software-defined radio prototyping

This work addresses the limitations of existing wireless channel emulation approaches, which either rely on costly hardware or suffer from insufficient fidelity due to model simplifications, thereby hindering high-fidelity testing for software-defined radio (SDR) platforms such as USRP. To overcome these challenges, the paper presents the first purely software-based, end-to-end, real-time digital twin framework that fully emulates USRP communication systems at the I/Q signal level without requiring dedicated hardware. The framework supports multiple transceivers, MIMO configurations, multi-band operation, heterogeneous sampling rates, node mobility, antenna radiation patterns, and diverse channel models. It is also compatible with mainstream open-source SDR ecosystems, including GNU Radio, srsRAN, and OpenAirInterface. Experimental results demonstrate that the proposed framework enables high-fidelity, real-time simulation entirely in software, significantly reducing development and testing costs.

This work presents a fully connected four-node wireless mesh network based on the Zynq UltraScale+ RFSoC platform to support multi-stream, real-time, uncompressed 4K video transmission. By designing a custom physical and MAC layer within a shared 200 MHz bandwidth, the system achieves, for the first time, a low-latency, digitally controlled frequency-division duplexing 2×2 MIMO link with runtime dynamic reconfiguration capability. The implementation concurrently operates twelve 99.84 Mbps links, delivering an aggregate throughput of 1.2 Gbps—sufficient to transmit multiple synchronized 4K video streams. Furthermore, the platform provides real-time visualization and monitoring of key performance metrics, including error vector magnitude (EVM), signal-to-interference-plus-noise ratio (SINR), and bit error rate (BER).

Existing communication protocols for Flying Ad-hoc Networks (FANETs) are predominantly validated in simulation environments, neglecting real-world hardware constraints, software limitations, and cost considerations. Method: This paper presents a reproducible software–hardware co-testing platform based on Software-Defined Radio (SDR). Leveraging GNU Radio, we implement a multi-channel wireless communication system integrating an IEEE 802.11-compatible physical layer and a custom-designed multi-channel token-ring medium access control (MAC) protocol, enabling low-overhead, high-robustness inter-UAV position information exchange. Results: The system is experimentally validated in real flight scenarios with two UAVs, confirming the effectiveness and stability of the multi-channel mechanism. All modular source code, hardware interface specifications, and system architecture diagrams are publicly released under open-source licenses, significantly enhancing research transparency, experimental reproducibility, and practical engineering deployability.

To address physical-layer modeling distortions and the inability to accurately capture deep-fading mitigation effects in mid-band digital wireless communication system simulations, this paper proposes a comprehensive end-to-end physical-layer modeling framework for the mid-band. Departing from conventional baseband simplifications, it establishes, for the first time, a unified discrete-time complex baseband model that jointly captures pulse shaping, up/down-conversion, mixing, carrier synchronization, and symbol timing recovery. Implemented in MATLAB for a single-input single-output (SISO) system, the framework demonstrates that temporal alignment and frequency-offset coupling among modules critically govern deep-fading mitigation behavior. The proposed approach significantly enhances simulation fidelity and interpretability for mid-band systems, offering both pedagogical clarity and engineering practicality. It provides a high-fidelity platform for PHY-layer algorithm design and performance evaluation.

Provable covert communication based on the square-root law (SRL) remains experimentally unvalidated in the radio-frequency (RF) domain; existing demonstrations are confined to optical channels. Method: This work presents the first RF implementation of a mathematically provable covert communication system using software-defined radio (SDR), achieving high-precision time–frequency synchronization and ultra-low-power modulation under strict SRL constraints. Contribution/Results: Experimental results closely match information-theoretic predictions, empirically validating the SRL’s applicability in RF environments and refuting the conventional assumption that standard RF links are inherently unsuitable for covert transmission. By bridging the gap between theory and practice, this study establishes the first empirical foundation for RF-based low-probability-of-detection (LPD) communication, providing both critical experimental evidence and a practical technical pathway toward real-world deployment.

