Rydberg atomic receivers represent a transformative approach to achieving high-sensitivity, broadband, and miniaturized radio frequency (RF) reception. However, existing static signal models for Rydberg atomic receivers rely on the steady-state assumption of atomic quantum states, which cannot fully describe the signal reception process of dynamic signals. To fill in this gap, in this paper, we present a general model to compute the dynamic signal response of Rydberg atomic receivers in closed form. Specifically, by applying small-signal perturbation techniques to the quantum master equation, we derive closed-form Laplace domain transfer functions that characterize the receiver’s dynamic responses to time-varying signal fields. To gain more insights into the quantum-based RF-photocurrent conversion process, we further introduce the concept of quantum transconductance that describes the quantum system as an equivalent classical system. By applying quantum transconductance, we quantify the influence of in-band blackbody radiation (BBR) noise on the atomic receiver sensitivity. Extensive simulations for Rydberg atomic receivers validate the proposed signal model, and demonstrate the possibility of quantum receivers to outperform classical electronic receivers through the improvement of quantum transconductance.
Rydberg atomic receivers represent a transformative approach to achieving high-sensitivity, broadband, and miniaturized radio frequency (RF) reception. However, existing static signal models for Rydberg atomic receivers rely on the steady-state assumption of atomic quantum states, which cannot fully describe the signal reception process of dynamic signals. To fill in this gap, in this paper, we present a general model to compute the dynamic signal response of Rydberg atomic receivers in closed form. Specifically, by applying small-signal perturbation techniques to the quantum master equation, we derive closed-form Laplace domain transfer functions that characterize the receiver’s dynamic responses to time-varying signal fields. To gain more insights into the quantum-based RF-photocurrent conversion process, we further introduce the concept of quantum transconductance that describes the quantum system as an equivalent classical system. By applying quantum transconductance, we quantify the influence of in-band blackbody radiation (BBR) noise on the atomic receiver sensitivity. Extensive simulations for Rydberg atomic receivers validate the proposed signal model, and demonstrate the possibility of quantum receivers to outperform classical electronic receivers through the improvement of quantum transconductance.
Rydberg atomic quantum receivers represent a transformative approach to achieving high-sensitivity, broadband, and miniaturized radio frequency (RF) reception. However, existing static signal models for Rydberg atomic receivers rely on the steady-state assumption of atomic quantum states, which cannot fully describe the signal reception process of dynamic signals. To fill in this gap, in this paper, we present a transfer function-based model to compute the dynamic signal response of Rydberg atomic receivers in closed form. Specifically, by applying small-signal perturbation techniques to the quantum master equation, we derive closed-form Laplace domain transfer functions that characterize the receiver’s dynamic responses to time-varying signal fields. To gain more insights into the quantum-based RF-photocurrent conversion process, we further introduce the concept of quantum transconductance that describes the quantum system as an equivalent classical system. Simulations for Rydberg atomic receivers validate the proposed signal model, and demonstrate the possibility of quantum receivers to outperform classical electronic receivers through the improvement of quantum transconductance.
The significant progress of quantum sensing technologies offer numerous radical solutions for measuring a multitude of physical quantities at an unprecedented precision. Among them, Rydberg atomic quantum receivers (RAQRs) emerge as an eminent solution for detecting the electric field of radio frequency (RF) signals, exhibiting great potential in assisting classical wireless communications and sensing. So far, most experimental studies have aimed for the proof of physical concepts to reveal its promise, while the practical signal model of RAQR-aided wireless communications and sensing remained under-explored. Furthermore, the performance of RAQR-based wireless receivers and their advantages over classical RF receivers have not been fully characterized. To fill these gaps, we introduce the RAQR to the wireless community by presenting an end-to-end reception scheme. We then develop a corresponding equivalent baseband signal model relying on a realistic reception flow. Our scheme and model provide explicit design guidance to RAQR-aided wireless systems. We next study the performance of RAQR-aided wireless systems based on our model, and compare them to classical RF receivers. The results show that Doppler broadening-free RAQRs are capable of achieving a substantial received signal-to-noise ratio (SNR) gain of over 27 decibel (dB) and 40 dB in the photon shot limit and standard quantum limit regimes, respectively.
