High Data Rate Wireless Research Articles

Antennas and Arrays for 60 GHz High Data Rate Wireless Applications

The 60 GHz band has approximately 7 GHz bandwidth with the frequency range 57-64 GHz worldwide. This band is unlicensed and the research for this band is going on very rapidly since last few years. This paper presents the technical review of high data rate 60 GHz technology and the development of antennas and arrays for 60 GHz applications. The paper covers the introduction to 60 GH bands for various regions. The advantages, the disadvantages and the potential applications of 60 GHz technology are discussed. The detailed propagation characteristics of 60 GHz band are presented and analyzed. Based upon analysis of the propagation characteristics of 60 GHz band, the requirements for antenna design are discussed. The antennas and the arrays design along with the challenges in antenna and array design for 60 GHz technology are presented. The detailed review of various types of 60 GHz antennas and arrays such as high gain antennas, 60 GHz antenna arrays, switched beam array systems, phased array systems etc are discussed and analyzed. Performance comparison of various antennas and arrays is also presented in this paper. The presented 60 GHz technology introduction, propagation characteristics analysis, antenna design types, parameters analysis, challenges etc are helpful in the antennas and arrays design for 60 GHz high data rate wireless systems.

Design of Eight Parallel 512-Point MDF FFT/IFFT Processor for WPAN Applications

This paper presents a high-speed FFT algorithm for high data rate wireless personal area network applications. In a wireless personal area network, the FFT/IFFT block leads the major role. Computational requirements of FFT processors are a heavy burden in most real-time applications. From the previous work, it can be recognized that most of the FFT structures follow the divide and conquer algorithms, which improve the computational efficiency. In the proposed model, a new design of 512-point FFT/IFFT processor is derived by mixed approach for a Radix-26 algorithm, which has been presented and implemented using the Eight Parallel Multipath Delay Feedback (MDF) architecture. In this work, three distinct complex multiplication approaches are derived; from the analysis, a mixed approach has been proposed to reduce the multiplier complexity and also the equivalent normalized area. The proposed design is compiled and simulated with 90[Formula: see text]nm CMOS technology optimized for a 1.2[Formula: see text]V supply voltage. The proposed Mixed Radix-26 algorithm has been verified and validated using existing architectures. It has been found that the proposed mixed approach for Radix-26 algorithm reduces the normalized area by 8.603% compared with verified architectures. Also, the multiplier complexity is reduced by more than 33% using Canonical Signed Digit constant multiplier. The proposed architecture is suitable for applications like OFDM based WPAN applications at high data processing rates.

Joint PAPR reduction and sidelobe suppression in NC-OFDM based cognitive radio using wavelet packet and SC techniques

Non-contiguous orthogonal frequency division multiplexing (NC-OFDM) is an appropriate transmission technique for cognitive radio (CR) systems. It guarantees an efficient spectrum utilization for high data rate wireless systems. However, NC-OFDM system suffers from two main problems, which are the high peak-to-average power ratio (PAPR) and the high sidelobe level. In this paper, two techniques are proposed to jointly reduce the PAPR and suppress the out-of-band (OOB) radiation caused by the high sidelobe levels. In both of the two proposed techniques, an inverse discrete wavelet packet transform (IDWPT) is used, once with the signal cancellation (SC) for the first proposed technique (IDWPT-SC), and once again with the sub-signal cancellation (Sub-SC) for the second proposed technique (IDWPT-Sub-SC). The use of the IDWPT helps decreasing the fluctuations in the transmitted signal, and hence reduces the PAPR and the OOB radiation. The simulation results show that, the proposed techniques provide better PAPR and sidelobe cancellation performance compared to the other techniques. Moreover, the two proposed techniques also conserve almost the same computational complexity as the other techniques.

Fast Content Delivery via Distributed Caching and Small Cell Cooperation

The demand for higher and higher wireless data rates is driven by the popularity of mobile video content delivery through wireless devices such as tablets and smartphones. To achieve unprecedented mobile content delivery speeds while reducing backhaul cost and delay, in this paper we propose a new system architecture that combines two recent ideas, distributed caching of content in small cells (FemtoCaching), and, cooperative transmissions from nearby base stations (Coordinated Multi-Point). A key characteristic of the proposed architecture is the interdependence between the caching strategy and the physical layer coordination. Specifically, the caching strategy may cache different content in nearby base stations (BSs) to maximize the cache hit ratio, or cache the same content in multiple nearby BSs such that the corresponding BSs can transmit concurrently, e.g., to multiple users using zero-forcing beamforming, and achieve multiplexing gains. Such interdependency allows a joint cross-layer optimization. Given the popularity distribution of the content, the available cache size, and the network topology, we devise near-optimal strategies of caching such that the system throughput is maximized or the system delay is minimized. Under realistic scenarios and assumptions, our analytical and simulation results show that our system yields significantly faster content delivery, which can be one order of magnitude faster than that of legacy systems.

