High Data Rate Requirements Research Articles

Efficient in Vivo Neural Signal Compression Using an Autoencoder-Based Neural Network.

Conventional in vivo neural signal processing involves extracting spiking activity within the recorded signals from an ensemble of neurons and transmitting only spike counts over an adequate interval. However, for brain-computer interface (BCI) applications utilizing continuous local field potentials (LFPs) for cognitive decoding, the volume of neural data to be transmitted to a computer imposes relatively high data rate requirements. This is particularly true for BCIs employing high-density intracortical recordings with hundreds or thousands of electrodes. This article introduces the first autoencoder-based compression digital circuit for the efficient transmission of LFP neural signals. Various algorithmic and architectural-level optimizations are implemented to significantly reduce the computational complexity and memory requirements of the designed in vivo compression circuit. This circuit employs an autoencoder-based neural network, providing a robust signal reconstruction. The application-specific integrated circuit (ASIC) of the in vivo compression logic occupies the smallest silicon area and consumes the lowest power among the reported state-of-the-art compression ASICs. Additionally, it offers a higher compression rate and a superior signal-to-noise and distortion ratio.

Design and evaluation of space‐time coded multiple input multiple output‐orthogonal frequency division multiplexing physical layer

SummaryTwo fundamental aspects of wireless communication, which make it challenging and interesting, are fading and interference. Multiple input multiple output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques when utilized together effectively combat fading and interference thereby achieving the requirement of high data rate and high performance. In this paper, a 2 × 1 MIMO‐OFDM baseband model of the physical layer according to IEEE 802.16.1 standard employing 256 subcarriers capable of transmitting 192 Mbps in a 21‐MHz bandwidth frequency selective fading channel is designed. All essential blocks of the communication system like channel coding, modulation, time synchronization, frequency synchronization, channel estimation, residual carrier frequency offset (CFO) estimation, and channel decoding are covered at the algorithm level. A two‐step time synchronization method is used in this work to avoid any ambiguity in frame detection. A long preamble, consisting of three short preambles, is designed to aid in time synchronization, frequency synchronization, and channel estimation. To evaluate the performance of the proposed design, simulations were carried out in MATLAB‐SIMULINK.

Development and verification of an on-board integrated optics scheme for a 50G/10G combo PON system

We propose an on-board integrated optics (OBO) scheme within a 50G/10G combo passive optical network (PON) system, for the first time to our best knowledge, which can achieve high port density, low cost, and low power consumption required by the 50G PON system. We provide an OBO scheme that integrates record-high power distributed feedback (DFB) lasers, low insertion loss silicon modulators, a planar lightwave circuit wavelength-division multiplexer, and avalanche photodiodes on a single board, which can solve key issues faced by the demand of coexistence and smooth evolution from 10G to 50G PON for global access network operators. In this system, the slope efficiency of the lasers has been optimized at high temperatures, allowing the output power of the lasers to achieve a record-breaking 23.5 dBm at 1577 and 1342 nm, while reducing cooling power consumption to realize low carbon emission in access networks. We developed a low-loss broadband silicon modulator to meet the large power budget and high data rate requirements of 50G PON by optimizing doping parameters and constructing electrodes that match the driver. This silicon modulator has a 6.6 dB insertion loss and an electro-optic bandwidth of more than 38 GHz, making it the ideal silicon modulator for 50G PON systems. In addition, we verify the end-to-end performance, including receiver sensitivity in the upstream direction and the dispersion penalty in the downstream direction. This suggests that the OBO scheme can satisfy the criteria of the 50G PON system according to the ITU-T G.9804 standard series.

