研究简介
6G发展的新趋势为无线传输技术的发展提供了新的机遇。具体而言,大规模MIMO向超大规模MIMO的演进显著提升了空间分辨率;毫米波和太赫兹高频信道在空间域和时间域呈现稀疏特性;通过融合超大规模MIMO,定位通信感知一体化技术能够提供超高精度的定位和感知能力。通过挖掘超大规模MIMO的超高空间分辨率和毫米波/太赫兹高频信道的稀疏性,时延多普勒对齐调制(DDAM,Delay-Doppler Alignment Modulation)通过空间-时延-多普勒域信号处理,能够实现多普勒和信道时延扩展的联合调控。DDAM的核心思想是时延-多普勒补偿和逐径波束赋形。通过在发射机或接收机端引入匹配各条路径的时延和多普勒相移,结合逐径波束赋形,可以消除每条径的多普勒效应,并且所有多径信号分量能够同时到达接收机。从而,DDAM可以将时频双选信道转化为时不变无ISI信道,无需进行复杂的信道均衡或多载波传输。对于时不变频率选择性信道,DDAM退化为时延对齐调制(DAM,Delay Alignment Modulation)。
超大规模天线DDAM传输示意图
研究特点
针对时不变频率选择性信道,通过建立可调控信道时延扩展的DAM处理架构,能够实现高效的单载波和多载波传输。完美DAM可以将频率选择性信道转化为无ISI信道。当完美DAM不可行时,可以通过普适DAM调控信道时延扩展,同时充分利用多径信号分量。
稀疏多径信道
完美DAM
普适DAM
DAM通信优势
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可调控信道时延扩展
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无符号间干扰单载波和多载波通信的统一架构,免于复杂的信道均衡
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降低保护间隔开销
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低信号处理时延和低复杂度接收机
DAM感知优势
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低峰旁比
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抗多普勒频偏
此外,针对时频双选信道,基于空间-时延-多普勒域处理的DDAM能够联合调控多普勒和信道时延扩展,可以将时频双选信道转化为时不变的无符号间干扰信道,无需进行复杂的信道均衡或多载波传输。
研究成果
期刊
[1] H. Lu and Y. Zeng, “Delay alignment modulation: Enabling equalization-free single-carrier communication,” IEEE Wireless Commun. Lett., vol. 11, no. 9, pp. 1785–1789, Sep. 2022.
论文链接:https://ieeexplore.ieee.org/document/9790794
[2] H. Lu and Y. Zeng, “Delay alignment modulation: Manipulating channel delay spread for efficient single- and multi-carrier communication,” IEEE Trans. Commun., vol. 71, no. 11, pp. 6316–6331, Nov. 2023.
论文链接:https://ieeexplore.ieee.org/document/10225416
[3] Z. Xiao and Y. Zeng, “Integrated sensing and communication with delay alignment modulation: Performance analysis and beamforming optimization,” IEEE Trans. Wireless Commun., vol. 22, no. 12, pp. 8904–8918, Dec. 2023.
论文链接:https://ieeexplore.ieee.org/document/10105893
[4] H. Lu, Y. Zeng, S. Jin, and R. Zhang, “Single-carrier delay alignment modulation for multi-IRS aided communication,” IEEE Trans. Wireless Commun., 2023.
论文链接:https://ieeexplore.ieee.org/document/10231105
[5] H. Lu and Y. Zeng, “Delay-Doppler alignment modulation for spatially sparse massive MIMO communication,” IEEE Trans. Wireless Commun., 2023.
论文链接:https://ieeexplore.ieee.org/document/10314448
会议
[1] Z. Xiao and Y. Zeng, “Integrated sensing and communication with delay alignment modulation,” in Proc. IEEE Int. Conf. Commun. (ICC), May 2022, pp. 793–798.
论文链接:https://ieeexplore.ieee.org/document/9839117
[2] Z. Xiao, Y. Zeng, D. W. K. Ng, and F. Wen, “Exploiting double timescales for integrated sensing and communication with delay-Doppler alignment modulation,” in Proc. IEEE Int. Conf. Commun. (ICC), May 2023, pp. 5731–5736.
论文链接:https://ieeexplore.ieee.org/document/10279599
[3] X. Wang, H. Lu, and Y. Zeng, “Multi-user delay alignment modulation for millimeter wave massive MIMO,” in Proc. IEEE Global Commun. Conf. (GLOBECOM), Dec. 2023, pp. 6970-6975.
论文链接:https://ieeexplore.ieee.org/document/10437061
[4] D. Ding, Y. Zeng, and D. Wang, “Channel estimation for delay alignment modulation,” in Proc. IEEE Wireless Commun. Netw. Conf. Workshops (WCNCW), 2024.
论文链接:https://arxiv.org/abs/2206.09339
[5] J. Zhang and Y. Zeng, “Delay alignment modulation with hybrid beamforming for spatially sparse communications,” in Proc. IEEE Wireless Commun. Netw. Conf. (WCNC), 2024.
论文链接:https://arxiv.org/abs/2307.08210
[6] Z. Zhou, Z. Xiao, and Y. Zeng, “Fractional delay alignment modulation for spatially sparse wireless communications,” in Proc. IEEE Wireless Commun. Netw. Conf. (WCNC), 2024.
论文链接:https://arxiv.org/abs/2403.19951
预印本
[1] X. Wang, H. Lu, Y. Zeng, X. Xu, and J. Xu, “Achievable rate region and path-based beamforming for multi-user single-carrier delay alignment modulation,” arXiv:2309.00391, 2023.
论文链接:https://arxiv.org/abs/2309.00391
[2] Z. Xiao, Y. Zeng, D. W. K. Ng, and F. Wen, “Integrated sensing and channel estimation by exploiting dual timescales for delay-Doppler alignment modulation,” arXiv:2310.11326, 2023.
论文链接:https://arxiv.org/abs/2310.11326