Wireless Communication Transmission Research Articles

Broadband, Single‐Layered, and Optically Transparent Reflective Phase‐Shifting‐Surface Array for Beam Manipulation and Enhanced Wireless Communications

AbstractOptically transparent electromagnetic devices play a crucial role in modern society, yet conventional optically transparent millimeter‐wave devices suffer from high return loss, limited phase shift, narrow bandwidth, high profile, and low optical transparency. Current materials, fabrication processes, and design methodologies restrict the development of high‐performance optically transparent reflective phase‐shifting‐surface arrays or reflectarrays. To address this, a design concept for broadband, single‐layered, and optically transparent reflectarray antennas is reported, which can be integrated with glass windows for beam manipulation and enhanced indoor signal coverage and wireless communications. The proposed reflectarray element employs a single‐layered cyclic olefin copolymer (COC) medium as the dielectric substrate, with fine metal line (FML) patterns under 50 µm width to create multi‐resonant structures for phase range broadening. This architecture combines multi‐resonant phase‐shifting elements with minimal FML structures and low‐loss COC substrate, achieving exceptional antenna performance while ensuring high optical transparency. Wireless communication transmission experiments validate the functionality and performance advantages of the fabricated optically transparent reflectarray. These results substantiate the immense potential and broad application prospects of the novel optically transparent COC dielectric material, the FML structure, and the proposed design concepts and methods in advancing high‐performance optically transparent reflectarrays and related communication systems.

QPSK-modulation Wireless Transmitter Based on Time-domain Coding Metasurface

In this paper, a wireless communication system based on time-domain digital coding metasurface with Quadrature Phase Shift Keying (QPSK) modulation is proposed. The aperture-coupled resonant rings on the metal patches of the metasurface elements create an asymmetry along the x-axis, resulting in a phase difference. The Field Programmable Gate Array (FPGA) is used to change the conduction and cutoff states of pin diodes, which can control the phase responses of the metasurface elements, forming four coding states. Within a certain period, the FPGA dynamically modulates the high and low levels, thus controlling the reflection characteristics of the metasurface. When the information is converted into a binary bitstream and written into the FPGA, represented by high and low levels, the baseband signal is modulated onto the carrier by the metasurface. This system replaces the functionality of mixers in traditional wireless communication systems, further simplifying the architecture of wireless communication systems. The overall system is demonstrated by an experiment with a picture transmitted and received in real time, showing promise in future low-cost wireless communication transmission systems.

Research on Wearable Devices Based on the Internet of Things

Wearable devices are closely related to people's lives. This project is based on WIFI wireless communication transmission technology, supplemented by Cortex-M3 microprocessor and MQ-7 gas sensor to design a wearable device. This wearable device can not only achieve basic clock timing, but also achieve functions such as CO concentration detection, voice intelligent recognition, and automatic alarm. In addition, the device adopts an embedded design and adds blockchain technology to achieve data information security and privacy protection.

Product manifold optimization-based joint beamforming for RIS-aided MIMO systems: A fairness based approach

Reconfigurable intelligent Surface (RIS) can effectively improve the communication quality and extend the signal coverage range by reconfiguring the wireless communication transmission environment, which is very suitable for millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems. In this paper, a product manifold optimization-based beamforming design (PMO-BD) algorithm for a RIS-assisted multi-user MIMO system is proposed to enhance fairness among users. We establish a lower bound for the minimum signal-to-interference-plus-noise ratio (SINR) among users as the optimization objective, which is subjected to multiple constraints. By maximizing the lower bound to ensure the quality of service (QoS) for each user, fairness among users get improved. The PMO-BD algorithm exploits the internal structure of the product manifold to deal with the high dimension and nonlinear characteristics of the problem effectively, thereby reducing algorithm complexity and enhancing convergence rates. Simulation results verify the advantages of the proposed PMO-BD algorithm in comparison to other algorithms.

PERFORMANCE ANALYSIS OF OPTICAL WIRELESS COMMUNICATION SYSTEM DESIGNED BY USING DIFFERENT FILTERS

Free space optical communication (FSO) technology, which has been developing in recent years, is advantageous compared to other wireless communication technologies due to its features such as high bandwidth, low latency, and high security. Since the FSO system is sensitive to atmospheric events, it needs various signal processing and filtering techniques to reduce the deterioration in the quality of the signal. The FSO free space channel has several channel types, such as the scattered channel and the optical wireless communication (OWC) channel. In this study, comparisons were made using various filters in an FSO system designed using the optical wireless communication (OWC) transmission channel model, and the system was analyzed based on the results obtained.