For 5G applications, high-gain patch antenna in Ka-Band

<span>The fifth generation (5G) of telecommunications is an attractive application for many researchers during the last years. The 5G requires high date rate with low latency communication medium and patch antenna was used recently for this application. In this article a patch antenna for 5G at 38 GHz was proposed. This article worked on enhancing the gain of patch antenna at Ka-Band and reducing side lobes level (SLL) in radiation pattern. The gain of the patch antenna was improved using a reflector layer located under antenna’s ground with free space air gap separating between two layers. Moreover, the SLL were reduced to satisfy low latency condition for 5G communications. The proposed antenna shows high gain around 8.10 dB with high front-to-back (F/B) ratio of 16.24 dB and wide operating bandwidth around 1.4 GHz for high data rate requirements as well as having reduced overall size antenna. The article based on analytical calculations for patch dimensions and optimization procedure to achieve the desired performance of antenna. Computer simulation technology (CST) had been used as an environment for simulation.</span>

Performance analysis of mmWave/sub-terahertz communication link for 5G and B5G mobile networks

Abstract Millimeter (mmWave) and sub-terahertz communication is a key technology to support high data rate requirements of 5G and B5G mobile networks. However this field is still in its initial development stage because of the various technical difficulties in its practical implementation due to inherently distinct propagation properties of mmWave/sub-terahertz frequencies. A thorough investigation of mmWave/sub-terahertz communication link is required in order to successfully deploy these frequency bands in 5G and B5G mobile networks. This paper investigates the effect of atmospheric conditions like dry air, humidity, rain, snow, fog and foliage on the performance of the mmWave/sub-terahertz link. The work also presents a mathematical analysis of the coverage of mmWave/sub-terahertz communication link and investigates the effect of various parameters like frequency, bandwidth, transceiver antenna gain, path loss coefficient (LOS, NLOS case) and system noise on its performance.

Design of 60 GHz millimeter‐wave SIW antenna for 5G WLAN/WPAN applications

AbstractBroadband millimeter Wave (mmWave) transmission at the 60 GHz band is a great prospect to meet the demanding high data rate requirements of future wireless personal area network (WPAN) and wireless local area network (WLAN) 5G networks. This paper proposes a single layer H‐plane sectoral horn mmWave antenna at 60 GHz using substrate integrated waveguide (SIW) technology for the future high‐speed short range WPAN and WLAN networks. The benefits of the proposed antenna are high gain, low cost, small size, and ease of integration with other planar circuits. The proposed SIW horn is constructed with RT/duroid 5880 substrate, which has a relative permittivity and loss tangent with a thickness of 0.508 mm. The novelty of this work is; a wider bandwidth is achieved by adding striplines at the horn aperture to match the antenna with air and to increase the antenna operating bandwidth. In addition, the antenna gain is improved by adding a dielectric lens with the striplines at the radiating end. During these steps, the antenna parameters are tuned and optimized to achieve the best results as compared to related previous studies. The proposed antenna's performance is analyzed in terms of gain, return loss (S11) and radiation pattern at a frequency of 60 GHz. Simulation results are carried out by using industry standard software, Computer Simulation Technology (CST) microwave studio. The designed antenna achieves a peak gain of 13 dB and impedance bandwidth when , 8.6 GHz (13.688%) for the reflection coefficient of . The results show that the proposed antenna achieves stable tunable 60 GHz frequency performance, which makes it feasible to deploy in WLAN/WPAN operating in mmWave bands.

Fiberless optical communication: issues and challenges

Abstract To fulfill the requirement of high data rate with variable quality of service, optical wireless communication is a better option in comparison to existing RF system and is a favorable technological candidate for future optical communication. In wireless optical communication, information is transmitted by propagation of optical wave through the atmosphere. The detrimental effects of channel parameters can acutely limit the utility of an optical wireless communication system. The paper first reviews different channel models in the context to outdoor wireless communication. Different impairments that affect the performance of outdoor optical communication systems and different techniques to mitigate these impairments are then investigated. The upper layer protocols for free space optical communication are also discussed.

