Image interference is a common issue in heterodyne reception structures, introducing co-channel interference and degrading performance. Although the heterodyne structure significantly improves the sensitivity of the Rydberg-atom-based receiver, the presence of image interference limits its practical application. In this work, we design a quadrature reception structure with a Rydberg-atom-based receiver and experimentally evaluate its performance. This architecture provides orthogonal receiving channels, down-converting input signals into complex form and enabling the separation of image-frequency components. Experiments confirm that conventional heterodyne reception suffers from image interference, while our quadrature structure effectively cancels it after channel compensation. The demonstrated Rydberg-atom-based quadrature receiver shows strong potential for wireless communication and precision measurement, especially in multi-signal environments.
Image interference is a common issue in heterodyne reception structures, introducing co-channel interference and degrading performance. Although the heterodyne structure significantly improves the sensitivity of the Rydberg-atom-based receiver, the presence of image interference limits its practical application. In this work, we design a quadrature reception structure with a Rydberg-atom-based receiver and experimentally evaluate its performance. This architecture provides orthogonal receiving channels, down-converting input signals into complex form and enabling the separation of image-frequency components. Experiments confirm that conventional heterodyne reception suffers from image interference, while our quadrature structure effectively cancels it after channel compensation. The demonstrated Rydberg-atom-based quadrature receiver shows strong potential for wireless communication and precision measurement, especially in multi-signal environments.
As a key enabler for next-generation wireless systems, integrated sensing and communication (ISAC) requires significantly higher receiver sensitivity than conventional architectures to achieve long-range target detection, thereby introducing new challenges in receiver design. Among potential solutions, Rydberg atomic quantum receivers (RAQRs) have attracted growing attention for their unique quantum sensing capabilities. By exploiting the exceptional responsiveness of Rydberg atoms to electromagnetic fields, RAQRs enable direct and highly sensitive measurement of radio-frequency (RF) signals without relying on traditional antenna-based front ends. However, this enhanced sensitivity also renders them more vulnerable to interference, particularly from undesired targets and long-delay multipath components. To address this limitation, this article presents practical strategies for improving the interference robustness and selective reception performance of RAQRs in ISAC scenarios. Specifically, we begin with a comprehensive overview of RAQR principles and identify the interference-related challenges encountered in ISAC applications. Building on this foundation, we introduce the Actively Selective RAQR (AS-RAQR) architecture, which integrates tunable gating mechanisms to actively suppress unwanted signals. The proposed design is validated through representative case studies, followed by a discussion of open challenges and future research directions.
Superdirective receive arrays, whose gain can exceed that of traditional antenna arrays, have been historically challenging to realize due to high sensitivity to white noise, strong mutual coupling, and the complexity of designing receive matching networks in conventional systems. This paper proposes and analyzes a novel superdirective receiver architecture based on an array of Rydberg atomic sensors to overcome these fundamental limitations. By leveraging the quantum properties of Rydberg atoms, the proposed receiver is inherently immune to the internal thermal noise that plagues traditional receivers. As a result, the system performance is primarily limited by external background noise and fundamental quantum noise. We develop a comprehensive signal and noise model and the-oretically derive the upper bound on the directivity gain for the proposed Rydberg-based receiver. Furthermore, we prove that for multi-user scenarios, the effective channel vectors for different users become asymptotically orthogonal as the number of sensors approaches infinity, enabling high-capacity spatial multiplexing even with deep sub-wavelength element spacing. Extensive simulations demonstrate the superior performance of the proposed system over traditional superdirective receivers and validate our theoretical findings. The results highlight Rydberg atomic arrays as a promising technology for developing ultra-sensitive, compact, and broadband superdirective receivers for next-generation communication and sensing applications.
Rydberg atomic quantum receivers (RAQR) exhibit exceptional sensitivity to radio-frequency (RF) signals, positioning them as promising candidates for next-generation wireless systems. Extending their capabilities to orthogonal frequency-division multiplexing (OFDM), however, requires atomic responses that go beyond broadband reception and are tailored to the structured interference of multicarrier signals. To bridge this gap, we develop an atomic-comb Rydberg receiver based on six-wave mixing (SWM) transduction. In particular, injecting a multi-tone local oscillator (LO) into the RAQR generates frequency-shifted replicas of the intrinsic SWM response. By subtly tuning the amplitude and phase of each LO tone, constructive and destructive interference can be selectively induced to preserve desired response components while attenuating harmful frequency offsets. Furthermore, we harness the response-reshaping capability of the proposed atomic comb to proactively mitigate OFDM interference. More explicitly, by exploiting the discrete difference-frequency structure of both carrier-frequency-offset (CFO)-induced and phase-noise (PN)-induced inter-carrier interference (ICI), we optimize the atomic-comb response to suppress dominant ICI components directly. We further reveal an intrinsic coupling between spectral shaping and the time-domain effective channel memory, motivating a joint optimization of both ICI and inter-symbol interference (ISI), which simultaneously suppresses inter-carrier leakage and post-cyclic-prefix (CP) tail energy. Extensive simulation results validate our atomic-comb design, unveiling that the proposed atomic comb can effectively reshape the receiver response over the OFDM, while mitigating ICI, shortening the effective channel memory, and substantially lowering CP overhead.
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.
Rydberg atoms exhibit both remarkable sensitivity to electromagnetic fields making them promising candidates for revolutionizing field sensors and, unlike conventional antennas, they neither disturb the measured field nor necessitate extensive calibration procedures. In this study, we propose a receiver design for data-modulated signal reception near the 2.4 GHz Wi-Fi frequency band, harnessing the capabilities of warm Rydberg atoms. Our focus lies on exploring various quadrature amplitude modulations and transmission frequencies through heterodyne detection. We offer a comprehensive characterization of our setup, encompassing the atomic response frequency range, attainable electric field amplitudes, and sensitivity, which we estimate to be equal to 0.50 µV cm −1 Hz −0.5 . Additionally, we delve into analyzing communication errors using Voronoi diagrams and evaluating the communication channel capacity across different modulation schemes. We find that the maximum achievable capacity for a single communication channel equals 19.3 Mbps and can be achieved using the Q A M 4 scheme.
With the escalating development of the quantum information technologies, the Rydberg atomic receiver has been envisioned as a promising alternative to its classical electronic counterparts, attracting extensive attentions from both physics and electronic engineering disciplines. By exploiting the electrical acuteness of Alkali atoms with diverse Rydberg energy states for electromagnetic field measurement, Rydberg atomic receiver is capable of surmounting the inherent limitations on the operating bandwidth and detection sensitivity of the classical electronic counterparts. Against this background, this article provides an extensive overview of Rydberg atomic communication and sensing from fundamental theory, critical technologies to practical implementations. Firstly, the milestones of the Rydberg atomic receiver evolution was introduced. Then we provide a clear understanding of Rydberg atomic receiver mechanisms from the perspective of classical communication and sensing, and highlight the unprecedented advantages over traditional electronic receivers as well as the technical challenges. Afterwards, necessary fundamentals are presented including the Rydberg atoms, typical non-coherent/coherent structures, and explicit experimental configurations, followed by discussions on state-of-the-art development of the Rydberg atomic receiver. Specifically, advancements on electric-field detection methods for accurate measurement of amplitude, phase, frequency and polarization, are extensively investigated. Based on the established methodologies, recent innovations in Rydberg atomic communication and sensing are reviewed, ranging from waveform design and array-based signal processing to radar applications like localization, imaging and remote sensing, with practical experimental results presented. Finally, we summarize the promising research trends around Rydberg atomic receiver.