This paper addresses the critical sensitivity issue of narrow-beam communication systems to physical misalignments and exploits the potential of Integrated Sensing and Communications (ISAC) technology to propose a sensor-free antenna tilt failure detection and estimation framework. The proposed methods utilize environmental static clutter as geometric anchors to monitor systematic gain shifts in clutter heat maps. The proposed methods are introduced for precise antenna tilt detection and estimation using the standard 5G NR frame structure and two different waveforms. Numerical results show the potential of the proposed framework to enable autonomous, self healing network maintenance without the need for external sensors.

This paper presents a real-world experimental analysis of a modular reconfigurable intelligent surface (RIS) prototype designed to operate in the 5G N78 band. Unlike most RIS studies in the literature that focus on simulations or controlled setups, the proposed system is validated through three phases consisting of indoor measurements, outdoor long-range tests, and deployment in a live commercial 5G standalone network. The RIS is exploited to enhance coverage in a non-line-of-sight (NLoS) zone, identified through baseline drive tests. Results show promising gains in RSRP and SINR, while also restoring 5G service at user locations where access was previously not available. The results highlight the practical potential of RIS for coverage enhancement in operational 5G networks.

Reconfigurable intelligent surface (RIS) has emerged as a groundbreaking technology for 6G wireless communication networks, enabling cost-effective control over wireless propagation environment. By dynamically manipulating its codebook so as to deflect the direction of the reflected electromagnetic wave, RIS can achieve enhanced signal quality, extended coverage, and interference mitigation. This study presents experimental performance of ZTE Dynamic 2.0 RIS products through a series of real-world tests conducted on Turkcell's millimeter-wave (mmWave) testbed. The evaluation involves network coverage extension in urban areas, multi-user efficiency, and the integration of virtual reality technology to support immersive applications in next-generation 6G networks. Through a comprehensive measurement-based analysis, the performance of the RIS product is demonstrated, highlighting its potential to address critical challenges in mmWave communications and to enable advanced 6G use cases.

Despite the growing interest in the integration of reconfigurable intelligent surfaces (RIS) into next-generation wireless communications systems, a critical gap remains in understanding what the dimensions of an RIS must be to provide meaningful performance gains across realistic deployment scenarios. This paper addresses this challenge by presenting a practical and scenario-aware methodology for determining optimal RIS dimensions, tailored to specific frequency bands, environments, and use cases. Leveraging a realistic simulation model that incorporates angular scattering characteristics, practical network node locations, and propagation constraints, we evaluate the RIS-assisted performance in a diverse set of configurations. For selected use-cases, we quantify key performance indicators such as average signal-to-noise ratio and outage probability, and we demonstrate how RIS size impacts system reliability. Our findings show that RIS deployment effectiveness is highly sensitive to both physical size and geometric placement, and that there is no one-size-fits-all solution. The proposed framework, supported by detailed use case tables and validated through comprehensive simulations, offers design guidelines for operators and vendors seeking to deploy RIS in practical wireless network settings.

Reconfigurable intelligent surface (RIS) has emerged as a key technology for achieving smart and adaptive propagation environments. Although RISs provide an energy- and cost-efficient solution, static reflective surfaces (SRSs) reflecting incident radio signals toward particular angles without a power source or electronic control circuitry become an environmentally sustainable alternative for enhancing coverage in blind spots. In this paper, an SRS is designed and developed for next generation millimeter-wave wireless networks, which has a pre-determined reflection angle. The performance evaluation has been carried out in an outdoor environment using commercial network equipment. The reference signal received power and signal-to-interference-plus-noise ratio measurement results on a customer premises equipment terminal demonstrate that the designed SRS can be successfully used to boost the reflected signals towards pre-determined directions, providing the extended network coverage.

