1.
Gong, Tierui; Chandra, Aveek; Yuen, Chau; Guan, Yong Liang; Dumke, Rainer; See, Chong Meng Samson; Debbah, Mérouane; Hanzo, Lajos
Rydberg Atomic Quantum Receivers for Classical Wireless Communication and Sensing Journal Article
In: IEEE Wireless Communications, vol. 32, no. 5, pp. 90–100, 2025, ISSN: 1558-0687.
Abstract | Links | BibTeX | Tags: Atomic measurements, Electric fields, Electrons, Energy states, Laser beams, Quantum communication, Radio frequency, Receivers, RF signals, Rydberg atoms
@article{gong_rydberg_2025,
title = {Rydberg Atomic Quantum Receivers for Classical Wireless Communication and Sensing},
author = {Tierui Gong and Aveek Chandra and Chau Yuen and Yong Liang Guan and Rainer Dumke and Chong Meng Samson See and Mérouane Debbah and Lajos Hanzo},
url = {https://ieeexplore.ieee.org/document/10972179},
doi = {10.1109/MWC.015.2400381},
issn = {1558-0687},
year = {2025},
date = {2025-10-01},
urldate = {2025-10-08},
journal = {IEEE Wireless Communications},
volume = {32},
number = {5},
pages = {90–100},
abstract = {Rydberg atomic quantum receivers (RAQRs) are emerging quantum precision sensing platforms designed for receiving radio frequency (RF) signals. It relies on the creation of Rydberg atoms from normal atoms by exciting one or more electrons to a very high energy level, thereby making the atom sensitive to RF signals. RAQRs realize RF-to-optical conversions based on atom-light interactions relying on the so-called electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) so that the desired RF signal can be read out optically. The large dipole moments of Rydberg atoms associated with rich choices of Rydberg states facilitate an ultra-high sensitivity (textbackslashsimtextbackslashtextnv/textbackslashtextcm/textbackslashsqrttextbackslashtextHz) and an ultra-broadband tunability (direct-current to Terahertz). RAQRs also exhibit compelling scalability and lend themselves to the construction of innovative, compact receivers. Initial experimental studies have demonstrated their capabilities in classical wireless communications and sensing. To fully harness their potential in a wide variety of applications, we commence by outlining the underlying fundamentals of Rydberg atoms, followed by the principles and schemes of RAQRs. Then, we overview the state-of-the-art studies from both physics and communication societies. Furthermore, we conceive Rydberg atomic quantum single-input single-output (RAQ-SISO) and multiple-input multiple-output (RAQ-MIMO) schemes to facilitate the integration of RAQRs with classical wireless systems. Finally, we conclude with a set of potent research directions.},
keywords = {Atomic measurements, Electric fields, Electrons, Energy states, Laser beams, Quantum communication, Radio frequency, Receivers, RF signals, Rydberg atoms},
pubstate = {published},
tppubtype = {article}
}
Rydberg atomic quantum receivers (RAQRs) are emerging quantum precision sensing platforms designed for receiving radio frequency (RF) signals. It relies on the creation of Rydberg atoms from normal atoms by exciting one or more electrons to a very high energy level, thereby making the atom sensitive to RF signals. RAQRs realize RF-to-optical conversions based on atom-light interactions relying on the so-called electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) so that the desired RF signal can be read out optically. The large dipole moments of Rydberg atoms associated with rich choices of Rydberg states facilitate an ultra-high sensitivity (textbackslashsimtextbackslashtextnv/textbackslashtextcm/textbackslashsqrttextbackslashtextHz) and an ultra-broadband tunability (direct-current to Terahertz). RAQRs also exhibit compelling scalability and lend themselves to the construction of innovative, compact receivers. Initial experimental studies have demonstrated their capabilities in classical wireless communications and sensing. To fully harness their potential in a wide variety of applications, we commence by outlining the underlying fundamentals of Rydberg atoms, followed by the principles and schemes of RAQRs. Then, we overview the state-of-the-art studies from both physics and communication societies. Furthermore, we conceive Rydberg atomic quantum single-input single-output (RAQ-SISO) and multiple-input multiple-output (RAQ-MIMO) schemes to facilitate the integration of RAQRs with classical wireless systems. Finally, we conclude with a set of potent research directions.