Energy-Efficient Device-to-Device Communications for Green Smart Cities

To afford effective service of real-time monitoring and responses for smart cities, it is desired to provide ubiquitous network connections and high data rate services. However, the huge demands for ubiquitous high data rate wireless communications have caused a sharp increase in energy consumption and green house gas emission. In order to realize a sustainable smart city, it is critical to incorporate green communication technique into smart city developments. Device-to-device (D2D) communication has been recognized as one of the key technologies to improve data rate and reduce power consumption, which allows two physically nearby located user equipments to communicate directly with each other. In this paper, with the target of achieving green communications through D2D, we investigate the joint optimization of uplink subcarrier assignment (SA) and power allocation (PA) in D2D underlying cellular networks. Specifically, the problem formulation is to minimize the energy cost of all users in the system while guaranteeing the required data rate of both the D2D user equipments (DUEs) and cellular user equipments. Such an optimization problem is in general a mixed-integer nonlinear programming problem that is NP-hard. To make this problem tractable, we decompose it into the SA and PA subproblems. In particular, we design a heuristic algorithm to assign subcarrier by assuming that the transmit power is evenly allocated over all subcarriers. After that, we solve the PA subproblem by exploiting the difference between the concave function (D.C.) structure of the constraints and transform it into a convex optimization problem. Simulation results demonstrate the remarkable improvement in terms of power consumption by using our algorithms.

Research on the thermal network optimization of wet axle based on high performance computing and wireless data transmission

High performance computing promotes the solution of large mathematical models of complex mechanical systems and lays a foundation for the theoretical analysis of complicated and difficult problems in the mechanical field. At the same time, the high reliability transmission of wireless data makes it possible for a variety of motion state mechanical systems to measure and control. In this paper, we present the energy loss model of the wet axle transmission system based on bond graph theory, and obtain the heat source boundary condition of the thermal analysis of the wet axle by calculating the mathematical model of the energy loss. Moreover, thermal network method is proposed to analysis heat accumulation and disequilibrium of multistage closed wet axle, by analyzing heat source distribution and heat transfer characteristics among machine elements, oil and air, finally the mathematic model of thermal analysis is established. The thermal numerical calculation of the thermal network for the complex mechanical system and the verification of the whole vehicle test for the results of the thermal calculation have been realized, then thermal optimization is done for wet axle heat equilibrium. Theory and experiment results indicate that heat accumulation in wet hub and heat disequilibrium of different parts are severe especially under efficient operating condition; thermal network calculation and optimization results verified by real vehicle experiment are true and valid. The research proves that high performance computer and high reliable wireless data transmission technology have promoted the optimization design of complex mechanical system.

A Novel 60 GHz Wideband Coupled Half-Mode/Quarter-Mode Substrate Integrated Waveguide Antenna

A novel wideband substrate integrated waveguide (SIW) antenna topology, consisting of coupled half-mode and quarter-mode SIW resonant cavities, is proposed for operation in the 60 GHz band. This innovative topology combines a considerable bandwidth enhancement and a low form factor with compatibility with low-cost printed circuit board manufacturing processes, making it excellently suited for the next generation, high data rate wireless applications. Moreover, exploiting SIW technology, a high antenna-platform isolation is obtained, enabling dense integration with active electronics without harmful coupling. The computer-aided design process yields an antenna that covers the entire 57–64 GHz IEEE 802.11ad band with a measured fractional impedance bandwidth of 11.7% (7 GHz). The measured maximum gain and radiation efficiency of the prototype are larger than 5.1 dBi and 65%, respectively, within the entire impedance bandwidth.