Satellite Image Compression Guided by Regions of Interest

Small satellites empower different applications for an affordable price. By dealing with a limited capacity for using instruments with high power consumption or high data-rate requirements, small satellite missions usually focus on specific monitoring and observation tasks. Considering that multispectral and hyperspectral sensors generate a significant amount of data subjected to communication channel impairments, bandwidth constraint is an important challenge in data transmission. That issue is addressed mainly by source and channel coding techniques aiming at an effective transmission. This paper targets a significant further bandwidth reduction by proposing an on-the-fly analysis on the satellite to decide which information is effectively useful before coding and transmitting. The images are tiled and classified using a set of detection algorithms after defining the least relevant content for general remote sensing applications. The methodology makes use of the red-band, green-band, blue-band, and near-infrared-band measurements to perform the classification of the content by managing a cloud detection algorithm, a change detection algorithm, and a vessel detection algorithm. Experiments for a set of typical scenarios of summer and winter days in Stockholm, Sweden, were conducted, and the results show that non-important content can be identified and discarded without compromising the predefined useful information for water and dry-land regions. For the evaluated images, only 22.3% of the information would need to be transmitted to the ground station to ensure the acquisition of all the important content, which illustrates the merits of the proposed method. Furthermore, the embedded platform's constraints regarding processing time were analyzed by running the detection algorithms on Unibap's iX10-100 space cloud platform.

Digital twin‐enabled deep reinforcement learning for joint scheduling of ultra‐reliable low latency communication and enhanced mobile broad band: A reliability‐guaranteed approach

AbstractIn the coexistence of ultra‐reliable low latency communication (URLLC) and enhanced mobile broad band (eMBB) in 5G networks, the arriving URLLC traffic with strict latency requirements will be scheduled by puncturing ongoing eMBB transmissions, negatively impacting eMBB data rate. In this article, we add reliability measurement for eMBB users with high data rate requirements. The scheduling problem is formulated as an optimization problem with the goal of maximizing the data rate of eMBB users while meeting the requirements of URLLC latency and eMBB data rate. To jointly optimize resource allocation policy and puncturing policy, an algorithm based on deep reinforcement learning (DRL) is introduced. Considering that the utilization of DRL in the resource scheduling problem is limited due to the nonstationary communication environment, a digital twin‐enabled DRL architecture is presented to fine‐tune the DRL model according to feedback from the real‐world network. The DRL agent can explore in the digital twin model, avoiding the loss of quality of service caused by exploration in the real‐world environment. According to simulation results, the approach proposed in this article can improve the reliability of eMBB users with data rate requirements.

On the Optimization of Integrated Terrestrial-Air-Underwater Architecture Using Optical Wireless Communication for Future 6G Network

Optical wireless communication (OWC) is one of the promising solution to enhance the capacity of the next generation cellular as well as fiber-wireless (FiWi) broadband access networks. The proposed work aims to complement an OWC system by utilizing unmanned aerial vehicles (UAV) to improve the performance of an integrated terrestrial-air-underwater (TAU) communication framework. Specifically, an integrated FiWi based UAV assisted hybrid free-space optical (FSO) and underwater wireless optical communication (UWOC) system is proposed to meet high data rate requirement between a terrestrial ground station and an autonomous underwater vehicle (AUV). The performance of the proposed scheme is compared against the conventional radio frequency (RF) based TAU communication framework. We also optimize the divergence angle of the optical beam of FSO link using a novel COgnition-based divergence angle tracking (CODAT) algorithm such that the outage probability of FSO links is minimized and the data rate requirement of AUV is also satisfied. The impact of the position of over-sea surface (OSS) relay and UAV altitude on the performance of the proposed system is also analyzed. Through the obtained results it has been shown that the proposed OWC based integrated TAU communication framework outperforms the conventional RF based TAU communication framework.

