High-speed Wireless Data Transmission Research Articles

Wireless data transmission in the 560-GHz band utilizing terahertz wave generated through photomixing of a pair of distributed feedback lasers injection-locking to a Kerr micro-resonator soliton comb

The increasing demand for higher data rates in 6G mobile wireless systems has sparked a keen interest in terahertz (THz) waves as a high-frequency, high-bandwidth carrier. This study presents a novel approach to wireless data transmission at 560 GHz, leveraging the use of THz waves generated through the injection-locking of a pair of distributed feedback lasers into a Kerr micro-resonator soliton comb. Experimental results demonstrate a Q-factor of 6.23 in 1-Gbit/s on-off-keying data transmission, which closely approaches the error-free limit represented by a Q-factor of 6.36. Additionally, the study achieves low error vector magnitudes for various modulation formats: 23.9% for 1-GBaud binary-phase-shift-keying, 23.6% for 1-GBaud quadrature-phase-shift-keying, and 8.07% for 0.1-GBaud 16-quadrature-amplitude modulation. This innovative approach holds promise for achieving high-quality, high-speed wireless data transmission, thereby advancing THz communication technology for integration into 6G systems.

Development of cyber-physical system security management process model

Cyber-physical systems (CPS) combine general-purpose information and telecommunication systems and industrial networks and devices (controllers), forming a heterogeneous hierarchical distributed information technology computing environment designed for control and monitoring of technological processes. FSCs are being actively implemented in the industrial, urban and household spheres, allowing for more efficient use of resources, as well as transferring management and feedback processes to a new level. CPS are formed as a result of the aggregation of several heterogeneous information and telecommunication systems, which makes them susceptible to the destructive factors of the digital environment – cyber attacks. The peculiarities of the construction and functioning of the CPS require a new approach to defining attack surfaces and modelling threats. This is due to the fact that the "traditional" goals of attackers - the availability, integrity and confidentiality of information processed in the system - are not the only ones. In addition, the value of the information itself can be extremely low. At the same time, control and feedback processes play a decisive role in a cyber-physical system. Their stability directly affects the ability of the FSC to perform target functions, as well as the physical safety of technological facilities, personnel and consumers. Depending on the degree of criticality of the technological processes of the real world, which are controlled by the cyber-physical system, the violation of these flows inside it can lead to serious consequences, such as large material damage or a threat to the life and health of people. The severity of the identified threats is confirmed by the constantly growing number of attacks on CPS and the consequences, including potential ones, to which these attacks lead. In addition, it should be noted that in the context of the rapid development and improvement of programmable control devices (Programmable Logic Controller (PLC)), making them more accessible in the mass market segment, as well as the proliferation of high-speed wireless data transmission networks, the concept of a smart home is gaining wider application. This approach implies the integration of PLCs that interact with each other and the control centre via multi-service broadband wireless networks into the domestic environment. Thus, the concept of a smart home is based on the implementation of FSCs in places of permanent residence of people with the transfer of automatic control functions of climatic equipment, lighting, household appliances, physical elements of protection against intrusions to them. At the same time, it is extremely important to ensure the information security of the CFS. To ensure the required level of their security, it is necessary to effectively solve the problems of managing the process of ensuring their information security. The article proposes an approach to the development of a model for the information security management process of a CFS operating in a smart home.

Visible Light Communication System Technology Review: Devices, Architectures, and Applications

Visible light communication (VLC) is an advanced, highly developed optical wireless communication (OWC) technology that can simultaneously provide lighting and high-speed wireless data transmission. A VLC system has several key advantages: ultra-high data rate, secure communication channels, and a lack of interference from electromagnetic (EM) waves, which enable a wide range of applications. Light-emitting diodes (LEDs) have been considered the optimal choice for VLC systems since they can provide excellent illumination performance. However, the quantum confinement Stark effect (QCSE), crystal orientation, carrier lifetime, and recombination factor will influence the modulation bandwidth, and the transmission performance is severely limited. To solve the insufficient modulation bandwidth, micro-LEDs (μ-LEDs) and laser diodes (LDs) are considered as new ideal light sources. Additionally, the development of modulation technology has dramatically increased the transmission capacity of the system. The performance of the VLC system is briefly discussed in this review article, as well as some of its prospective applications in the realms of the industrial Internet of Things (IoT), vehicle communications, and underwater wireless network applications.