Movable Typography Inspired Tunable Meta‐Cylinder for Multi‐Directional Microwave Beam Shaping

AbstractIn this paper, a multi‐directional microwave beam shaping function through a tunable meta‐cylinder inspired by the movable typography technology is demonstrated. The meta‐cylinder is constructed with stacked identical octagonal layers. On each side wall of the octagonal layer, a 1D metasurface row is patterned. The metasurface rows on different side walls are designed to reflect microwave at different phase delays. As a result, each facet of the meta‐cylinder can be arranged into different metasurface row combinations and reflect a microwave into different beam shapes when rotating the stacked octagonal layers to different states. In addition, the rotation causes the same phase delay distribution change in all meta‐cylinder facets at the same time, therefore the meta‐cylinder can manipulate the microwave from different directions in the same way simultaneously. Based on this approach, a multi‐directional beam focusing function with tunable focal length is experimentally demonstrated. The dynamical beaming shaping of the microwave in multi‐direction will have high application potential in wireless communication and microwave signal transmission and omnidirectional antennas.

Representation of data by their residual images during transmission and reception of messages in wireless information and telecommunication systems under interference conditions

The article is devoted to the development of new methods used in information technologies for monitoring the results of telemetry in conditions of various types of interference, the need for which is most acute in the development of automated systems for monitoring the technical condition of complex complexes and systems. To resolve the contradictions, a new non-traditional approach is proposed that uses diagnostic methods for obtaining estimates of measurement results, the basis of which is the non-traditional representation of measurement data by their residual images during data transmission and reception in wireless information communications.

Nonlinear Testing-based EMI Characterization of Wireless Communication Transmitter with Microwave Power Amplifier

Nonlinear Testing-based EMI Characterization of Wireless Communication Transmitter with Microwave Power Amplifier

Channel-Agnostic Training of Transmitter and Receiver for Wireless Communications.

Wireless communications systems are traditionally designed by independently optimising signal processing functions based on a mathematical model. Deep learning-enabled communications have demonstrated end-to-end design by jointly optimising all components with respect to the communications environment. In the end-to-end approach, an assumed channel model is necessary to support training of the transmitter and receiver. This limitation has motivated recent work on over-the-air training to explore disjoint training for the transmitter and receiver without an assumed channel. These methods approximate the channel through a generative adversarial model or perform gradient approximation through reinforcement learning or similar methods. However, the generative adversarial model adds complexity by requiring an additional discriminator during training, while reinforcement learning methods require multiple forward passes to approximate the gradient and are sensitive to high variance in the error signal. A third, collaborative agent-based approach relies on an echo protocol to conduct training without channel assumptions. However, the coordination between agents increases the complexity and channel usage during training. In this article, we propose a simpler approach for disjoint training in which a local receiver model approximates the remote receiver model and is used to train the local transmitter. This simplified approach performs well under several different channel conditions, has equivalent performance to end-to-end training, and is well suited to adaptation to changing channel environments.

Review of wireless communication transmission technology

With the advancement of modern science and technology, wireless communication technology has grown rapidly. A number of common standards for wireless data transmission have emerged, primarily for long-distance and short-range wireless communication. This paper compares several common wireless communication transmission technologies, including satellite communication, Bluetooth, WiFi, NFC, etc. Wireless communication technology has now entered the 5G stage. From the previous SMS to the current video conference, the transmission rate and transmission accuracy have been greatly improved. Wi-Fi facilities everywhere in the city, Bluetooth transmission, mobile phone NFC payment, etc. are convenient and improve people's lives. Wireless communication technology also has many applications, such as 5G technology, Internet of Things technology, and the development of artificial intelligence technology.

PDM-OFDM 1-bit DSM 1024QAM/4096QAM signals at W-band transmission over 4.6-km wireless distance.

In this Letter, we propose the application of delta-sigma modulation (DSM) higher-order quadrature amplitude modulation (QAM) technology in long-distance transmission of W-band wireless communication, and demonstrate, for the first time to the best of our knowledge, the wireless transmission of millimeter wave signals in the W-band based on 1-bit DSM quantization using polarization-division-multiplexed orthogonal frequency division multiplexing (PDM-OFDM) 1024QAM/4096QAM for 4.6 km. We successfully achieved a bit error rate (BER) of 40-Gbit/s PDM-OFDM 1024QAM and 48-Gbit/s PDM-OFDM 4096QAM after 4.6-km wireless transmission, both lower than the soft decision forward error correction (SD-FEC) of 4.2 × 10-2. To the best of our knowledge, this is the first time that up to 4096QAM signals have been quantized and transmitted based on 1-bit DSM in a 4.6-km-long distance W-band millimeter wave system.

