High Data Rate Communication Systems Research Articles

Neural networks empowered: a machine learning-enabled, Gyro mmID for enhanced virtual reality and motion tracking applications

Abstract With the emerging developments in millimeter-wave/5G technologies, the potential for wireless Internet of things devices to achieve widespread sensing, precise localization, and high data-rate communication systems becomes increasingly viable. The surge in interest surrounding virtual reality (VR) and augmented reality (AR) technologies is attributed to the vast array of applications they enable, ranging from surgical training to motion capture and daily interactions in VR spaces. To further elevate the user experience, and real-time and accurate orientation detection of the user, the authors proposes the utilization of a frequency-modulated continuous-wave (FMCW) radar system coupled with an ultra-low-power, sticker-like millimeter-wave identification (mmID). The mmID features four backscattering elements, multiplexed in amplitude, frequency, and spatial domains. This design utilizes the training of a supervised learning classification convolutional neural network, enabling accurate real-time three-axis orientation detection of the user. The proposed orientation detection system exhibits exceptional performance, achieving a noteworthy accuracy of 90.58% over three axes at a distance of 8 m. This high accuracy underscores the precision of the orientation detection system, particularly tailored for medium-range VR/AR applications. The integration of the FMCW-based mmID system with machine learning proves to be a promising advancement, contributing to the seamless and immersive interaction within virtual and augmented environments.

Verification and Modeling of the Maritime Channel for Maritime Communications and Navigation Networks

This paper presents a geometric stochastic channel model designed for analyzing maritime communication and navigation services between moving ships using the C-band or sub-6 GHz spectrum, which aligns with the focus of emerging 5G networks on land. The channel model is validated through channel measurements conducted both on the sea and land. A software tool has been developed to integrate and analyze these measurements, which is included with this publication. The main challenge in developing the channel model for maritime services lies in the dynamic nature of the sea surface, leading to constantly changing reflection conditions due to varying reflectors and scatterers on the water. Additionally, the motion conditions of the transmitter and receiver on ships change in all three dimensions, depending on the sea state. To address these complexities, data from several measurement campaigns in diverse areas were collected. The analysis involved examining the propagation conditions over the sea with variations in sea surface roughness, antenna heights, and used bandwidths. Moreover, additional propagation conditions over nearby land were also taken into account. The study demonstrates that the changing antenna height on the ship, influenced by sea conditions, significantly affects the reflection and scattering conditions. The research aims to develop reliable, high-data rate, and broadband marine communication systems. Therefore, a measurement bandwidth of 120MHz was employed to derive the propagation model. This model not only offers absolute timing information but can also be used for time-based ranging or positioning systems. The proposed geometric stochastic channel model provides valuable insights into the complex maritime communication and navigation environment. By accounting for the continuously evolving sea surface and its impact on antenna height, the model offers a robust framework for studying and optimizing marine communication systems. The availability of a software tool integrating real-world measurements further enhances the usability and practicality of the channel model for future maritime communication research and deployment.

Performance analysis of a hybrid FSO/mmWave/THz system for short-range communication under rain and fog conditions

For fronthaul cellular networks, the suitability of a hybrid free space optical (FSO)/radio frequency (RF) high data rate communication systems such as millimeter wave (mmWave) and terahertz (THz) with reliable connectivity under weather conditions (rain and fog) is proposed and analyzed. The aim of this hybrid system is to suit short-range communication covering 5G/6G and beyond cellular networks. The 4 pulse amplitude modulation (PAM) scheme parallel transmission and adaptive receiver approach is considered for the work. The theoretical work on estimating the attenuation characteristics under various weather conditions is carried out followed by the simulation of a hybrid communication system for obtaining the received power at different link lengths. Based on the received power for a data rate of 1 Gbps signal-to-noise ratio (SNR) and bit error rate (BER) is calculated for a link length of 0.2 km, 0.5 km, and 1 km for 4 PAM. For varying fog conditions, mmWave/THz carrier is found to be suitable with a BER of 10−10 at a link length of 0.5 km. For varying rain rates, FSO performs well with a BER of 10−8. The link length and performance can be improved with increased transmit power in both communication systems. The THz carrier offers a high data rate, and a hybrid system is proposed with FSO/THz to have reliable connectivity in harsh weather scenarios.