A 20.8-Gbps dual-carrier wireless communication link in 220-GHz band

With the successful demonstration of terahertz (THz) high-speed wireless data transmission, the THz frequencies are now becoming a worth candidate for post-5G wireless communications. On the other hand, to bring THz communications a step closer to real scenario application, solving high data rate realtime transmission is also an important issue. This paper describes a 220-GHz solid-state dual-carrier wireless link whose maximum transmission real-time data rates are 20.8 Gbps (10.4 Gbps per channel). By aggregating two carrier signals in the THz band, the contradiction between high real-time data rate communication and low sampling rate analog-to-digital (ADC) and digital-to-analog converter (DAC) is alleviated. The transmitting and receiving front-ends consist of 220-GHz diplexers, 220-GHz sub-harmonic mixers based on anti-parallel Schottky barrier diodes, G-band low-noise amplifiers (LNA), WR-4.3 band high-gain Cassegrain antennas, high data rates dual-DAC and -ADC baseband platform and other components. The low-density parity-check (LDPC) encoding is also realized to improve the bit error rate (BER) of the received signal. Modulated signals are centered at 214.4 GHz and 220.6 GHz with -11.9 dBm and -13.4 dBm output power for channel 1 and 2, respectively. This link is demonstrated to achieve 20.8-Gbps real-time data transmission using 16-QAM modulation over a distance of 1030 m. The measured signal to noise ratio (SNR) is 17.3 dB and 16.5 dB, the corresponding BER is 8.6e-7 and 3.8e-7, respectively. Furthermore, 4K video transmission is also carried out which is clear and free of stutter. The successful transmission of aggregated channels in this wireless link shows the great potential of THz communication for future wireless high-rate real-time data transmission applications.

Spatiotemporal Dielectric Metasurfaces for Unidirectional Propagation and Reconfigurable Steering of Terahertz Beams.

Next-generation devices for low-latency and seamless communication are envisioned to revolutionize information processing, which would directly impact human lives, technologies, and societies. The ever-increasing demand for wireless data traffic can be fulfilled by the terahertz band, which has received tremendous attention as the final frontier of the radio spectrum. However, attenuation due to atmospheric humidity and free-space path loss significantly limits terahertz signal propagation. High-gain antennas with directional radiation and reconfigurable beam steering are indispensable for loss compensation and terahertz signal processing, which are associated with spatial and temporal dimensions, respectively. Here, experimental demonstration of a spatiotemporal dielectric metasurface for unidirectional propagation and ultrafast spatial beam steering of terahertz waves is shown. The spatial dimension of the metasurface provides a solution to eliminate backscattering of collimated unidirectional propagation of the terahertz wave with steerable directionality. Temporal modulation of the spatial optical properties enables ultrafast reconfigurable beam steering. Silicon-based spatiotemporal devices amalgamate the rich physics of metasurfaces and technologies that are promising for overcoming the bottlenecks of future terahertz communication, such as high-speed and secure wireless data transmission, beamforming and ultrafast data processing.

Peak power reduction in multicarrier systems using Goppa codes

Multicarrier modulation (MCM) schemes are in use in both wireless and wired communication systems for transfer of multimedia data and is an attractive solution to high speed wireless data transmission system. OFDM, the most widely used MCM technology is extensively used in the field of radio communications yielding a high data rate in mobile environment in presence of a hostile radio channel. Although OFDM is robust to frequency selective fading, it has a problem of PAPR ratio, which is prominent especially in the uplink of a mobile terminal. It is critical to maintain the efficiency of power amplifier due to the limited battery power. High PAPR occurs due to large fluctuations in OFDM signal envelope and requires a highly linear (HPA), which are expensive, bulky and difficult to manufacture. In order to reduce the PAPR, several techniques have been proposed which can be broadly classified as distortion based and distortion less schemes. In this paper a coded OFDM scheme using Goppa codes has been proposed which shows an improvement on reducing the peak power of transmitted signals compared to the uncoded signals along with error correction and detection.

Adaptive Sub-Nyquist Spectrum Sensing for Ultra-Wideband Communication Systems

With the ever-increasing demand for high-speed wireless data transmission, ultra-wideband spectrum sensing is critical to support the cognitive communication over an ultra-wide frequency band for ultra-wideband communication systems. However, it is challenging for the analog-to-digital converter design to fulfill the Nyquist rate for an ultra-wideband frequency band. Therefore, we explore the spectrum sensing mechanism based on the sub-Nyquist sampling and conduct extensive experiments to investigate the influence of sampling rate, bandwidth resolution and the signal-to-noise ratio on the accuracy of sub-Nyquist spectrum sensing. Afterward, an adaptive policy is proposed to determine the optimal sampling rate, and bandwidth resolution when the spectrum occupation or the strength of the existing signals is changed. The performance of the policy is verified by simulations.

