Demodulation of Weighted Fractional Fourier Transform Encrypted Chaotic Direct Spread Signals over Multipath Fading Channels
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摘要: 为了在多径信道下解调加权分数傅里叶变换加密的混沌直扩(WFRFT-CD3S)信号，该文提出一种广义信道差分解调算法。在WFRFT-CD3S系统的发射端先对信息码进行差分调制，接收端将差分码与信道的乘积视为广义信道，并通过本地扩频序列构建频域匹配滤波器以估计广义信道冲击响应。接收端通过解差分广义信道冲击响应的估计值来合并各径能量并恢复信息码。对所提算法的误码率进行了理论分析，数值仿真验证了理论分析结果。数值仿真结果表明提出的解调算法可以在低信噪比下解调多径WFRFT-CD3S信号，保证了WFRFT-CD3S系统抗能量检测的能力。Abstract: To demodulate the Weighted FRactional Fourier Transform encrypted Chaotic Direct Sequence Spread Spectrum (WFRFT-CD3S) signal over multipath fading channels, a generalized channel differential demodulation algorithm is proposed. The transmitter of the WFRFT-CD3S system modulates differentially the message bits. The receiver regards the product of the differential code and the channel as a generalized channel, and constructs a frequency-domain matched filter through the local spreading sequence to estimate the generalized channel impulse response. The receiver combines the path energies and recovers the message bits by de-differentiating the estimates of the generalized channel impulse response. The bit error rate of the proposed algorithm is analyzed theoretically, and the theoretical results are verified by numerical simulation. The numerical simulation results show that the proposed demodulation algorithm can demodulate the multipath WFRFT-CD3S signal under low signal-to-noise ratio, which ensures the anti-energy detection capability of the WFRFT-CD3S system.
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[1] KADDOUM G. Wireless chaos-based communication systems: A comprehensive survey[J]. IEEE Access, 2016, 4: 2621–2648. doi: 10.1109/ACCESS.2016.2572730 [2] SEDAGHATNEJAD S and FARHANG M. Detectability of chaotic direct-sequence spread-spectrum signals[J]. IEEE Wireless Communications Letters, 2015, 4(6): 589–592. doi: 10.1109/LWC.2015.2469776 [3] YUAN Guogang, CHEN Zili, GAO Xijun, et al. A synchronization approach based on bidirectional correlation search for aperiodic chaotic direct sequence spread spectrum signals[J]. IEEE Access, 2020, 8: 190390–190402. doi: 10.1109/ACCESS.2020.3031906 [4] NOVOSEL L, ŠIŠUL G, ILIĆ Ž, et al. Performance enhancement of LR WPAN spread spectrum system using chaotic spreading sequences[J]. AEU - International Journal of Electronics and Communications, 2020, 118: 153131. doi: 10.1016/j.aeue.2020.153131 [5] YUAN Guogang, CHEN Zili, GAO Xijun, et al. Enhancing the security of chaotic direct sequence spread spectrum communication through WFRFT[J]. IEEE Communications Letters, 2021, 25(9): 2834–2838. doi: 10.1109/LCOMM.2021.3096388 [6] 刘芳, 程莫文, 陈立志. 混沌直扩信号的抗盲估计传输方法[J]. 航空学报, 2022, 43(2): 325108.LIU Fang, CHENG Mowen, and CHEN Lizhi. Anti-blind estimation transmission method for chaotic DSSS signals[J]. Acta Aeronautica et Astronautica Sinica, 2022, 43(2): 325108. [7] MUKHOPADHYAY S and LEUNG H. Blind system identification using symbolic dynamics[J]. IEEE Access, 2018, 6: 24888–24903. doi: 10.1109/ACCESS.2018.2832616 [8] HAN Qin, YANG Ling, DU Juan, et al. Blind equalization for chaotic signals based on echo state network and Kalman filter under nonlinear channels[J]. IEEE Communications Letters, 2021, 25(2): 589–592. doi: 10.1109/LCOMM.2020.3032587 [9] ZHANG Daoqing and JIANG Mingyan. Hetero-dimensional multitask neuroevolution for chaotic time series prediction[J]. IEEE Access, 2020, 8: 123135–123150. doi: 10.1109/ACCESS.2020.3007142 [10] HUANG Weijian, LI Yongtao, and HUANG Yuan. Deep hybrid neural network and improved differential neuroevolution for chaotic time series prediction[J]. IEEE Access, 2020, 8: 159552–159565. doi: 10.1109/ACCESS.2020.3020801 [11] XU Xinzhi and GUO Jingbo. Combined equalization and demodulation of chaotic direct sequence spread spectrum signals for multipath channels[J]. Circuits, Systems, and Signal Processing, 2013, 32(6): 2957–2969. doi: 10.1007/s00034-013-9599-y [12] YAHIA M, RADI D, GARDINI L, et al. Use of chebyshev polynomial Kalman filter for pseudo-blind demodulation of CD3S signals[J]. International Journal of Control, Automation and Systems, 2015, 13(5): 1193–1200. doi: 10.1007/s12555-014-0283-1 [13] 陈鹏, 袁国刚, 王永川, 等. 多径CD3S信号的混合卡尔曼滤波解调[J]. 华中科技大学学报:自然科学版, 2018, 46(11): 76–80. doi: 10.13245/j.hust.181114CHEN Peng, YUAN Guogang, WANG Yongchuan, et al. Demodulation of CD3S signals through mixed Kalman filtering for multipath channel[J]. Journal of Huazhong University of Science and Technology:Natural Science Edition, 2018, 46(11): 76–80. doi: 10.13245/j.hust.181114 [14] PATEL M K, BERBER S M, and SOWERBY K W. Maximal ratio combining using channel estimation in chaos based pilot-added DS-CDMA system with antenna diversity[J]. Wireless Communications and Mobile Computing, 2017, 2017: 3607167. doi: 10.1155/2017/3607167 [15] TAYEBI A, BERBER S, and SWAIN A. A new approach for error rate analysis of wide-band DSSS-CDMA system with imperfect synchronization under jamming attacks[J]. Wireless Personal Communications, 2018, 98(4): 3583–3610. doi: 10.1007/s11277-017-5030-5 [16] AKBAR N, YAN Shihao, KHATTAK A M, et al. On the pilot contamination attack in multi-cell multiuser massive MIMO networks[J]. IEEE Transactions on Communications, 2020, 68(4): 2264–2276. doi: 10.1109/TCOMM.2020.2967760 [17] XU Weiyang, YUAN Chang, XU Shengbo, et al. On pilot spoofing attack in massive MIMO systems: Detection and countermeasure[J]. IEEE Transactions on Information Forensics and Security, 2021, 16: 1396–1409. doi: 10.1109/TIFS.2020.3036805 [18] FANG Xiaojie, SHA Xuejun, and MEI Lin. Guaranteeing wireless communication secrecy via a WFRFT-based cooperative system[J]. China Communications, 2015, 12(9): 76–82. doi: 10.1109/CC.2015.7275261 [19] WANG Xiaolu, MEI Lin, WANG Zhenduo, et al. On the probability density function of the real and imaginary parts in WFRFT signals[J]. China Communications, 2016, 13(9): 44–52. doi: 10.1109/CC.2016.7582295 -
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