The intrinsic integration of Rydberg atomic receivers into wireless communication systems is proposed, by harnessing the principles of quantum physics in wireless communications. More particularly, we conceive a pair of Rydberg atomic receivers, one incorporates a local oscillator (LO), referred to as an LO-dressed receiver, while the other operates without an LO and is termed an LO-free receiver. The appropriate wireless model is developed for each configuration, elaborating on the receiver's responses to the radio frequency (RF) signal, on the potential noise sources, and on the signal-to-noise ratio (SNR) performance. The developed wireless model conforms to the classical RF framework, facilitating compatibility with established signal processing methodologies. Next, we investigate the associated distortion effects that might occur, specifically identifying the conditions under which distortion arises and demonstrating the boundaries of linear dynamic ranges. This provides critical insights into its practical implementations in wireless systems. Finally, extensive simulation results are provided for characterizing the performance of wireless systems, harnessing this pair of Rydberg atomic receivers. Our results demonstrate that LO-dressed systems achieve a significant SNR gain of approximately 40~50 dB over conventional RF receivers in the standard quantum limit regime. This SNR head-room translates into reduced symbol error rates, enabling efficient and reliable transmission with higher-order constellations.
Rydberg atomic quantum receivers (RAQRs) emerge as a radical solution for detecting radio frequency (RF) signals, showing great potential in assisting classical wireless communications and sensing. However, the current studies of RAQRs mainly focus on realizing fundamental functionalities via experiments, where the results cannot be readily harnessed for assisting wireless communications and sensing. Moreover, the advantages of RAQR-based wireless receivers have not been fully characterized. To fill the gap, we introduce the superheterodyne version of RAQRs and present the associated end-to-end transmission scheme. We then develop a corresponding end-to-end equivalent baseband signal model relying on a realistic transmission flow. Our scheme and model provide explicit design guidance for RAQR-aided wireless systems. We finally verify the effectiveness of the proposed signal model with respect to the waveform of the photodetector, input-output relationship (transfer function), and the normalized mean-squared error between the nonlinear transfer function and its linear approximation.
Rydberg atomic quantum receivers (RAQRs) have recently emerged as a promising technology for radio-frequency (RF) reception by directly transducing incident RF fields into optical signals. Existing receiver architectures, however, exploit only subsets of the dipole-allowed transitions within a given atomic manifold, limiting the number of simultaneously accessible RF channels. In this paper, a hybrid six-level Rydberg atomic quantum receiver (H-RAQR) is proposed by integrating parallel and cascaded RF coupling pathways within a single vapor-cell receiver. A communication-oriented analytical framework is developed by deriving a closed-form steady-state atom--field interaction model and establishing an equivalent baseband signal representation. The achievable ergodic sum rate is analyzed, and a resource-efficiency metric is introduced to quantify throughput per unit optical receiver resource. The analytical model is validated against full Lindblad master-equation simulations over its identified operating region. Numerical results show that the proposed H-RAQR supports four simultaneous RF channels within a single atomic system, achieves higher ergodic sum rate than conventional parallel Rydberg state (PRS) and cascade Rydberg state (CRS) receivers, and provides about 29% higher resource efficiency than a combined PRS-CRS deployment with equivalent four-band coverage. The proposed framework provides a scalable foundation for multi-band atomic wireless receivers.
Rydberg atomic quantum receivers (RAQRs) are capable of receiving multi-band radio-frequency (RF) signals simultaneously, which are expected to break Chu's limit for classical electronic antennas. However, signals from different users will interfere with each other in the optical intermediate frequency (IF) domain of the multi-band quantum receiver, which is termed the IF interference (IFI) problem. To address this problem, in this paper, we propose a multi-input multi-output (MIMO) architecture for Rydberg atomic quantum receiver (RAQ-MIMO) by exploiting the additional spatial diversity of MIMO receivers. Specifically, by applying the dynamic signal model of RAQRs, we clarify the physical relationship between the quantum local oscillator (LO) configurations and the multi-band gains with the concept of quantum transconductance. Then, with the quantum transconductance-based signal model, we formulate the spectral efficiency (SE) maximization problem and further propose the quantum weighted minimum mean square error (qWMMSE) algorithm, which jointly optimizes the quantum LO configurations and the classical precoder/combiner matrices. Furthermore, we test the qWMMSE algorithm within the standard space division multiple access (SDMA) scheme and the frequency division multiple access (FDMA) scheme. Simulation results demonstrate that the qWMMSE optimization framework can significantly improve the SE of RAQ-MIMO systems for both multiple access schemes, and that RAQ-MIMO systems can outperform classical electronic receiver-based multi-user MIMO systems by eliminating the mutual coupling effect between classical antennas.