Room-Temperature Oscillation of Resonant Tunneling Diodes close to 2 THz and Their Functions for Various Applications

Compact and coherent source is a key component for various applications of the terahertz (THz) wave. We report on our recent results of THz oscillators using resonant tunneling diodes (RTDs). To achieve high-frequency oscillation, the electron delay time of RTD was reduced with a narrow quantum well and an optimized collector spacer thickness. Conduction loss at the air bridge connecting RTD and slot antenna, which works as a resonator and a radiator, was also reduced. By these structures, a fundamental oscillation up to 1.92 THz was obtained at room temperature. Theoretical calculation shows that an oscillation over 2 THz is further expected by improved structures of RTD and antenna. Using the offset slot antenna and two-element array configuration, high output power of 0.61 mW was obtained at 620 GHz. A direct intensity modulation of RTD oscillators up to 30 GHz, which is useful for high-speed wireless data transmission, was demonstrated. By the integration of a varactor diode, wide frequency sweep of 580–700 GHz in a single device and 580–900 GHz in a four-element array were also demonstrated. This result expands possible applications of RTD oscillators.

ENGLISH

2 ABSTRACT: Light Emitting Diodes are set to penetrate many areas of everyday life. An interesting property of these devices in addition to their lightening capabilities , is that they can also be utilised for data transmissions as well. LED's require low power for their operation and have very high switching speeds. This dual purpose application can reduce our dependency on the densely used means of communication the Radio frequency communication.. Visible light communication (VLC) technique using White Light Emitting Diode (LED ) is a promising technology for next generation communication for short range , high speed wireless data transmission. LEDs have a number of advantages, one of which is long life expectancy. LEDs' ability to transfer information signals over light makes it a very good communication medium. Now the light we use in our daily life is not only be used for providing light but also for communication. However, like many emerging technologies, VLC has many technical issues that need to be addressed. Using visible light for data transmission entails many advantages and eliminates most drawbacks of transmission via electromagnetic waves outside the visible spectrum .In this paper, inexpensive transmitter and receiver of (VLC) system is designed and implemented experimentally for transmitting data between two computers using Hyper Terminal software.

Optical Repeater Assisted Visible Light Device-to-Device Communications

Device-to-device (D2D) communication is considered a promising technique to provide wireless peer-to-peer communication services. Due to increasing demand on mobile services, available spectrum for radio frequency (RF) based communications becomes scarce. Recently, visible light communications (VLC) has evolved as a high speed wireless data transmission technology for indoor environments with abundant available bandwidth. In this paper, a novel VLC based D2D communication that provides wireless peer-to-peer communication is proposed. Potential low operating power devices for an efficient D2D communication over increasing distance of separation between devices is analyzed. Optical repeaters (OR) are also proposed to enhance the performance in an environment where direct D2D communications yield degraded performance. Simulation results show that VLC plays an important role in providing efficient D2D communication up to a distance of 1 m between devices. It is also found that the OR significantly improves the coverage distance up to 3.5 m. Keywords—Visible light communication, light emitting diode, device-to-device, optical repeater.

Design of Intelligent Vehicle Monitoring System Based on μC-OS

This paper establishes a set wireless intelligent vehicle monitoring system can be used in car based on S3C2440 and UC-OS, including hardware design, software design, system terminal high-speed wireless data transmission and monitoring platform. The experimental results show that the system have high detection sensitivity and high accuracy, and that can effectively prevent drunk driving and theft has very good practical value.

A High-Speed Wireless Transmission Scheme for Wireless Sensor Network

Along with more extensive application of wireless sensor network (WSN) technology, real-time and a large amount of data transmission requires WSN system to achieve high-speed transmission. Therefore, a high-speed wireless data transmission scheme is an essential requirement in WSN environment. We propose a modified WiFi (Wireless Fidelity) protocol for wireless transmission and high speed serial peripheral interface, and design a single-node system to test the scheme. The experimental result shows that the average transmission rate of the system can reach 893.1kb/s, meet the demand for high-speed wireless transmission.

BER Degradation of MC-CDMA at High SNR with MMSE Equalization and Residual Frequency Offset

Multicarrier Code Division Multiple Access (MC-CDMA) is an attractive technique for high speed wireless data transmission in view of its advantages over orthogonal frequency division multiplexing. In this paper, we analyze the performance of fully loaded downlink MC-CDMA systems with minimum mean square error (MMSE) equalizer in the presence of residual frequency offset (RFO) in multipath Rayleigh fading channels. We first show that as the SNR is increased beyond a value, referred as threshold SNR, the performance degrades. We then analyze the cause for this behavior and propose a remedy to prevent the degradation by regularizing the coefficient(s) of the equalizer, and use the regularized equalizer for SNRs beyond the threshold value. We suggest two methods for estimating this SNR, one gives close to the true value but requires the knowledge of RFO and the channel state information (CSI), while the other gives an approximate value but requires only CSI. We show that the regularization based on the approximate value also prevents the degradation, but the performance at higher SNRs is slightly poorer compared to that with the better estimate. Numerical and simulation results are provided to support the analysis.