Retracted: Mathematical Methods on Optimal Frequency Selection Model for Wireless Communication Transmission Signal under 5G Internet of Everything

Retracted: Mathematical Methods on Optimal Frequency Selection Model for Wireless Communication Transmission Signal under 5G Internet of Everything

Engineering Metal-Organic Frameworks with Tunable Colors for High-Performance Wireless Communication.

Metal-organic frameworks (MOFs) have emerged as excellent platforms possessing tunable and controllable optical behaviors that are essential in high-speed and multichannel data transmission in optical wireless communications (OWCs). Here, we demonstrate a novel approach to achieving a tunable wide modulation bandwidth and high net data rate by engineering a combination of organic linkers and metal clusters in MOFs. More specifically, two organic linkers of different emission colors, but equal molecular length and connectivity, are successfully coordinated by zirconium and hafnium oxy-hydroxy clusters to form the desired MOF structures. The precise change in the interactions between these different organic linkers and metal clusters enables control over fluorescence efficiency and excited state lifetime, leading to a tunable modulation bandwidth from 62.1 to 150.0 MHz and a net data rate from 303 to 363 Mb/s. The fabricated color converter MOFs display outstanding performance that competes, and in some instances surpasses, those of conventional materials commonly used in light converter devices. Moreover, these MOFs show high practicality in color-pure wavelength-division multiplexing (WDM), which significantly improved the data transmission link capacity and security by the contemporary combining of two different data signals in the same path. This work highlights the potential of engineered MOFs as a game-changer in OWCs, with significant implications for future high-speed and secure data transmission.

A Mechanism on Video Tracking and Recognition with Fast Transmission in Wireless Communications

A Mechanism on Video Tracking and Recognition with Fast Transmission in Wireless Communications

Multimode OAM Convergent Transmission With Co-Divergent Angle Tailored by Airy Wavefront

Wireless backhaul offers a more cost-effective, time-efficient, and reconfigurable solution than wired backhaul to connect the edge-computing cells to the core network. As the amount of transmitted data increases, the low-rank characteristic of Line-of-Sight (LoS) channel severely limits the growth of channel capacity in the point-to-point backhaul transmission scenario. Orbital Angular Momentum (OAM), also known as vortex beam, is considered a potentially effective solution for high-capacity LoS wireless transmission. However, due to the shortcomings of its energy divergence and the specificity of multi-mode divergence angles, OAM beams have been difficult to apply in practical communication systems for a long time. In this work, a novel multi-mode convergent transmission with co-scale reception scheme is proposed. OAM beams of different modes can be transmitted with the same beam divergent angle, while the wavefronts are tailored by the ring-shaped Airy compensation lens during propagation, so that the energy will converge to the same spatial area for receiving. Based on this scheme, not only is the Signal-to-Noise Ratio (SNR) greatly improved, but it is also possible to simultaneously receive and demodulate OAM channels multiplexed with different modes in a limited space area. Through prototype experiments, we demonstrated that 3 kinds of OAM modes are tunable, and different channels can be separated simultaneously with receiving power increasing. The measurement isolations between channels are over 11 dB, which ensures a reliable 16-QAM multiplexing wireless transmission demo system. This work may explore the potential applications of OAM-based multi-mode convergent transmission in LoS wireless communications.

A Centralized Multi-User Anti-Composite Intelligent Interference Algorithm Based on Improved Q-Learning

This paper proposes a central anti-jamming algorithm (CAJA) based on improved Q-learning to further solve the communication challenges faced by multi-user wireless communication networks in terms of external complex malicious interference. This will also reduce the dual factors restricting wireless communication quality, the impact of inter-user interference within the network, and the effect of external malicious interference on the communication system to improve multi-user wireless communication transmission. Firstly, a central base station that coordinates and allocates channels for users within the network is set up using multi-user wireless communication network architecture to constitute a centralized wireless communication network. Secondly, the multi-user system is modeled using the single-user Markov decision process in which the central base station is the main body. Finally, an improved Q-learning algorithm is used to improve overall system transmission income using the central base station, based on the network user number sequential decision action for avoiding external malicious interference. It is designed to avoid the impact of internal network interference on transmission performance during the early stage of communication, achieving overall system transmission income improvement. Simulation results show that in comparison to the existing multi-user independent Q-learning anti-jamming algorithm and the traditional orthogonal frequency-hopping scheme, the proposed algorithm significantly improves overall system transmission performance.