Adaptive LDPC coded high data rate based IR-UWB combined with VMIMO system for vehicular communication links

The automotive industry is developing significantly with the evolution of vehicular networks, intelligent transportation systems, and autonomous cars. These technologies are made achievable by recent advances in software, hardware, and communication systems, along with various applications and standardization efforts. On the other side, many impairments have existed due to these evolving, limiting the process of vehicular networks. So, this paper proposes an implementation of adaptive LDPC-coded, high data rate-based Impulse Radio-Ultra Wide Band (IR-UWB) combined with Virtual Multiple Input Multiple Output (VMIMO) systems for Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) wireless communications. Furthermore, they are merged with orthogonal pulse shaping using a modified Hermite pulse. Besides, the paper compares Zero-Forcing (ZF) and Minimum Mean Square Error (MMSE) detection techniques. To enhance and mitigate the existing impairments facing the vehicular networks. The proposed system’s performance is evaluated using both techniques, utilizing Bit Error Rate (BER), processing time, and resultant throughput analysis for both channel models. The simulation results include Non-Line of Sight (NLoS) and Line of Sight (LoS) scenarios for both channel models. Moreover, the simulation considers the effect of path loss and noise on the transmitted signal. In addition, the recent LDPC decoding algorithm termed “Modified Implementation Efficient Reliability Ratio Weighted Bit Flipping” (MIERRWBF) is evaluated through all latter channel models. At last, a novel adaptive LDPC decoder is proposed to further enhance the performance of all vehicular communication links under study. Consequently, the paper proposed an integrated adaptive LDPC-coded high data rate communication system to enhance vehicular communications using VMIMO mixed with modified Hermite orthogonal pulse shaping and deploying the MMSE recommended detection technique.

A Low-Phase-Noise 8 GHz Linear-Band Sub-Millimeter-Wave Phase-Locked Loop in 22 nm FD-SOI CMOS.

Low-phase noise and wideband phased-locked loops (PLLs) are crucial for high-data rate communication and imaging systems. Sub-millimeter-wave (sub-mm-wave) PLLs typically exhibit poor performance in terms of noise and bandwidth due to higher device parasitic capacitances, among other reasons. In this regard, a low-phase-noise, wideband, integer-N, type-II phase-locked loop was implemented in the 22 nm FD-SOI CMOS process. The proposed wideband linear differential tuning I/Q voltage-controlled oscillator (VCO) achieves an overall frequency range of 157.5-167.5 GHz with 8 GHz linear tuning and a phase noise of -113 dBc/Hz @ 100 KHz. Moreover, the fabricated PLL produces a phase noise less than -103 dBc/Hz @ 1 KHz and -128 dBc/Hz @ 100 KHz, corresponding to the lowest phase noise generated by a sub-millimeter-wave PLL to date. The measured RF output saturated power and DC power consumption of the PLL are 2 dBm and 120.75 mW, respectively, whereas the fabricated chip comprising a power amplifier and an integrated antenna occupies an area of 1.25 × 0.9 mm2.

Variable-Phase-Shift Based High Data Rate Sub-THz FSK Transmitter Design: Theory and Implementation

Targeting the new generation of high data rate communication systems at sub-terahertz (THz), a fully integrated, energy and area efficient, 196 GHz frequency-shift keying (FSK) transmitter was designed and prototyped in a 55-nm SiGe process. By analyzing the transient dynamics of a loop of coupled oscillators, a new direct modulation technique for frequency modulation is presented. It is shown that an instantaneous frequency shift can be realized in theory as long as the coupling mode of the coupled oscillators loop system does not change. By controlling the phase shift in a system of tunable couplers, a 10 Gb/s single channel data rate wireless link was demonstrated, which is the first FSK wireless transmitter at sub-THz frequencies, and is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\times $ </tex-math></inline-formula> higher compared with all other previously published CMOS/BiCMOS wireless FSK transmitters. The achieved single channel data rate and energy efficiency per bit are comparable to other recently published sub-THz transmitters with more complicated modulation schemes like M-ary amplitude-shift keying (ASK), phase-shift keying (PSK), or quadratic-amplitude modulation (QAM).

