arXiv subjects

Shanchi Wu

Publications and source records attributed to Shanchi Wu.

7 recordsLinked to original sources

arXiv2026

Weight Hybrid Architecture of Rydberg-Atomic Sensors

Rydberg atomic quantum receivers have been seen as novel radio frequency measurements and the high sensitivity to a large range of frequencies makes it attractive for communications reception. However, their performance can be significantly degraded by hardware-induced noise, particularly the noise from laser, which impacts the overall system noise floor and exhibits correlation. To address this challenge, this paper proposes a weight hybrid (WH) architecture for Rydberg-atomic sensors, a novel four-channel combining scheme designed for atomic sensors operating in correlated noise environments. By jointly processing dual signal channels and dual noise reference channels, the WH architecture effectively mitigates noise contributions from lasers and other hardware components. All channels are optimally combined via maximum likelihood estimation within an expectation maximization framework, enabling robust signal extraction under correlated noise. Moreover, the proposed WH architecture is universal and can be readily extended to other types of Rydberg receivers to achieve consistent performance improvements.

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arXiv2025

Low-Complexity Rydberg Array Reuse: Modeling and Receiver Design for Sparse Channels

Rydberg atomic quantum receivers have been seen as novel radio frequency measurements and the high sensitivity to a large range of frequencies makes it attractive for communications reception. However, current implementations of Rydberg array antennas predominantly rely on simple stacking of multiple single-antenna units. While conceptually straightforward, this approach leads to substantial system bulkiness due to the unique requirements of atomic sensors, particularly the need for multiple spatially separated laser setups, rendering such designs both impractical for real-world applications and challenging to fabricate. This limitation underscores the critical need for developing multiplexed Rydberg sensor array architectures. In the domain of conventional RF array antennas, hybrid analog-digital beamforming has emerged as a pivotal architecture for large-scale millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems, as it substantially reduces the hardware complexity associated with fully-digital beamforming while closely approaching its performance. Drawing inspiration from this methodology, we conduct a systematic study in this work on the design principles, equivalent modeling, and precoding strategies for low-complexity multiplexed Rydberg array, an endeavor crucial to enabling practical and scalable quantum-enhanced communication systems.

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arXiv2025

Characterization of Rydberg-Atom Signal Reception of Dual-Frequency Signals Coupled with Two Energy Levels

Rydberg atomic sensors have been adopted for novel radio frequency (RF) measurement technique and the sensing capability for signals in multiple frequencies makes it attractive for multi-user communication. However, unlike traditional antennas where the signals in multiple frequencies are orthogonal, the received signals of atomic sensors corresponding to different energy levels will be downconverted to the baseband simultaneously, resulting in multi-user interference. Thus, in this paper, we analyze the mutual interference characteristics of two RF signals with different carrier frequencies coupling different energy levels. We introduce the joint response coefficient based on the receiver characteristics and analyze the interference of one user to another. We analyze the bit-error rate (BER) and symbol-error rate (SER) for two signals coupling two different energy levels. We also conduct experiments to validate the BER and SER results.

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arXiv2023

Atomic superheterodyne receiver Sensitivity estimation based on homodyne readout

The electric field measurement sensitivity based on the Rydberg atomic vapor cell has great theoretical advantages over traditional dipole antennas. We combine the Rydberg atomic heterodyne receiver and the Mach-Zehnder interferometer (MZI) with high phase detection sensitivity to evaluate the system reception sensitivity based on the transmitted laser phase shift. We conduct a theoretical investigation into the impacts of local microwave electric field frequency detuning, and laser frequency detuning on enhancing the sensitivity of heterodyne Rydberg atomic receiver based on MZI. To optimize the output signal amplitude given the input microwave signal, we derive the steady-state solutions of the atomic density matrix. Numerical results show that laser frequency detuning and local microwave electric field frequency detuning can improve the system detection sensitivity, which can help the system achieve extra sensitivity gain. It also shows that the phase-based readout scheme of heterodyne Rydberg atomic receiver based on MZI can achieve better sensitivity than the intensity-based readout scheme of heterodyne Rydberg atomic receiver.

physics.atom-ph↗

arXiv2023

Theoretical Analysis of Heterodyne Rydberg Atomic Receiver Sensitivity Based on Transit Relaxation Effect and Frequency Detuning

We conduct a theoretical investigation into the impacts of local microwave electric field frequency detuning, laser frequency detuning, and transit relaxation rate on enhancing heterodyne Rydberg atomic receiver sensitivity. To optimize the output signal amplitude given the input microwave signal, we derive the steady-state solutions of the atomic density matrix. Numerical results show that laser frequency detuning and local microwave electric field frequency detuning can improve the system detection sensitivity, which can help the system achieve extra sensitivity gain. It also shows that the heterodyne Rydberg atomic receiver can detect weak microwave signals continuously over a wide frequency range with the same sensitivity or even more sensitivity than the resonance case. To evaluate the transit relaxation effect, a modified Liouville equation is used. We find that the transition relaxation rate increases the time it takes to reach steady state and decreases the sensitivity of the system detection.

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arXiv2021

Quantumized Microwave Detection Based on $Λ$-Type Three-level Superconducting System: HMM Modeling and Performance Prediction

We adopt artificial $Λ$-type three-level system with superconducting devices for microwave signal detection, where the signal intensity reaches the level of discrete photons instead of continuous waveform. Based on the state transition principles of the three-level system, we propose a statistical model for microwave signal detection. Moreover, we investigate the achievable transmission rate and signal detection based on the statistical model. It is predicted that the proposed detection can achieve significantly higher sensitivity compared with the currently deployed 4G/5G communication system. We further characterize the received signal considering the saturation phonomenon, which reveals negligible performance degradation caused by saturation under weak received power regime.

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arXiv2020

Weak Radio Frequency Signal Detection Based on Piezo-Opto-Electro-Mechanical System: Architecture Design and Sensitivity Prediction

We propose a novel radio-frequency (RF) receiving architecture based on micro-electro-mechanical system (MEMS) and optical coherent detection module. The architecture converts the received electrical signal into mechanical vibration through the piezoelectric effect and adopts an optical detection module to detect the mechanical vibration. We analyze the response function of piezoelectric film to an RF signal, the noise limited sensitivity of the optical detection module and the system transfer function in the frequency domain. Finally, we adopt simple on-off keying (OOK) modulation with bandwidth 1 kHz and carrier frequency 1 GHz, to numerically evaluate the detection sensitivity. The result shows that, considering the main noise sources in wireless channel and circuits, the signal detection sensitivity can reach around -160 dBm with a 50 $Ω$ impedance. Such sensitivity significantly outperforms that of the currently deployed Long Term Evolution (LTE) system, when normalizing the transmission bandwidth also to 1 kHz.

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