Rydberg atomic quantum receivers (RAQRs) have emerged as highly sensitive receivers for future communication and sensing systems. However, conventional RAQRs are primarily effective for single-carrier and narrowband reception, typically with an operational bandwidth of only a few hundred kilohertz. To enable the reception of multi-carrier signals with larger bandwidth, we propose a multi-carrier Rydberg atomic quantum receiver (MC-RAQR) architecture based on a five-level quantum system model. We analyze the amplitude and phase of the output laser in MC-RAQR and extract the baseband electrical signal for signal processing. Furthermore, we quantify the performance of MC-RAQR in multi-carrier communication and sensing by studying the channel capacity and distance estimation, respectively. Numerical results show that the MC-RAQR is capable of achieving a bandwidth of $7.2$ MHz, which is an order of magnitude larger than conventional RAQRs. Besides, compared to conventional receivers, MC-RAQR can improve the capacity and distance estimation by $18$-fold and $10^3$-fold, respectively. This validates the superiority of MC-RAQR in receiving multi-carrier signal, and demonstrates its compatibility in detecting waveforms such as orthogonal frequency‐division multiplexing.

Visual-Depth-Thermal (VDT) salient object detection (SOD) aims to jointly exploit RGB, depth and thermal cues to segment the most visually significant regions. However, most existing VDT SOD models are heavy in parameters and computational cost, limiting their deployment on real-world and edge devices. To tackle this, we propose SGNet, a structure-guided lightweight network for efficient VDT SOD. Specifically, we design a lightweight Tri-modal Fusion Module (TFM) to integrate three modalities at the semantic level, and a Shared Structure Extraction Module (SSEM) to extract common structural information from depth and thermal modalities. A Structure Refine Module (SRM) further injects the extracted structure into the deepest semantic features, while a Multiscale Feature Refinement Module (MFRM) progressively decodes multi-level features under deep supervision to produce saliency maps with clear boundaries. Benefiting from these modules, SGNet achieves competitive performance on the VDT2048 benchmark with only 5.51 M parameters and a real-time speed of 120 FPS at 320 × 320 resolution, surpassing state-of-the-art methods while remaining deployment-friendly.

Multiple-input multiple-output (MIMO) has been a key technology for wireless systems for decades. For typical MIMO communication systems, antenna array elements are usually separated by half of the carrier wavelength, thus termed as co-located MIMO. In this paper, we investigate the performance of multi-user sparse MIMO communication, with sparse arrays at both the transmitter and receiver side, i.e., the array elements are separated by more than half wavelength. Given the same number of array elements, the performance of sparse MIMO is compared with co-located MIMO. On one hand, sparse MIMO has a larger aperture, which can achieve narrower main lobe beams that make it easier to resolve densely located users. Besides, increased array aperture also enlarges the near-field communication region, which can enhance the spatial multiplexing gain, thanks to the spherical wavefront property in the near-field region. On the other hand, element spacing larger than half wavelength leads to undesired grating lobes, which, if left unattended, may cause severe multi-user interference (MUI). Specifically, we first study the spatial multiplexing gain of the basic single-user sparse MIMO communication system, where a closed-form expression of the near-field effective degree of freedom (EDoF) is derived. The result shows that EDoF increases with the array sparsity for sparse MIMO before reaching its upper bound, which equals to the minimum value between the transmit and receive antenna numbers. Furthermore, the scaling law for the achievable data rate with varying array sparsity is analyzed and an array sparsity-selection strategy is proposed.We then consider the more general multi-user sparse MIMO communication system. It is shown that sparse MIMO is less likely to experience severe MUI than co-located MIMO, especially when users are densely located, thanks to the non-uniform distribution of spatial angle difference among users. Finally, numerical results are provided to validate our theoretical analysis.

In this paper, a fast Fourier transform (FFT)-enhanced low-complexity super-resolution sensing algorithm for near-field source localization with both angle and range estimation is proposed. Most traditional near-field source localization algorithms suffer from excessive computational complexity or incompatibility with existing array architectures. To address such issues, this paper proposes a novel near-field sensing algorithm that combines coarse and fine granularity of spectrum peak search. Specifically, a spectral pattern in the angle domain is first constructed using FFT to identify potential angles where sources are present. Afterwards, a 1D beamforming is performed in the distance domain to obtain potential distance regions. Finally, a refined 2D multiple signal classification (MUSIC) is conducted within each narrowed angle-distance region to estimate the precise location of the sources. Numerical results demonstrate that the proposed algorithm can significantly reduce the computational complexity of 2D spectrum peak searches and achieve target localization with high-resolution.

The field of image aesthetics assessment (IAA) is rapidly advancing due to its wide applications. However, relying solely on single-modal information for aesthetic evaluation presents inherent limitations. While multimodal IAA models incorporating user comments have achieved significant advancements, these comments are often unavailable due to privacy concerns and practical considerations, and they also introduce additional computational overhead during inference. To address this issue, we propose a cross-modal hierarchical knowledge distillation method, termed HKD-IAA, to enhance the performance of unimodal image models effectively. Specifically, HKD-IAA comprises four components: feature extraction, feature decomposition, hierarchical knowledge distillation, and dynamic decay. During training, we first decompose the extracted features into a weighted sum of basic aesthetic elements and their corresponding weights, thereby reducing the learning difficulty for the student model. Building on this, we design a new hierarchical knowledge distillation framework, which aligns features at the feature, relation, and response levels to effectively transfer the knowledge from the teacher model. Finally, we introduce a dynamic decay strategy to adjust the weight of the distillation loss, thereby enhancing the student model's learning effectiveness during training. Extensive experiments on two benchmark datasets validate that the proposed method achieves state-of-the-art performance using only visual modal data. Our code is available athttps://github.com/Hangwei-Chen/HKD-IAA.