On Millimeter Wave and THz Mobile Radio Channel for Smart Rail Mobility

As a widely acknowledged efficient and green transportation model, rail traffic is expected to evolve into a new era of “smart rail mobility” whereby infrastructure, trains, and travelers will be interconnected to achieve optimized mobility, higher safety, and lower costs. Thus, a seamless high-data rate wireless connectivity with up to dozens of gigahertz bandwidth is required. Such a huge bandwidth requirement motivates the exploration of the underutilized millimeter (mm) wave and terahertz (THz) bands. In this paper, the motivations for developing millimeter wave and THz communications for railway are clarified by first defining the applications and scenarios required for smart rail mobility. Ray-tracing simulations at 100 GHz imply that to form high-gain directional antenna beams, dynamic beamforming strategies and advanced handover design are critical for the feasibility of THz communications to enable smart rail mobility.

Silicon Millimeter-Wave, Terahertz, and High-Speed Fiber-Optic Device and Benchmark Circuit Scaling Through the 2030 ITRS Horizon

This paper reviews the technology requirements of future 100–300-GHz millimeter-wave (mm-wave) systems-on-chip (SOI) for high data rate wireless and sensor applications, as well as for 100–300-GBaud fiber-optic communication systems. Measurements of state-of-the-art silicon metal–oxide–semiconductor field-effect transistors (MOSFETs), SiGe heterojunction bipolar transistors (HBTs), and of a variety of HBT-HBT and MOS-HBT cascodes are presented from dc to 325 GHz. The challenges facing mm-wave MOSFET and SiGe HBT device and benchmark circuit scaling toward 2–3-nm gate length and beyond 2-THz transistor $f{\mathrm {MAX}}$ are discussed for the first time based on technology computer-aided design (TCAD) and atomistic simulations. Finally, simulations of the scaling of the SiGe HBT analog and mixed-signal mm-wave benchmark circuit performance across future technology nodes predict that PAs with 45% power added efficiency (PAE) at 220 GHz, track and hold amplifiers (THAs) with over 140-GHz bandwidth, and transimpedance amplifiers (TIAs) with 250-GHz bandwidth and less than 5-dB noise figure will become feasible by 2030. Comparison of simulations and measurements for representative benchmark circuits such as TIAs, THAs, linear modulator drivers, digital-to-analog converters (DACs), and power amplifiers (PAs), fabricated in advanced SiGe BiCMOS and nanoscale SOI complementary metal–oxide–semiconductor (CMOS) technologies, and operating at 120 Gb/s and above 100 GHz, respectively, are presented to support the credibility of the benchmark circuit scaling exercise.

Capacity Analysis of MIMO in Non-Uniform Nakagami Channel with Linear Receiver

ABSTRACTMultiple-input–multiple-output (MIMO) systems have emerged as a promising solution to provide high data rate wireless services in a rich scattering environment. This paper deals with the performance analysis of the MIMO system in correlated non-uniform phase distributed Nakagami-m channel with linear receiver. Authors have considered spatial diversity scheme i.e, vertical bell laboratories layered space-time (V-BLAST) systems in correlated MIMO Nakagami-m fading channels with equal power distribution among the transmitter side antennas. Also, they consider that the channel state information (CSI) is available only at the receiver. The paper presents a detailed analysis of the channel capacity in correlated and uncorrelated channel condition and validated the result with appropriate mathematical model. The effect of Doppler shift and Nakagami-m fading parameter m on the channel ergodic and outage capacity has been analyzed here.

Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

A Multilayer LTCC Solution for Integrating 5G Access Point Antenna Modules

An integrated solution for the development of multilayer antenna modules for fifth-generation (5G) communications, based on low temperature cofired ceramic (LTCC), is presented. The design exploits the 3-D integration capabilities of the LTCC process, enabling the realization of a full-corporate feed network (CFN) in vertical configuration. A novel implementation of the CFN employing dielectric-embedded parallel plate waveguides (PPWs) is proposed. The PPW lines are delimited by via-rows. As opposed to standard substrate-integrated waveguide feed networks, guided fields are orthogonal to the via-rows and propagate along the vertical axis of the structure. The CFN feeds four long slots, without any coupling structure, and provides broadband operation. The final prototype comprises 18 LTCC tapes, with a total thickness of 3.4 mm. The measured −10-dB impedance bandwidth spans from 51.2 to 66 GHz (>25.2%). The module generates a fixed broadside beam, but multibeam operation in $H$ -plane can be easily achieved. In the 50–66-GHz band, the peak gain is 14.25 dBi and the average first side-lobe level in $H$ -plane is −20.6 dB. The proposed technology and the design concept are suited for highly integrated millimeter-wave systems, such as access points in the future $V$ -band high data-rate wireless networks.