Vehicle Behavior-Cognition-Based Particle-Filter-Enabled mmWave Beam Tracking for Connected Automated Vehicles

Considering the low-latency and high data rate requirements for automated vehicles (AVs), the millimeter-wave (mmWave) technology can support tens of Gb/s raw sensor information sharing for connected AVs (CAVs). However, the challenging problem is how to achieve fast and robust mmWave beam tracking for CAVs. To solve this problem, we propose a novel vehicle behavior cognition-based particle-filter (VBC-PF)-enabled beam tracking algorithm. The beam-space subset is predicted based on the beam change rate and the position-yaw information from the vehicle behavior cognition in CAVs, which effectively reduces the beam search overhead. In the proposed VBC-PF algorithm, the particle weight updating schemes are designed based on the optimal vehicle behavior cognition to avoid the particle divergence and the error accumulation. Simulation and hardware testbed results verify that the accuracy and efficiency of the proposed VBC-PF algorithm outperform the conventional particle filter (PF) and the extended Kalman filter (EKF) algorithms.

Coverage Analysis of mmWave and THz-Enabled Aerial and Terrestrial Heterogeneous Networks

Heterogeneous networks (HetNets) are becoming a promising solution for future wireless systems to satisfy the high data rate requirements. This paper introduces a stochastic geometry framework for the analysis of the downlink coverage probability in a multi-tier HetNet consisting of a macro-base station (MBS) operating at sub-6 GHz, millimeter wave (mmWave)-enabled unmanned aerial vehicles (UAVs) operating at 28 GHz, and small BSs operating both at mmWave and THz frequencies. The analytical expressions for the coverage probability for each tier have been derived in the paper. Monte Carlo simulations are then performed to validate the analytical expressions. The effectiveness of the HetNet is analyzed on various performance metrics including association and coverage probabilities for different network parameters. We show that the mmWave and THz-enabled cells provide significant improvement in the achievable data rates because of their high available bandwidths, however, they have a degrading effect on the coverage probability due to their high propagation losses.

Improved Spectral Efficiency and Connectivity in RSMA based 5G V2X Systems

Vehicle to everything (V2X) faces several challenges including high data rate, low latency and stable connectivity requirements. Due to increased number of connected vehicles, Interference too appears to be a serious issue in V2X systems. Consequently, careful selection of multiple access techniques can lead to improved interference mitigation together with higher spectral efficiency and data rate. Vehicle mobility with growing traffic density is a demanding task that affects probability of vehicle connectivity, thereby resulting into requirement of sustained vehicle linkage for ongoing traffic safety. In this regard, our paper employs Rate Splitting Multiple Access (RSMA) technique, which considers change of both channel strength and direction for improved interference mitigation leading towards enhanced spectral efficiency. RSMA is optimized for weighted sum rate, further; it is integrated with mobility management to demonstrate sustained connectivity in the presence of increased traffic density. Presented results have been found promising, both in terms of spectral efficiency and stable connectivity. RSMA 5G V2X outperformed at higher Signal to noise ratio (SNR) values and on average achieved 25% better spectral efficiency compared to Non Orthogonal Multiple Access (NOMA) technique.

Joint Subcarrier Allocation, Modulation Mode Selection, and Trajectory Design in a UAV-Based OFDMA Network

The deployment of unmanned aerial vehicle (UAV) in scenarios with limited or no infrastructure can provide services for mobile devices flexibly. This letter investigates the UAV transmission energy minimization problem with high data rate and reliability requirements in a UAV-based Orthogonal Frequency Division Multiple Access (OFDMA) network. Considering that the formulated problem is a non-convex problem, we decompose the original problem into two subproblems: (i) joint subcarrier allocation and modulation mode selection subproblem, and (ii) UAV trajectory design subproblem. By solving these two subproblems, we propose the joint subcarrier allocation, modulation mode selection, and trajectory design (JSMT) algorithm. Simulation results show that the proposed JSMT algorithm can efficiently reduce the transmission energy of the UAV while meeting high data rate and reliability requirements.