2.
Mehrotra, Anand; Srivastava, Suraj; Reddy, N. Shanmughanadha; Jagannatham, Aditya; Hanzo, Lajos
Sparse Channel Estimation for MIMO OTFS/OTSM Systems Using Finite-Resolution ADCs Journal Article
In: IEEE Transactions on Communications, vol. 73, no. 6, pp. 3971–3987, 2025, ISSN: 1558-0857.
Abstract | Links | BibTeX | Tags: Bayes methods, Channel estimation, delay-Doppler, delay-sequency, Estimation, finite-resolution ADCs, Modulation, OFDM, OTFS, OTSM, Quantization (signal), Receivers, Signal processing algorithms, Signal resolution, sparsity, Time-domain analysis
@article{mehrotra_sparse_2025,
title = {Sparse Channel Estimation for MIMO OTFS/OTSM Systems Using Finite-Resolution ADCs},
author = {Anand Mehrotra and Suraj Srivastava and N. Shanmughanadha Reddy and Aditya Jagannatham and Lajos Hanzo},
url = {https://ieeexplore.ieee.org/document/10758799},
doi = {10.1109/TCOMM.2024.3502682},
issn = {1558-0857},
year = {2025},
date = {2025-06-01},
urldate = {2025-10-08},
journal = {IEEE Transactions on Communications},
volume = {73},
number = {6},
pages = {3971–3987},
abstract = {Variational Bayesian learning (VBL)-based sparse channel state information (CSI) estimation is conceived for multiple input multiple output (MIMO) orthogonal time frequency space (OTFS) and for orthogonal time sequence multiplexing (OTSM)-based systems relying on low-resolution analog-to-digital convertors (ADCs). First, the CSI estimation model is developed for MIMO-OTFS systems considering quantized outputs. Then a novel VBL technique is developed for exploiting the inherent DD domain sparsity. Subsequently, an end-to-end system model is derived for MIMO-OTSM systems, once again, using only finite-resolution ADCs. Similar to OTFS systems, it is demonstrated that the channel is sparse in the delay-sequency (DS)-domain. Thus the sparse CSI estimation problem of the MIMO-OTSM system can also be solved using the VBL technique developed for its OTFS counterpart. A bespoke minimum mean square error (MMSE) receiver is developed for data detection, which unlike the conventional MMSE receiver also accounts for the quantization error. Finally, finite-resolution ADCs emerge as a solution, offering reduced costs and energy consumption amid the growing challenge posed by energy-intensive high-resolution ADCs in Next-Generation (NG) systems. The efficacy of the proposed techniques is validated by simulation results, surpassing the state-of-the-art and signalling a transition towards more sustainable communication technologies.},
keywords = {Bayes methods, Channel estimation, delay-Doppler, delay-sequency, Estimation, finite-resolution ADCs, Modulation, OFDM, OTFS, OTSM, Quantization (signal), Receivers, Signal processing algorithms, Signal resolution, sparsity, Time-domain analysis},
pubstate = {published},
tppubtype = {article}
}
Variational Bayesian learning (VBL)-based sparse channel state information (CSI) estimation is conceived for multiple input multiple output (MIMO) orthogonal time frequency space (OTFS) and for orthogonal time sequence multiplexing (OTSM)-based systems relying on low-resolution analog-to-digital convertors (ADCs). First, the CSI estimation model is developed for MIMO-OTFS systems considering quantized outputs. Then a novel VBL technique is developed for exploiting the inherent DD domain sparsity. Subsequently, an end-to-end system model is derived for MIMO-OTSM systems, once again, using only finite-resolution ADCs. Similar to OTFS systems, it is demonstrated that the channel is sparse in the delay-sequency (DS)-domain. Thus the sparse CSI estimation problem of the MIMO-OTSM system can also be solved using the VBL technique developed for its OTFS counterpart. A bespoke minimum mean square error (MMSE) receiver is developed for data detection, which unlike the conventional MMSE receiver also accounts for the quantization error. Finally, finite-resolution ADCs emerge as a solution, offering reduced costs and energy consumption amid the growing challenge posed by energy-intensive high-resolution ADCs in Next-Generation (NG) systems. The efficacy of the proposed techniques is validated by simulation results, surpassing the state-of-the-art and signalling a transition towards more sustainable communication technologies.
