地降低了Bob和Eve间的安全间隙。
본문침대고사절은신도모형하적물리층안전문제，제출일충기우산여Polar마적、옹유편마비특적가신도계산적물리층안전편마방안。방안고필도신도조성대역마결과적영향，통과Bhattacharyya삼수평고각신식비특적회복차착개솔，병장저회복차착개솔응용우편마비특적가신도계산。이론증명소제출적방안가사절은자보지교고오마솔，동시합법용호재고우자신신조비문한시보증교저오마솔。수치방진결과표명소제출적안전편마방안능구유효지감소안전간극。당절은신도질량비합법신도질량초차시절은자오마솔능신속핍근0．5，이합법신도적오마솔능구강도10－5이하，대대지강저료Bob화Eve간적안전간극。
A physical layer secrecy coding scheme based on punctured polar codes is proposed in the paper,which aims at the physical layer secure problem under Gaussian wiretap channel,where the punctured position is calculated by the reliabili-ty of code-bit.Considering different effects of channel noise on the decoding results,the recovery-error probability of informa-tion-bits related to the Bhattacharyya parameter of Gaussian channel is useful for calculating the reliability of code-bit,which contributes to the decision of the punctured positions.Theoretical analysis shows that the eavesdropper has high bit error rate (BER)under SNR threshold,while the authorized user can keep low BER when the noise is over the SNR threshold.Numeri-cal simulation results show that the proposed puncturing scheme reduces the security gap efficiently.The BER of eavesdropper gets close to 0.5 rapidly even though his channel is only a little worse than the authorized channel,while the BER for the au-thorized channel could fall below a 10-5 .The gap for security between Bob and Eve reduces greatly.