Optimal Power Allocation for Achieving Secure Green Cognitive Radio Networks

In cognitive radio networks, wireless nodes adapt to the surrounding radio environment and utilize the spectrum of licensed users. The cognitive radio environment is dynamic, and wireless channels are accessible by both legitimate and illegitimate users. Therefore, maintaining the security of cognitive radio networks is a challenging task, which must be addressed thoroughly. Further, with the recent exponential surge in wireless nodes and associated high data rate requirements, energy consumption is also growing at an unprecedented rate. Hence, energy efficiency becomes an important metric that must be considered in the design of future wireless networks. Accordingly, by considering the great ecological and economic benefits of green wireless networks, this work focus on energy-efficient resource allocation in secure cognitive radio networks. Since physical-layer security is an emerging technique that improves the security of communication devices, in this paper, an ergodic secure energy efficiency problem for a cognitive radio network is formulated with a primary user, a secondary user, and an eavesdropper. As the formulated problem is non-convex, a concave lower bound is applied to transform the original non-convex problem into a convex one. Further, by adopting the fractional programming and dual decomposition techniques, optimal power allocation strategies are obtained with the aim of maximizing the ergodic secure energy efficiency of the secondary user with constraints on the average interference power and average transmit power. Numerical examples are used to demonstrate the effectiveness of the proposed algorithm.

Design and Analysis of Joint Source-Channel Code System with Fixed-Length Code

As the demands of multimedia and data services increase, efficient communication systems are being investigated to meet the high data rate requirements. Joint source-channel coding (JSCC) schemes were proposed for improving overall system performance. However, existing JSCC systems may suffer a symbol error rate (SER) performance loss when residual source redundancy is not fully exploited. This paper presents a novel, low-complexity JSCC system, which consists of a fixed-length source block code and an irregular convolutional channel code. A simple approach is proposed to design source codes that minimize the SER of source detection and guarantee the convergence of iterative source-channel decoding (ISCD). To improve the waterfall performance of ISCD, the channel code is optimized by using the extrinsic information transfer (EXIT) chart and the concept of irregular code. The channel code is constituted by recursive non-systematic convolutional (RNSC) subcodes. The weights of subcodes are optimized to make the EXIT curves of the channel decoder and the source decoder well-matched, and therefore, a near-capacity performance is achieved. Simulation results show that the proposed system achieves more than 1 dB gains and 0.3 dB gains compared to the separate source-channel code system and the other optimal JSCC systems, respectively. Additionally, the performance of the proposed system is within 1 dB deviation from the Shannon limit capacity.

Efficient Allocation of Resource-Intensive Mobile Cyber–Physical Social System Applications on a Heterogeneous Mobile Ad Hoc Cloud

Mobile ad hoc cloud (MAC) is one of the key enabling technologies for realizing mobile cyber-physical–social systems (MCPSSs). A MAC is a distributed computing infrastructure that enables mobile devices to share computing resources in an ad hoc environment. Resource allocation is one of the key components of MAC and plays a vital role in system and application performance. Existing resource allocation schemes are designed to utilize single wireless communication technology (WCT) or rely on an eclectic system that exclusively selects single communication technology. Moreover, these schemes do not consider link lifetime, which significantly affects application performance. Consequently, these schemes cannot satisfy low latency and high data rate requirements of emerging resource-intensive MCPSS applications, such as merged reality-based multiplayer games. Thus, this work proposes a new resource allocation scheme that simultaneously uses multiple WCTs and considers link lifetime during the resource allocation process. This study also proposes a Markov chain-based link lifetime prediction mechanism. In comparison with existing mechanisms, the proposed link lifetime prediction mechanism considers the history of a user's visited locations and time spent at each location. The performance of the proposed scheme is evaluated in a wide range of network and application scenarios using Network Simulator 3.