The advent of the sixth generation (6G) wireless networks heralds a transformative era for mobile communication, where the integration of cutting-edge technologies like Reconfigurable Intelligent Surfaces (RISs) is paramount in addressing the burgeoning demands for energy efficiency, high data rates, reliable connectivity, and enhanced coverage in densely populated areas. RISs have attracted the attention of academia as well as the industry and emerged as a beacon of innovation, offering a novel paradigm to reconfigure the wireless propagation environment beneficially, thereby enhancing the overall network performance. It is envisioned that the deployment of numerous RISs in a mobile network will serve user equipments (UEs) to boost various key performance indicators (KPIs), with lower energy consumption compared to alternative solutions (e.g., relays, and network-controlled repeaters). However, the knowledge of whether or not a UE is being served through an RIS, and if so, which RIS it is being served by, is crucial and beneficial for various network planning and operational reasons. In this article, we address the importance and the benefits of RIS identification in a mobile network. Additionally, we guide the readers and researchers by introducing alternative methods to enable RIS identification. Through the lens of this research, we shed light on various benefits for, the challenges to, and future opportunities in the identification of RISs serving mobile users in complex network environments, highlighting the necessity for advanced identification strategies to fully harness the potential of RIS technology in next-generation wireless systems.

This paper investigates the angular characteristics of interference caused by Reconfigurable Intelligent Surfaces (RISs) in overlapping millimeter-Wave network deployments. A simulation-based framework is proposed to analyze the instantaneous and average interference power and interference-to-noise ratio (INR) experienced by unintended users, using structured RIS configurations and bi-static scattering models. Results show that RIS-induced interference is directional, increases with RIS size, and is underestimated by random RIS configuration models. The impact of spatial correlation under Rayleigh fading is also examined, highlighting the importance of correlation-aware planning for reliable RIS coexistence in 5G-Advanced and beyond.

Reconfigurable intelligent surfaces (RISs) have recently emerged as a promising technology to enhance spectral and energy efficiency in next-generation wireless networks. However, the interference that RIS may induce, especially in multi-operator and spectrally and spatially overlapping deployments, remains largely unexplored. In this work, we present a field measurement campaign at the millimeter-wave (mmWave) band to investigate the interference effects of RIS in scenarios involving two independent mobile networks. Key performance indicators, such as reference signal received power (RSRP) and signal-to-interference-noise ratio (SINR) are systematically observed for user equipment (UE) exposed to RIS configurations optimized for other UEs. The results are benchmarked against a simulation-based model, revealing both consistencies and deviations between practical measurements and theoretical predictions. Our findings highlight the angular and directional structure of RIS-induced interference, providing measurement-driven insights for network coexistence, multi-operator support, and deployment planning.

In this letter, we propose a novel reconfigurable intelligent surface (RIS)-assisted transmission scheme called RIS-aided enhanced receive spatial modulation (RIS-ERSM). To achieve high spectral efficiency and reliability, RIS-ERSM leverages both M-ary modulated data symbols and receive antenna (RA) combinations. In this scheme, an RIS is partitioned into multiple groups based on incoming bits, with each group specifying one antenna from the selected antenna combination. Furthermore, an upper bound on average bit error rate (ABER) is derived. Computer simulation results demonstrate the superiority of the proposed scheme over benchmark schemes in terms of error performance.

This paper presents a novel index modulation (IM) technique named hybrid reconfigurable intelligent surface (RIS) enabled enhanced reflection modulation (Hyb-ERM), which capitalizes on the hybrid RIS architecture comprising both active and passive elements. In Hyb-ERM, a hybrid RIS is partitioned into groups, with information bits transmitted through both conventional M-ary phase shift keying (PSK) modulated symbols and the number of active RIS groups. This approach, particularly the manipulation of transmitted symbols by the hybrid RIS based on the number of active groups, is designed to improve the minimum Euclidean distance, thereby significantly enhancing error performance. We have derived a theoretical upper bound for the bit error probability (BEP) and proposed two low-complexity detectors as alternatives to the maximum likelihood (ML) detector. Extensive simulation results validate the effectiveness of Hyb-ERM, showing its superior error performance compared to benchmark schemes under both ideal and non-ideal channel conditions. This study underscores the potential of Hyb-ERM in advancing RIS-assisted communications, paving the way for more efficient and robust 6G wireless networks.