Integrated super-resolution sensing and communication (ISSAC) is a promising technology to achieve extremely high sensing performance for critical parameters, such as the angles of the wireless channels. In this paper, we propose an ISSAC-based channel estimation method, which requires little or even no pilot, yet still achieves accurate channel state information (CSI) estimation. The key idea is to exploit the fact that subspace-based super-resolution algorithms such as multiple signal classification (MUSIC) do not require a priori known pilots for accurate parameter estimation. Therefore, in the proposed method, the angles of the multi-path channel components are first estimated in a pilot-free manner while communication data symbols are sent. After that, the multi-path channel coefficients are estimated, where very little pilots are needed. The reasons are two folds. First, compared to the conventional channel estimation methods purely relying on channel training, much fewer parameters need to be estimated once the multi-path angles are accurately estimated. Besides, with angles obtained, the beamforming gain is also enjoyed when pilots are sent to estimate the channel path gains. To rigorously study the performance of the proposed method, we first consider the basic line-of-sight (LoS) channel. By analyzing the minimum mean square error (MMSE) of channel estimation and the resulting beamforming gains, we show that our proposed method significantly outperforms the conventional methods purely based on channel training. We then extend the study to the more general multipath channels. Simulation results are provided to demonstrate our theoretical results.

Integrated sensing and communication (ISAC) is a promising technology to simultaneously provide high performance wireless communication and radar sensing services in future networks. In this paper, we propose the concept of integrated super-resolution sensing and communication (ISSAC), which uses super-resolution algorithms in ISAC systems to achieve extreme sensing performance for those critical parameters, such as delay, Doppler, and angle of the sensing targets. Based on practical fifth generation (5G) New Radio (NR) wave forms, the signal processing techniques of ISSAC are investigated and prototyping experiments are performed to verify the achievable performance. To this end, we first study the effect of uneven cyclic prefix (CP) lengths of 5G NR orthogonal frequency division multiplexing (OFDM) waveforms on various sensing algorithms. Specifically, the performance of the standard Periodogram based radar processing method, together with the two classical super resolution algorithms, namely, MUltiple SIgnal Classification (MUSIC) and Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT) are analyzed in terms of the delay and Doppler estimation. To resolve the uneven CP issue, a new structure of steering vector for MUSIC and a new selection of submatrices for ESPRIT are proposed. Furthermore, an ISSAC experimental platform is setup to validate the theoretical analysis, and the experimental results show that the performance degradation caused by unequal CP length is insignificant and high-resolution delay and Doppler estimation of the target can be achieved with 5G NR waveforms.

Intelligent Internet of Things (IIoT) is comprised of various wireless and wired networks for industrial applications, which makes it complex and heterogeneous.The openness of IIoT has led to the intractable problems of network security and management. Many network security and management functions rely on network traffic prediction techniques, such as anomaly detection and predictive network planning. Predicting IIoT network traffic is significantly difficult because its frequently updated topology and diversified services lead to irregular network traffic fluctuations. Motivated by these observations, we proposed a reinforcement learning-based mechanism in this article. We modeled the network traffic prediction problem as a Markov decision process, and then, predicted network traffic by Monte Carlo Q-learning. Furthermore, we addressed the real-time requirement of the proposed mechanism and we proposed a residual-based dictionary learning algorithm to improve the complexity of Monte Carlo Q-learning. Finally, the effectiveness of our mechanism was evaluated using the real network traffic.

Vehicular Ad-Hoc Networks (VANETs) have received a great attention recently due to their potential and various applications. However, the initial phase of the VANET has many research challenges that need to be addressed, such as the issues of security and privacy protection caused by the openness of wireless communication networks among the city-wide applied regions. Specially, anomaly detection for a VANET has become a challenging problem, due to the changes in the scenario of VANETs comparing with traditional wireless networks. Motivated by this issue, we focus on the problem of anomaly detection in VANETs, and propose an effective anomaly detection approach based on the convolutional neural network in this paper. The proposed approach takes into account the spatio-temporal and sparse features of VANET traffic, and it uses a convolutional neural network architecture and a loss function based on Mahalanobis distance for anomaly detection. Furthermore, a comprehensive assessment is provided to validate the proposed approach, which illustrates the effectiveness of this approach.

The end-to-end network traffic information is the basis of network management in large-scale IP backbone networks. To obtain exact network traffic data, a prevalent idea is to employ NetFlow or sFlow on all routers of the network. However, this method not only increases operational expenditures, it also affects the network load. Motivated by this issue, we propose an optimized traffic measurement method based on reinforcement learning in this paper, which can collect most of the network traffic data by activating NetFlow on a subset of interfaces of routers in a network. We use the Q- learning-based approach to deal with the problem of the interface-selection, and propose an approach to compute the reward. Furthermore, a modified Q- learning approach is proposed to handle the problem of interface-selection. The method is evaluated by the real data from the Abilene and GEANT backbone networks. Simulation results show that the proposed method can improve the efficiency of traffic measurement distinctly.