[1] Lai, Chengzhe and Lu, Rongxing and Zheng, Dong and Shen, Xuemin, “ Security and privacy challenges in 5G-enabled vehicular networks," IEEE Network, vol. 34, no. 2, pp 37-45, 2020.
[2] Taheribakhsh, Morteza and Jafari, AmirHossein and Peiro, Mahdi Moazzami and Kazemifard, Nasrin, “5g implementation: Major issues and challenges," IEEE 25th International Computer Conference, Computer Society of Iran (CSICC),pp 1-5, 2020
[3] Al-Falahy, Naser and Alani, Omar Y, “Technologies for 5G networks: Challenges and opportunities," It Professional, vol. 19, no.1, pp 12-20, 2017.
[4] Khichar, Sunita and Santipach, Wiroonsak and Wuttisittikulkij, Lunchakorn and Parnianifard, Amir and Chaudhary, Sushank, “Efficient Channel Estimation in OFDM Systems Using a Fast Super-Resolution CNN Model," Journal of Sensor and Actuator Networks, vol.13, no.5, pp. 55, MDPI 2024.
[5] Chaudhary, Sushank and Sharma, Abhishek and Naeem, Muhammad Ali and Meng, Yahui, “ Target Detection in Challenging Environments: Photonic Radar with a Hybrid Multiplexing Scheme for 5G Autonomous Vehicles," Sustainability, vol.16, no.3 , pp 991, MDPI 2024.
[6] B. Ai et al., “Challenges Toward Wireless Communications for High-Speed Railway” IEEE Transactions on Intelligent Transportation Systems, vol. 15, no. 5, pp. 2143-2158, Oct.
[7] R. He et al., “ High-Speed Railway Communications: From GSM-R to LTE-R," IEEE Vehicular Technology Magazine, vol. 11, no. 3, pp. 49-58, Sept. 2016, doi: 10.1109/MVT.2016.2564446.
[8] R. He et al., "5G for Railways: Next Generation Railway Dedicated Communications," IEEE Communications Magazine, vol. 60, no. 12, pp. 130-136, December 2022, doi: 10.1109/MCOM.005.2200328.
[9] B. Ai, A. F. Molisch, M. Rupp and Z. -D. Zhong, "5G Key Technologies for Smart Railways," Proceedings of the IEEE, vol. 108, no. 6, pp. 856-893, June 2020, doi: 10.1109/JPROC.2020.2988595.
[10] C. Zhang, G. Wang, M. Jia, R. He, L. Zhou and B. Ai, "Doppler Shift Estimation for Millimeter-Wave Communication Systems on High-Speed Railways," IEEE Access, vol. 7, pp. 40454-40462, 2019, doi: 10.1109/ACCESS.2018.2861889.
[11] Z. Gong, C. Li, F. Jiang and M. Z. Win, "Data-Aided Doppler Compensation for High-Speed Railway Communications Over mmWave Bands," IEEE Transactions on Wireless Communications, vol. 20, no. 1, pp. 520-534, Jan. 2021, doi: 10.1109/TWC.2020.3026158.
[12] T. Kim, K. Ko, I. Hwang, D. Hong, S. Choi and H. Wang, "RSRP-Based Doppler Shift Estimator Using Machine Learning in High-Speed Train Systems," IEEE Transactions on Vehicular Technology, vol. 70, no. 1, pp. 371-380, Jan. 2021, doi: 10.1109/TVT.2020.3044175.
[13] Y. Wang, G. Wang, R. He, B. Ai and C. Tellambura, "Doppler Shift and Channel Estimation for Intelligent Transparent Surface Assisted Communication Systems on High-Speed Railways," IEEE Transactions on Communications, vol. 71, no. 7, pp. 4204-4215, July 2023, doi: 10.1109/TCOMM.2023.3275590.
[14] J. Li and Y. Zhao, ''Radio environment map-based cognitive Doppler spread compensation algorithms for high-speed rail broadband mobile communications,'' EURASIP J. Wireless Commun. Netw., vol. 2012, no. 1, pp. 1–18, 2012. doi: 10.1186/1687-1499-2012-263.
[15] Z. Hou, Y. Zhou, L. Tian, J. Shi, Y. Li and B. Vucetic, "Radio Environment Map-Aided Doppler Shift Estimation in LTE Railway," in IEEE Transactions on Vehicular Technology, vol. 66, no. 5, pp. 4462-4467, May 2017, doi: 10.1109/TVT.2016.2599558.
[16] R. Hadani et al., "Orthogonal Time Frequency Space Modulation," 2017 IEEE Wireless Communications and Networking Conference (WCNC), San Francisco, CA, USA, 2017, pp. 1-6, doi: 10.1109/WCNC.2017.7925924.
[17] R. Hadani and A. Monk, ''OTFS: A new generation of modulation addressing the challenges of 5G,'' Preprint, 2018, arXiv:1802.02623.
[18] Z. Wei et al., "Orthogonal Time-Frequency Space Modulation: A Promising Next-Generation Waveform," IEEE Wireless Communications, vol. 28, no. 4, pp. 136-144, August 2021, doi: 10.1109/MWC.001.2000408.
[19] P. Raviteja, K. T. Phan and Y. Hong, "Embedded Pilot-Aided Channel Estimation for OTFS in Delay–Doppler Channels," IEEE Transactions on Vehicular Technology, vol. 68, no. 5, pp. 4906-4917, May 2019, doi: 10.1109/TVT.2019.2906357.