Radio over plastic optical fibers – a tutorial and review

Abstract In this paper, recent advancements in radio over plastic optical fibers are reviewed. Plastic fibers are used in short-range, high data rate communication systems and are considered to be consumer-friendly as they are simpler to install, easy to maintain and its associated components are inexpensive. A few of the challenges faced in employing plastic fibers are its high attenuation and modal dispersion, which limits the transmission range. However, plastic fibers are considered to be a low-cost alternative to be employed in short-range fiber-to-the-home (FTTH) networks as compared to the commonly known silica optical fiber. Advancement from 4G to 5G has paved a way for plastic fiber, which can be employed for simultaneous multi-format transmissions supporting 5G networks. In this paper, the evolution of multi-format transmission and its challenges are also discussed, along with the applications of plastic fibers in systems employing various techniques. Furthermore, the paper discusses the challenges and future prospects of radio over plastic fibers to guide a way for further research in this domain for improving the quality of transmission and linking it with other cutting-edge technologies such as machine learning and blockchain.

An efficient approach for sub-carrier allocation in MIMO MC-CDMA systems

Abstract Sub-carrier allocation is an important process that directly affects users data and bit error rates for multi-user multi-carrier systems. The most important feature of the allocation process is to assign the sub-carriers to the active users in proportion to their needs to provide high-speed data transmission and reduce the bit error rates. In this study, an efficient subcarrier allocation algorithm has been proposed based on both capacity and fairness criteria for a MIMO MC-CDMA system, which is preferred as the multiplexing scheme in high data rate communication systems. The proposed algorithm achieves not only better error rate performance but also increases the total data rate compared to other algorithms

High-Frequency Vacuum Electron Devices

Vacuum electron devices at frequencies of millimeter waves and terahertz play highly important roles in the modern high-data rate and broadband communication system, high-resolution detection and imaging, medical diagnostics, magnetically confined nuclear fusion, etc [...]

A prominent approach to design low noise amplifiers for 802.11 wireless receiver frontends

With the efforts of innovative consortium, wireless local area network (WLAN) became alternative standard in wireless local area networking applications. From the beginning the data rate keeps pace from mega bits per second (Mbps) up to giga bits per second. The ease of adaptability of WLAN protocol and the need for high data rate communication system made a reason to develop a solution and to incorporate real time wireless transceivers on network interface cards and FPGAs. Over the past decade, the RFIC technology became the hive of communication industry, with the proliferation of 802.11 a, g, n, ac, ad wireless protocols. The applications like ultra wide band (UWB), digital TV broadcasting and global positioning system found their way to main-stream gadgets. With the design preferences such as interconnect parasitics, interconnects and coupling between devices the passive elements must be precisely designed. In this article, novel requirements of low noise amplifier (LNA) design for 2.4 GHz application with noise modelling is presented.

Special Issue on Edge Intelligence for Immersive Communications

With the explosive growth of smart devices and development of wireless technology, numerous new applications such as Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR), autonomous driving and intelligent manufactory enter our daily life and put stringent requirements on the current communications technologies. Boosted by multimedia applications and Internetof-Things (IoT), immersive communications is considered to bring a novel vision on the development of advanced communications systems and networks. Nevertheless, to fully explore the immersive experience and applications, ultrareliable, low latency and high data rate communications systems are required. However, the conventional access network can hardly accommodate such stringent requirements, due to limited capacity and long latency on the backhaul links. Novel approaches that bring various network functions and contents to the network edge, i.e., mobile edge computing and caching, are promising to tackle the aforementioned challenges.

Millimeter wave difference-frequency mixing by mobile carriers in gated monolayer graphene with broken centrosymmetry

Motivated by the device application potential of microwave difference-frequency generation (DFG) in graphene, we develop a theory of this second-order non-linear phenomenon in individual graphene layers lacking center-of-inversion symmetry due to their interaction with a substrate such as SiC or h-BN. Using the Boltzmann equation techniques, we calculate the microwave DFG conductivity of the graphene layer where the number of free carriers is controlled by an external gate voltage. The results obtained shed light on how the doping level of graphene, as well as a substrate-induced bandgap in the graphene’s electronic spectrum, affects the efficiency of the graphene-based frequency downconversion from the millimeter wave band to the microwave one. In particular, it is shown that there are some possibilities to maximize the output power of the microwave DFG by selecting graphene/substrate pairs with smaller substrate-induced bandgap values and by tuning, in the proper way, the Fermi energy of charge carriers via electrostatic gating. The gate controllable DFG enhancement can be achieved in gapped and doped graphene samples at the electron concentration level of the order of cm−2, thus paving the way to electrically tunable frequency downconvertors for millimeter wave applications in high data rate communication systems and signal processing.