Plate Condition Monitoring System Based on LoRa Wireless Transmission

In the process of tension stringing of transmission lines, the condition of the plate needs manual reporting, so its safety is poor, and its efficiency is low. To solve this problem, this study constructs a plate condition monitoring system of tension stringing based on the LoRa wireless transmission. This system consists of a data acquisition system, a wireless communication transmission system, and a monitoring and warning center. The STM32 is used to process the data collected by the sensors, and the LoRa wireless communication system is designed by way of adaptive dynamic change of LoRa’s network ID, and the networking mode of the multi-node relay, and the data is sent to the upper computer from a distance, and the upper computer software is implemented by MFC, which can monitor the condition of the plate in real-time. The test results show that the packet loss rate of LoRa is less than 5%, and the condition data of the plate can be transmitted to the monitoring software through LoRa and displayed. This system has the advantages of strong confidentiality, far transmission, and high safety, which can be used for real-time monitoring of the condition of the plate in the process of tension stringing.

Spatial‐Division‐Assisted Multi‐Level Amplitude‐Programmable Metasurface for Dual‐Band Direct Wireless Communication

AbstractWith the rapid development of electromagnetic (EM) wave manipulation technique, programmable metasurfaces with real‐time EM responses (e.g., phase, amplitude) have emerged as a new type of wireless communication transmitter, which has the advantages of simple architecture and low cost. Here, it has been proposed a design strategy of dual‐band wireless communication system based on a spatial‐division‐assisted multi‐level amplitude‐programmable metasurface. The carrier frequency and modulation scheme of each physical channel can be independently designed by changing the external bias voltages and the spatial‐coding sequences applied onto the metasurface. As the proof‐of‐concept, experiments are conducted to prove the feasibility of the system in sub 6G communication band. Two pictures are successfully transmitted via high and low‐frequency channels using binary amplitude‐shift keying and 4 amplitude‐shift keying modulation schemes, respectively.

Ultra-narrow linewidth dual-cavity opto-mechanical microwave oscillator based on radial guided acoustic modes of single-mode fiber

A dual-cavity opto-mechanical microwave oscillator (OM-MO) for microwave photonic (MWP) generation with ultra-narrow linewidth based on radial (R) guided acoustic modes of a single-mode fiber (SMF) is proposed and investigated experimentally. The dual-cavity OM-MO consists of a 5 km SMF main ring, which provides forward stimulated Brillouin scattering (FSBS) gain, and a 300 m SMF subring that achieves single-frequency output of the R07 guided acoustic mode based MWP (R07-MWP) with Vernier effect. At 300 mW 980 nm pump threshold power, the 319.79 MHz R07-MWP is generated by adjusting polarization controllers based on nonlinear polarization rotation effect, corresponding to the 7437th harmonic of the 43 kHz cavity round trip frequency. The 3 Hz ultra-narrow linewidth of R07-MWP is achieved by decreasing the intrinsic linewidth of the passive ring resonator. The acoustic-mode and longitudinal-mode suppression ratios reach 22 and 36 dB, respectively. Within 20 min of the stability experiment, the power and frequency stability fluctuation of the R07-MWP are ±1 dB and ±0.05 MHz, respectively. This ultra-narrow linewidth MWP generation technology has great potential in the communication field, especially in long-distance wireless communication transmission.

The Design and Development of a Microstrip Antenna for Internet of Things Applications.

The Internet of Things (IoT) has become a part of modern life where it is used for data acquisition and long-range wireless communications. Regardless of the IoT application profile, every wireless communication transmission is enabled by highly efficient antennas. The role of the antenna is thus very important and must not be neglected. Considering the high demand of IoT applications, there is a constant need to improve antenna technologies, including new antenna designs, in order to increase the performance level of WSNs (Wireless Sensor Networks) and enhance their efficiency by enabling a long range and a low error-rate communication link. This paper proposes a new antenna design that is able to increase the performance level of IoT applications by means of an original design. The antenna was designed, simulated, tested, and evaluated in a real operating scenario. From the obtained results, it ensured a high level of performance and can be used in IoT applications specific to the 868 MHz frequency band.By inserting two notches along x axis, we find an optimal structure of the microstrip patch antenna with a reflection coefficient of -34.3 dB and a bandwidth of 20 MHz. After testing the designed novel antenna in real IoT operating conditions, we concluded that the proposed antenna can increase the performance level of IoT wireless communications.