Orthogonal frequency division multiplexing with index modulation (OFDM-IM), which transmits information bits through ordinary constellation symbols and indices of active subcarriers, is a promising multicarrier transmission scheme and has attracted the attention of researchers due to numerous benefits such as flexibility and simplicity. Nonetheless, OFDM-IM cannot satisfy the needs of future wireless communication services such as superior reliability, high data rates, and low complexity. In this article, we propose a novel OFDM-IM scheme named coordinate interleaved OFDM with repeated in-phase/quadrature IM (CI-OFDM-RIQIM), which provides superior error performance and enhanced spectral efficiency due to its diversity order of two and clever subcarrier activation pattern (SAP) detection mechanism, respectively. In addition, CI-OFDM-RIQIM is further extended to coordinate interleaved OFDM with in-phase/quadrature IM (CI-OFDM-IQIM) by doubling information bits transmitted by IM. Furthermore, log-likelihood ratio (LLR) based low-complexity detectors are designed for both proposed schemes. Theoretical analyses are performed and an upper bound on the bit error probability is derived. Comprehensive computer simulations under perfect and imperfect channel state information (CSI), are conducted to compare the proposed and reference schemes. It is shown that CI-OFDM-RIQIM and CI-OFDM-IQIM show superior results and can be considered promising candidates for next-generation wireless communication systems.

Reconfigurable intelligent surface (RIS) has been one of the most exciting and attractive topics in the beyond 5G era. Its advantages especially in providing coverage extension, signal-to-noise ratio and throughput enhancement, physical-layer security under non-line-of-sight (NLoS) conditions, and the support in other enabler 6G technologies and functionalities such as massive multiple-input multiple-output (mMIMO) schemes and joint communications and sensing (JCAS) have been popular research topics for the wireless communications community. Hence, the industrial initiative has also moved few steps forward to provide preliminary RIS prototypes those would be expected to support field trials and proof-of-concept (PoC) studies through the standardization stages. However, due to both the high costs associated with the production process (i.e., based on the PIN-diode-based designs) and the limited functionality of current prototypes (e.g., reflective-only opaque designs without any active elements), a clear conclusion has not been reached regarding the utilization of RIS hardwares within mobile communications networks. As we approach the standards and preliminary systems and network designs of 6G technology, measurement-based approaches towards clarifying the use cases of RIS hardware are seen not to respond to all possible requirements of poC studies. At this point, in order to examine the advantages of RIS technology, realistic computer simulations are believed to be capable of dispelling the uncertainty cloud in front of this technology. For this purpose, in this paper, a realistic surface scattering approach that addresses major drawbacks of the current reference evaluation methods has been proposed, and preliminary results have been exhibited.

Users’ desire for enhanced performance drive the inevitable technological progress on vertical applications in wireless communication systems. To meet these demands, researchers vigorously investigate potential 6G and beyond technologies and solutions. Reconfigurable intelligent surfaces (RISs) have risen in popularity and attracted the attention of academia as well as industry and seem to be a promising candidate for 6G technology. RISs are reflective metamaterials with many configurable elements consisting of pin diodes that have the ability to manipulate the impinging signals' properties, hence, enabling some sort of virtual control over the wireless channel. In this paper, we propose a novel over-the-air index modulation (IM) scheme through the use of a hybrid RIS with active and passive partitions to convey additional IM bits over-the-air. In addition we propose another modified scheme that allows the transmission for even more IM bits but at the expense of certain tradeoffs. First, we present the system model for both of the proposed schemes. Furthermore, comprehensive computer simulation results are provided and discussed presenting the superior bit error rate (BER) performance and additional benefits of the proposed systems compared to similar benchmarks.

Thanks to its capacity for producing intelligent radio environments that are both efficient and affordable, reconfigurable intelligent surfaces technology is gaining recognition as a potential solution for advanced communication systems. Efficient information processing is crucial for smart surfaces to effectively respond to electromagnetic signals, however achieving this requires additional resources such as computing time, storage, energy, and bandwidth. To address these challenges, model-agnostic methods such as machine learning can be an effective solution, as ML employs trainable variables to examine raw data and generate valuable outcomes. This study introduces a novel approach that integrates a hybrid RIS and utilizes an uplink non-orthogonal multiple access transmission from the users to the base-station. The proposed scheme utilizes supervised learning for RIS partitioning to optimize RIS element distribution that minimizes interference between users situated in the RIS’s non-line-of-sight. The proposed system achieves similar achievable rates and fairness among users as the current advanced iterative algorithm described in existing literature, while significantly reducing the time and complexity involved. A theoretical outage probability formulation is derived along with computer simulations and comparisons presented to assess system outage and bit error probability results for varying quality-of-service conditions and successive interference cancellation scenarios.