EDCSuS: Sustainable Edge Data Centers as a Service in SDN-Enabled Vehicular Environment

Cloud computing has emerged as one of the popular technologies which provide on-demand services to the end users. Such services are hosted by massive geo-distributed data centers (DCs). Nowadays, connected vehicles in a smart city can also avail cloud services through Internet using cellular technologies. But, the advent of 5G technology has posed challenges for DCs such as-low latency and higher data rate requirements. To handle these challenges, edge-DCs (EDCs) can be deployed across a smart city to provide low latency services to the connected vehicles. In lieu of this, in this paper, EDCSuS: Sustainable EDC as a service framework in software defined vehicular environment is proposed. In EDCSuS, first, a software defined controller handles the incoming requests and suggest an optimal flow path. Second, a multi-leader multi-follower Stackelberg game is presented for resource allocation. Third, to improve the resource utilization, a cooperative resource sharing scheme is designed, thereby minimizing the energy consumption of servers in the EDCs. Lastly, a caching scheme is presented to avert excessive energy consumption for retracing the lost link due to vehicular mobility. The efficacy of the proposed scheme has been evaluated using extensive simulations with respect to various parameters. The results obtained prove the effectiveness of EDCSuS.

AoD-Adaptive Channel Feedback for FDD Massive MIMO Systems With Multiple-Antenna Users

In this paper, we propose an efficient feedback scheme for an angle of departure (AoD) based channel estimation in frequency division duplex (FDD) massive multiple-input multiple-output (MIMO) systems with multiple antennas at the users. The channel feedback scheme is based on zero-forcing block diagonalization (BD) and it is proposed for two distinct design cases; in case I, the number of streams intended for a user equals the number of antennas at that user; in case II, the number of streams is less than the number of receive antennas. Case I is applicable in scenarios where high data rate requirements are needed as it transmits data symbols over all of the available degrees of freedom of the system. Diversely, case II is applicable when reliability is a priority in the system as it uses the additional <i>receive</i> antennas at the user to achieve spatial diversity to enhance the link performance. The proposed scheme is analyzed for the two cases by quantifying the downlink rate gap from the case of perfect channel state information (CSI). Moreover, we design structured feedback codebooks based on optimal subspace packing in the Grassmannian manifold and show that these codes achieve close performance to the perfect CSI case. Additionally, a vector quantization scheme is proposed to quantize the user&#x2019;s channel matrix when optimal power allocation across multiple streams is adopted in the low signal-to-noise ratio (SNR) region. The feedback codebooks are based on optimal line packing in the Grassmannian manifold, where every vector of the user&#x2019;s channel matrix is quantized and sent to the BaseStation. The results demonstrate a fundamental trade-off between vector quantization, with power optimization across the data streams, and subspace quantization. Specifically, vector quantization codebooks outperform subspace-based codebooks in the low SNR region, while the situation is reversed in the high SNR region.

Terahertz Channel Propagation Phenomena, Measurement Techniques and Modeling for 6G Wireless Communication Applications: A Survey, Open Challenges and Future Research Directions

The Terahertz (THz)THzTerahertz band (0.3-3.0 THz), spans a great portion of the Radio Frequency (RF) spectrum that is mostly unoccupied and unregulated. It is a potential candidate for application in Sixth-Generation (6G) 6GSixth-Generation wireless networks, as it has the capabilities of satisfying the high data rate and capacity requirements of future wireless communication systems. Profound knowledge of the propagation channel is crucial in communication systems design, which nonetheless is still at its infancy, as channel modeling at THz frequencies has been mostly limited to characterizing fixed Point-to-Point (PtP) scenarios up to 300 GHz. Provided the technology matures enough and models adapt to the distinctive characteristics of the THz wave, future wireless communication systems will enable a plethora of new use cases and applications to be realized, in addition to delivering higher spectral efficiencies that would ultimately enhance the Quality-of-Service (QoS) to the end user. In this paper, we provide an insight into THz channel propagation characteristics, measurement capabilities, and modeling techniques for 6G communication applications, along with guidelines and recommendations that will aid future characterization efforts in the THz band. We survey the most recent and important measurement campaigns and modeling efforts found in literature, based on the use cases and system requirements identified. Finally, we discuss the challenges and limitations of measurement and modeling at such high frequencies and contemplate the future research outlook toward realizing the 6G vision.