60 GHz Front-End Components for Broadband Wireless Communication in 130 nm CMOS Technology

Abstract The over 5 GHz available spectral space allocated worldwide around the 60 GHz band, is very promising for very high data rate wireless short-range communications. In this article we present two key components for the 60 GHz front-end of a transceiver, in 130 nm RF CMOS technology: a single-balanced mixer with high Conversion Gain (CG), reduced Noise Figure (NF) and low power consumption, and an LC cross-coupled Voltage Controlled Oscillator (VCO) with very good linearity, with respect to Vctrl, and very low Phase Noise (PN). In both circuits, custom designed inductors and a balun structure for the mixer are employed, in order to enhance their performance. The VCO’s inductor achieves an inductance of 198 pH and a quality factor (Q) of 30, at 30 GHz. The balun shows less than 1 o Phase Imbalance (PI) and less than 0.2 dB Amplitude Imbalance (AI), from 57 to 66 GHz. The mixer shows a CG greater than 15 dB and a NF lower than 12 dB. In addition, the VCO achieves a Phase Noise lower than -106 dBc/Hz at 1 MHz offset, and shows great linearity for the entire band. Both circuits are biased with a 1.2 V supply voltage and the total power consumption is about 10.6 mW for the mixer and 10.92 mW for the VCO.

MINIMIZING HIGH PAPR IN OFDM SYSTEM USING CIRCULANT SHIFT CODEWORD

Orthogonal Frequency Division Multiplexing (OFDM) has been widely used in various high data rate wireless communications standards. The high peak-to-average power ratio (PAPR) has however been known to be a constant problem in OFDM systems. The high PAPR in the OFDM system has led to many problems such as signal distortion, energy spilling to the adjacent channel and reducing system performance gradually. In this paper, a technique involving the manipulation of codeword using circulant shift will be introduced. The key idea of the proposed technique is to generate scramble data sequences like the conventional selective mapping (SLM) technique. The simulation results showed that the proposed technique overcame original OFDM signals and conventional SLM with a 19.5% improvement and 1.1 dB difference from conventional SLM. Besides that, the proposed technique offered a lower computationally complexity where the number of IFFT blocks can be reduced by about 57% as compared to conventional SLM.

Efficient Terahertz detection in black-phosphorus nano-transistors with selective and controllable plasma-wave, bolometric and thermoelectric response.

The ability to convert light into an electrical signal with high efficiencies and controllable dynamics, is a major need in photonics and optoelectronics. In the Terahertz (THz) frequency range, with its exceptional application possibilities in high data rate wireless communications, security, night-vision, biomedical or video-imaging and gas sensing, detection technologies providing efficiency and sensitivity performances that can be “engineered” from scratch, remain elusive. Here, by exploiting the inherent electrical and thermal in-plane anisotropy of a flexible thin flake of black-phosphorus (BP), we devise plasma-wave, thermoelectric and bolometric nano-detectors with a selective, switchable and controllable operating mechanism. All devices operates at room-temperature and are integrated on-chip with planar nanoantennas, which provide remarkable efficiencies through light-harvesting in the strongly sub-wavelength device channel. The achieved selective detection (∼5–8 V/W responsivity) and sensitivity performances (signal-to-noise ratio of 500), are here exploited to demonstrate the first concrete application of a phosphorus-based active THz device, for pharmaceutical and quality control imaging of macroscopic samples, in real-time and in a realistic setting.

RescueNet: Reinforcement-learning-based communication framework for emergency networking

A new paradigm for emergency networking is envisioned to enable reliable and high data-rate wireless multimedia communication among public safety agencies in licensed spectrum while causing only acceptable levels of disruption to incumbent network communication. The novel concept of mission policies, which specify the Quality of Service (QoS) requirements of the incumbent networks as well as of the emergency networks involved in rescue and recovery missions, is introduced. The use of mission policies, which vary over time and space, enables graceful degradation in the QoS of the incumbent networks (only when necessary) based on mission policy specifications. A Multi-Agent Reinforcement Learning (MARL)-based cross-layer communication framework, “RescueNet,” is proposed for self-adaptation of nodes in emergency networks based on this new paradigm. In addition to addressing the research challenges posed by the non-stationarity of the problem, the novel idea of knowledge sharing among the agents of different ages (either bootstrapping or selective exploration strategies or both) is introduced to improve significantly the performance of the proposed solution in terms of convergence time and conformance to the mission policies.