Reconfigurable intelligent surfaces (RISs) bring great potential to the advancement of 6G and beyond wireless communication technologies. RISs introduce a great degree of flexibility, allowing some sort of virtual control over the wireless channel. Exploiting the flexibility introduced by RISs, we propose a novel RIS-enabled downlink (DL) non-orthogonal multiple access (NOMA) scheme where NOMA is enabled over-the-air rather than at the base station (BS) or the receiver (Rx). Here, the RIS is partitioned into distinctive groups where each part of the RIS serves a different user equipment (UE) to perform multiple accessing. The BS transmits an unmodulated signal to the RIS, and each partition modulates the impinging signal over-the-air by introducing a phase shift according to the incoming information bits to serve the corresponding UE. First, the end-to-end system model for the proposed system is presented. Furthermore, outage probability calculations, theoretical error probability analysis, and bit error rate (BER) derivations are discussed and reinforced with comprehensive computer simulation results.

Innovative reconfigurable intelligent surface (RIS) technologies are rising and recognized as promising candidates to enhance 6G and beyond wireless communication systems. RISs acquire the ability to manipulate electromagnetic signals, thus, offering a degree of control over the wireless channel and the potential for many more benefits. Furthermore, active RIS designs have recently been introduced to combat the critical double fading problem and other impairments passive RIS designs may possess. In this paper, the potential and flexibility of active RIS technology are exploited for uplink systems to achieve virtual non-orthogonal multiple access (NOMA) through power disparity over-the-air rather than controlling transmit powers at the user side. Specifically, users with identical transmit power, path loss, and distance can communicate with a base station sharing time and frequency resources in a NOMA fashion with the aid of the proposed hybrid RIS system. Here, the RIS is partitioned into active and passive parts and the distinctive partitions serve different users aligning their phases accordingly while introducing a power difference to the users' signals to enable NOMA. First, the end-to-end system model is presented considering two users. Furthermore, outage probability calculations and theoretical error probability analysis are discussed and reinforced with computer simulation results.

The march towards 6G is accelerating and future wireless network architectures require enhanced performance along with significant coverage especially, to combat impairments on account of the wireless channel. Reconfigurable intelligent surface (RIS) technology is a promising solution, that has recently been considered as a research topic in standards, to help manipulate the channel in favor of users' needs. Generally, in experimental RIS systems, the RIS is either connected to the transmitter (Tx) or receiver (Rx) through a physical backhaul link and it is controlled by the network and requires significant computation at the RIS for codebook (CB) designs. In this paper, we propose a practical user-controlled RIS system that is isolated from the network to enhance communication performance and provide coverage to the user based on its location and preference. Furthermore, a low-complexity algorithm is proposed to aid in CB selection for the user, which is performed through the wireless cloud to enable a passive and energy efficient RIS. Extensive experimental test-bed measurements demonstrate the enhanced performance of the proposed system while both results match and validate each other.

In this paper, an approximation of linearized electric vehicle (EV) system is performed. A second-order approximated model is obtained for fifth-order linearized EV system. The approximation is performed to clarify and demonstrate the applicability and usefulness of the approximation method used in this paper. This paper aims to estimate a suitable approximated model of order two, for a linearized EV system, by utilizing the factor division method. Comparisons based on time domain specifications are provided to demonstrate the practicality of the model. Even after performing the approximation, it is found that the model obtained is stable and retains the properties of the original system. For proving efficacy and effectiveness of the suggested method, step response, Bode response, Nyquist response, and impulse response are also presented.

This paper proposes a very low-power and high-speed CMOS voltage buffer for column drivers of flat panel displays. The proposed amplifier circuit employs two complementary input stages and an improved output stage. The proposed circuit draws only 2μΑ quiescent current while a 1nF capacitive load is connected at the output. It has only a 0.82us settling time within a full-swing output. The simulations of the proposed circuit are performed using LTSpice with AMS 0.35μm process parameters and a single 3.3V power supply. It is shown that the circuit has the best Figure-of-Merit value when compared to the previously published solutions.