This work addresses the limitations of existing RF measurement platforms, which rely on laboratory equipment or fixed infrastructure and thus lack the flexibility required for prolonged field-based spectrum monitoring. The authors propose a portable, battery-powered RF acquisition system integrating a HackRF One software-defined radio, a Raspberry Pi 5, a GNSS receiver, and a high-speed SSD to enable continuous IQ data recording with precise spatiotemporal metadata. Data are stored in the SigMF format at sustained write throughput of 75–85 MB/s without sample loss, while GNSS synchronization achieves timing errors under one second and meter-level positioning accuracy. Field experiments successfully captured characteristic propagation effects at 2.45 GHz—including vegetation attenuation, urban multipath, and indoor interference—demonstrating significantly enhanced deployment flexibility, environmental adaptability, and data fidelity for real-world RF sensing.

This study addresses the lack of accurate channel modeling for 3.4 GHz air-to-air (A2A) communications, which has hindered the design of unmanned aerial vehicle (UAV) communication systems. Leveraging an open-source, reconfigurable channel sounding platform built with USRP B210 and a GNSS-disciplined oscillator, the authors conducted spherical-trajectory flight experiments at the AERPAW Lake Wheeler testbed to systematically collect A2A channel measurements across varying altitudes, elevation angles, and relative headings. This work presents the first comprehensive characterization of sub-6 GHz A2A channel properties at 3.4 GHz and introduces a geometry-aware fading model that explicitly incorporates real flight trajectories. The study quantifies the relationship between RMS delay spread and link geometry and publicly releases both the lightweight sounding platform and the measured dataset, providing a reliable foundation for simulation, protocol design, and performance evaluation of UAV communication systems.

This work addresses the limitations of existing semantic error correction approaches, which often prioritize intent understanding over verbatim recovery accuracy and lack real-time validation. We propose a cross-layer semantic error correction framework that integrates physical-layer log-likelihood ratios (LLRs) from software-defined radio (SDR) platforms with semantic context derived from encoder-decoder language models to enable efficient, real-time correction. For the first time, we validate the real-time performance of such a method on a real-world SDR testbed, introducing middleware that supports FPGA-based LLR extraction and a universal interface for language model inference. Experimental results demonstrate that our cross-layer fusion approach significantly outperforms baseline methods relying solely on either the physical or semantic layer in terms of verbatim recovery accuracy.

This study investigates mutual interference between ultra-low-power (VLP) Wi-Fi 6E/7 and 5G NR systems operating in the 6 GHz band. Leveraging an OpenAirInterface-based software-defined radio testbed configured for the n102 band (40 MHz bandwidth, 30 kHz subcarrier spacing), the authors conduct conducted interference experiments with commercial VLP Wi-Fi devices—injecting Wi-Fi signals at varying power levels—and measure their impact on 5G gNB uplink and UE downlink performance in terms of throughput, block error rate, and signal-to-noise ratio. This work presents the first real-world conducted interference assessment of VLP Wi-Fi on a functional 5G NR system, quantifying interference thresholds and translating them into physical safety distances. Results show negligible 5G degradation when Wi-Fi interference remains below −75 dBm; UEs exhibit robustness at low data rates, and Wi-Fi beacon-only transmissions cause no harmful interference. The derived safety distances are substantially shorter than Listen-Before-Talk exclusion zones, confirming that compliant VLP devices do not pose a risk of harmful interference.

This work addresses the challenge of automatically translating user intent into physical-layer wireless signals for rapid prototyping by proposing the first multi-agent framework dedicated to wireless signal generation. The framework integrates a large language model with domain-specific knowledge retrieval (RadioWiki), I/Q sample synthesis (RadioAgent), and RF simulation-based validation (RadioEmulator), enabling end-to-end generation of real-world wireless signals from natural language through collaborative reasoning and closed-loop verification. The authors introduce RadioBench, a specialized evaluation benchmark, and demonstrate that their approach significantly outperforms existing methods in real hardware deployments, achieving breakthrough improvements in both signal fidelity and configuration feasibility.