Development of Efficient Resource Allocation Algorithm in Chunk Based OFDMA System

The emerging demand for diverse data applications in next generation wireless networks entails both high data rate wireless connections and intelligent multiuser scheduling designs. The orthogonal frequency division multiple access based system is capable of delivering high speed data rate and can operate in a multipath environment. OFDMA based system dividing an entire channel into many orthogonal narrow band subcarriers. Due to this, it is useful to eliminate inter symbol interferences which is a limit of total available data rates. In this paper, investigation about resource allocation problem for the chunk based Orthogonal Frequency Division Multiple Access (OFDMA) wireless multicast systems is done. In this paper, it is expected that the Base Station (BS) has multiple antennas in a Distributed Antenna System (DAS). The allocation unit is a group of contiguous subcarriers (chunk) in conventional OFDMA systems. The aim of this investigation is to develop an efficient resource allocation algorithm to maximize the total throughput and minimize the average outage probability over a chunk with respect to average Bit Error Rate (BER and total available power).

Distributed Association and Relaying With Fairness in Millimeter Wave Networks

Millimeter wave (mmWave) systems are emerging as an essential technology for enabling extremely high data rate wireless communications. The main limiting factors of mmWave systems are blockage (high penetration loss) and deafness (misalignment between the beams of the transmitter and receiver). To alleviate these problems, it is imperative to incorporate efficient association and relaying between terminals and access points. Unfortunately, the existing association techniques are designed for the traditional interference-limited networks, and thus are highly suboptimal for mmWave communications due to narrow-beam operations and the resulting non-negligible interference-free behavior. This paper introduces a distributed approach that solves the joint association and relaying problem in mmWave networks considering the load balancing at access points. The problem is posed as a novel stochastic optimization problem, which is solved by distributed auction algorithms where the clients and relays act asynchronously to achieve optimal client-relay-access point association. It is shown that the algorithms provably converge to a solution that maximizes the aggregate logarithmic utility within a desired bound. Numerical results allow quantification of the performance enhancements introduced by the relays, and the substantial improvements of the network throughput and fairness among the clients by the proposed association method as compared to standard approaches. It is concluded that mmWave communications with proper association and relaying mechanisms can support extremely high data rates, connection reliability, and fairness among the clients.

Millimeter Wave Networked Wearables in Dense Indoor Environments

Supporting high data rate wireless connectivity among wearable devices in a dense indoor environment is challenging. This is primarily due to bandwidth scarcity when many users operate multiple devices simultaneously. The millimeter-wave (mmWave) band has the potential to address this bottleneck, thanks to more spectrum and less interference because of signal blockage at these frequencies. In this paper, we explain the potential and challenges associated with using mmWave for wearable networks. To provide a means for concrete analysis, we present a system model that admits easy analysis of dense, indoor mmWave wearable networks. We evaluate the performance of the system while considering the unique propagation features at mmWave frequencies, such as human body blockages and reflections from walls. One conclusion is that the non-isotropy of the surroundings relative to a reference user causes variations in system performance depending on the user location, body orientation, and density of the network. The impact of using antenna arrays is quantified through analytic closed-form expressions that incorporate antenna gain and directivity. It is shown that using directional antennas, positioning the transceiver devices appropriately, and orienting the human user body in certain directions depending on the user location result in gigabits-per-second achievable ergodic rates for mmWave wearable networks.

Implementation and Performance Evaluation of OFDM System in Diverse Transmission Channel Using Simulink

Orthogonal Frequency Division Multiplexing (OFDM) has become a popular modulation method in high data rate wireless communications. It is a key modulation scheme that is especially suited for high-data-rate transmission in delay-dispersive environments because of its robustness to Inter-Symbol Interference (ISI) and multipath fading environment. It converts a high-rate data stream into a number of low-rate streams that are transmitted over parallel, narrowband channels which needs little or no equalization. OFDM also provides efficient spectrum utilization by use of single frequency networks (SFNs). Recently, OFDM has become the standard for physical layer implementation of various digital audio and video wireless communications such as DAB/DVB, wireless local access networks (WLANs) and wireless metropolitan area networks (WMANs). Moreover OFDM is a potential candidate for fourth-generation (4G) mobile wireless systems and beyond. In this paper, through Simulink implementation, we present a bit error rate (BER) performance analysis of OFDM system in diverse transmission channels. The results show that OFDM is well suited for high speed data transmission in mobile environment and channel coding combined with interleaving is mandatory for any wireless high speed transmission.