On the performance of optical wireless communication links impaired by time jitter, M-turbulence and pointing errors

The interest for the optical wireless communication systems increases significantly the last years due to the very high advantages of this technology. More specifically, the FSO links can achieve very high data rate and secure communications with low installation and operational cost. However, the main disadvantage of the FSO links is that their performance is dominated by the weather conditions and the turbulence of the atmosphere, where the optical beam propagates. The atmospheric turbulence mitigates significantly the performance of the FSO links and causes the scintillation effect, which results in rapid irradiance fluctuations at the receivers. Furthermore, another factor which increases the influence of the atmospheric turbulence and causes further fast changes at the receivers’ irradianceis the pointing errors. Additionally, the performance of most of the high data rate communication systems, is reduced by the time jitter effect, which causes the detection of each digital pulse before or later than the ideal time spot. Thus, in this work, the performance of a terrestrial FSO link is investigated, for first time under the simultaneous action of the M(alaga) atmospheric turbulence, the pointing errors and the time jitter effects for various, commonly used in FSO links, modulation schemes. Taking into account their joint influence, new accurate closed form mathematical expressions are derived for the average BER estimation. Finally, the corresponding numerical results and conclusions are shown and derived.

Effect of Controlling Parameters of Tone Reservation Based on Null Subcarriers (TRNS) on the Performance of OFDM Systems

High data rate communication systems usually implement Orthogonal Frequency Division Multiplexing (OFDM) to face frequency selectivity. High Peak to Average Power Ratio (PAPR) is an OFDM disadvantage that causes Bit Error Rate (BER) degradation and out-of-band (OOB) radiation when OFDM signal pass through nonlinear Power Amplifier (PA). In order to overcome this problem larger Input Back-Off (IBO) is required. However, large IBO decreases the PA efficiency. PAPR reduction techniques are used to reduce the required IBO, so that PA efficiency is saved. Several PAPR reduction methods are introduced in literature, among them Tone Reservation based on Null Subcarriers (TRNS) is downward compatible version of Tone Reservation (TR) with small excess in the average power and low computational complexity compared to others. As will be shown, TRNS is the best practical one of the four downward compatible techniques. Performance of TRNS is controlled by three parameters; number of peak reduction tones (PRTs), predefined threshold (Amax), and number of iterations (Itr). In order to increase PAPR reduction gain, enhance BER performance, and reduce the required IBO to follow the given power spectral density (PSD), we have to choose the values of these parameters adequately. Results showed that, we have to reduce the threshold value to the average (i.e. Amax =0 dB). Also, we have to increase number of PRTs. However, we have to maintain the spectrum shape. Finally, we have to choose moderate number of iterations (e.g. Itr ≈50), as excessive increase in number of iterations is not useful, especially at high PAPR values.

LED-Based Underwater Wireless Optical Communication for Small Mobile Platforms: Experimental Channel Study in Highly-Turbid Lake Water

Underwater collaborative work between small mobile platforms (SMP) such as divers, litter submarine or AUV, requires a high data rate communication system which is compact, reliable, affordable and eye-safe. The high bandwidth of LED-based underwater wireless optical communication (UWOC) is an advantage. Artificial, emulated as well as simulated, turbid underwater channel has been studied recently, but no practical nature water. To fully meet the requirements of challenging turbid underwater channel scenarios for SMP, we demonstrated a green LED-based UWOC system up to a bandwidth of 3.4 MHz in a highly-turbid nature lake water. Through a contrast wireless optical communication (WOC) experiment in air, turbid water channel is observed to compensates the receiving signal amplitude attenuates after propagating a longer attenuation length due to multiple-scattered light caused diffusion, and thus to be more like a single-input multi-output (SIMO) system. From our experimental observation, the SIMO channel model could be employed not only in turbulent UWOC, but also in highly turbid UWOC. Moreover, turbid water channel is observed a “frequency selection” effect, thus LED with lower threshold voltage at higher frequency would optimize bandwidth and link range, and a robust pre-code for interference cancellation would be a well-direct choice to constructing different UWOC system in highly turbid water for SMP. Our finding will provide a new reference complementing the current LED-based UWOC systems in realistic water environment.

Channel Characteristics of High-Speed Railway Station Based on Ray-Tracing Simulation at 5G mmWave Band

In order to satisfy the increasing demand for the higher transmission capacity of “smart station”, millimeter wave (mmWave) technology is expected to play a significant role in the high data rate communication system. Based on the ray-tracing simulation technology, this paper would study wireless channel characteristics of the three-dimensional (3D) model of high-speed railway station at the mmWave band. Key parameters such as path loss exponent, shadow fading factor, delay spread, Rician K-factor, angular spread, power angle spectrum, and spatial correlation are extracted and investigated. These channel characteristics are of value for the selection of antenna arrays and even the design of future 5G communication networks in the railway environment.