[20] P. Raviteja, K. T. Phan, Y. Hong and E. Viterbo, "Interference Cancellation and Iterative Detection for Orthogonal Time Frequency Space Modulation," IEEE Transactions on Wireless Communications, vol. 17, no. 10, pp. 6501-6515, Oct. 2018, doi: 10.1109/TWC.2018.2860011.
[21] S. Li et al., "A Tutorial to Orthogonal Time Frequency Space Modulation for Future Wireless Communications," 2021 IEEE/CIC International Conference on Communications in China (ICCC Workshops), Xiamen, China, 2021, pp. 439-443, doi: 10.1109/ICCCWorkshops52231.2021.9538891.
[22] P. Raviteja, Y. Hong, E. Viterbo and E. Biglieri, "Practical Pulse-Shaping Waveforms for Reduced-Cyclic-Prefix OTFS," IEEE Transactions on Vehicular Technology, vol. 68, no. 1, pp. 957-961, Jan. 2019, doi: 10.1109/TVT.2018.2878891.
[23] Z. Wei, W. Yuan, S. Li, J. Yuan and D. W. K. Ng, "Transmitter and Receiver Window Designs for Orthogonal Time-Frequency Space Modulation," IEEE Transactions on Communications, vol. 69, no. 4, pp. 2207-2223, April 2021, doi: 10.1109/TCOMM.2021.3051386.
[24] H. Zhang, X. Huang and J. A. Zhang, "Adaptive Transmission With Frequency-Domain Precoding and Linear Equalization Over Fast Fading Channels," in IEEE Transactions on Wireless Communications, vol. 20, no. 11, pp. 7420-7430, Nov. 2021, doi: 10.1109/TWC.2021.3083652.
[25] F. Liu, Z. Yuan, Q. Guo, Z. Wang and P. Sun, "Message Passing-Based Structured Sparse Signal Recovery for Estimation of OTFS Channels With Fractional Doppler Shifts," IEEE Transactions on Wireless Communications, vol. 20, no. 12, pp. 7773-7785, Dec. 2021, doi: 10.1109/TWC.2021.3087501.
[26] A. Pfadler, T. Szollmann, P. Jung and S. Stanczak, "Leakage Suppression in Pulse-Shaped OTFS Delay-Doppler-Pilot Channel Estimation," in IEEE Wireless Communications Letters, vol. 11, no. 6, pp. 1181-1185, June 2022, doi: 10.1109/LWC.2022.3160657.
[27] L. Xiang, Y. Liu, L. -L. Yang and L. Hanzo, "Gaussian Approximate Message Passing Detection of Orthogonal Time Frequency Space Modulation," IEEE Transactions on Vehicular Technology, vol. 70, no. 10, pp. 10999-11004, Oct. 2021, doi: 10.1109/TVT.2021.3102673.
[28] W. Yuan, Z. Wei, J. Yuan and D. W. K. Ng, "A Simple Variational Bayes Detector for Orthogonal Time Frequency Space (OTFS) Modulation," in IEEE Transactions on Vehicular Technology, vol. 69, no. 7, pp. 7976-7980, July 2020, doi: 10.1109/TVT.2020.2991443.
[29] R. Chong, S. Li, J. Yuan and D. W. K. Ng, "Achievable Rate Upper-Bounds of Uplink Multiuser OTFS Transmissions," IEEE Wireless Communications Letters, vol. 11, no. 4, pp. 791-795, April 2022, doi: 10.1109/LWC.2022.3145036.
[30] K. Deka, A. Thomas and S. Sharma, "OTFS-SCMA: A Code-Domain NOMA Approach for Orthogonal Time Frequency Space Modulation," IEEE Transactions on Communications, vol. 69, no. 8, pp. 5043-5058, Aug. 2021, doi: 10.1109/TCOMM.2021.3075237.
[31] V. Khammammetti and S. K. Mohammed, "OTFS-Based Multiple-Access in High Doppler and Delay Spread Wireless Channels," in IEEE Wireless Communications Letters, vol. 8, no. 2, pp. 528-531, April 2019, doi: 10.1109/LWC.2018.2878740.
[32] Y. Ma, G. Ma, N. Wang, Z. Zhong and B. Ai, "OTFS-TSMA for Massive Internet of Things in High-Speed Railway," IEEE Transactions on Wireless Communications, vol. 21, no. 1, pp. 519-531, Jan. 2022, doi: 10.1109/TWC.2021.3098033.
[33] Y. Ma et al., "Characteristics of Channel Spreading Function and Performance of OTFS in High-Speed Railway," IEEE Transactions on Wireless Communications, vol. 22, no. 10, pp. 7038-7054, Oct. 2023, doi: 10.1109/TWC.2023.3247736.
[34] A. F. Molisch, "Delay-Doppler Communications: Principles and Applications," IEEE Communications Magazine, vol. 61, no. 3, pp. 10-10, March 2023, doi: 10.1109/MCOM.2023.10080900.
[35] M. Berbineau et al., "Channel Models for Performance Evaluation of Wireless Systems in Railway Environments," IEEE Access, vol. 9, pp. 45903-45918, 2021, doi: 10.1109/ACCESS.2021.3066112.
[36] L. Liu et al., "Position-Based Modeling for Wireless Channel on High-Speed Railway under a Viaduct at 2.35 GHz," IEEE Journal on Selected Areas in Communications, vol. 30, no. 4, pp. 834-845, May 2012, doi: 10.1109/JSAC.2012.120516.
[37] A. Naikoti and A. Chockalingam,"Signal detection and channel estimation in OTFS," ZTE Communications, vol. 19, no. 4, pp. 16–33, Dec. 2021. doi: 10.12142/ZTECOM.202104003.