3.
Hong, Zekun; Sugiura, Shinya; Xu, Chao; Hanzo, Lajos
Precoded Faster-Than-Nyquist Signaling Using Optimal Power Allocation for OTFS Journal Article
In: IEEE Wireless Communications Letters, vol. 14, no. 1, pp. 173–177, 2025, ISSN: 2162-2345.
Abstract | Links | BibTeX | Tags: Bandwidth, Delays, Doppler shift, doubly selective fading, Faster-than-Nyquist signaling, information rate, Information rates, Interference, mutual information, OTFS, Precoding, Pulse shaping methods, Receivers, Resource management, Symbols, Time-frequency analysis
@article{hong_precoded_2025,
title = {Precoded Faster-Than-Nyquist Signaling Using Optimal Power Allocation for OTFS},
author = {Zekun Hong and Shinya Sugiura and Chao Xu and Lajos Hanzo},
url = {https://ieeexplore.ieee.org/document/10742918},
doi = {10.1109/LWC.2024.3491777},
issn = {2162-2345},
year = {2025},
date = {2025-01-01},
urldate = {2025-10-08},
journal = {IEEE Wireless Communications Letters},
volume = {14},
number = {1},
pages = {173–177},
abstract = {A precoded orthogonal time frequency space (OTFS) modulation scheme relying on faster-than-Nyquist (FTN) transmission over doubly selective fading channels is proposed, which enhances the spectral efficiency and improves the Doppler resilience. We derive the input-output relationship of the FTN signaling in the delay-Doppler domain. Eigenvalue decomposition (EVD) is used for eliminating both the effects of inter-symbol interference and correlated additive noise encountered in the delay-Doppler domain to enable efficient symbol-by-symbol demodulation. Furthermore, the power allocation coefficients of individual frames are optimized for maximizing the mutual information under the constraint of the derived total transmit power. Our performance results demonstrate that the proposed FTN-based OTFS scheme can enhance the information rate while achieving a comparable BER performance to that of its conventional Nyquist-based OTFS counterpart that employs the same root-raised-cosine shaping filter.},
keywords = {Bandwidth, Delays, Doppler shift, doubly selective fading, Faster-than-Nyquist signaling, information rate, Information rates, Interference, mutual information, OTFS, Precoding, Pulse shaping methods, Receivers, Resource management, Symbols, Time-frequency analysis},
pubstate = {published},
tppubtype = {article}
}
A precoded orthogonal time frequency space (OTFS) modulation scheme relying on faster-than-Nyquist (FTN) transmission over doubly selective fading channels is proposed, which enhances the spectral efficiency and improves the Doppler resilience. We derive the input-output relationship of the FTN signaling in the delay-Doppler domain. Eigenvalue decomposition (EVD) is used for eliminating both the effects of inter-symbol interference and correlated additive noise encountered in the delay-Doppler domain to enable efficient symbol-by-symbol demodulation. Furthermore, the power allocation coefficients of individual frames are optimized for maximizing the mutual information under the constraint of the derived total transmit power. Our performance results demonstrate that the proposed FTN-based OTFS scheme can enhance the information rate while achieving a comparable BER performance to that of its conventional Nyquist-based OTFS counterpart that employs the same root-raised-cosine shaping filter.