A Prominent Approach to Design Low Noise Amplifiers for 802.11 Wireless Receiver Frontends

With the efforts of innovative consortium, wireless local area network (WLAN) became alternative standard in wireless local area networking applications. From the beginning the data rate keeps pace from mega bits per second (Mbps) up to giga bits per second. The ease of adaptability of WLAN protocol and the need for high data rate communication system made a reason to develop a solution and to incorporate real time wireless transceivers on network interface cards and FPGAs. Over the past decade, the RFIC technology became the hive of communication industry, with the proliferation of 802.11 a, g, n, ac, ad wireless protocols. The applications like ultra wide band (UWB), digital TV broadcasting and global positioning system found their way to main-stream gadgets. With the design preferences such as interconnect parasitics, interconnects and coupling between devices the passive elements must be precisely designed. In this article, novel requirements of low noise amplifier (LNA) design for 2.4 GHz application with noise modelling is presented.

Neutrosophic data formation using Gaussian filter based costas coding for wireless communication systems

Outstanding advantages of OFDM helps high data rate communication systems such as Digital Video Broadcasting (DVB) and mobile worldwide interoperability for microwave access (mobile Wi-MAX). But, OFDM system grieves from grave issue of high PAPR. In OFDM system data output is superposition of multiple sub-carriers and leads to big data. In this case some instantaneous power output might increase greatly and become far higher than the mean power of system. In order to make Neutrosophic data for less PAPR criteria, Gaussian filter based Costas coding is proposed. This paper also proposes feeding the Orthogonal Frequency Division Multiplexed signal (OFDM) into a phase accumulator to obtain frequency modulation, with the aim of reducing the peak to average power ratio (PAPR). For associated radar with modulated waveform mentioned here can be used to enhance the performance. It is widely used to analyze the variation of the output waveform further, the implementation results using MATLAB show that the ratio of average power to peak power is reducing considerably in comparing with the conventional method. Consequently; the signal can assume to fade in a frequency selective channel without an equalizer.

Qualitative Analysis of Darlington Feedback Amplifier at 45nm Technology

The transistors are the key element of present communication system having high data rate. Some applications need high gain by using very low frequency, and then transistors are used. Amplifier is the key element in many applications of present high data rate communication system such as low noise amplifier (LNA), broadband amplifier, distributed and power amplifier. The Darlington pair amplifier is analyzed for high frequency performance and related effect of bandwidth. Broadband feedback Darlington pair amplifier is designed with enhanced gain, bandwidth and slew rate. This paper presents the comparison of single stage and three stage feedback Darlington feedback amplifier with reference to gain, bandwidth and slew rate. This paper is simulated on cadence analog design environment at GPDK 45nm technology. This paper shows that increase in gain, bandwidth and slew rate of three stage Darlington feedback amplifier can show better stability over the single stage Darlington feedback amplifier.

Experimental Demonstration of High-Speed 4 × 4 Imaging Multi-CAP MIMO Visible Light Communications

In general, visible light communication (VLC) systems, which utilise white light-emitting diodes (LEDs), only offer a bandwidth limited to the lower MHz region. Therefore, providing VLC-based high data rate communications systems using VLC becomes a challenging task. To address this challenge, we propose a solution based on multiplexing in both the frequency and space domains. We experimentally demonstrate a 4 ${\boldsymbol{\times }}$ 4 imaging multiple-input multiple-output (MIMO) VLC system (i.e., space multiplexing) utilising multiband carrierless amplitude and phase ( m -CAP) modulation (i.e., frequency multiplexing). Independently, both MIMO and m -CAP have separately shown the remarkable ability to improve the transmission speeds in VLC systems, and hence, here we combine them to further improve the net data rate. We investigate the link performance by varying the number of subcarriers m , link distance $\boldsymbol{L}$ , and signal bandwidth $\boldsymbol{B_{\text{sig}}}$ . From all the values tested, we show that a data rate of $\sim$ 249 Mb/s can be maximally achieved for m = 20, $B_{\text{sig}}$ = 20 MHz, and $\boldsymbol{L}$ = 1 m, at a bit error rate of ${3.2\times 10^{-3}}$ using LEDs with $\sim$ 4 MHz bandwidth.