Path Weight Complementary Convolutional Code for Type-II Bit-Interleaved Coded Modulation Hybrid ARQ System

Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new path weight complementary convolutional (PWCC) code used in the type-II BICM-HARQ system is proposed. The PWCC code is composed of the original code and the complimentary code. The path in trellis with large hamming weight of the complimentary code is designed to compensate for the path in trellis with small hamming weight of the original code. Hence, both of the original code and the complimentary code can achieve the performance of the good code criterion of corresponding code rate. The throughput efficiency of the BICM-HARQ system wit PWCC code is higher than repeat code system, a little higher than puncture code system in low signal-to-noise ratio (SNR) values and much higher than puncture code system, the same as repeat code system in high SNR values. These results are confirmed by the simulation.

Blind Modulation Classification Algorithm for Adaptive OFDM Systems

Adaptive modulation is an efficient method to increase the spectral efficiency of OFDM based high-speed wireless data transmission systems in multipath channel. Blind modulation classification schemes play an important role in adaptive modulation systems, eliminating the need for transmitting modulation information, thereby increasing spectral efficiency. In this paper, a novel blind modulation classification algorithm is derived from the finite alphabet property of information symbols and the equivalent parallel model of OFDM systems. The performances of the proposed algorithm and M2M4P algorithm [1] are tested and compared using Monte-Carlo simulations. It is found that, the novel algorithm yields performance better than that of M2M4P algorithm and with much less complexity.

Adaptive OFDM Systems With Imperfect Channel State Information

Adaptive modulation has been shown to have significant benefits for high-speed wireless data transmission when orthogonal frequency division multiplexing (OFDM) is employed. However, accurate channel state information (CSI) is required at the transmitter to achieve the benefits. Imperfect CSI arises from noisy channel estimates, which may also be outdated due to a delay in getting the CSI to the transmitter. In this paper, we study adaptive OFDM with imperfect CSI for the uncoded variable bit rate case, where a target bit error rate is set. A loading algorithm based on the statistics of the real channel is proposed. Performance results in terms of the average spectral efficiency are provided for adaptive OFDM systems when there is noisy channel estimation or CSI delay. The use of multiple estimates is then proposed to improve the performance. It is shown that multiple estimates from different frequencies or times can enhance the performance significantly, which enables the system to tolerate larger errors in channel estimation or longer delay in CSI

Highly integrated 60 GHz transmitter and receiver MMICs in a GaAs pHEMT technology

Highly integrated transmitter and receiver MMICs have been designed in a commercial 0.15 /spl mu/m, 88 GHz f/sub T//183 GHz f/sub MAX/ GaAs pHEMT MMIC process and characterized on both chip and system level. These chips show the highest level of integration yet presented in the 60 GHz band and are true multipurpose front-end designs. The system operates with an LO signal in the range 7-8 GHz. This LO signal is multiplied in an integrated multiply-by-eight (X8) LO chain, resulting in an IF center frequency of 2.5 GHz. Although the chips are inherently multipurpose designs, they are especially suitable for high-speed wireless data transmission due to their very broadband IF characteristics. The single-chip transmitter MMIC consists of a balanced resistive mixer with an integrated ultra-wideband IF balun, a three-stage power amplifier, and the X8 LO chain. The X8 is a multifunction design by itself consisting of a quadrupler, a feedback amplifier, a doubler, and a buffer amplifier. The transmitter chip delivers 3.7/spl plusmn/1.5 dBm over the RF frequency range of 54-61 GHz with a peak output power of 5.2 dBm at 57 GHz. The single-chip receiver MMIC contains a three-stage low-noise amplifier, an image reject mixer with an integrated ultra-wideband IF hybrid and the same X8 as used in the transmitter chip. The receiver chip has 7.1/spl plusmn/1.5 dB gain between 55 and 63 GHz, more than 20 dB of image rejection ratio between 59.5 and 64.5 GHz, 10.5 dB of noise figure, and -11 dBm of input-referred third-order intercept point (IIP3).

Performance of the 19-GHz high-speed wireless LAN system

This paper describes a new high-speed wireless LAN system in the 19-GHz band. This system features a maximum throughput of 15.2 Mbit/s, which is faster than Ethernet's. To achieve high speed wireless data transmission, we propose the new global scheduling multiple access (GSMA). This system consists of a control module (CM) and some user modules (UMS). One CM can communicate with up to ten UMs. This GSMA, in which all data transmission is managed in the CM, has both short-length and long-length frames, and concatenates multiple packets, so that it performs well with light traffic and heavy traffic: with minimal delay. For high-speed transmission and easy construction, DQPSK/differential detection is used as a modulation/demodulation scheme, and both FEC and ARQ are adopted as the error control method. In addition, as a countermeasure to shadowing and multipath fading, the CM has an omnibeam antenna, and each UM uses a 12-sector antenna, and sector selection diversity is carried out at the UM. This wireless LAN system is based on the RCR STD-34A Japanese radio system standard.