Vuong Bao Quoc, Gautier Roland, Fiche Anthony, Marazin Mélanie, Despina-Stoian Cristina
Univ Brest, CNRS, Lab-STICC, CS 93837, 6 Avenue Le Gorgeu, CEDEX 3, 29238 Brest, France.
School of Electrical Engineering, International University, Ho Chi Minh City 700000, Vietnam.
Sensors (Basel). 2022 Jul 14;22(14):5257. doi: 10.3390/s22145257.
This paper studies the secrecy coding analysis achieved by the self-jamming technique in the presence of an eavesdropper by considering a short-packet Full-Duplex (FD) transmission developed based on iterative blind or semi-blind channel estimation and advanced decoding algorithms. Indeed, the legitimate receiver and eavesdropper can simultaneously receive the intended signal from the transmitter and broadcast a self-jamming or jamming signal to the others. Unlike other conventional techniques without feedback, the blind or semi-blind algorithm applied at the legitimate receiver can simultaneously estimate, firstly, the Self-Interference (SI) channel to cancel the SI component and, secondly, estimate the propagation channel, then decode the intended messages by using 5G Quasi-Cyclic Low-Density Parity Check (QC-LDPC) codes. Taking into account the passive eavesdropper case, the blind channel estimation with a feedback scheme is applied, where the temporary estimation of the intended channel and the decoded message are fed back to improve both the channel estimation and the decoding processes. Only the blind algorithm needs to be implemented in the case of a passive eavesdropper because it achieves sufficient performances and does not require adding pilot symbols as the semi-blind algorithm. In the case of an active eavesdropper, based on its robustness in the low region of the Signal-to-Noise Ratio (SNR), the semi-blind algorithm is considered by trading four pilot symbols and only requiring the feedback for channel estimation processes in order to overcome the increase in noise in the legitimate receiver. The results show that the blind or semi-blind algorithms outperform the conventional algorithm in terms of Mean Square Error (MSE), Bit Error Rate (BER) and security gap (Sg). In addition, it has been shown that the blind or semi-blind algorithms are less sensitive to high SI and self-jamming interference power levels imposed by secured FD transmission than the conventional algorithms without feedback.
本文通过考虑基于迭代盲或半盲信道估计以及先进解码算法开发的短数据包全双工（FD）传输，研究了在存在窃听者的情况下自干扰技术实现的保密编码分析。实际上，合法接收者和窃听者可以同时从发射机接收预期信号，并向其他方广播自干扰或干扰信号。与其他无反馈的传统技术不同，应用于合法接收者的盲或半盲算法可以同时进行估计，首先估计自干扰（SI）信道以消除SI分量，其次估计传播信道，然后使用5G准循环低密度奇偶校验（QC-LDPC）码解码预期消息。考虑到被动窃听者的情况，应用了具有反馈方案的盲信道估计，其中将预期信道的临时估计和解码消息进行反馈，以改善信道估计和解码过程。在被动窃听者的情况下，仅需实现盲算法，因为它能实现足够的性能，且不像半盲算法那样需要添加导频符号。在主动窃听者的情况下，基于其在低信噪比（SNR）区域的鲁棒性，考虑采用半盲算法，通过牺牲四个导频符号并仅要求对信道估计过程进行反馈，以克服合法接收者中噪声的增加。结果表明，在均方误差（MSE）、误码率（BER）和安全间隙（Sg）方面，盲或半盲算法优于传统算法。此外，研究表明，与无反馈的传统算法相比，盲或半盲算法对安全FD传输施加的高SI和自干扰功率水平不太敏感。
