Channel Bandwidth Research Articles

Dynamic Characteristics Preserving Data Compressing Algorithm for Transactive Energy Management Frameworks

Several players are enabled in smart grids and involved in decision-making process. These players are fully interconnected in the transactive energy (TE) framework to operate the system optimally. By implementing the TE, the final decision are adopted after various consensus between participants. Hence, huge number of data and information are communicated in this framework which leads to complex communication algorithms and wide-bandwidth channels. Besides, the prosumers dataset in the TE framework are with low level of sparsity which is due to their independent interactions with peers and the grid. This article proves the low sparsity in the prosumers dataset and shows the shortcomings of the existing methods. A dynamic intelligent algorithm is proposed in this article to characterize the prosumers data based on the mutual information (MI) theorem. In addition, two data compression algorithms have been proposed in this article to reduce the bandwidth and space for communicating and storing purposes, respectively. The proposed algorithms for data modeling and compression provide compatible superlative performance with minimum information loss. This article saves more communication channel bandwidth by comparing the conventional methods. Fast and robust adaptation of the proposed algorithm facilitates the practical implementation of energy management in the TE framework when wide data transmission is needed. The performance of the proposed algorithms has been evaluated using simulated prosumers dataset and real-world residential and industrial consumer data.

High Bandwidth Thermal Covert Channel in 3-D-Integrated Multicore Processors

Exploiting thermal coupling among the cores of a processor to secretly communicate sensitive information is a serious threat in mobile, desktop, and server platforms. Existing works on temperature-based covert communication typically rely on controlling the execution of high-power CPU stressing programs to transmit confidential information. Such covert channels with high-power programs are typically easier to detect as they cause significant rise in temperature. In this work, we demonstrate that by leveraging vertical integration, it is sufficient to execute typical SPLASH-2 benchmark applications to transfer 200 bits per second (bps) of secret data via thermal covert channels. The strong vertical thermal coupling among the cores of a 3-D multicore processor increases the rates of covert communication by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.4\times $ </tex-math></inline-formula> compared to covert communication in conventional 2-D integrated circuits (ICs). Furthermore, we show that the bandwidth of this thermal communication in 3-D ICs is more resilient to thermal interference caused by applications running in other cores. This reduced interference significantly increases the danger posed by such attacks. We also investigate the effect of reducing intertier overlap between colluded cores and show that the covert channel bandwidth is reduced by up to 62% with no overlap.

Identifying some regularities of radio frequency propagation of a radar system by analyzing different environmental effects

Free space path loss is a function of frequency and propagation distance and the RF signal propagates at light speed in all directions in free space. The performance evaluation of wireless and radar communication technologies is related to understanding the propagation environments. This work presents the modeling of several RF propagation properties that include atmospheric attenuation due to rain, free space path loss, gas, and fog, as well as multipath propagations caused by ground bounces. The methodology discusses the developed model according to the series of (ITU) International Telecommunication Union references to radio wave propagation. This work discusses the Free Space Path Losses (FSPL), and Propagation Losses (PL) due to the atmosphere, precipitation, snow, rain, clouds, fog, atmospheric lensing and absorption, and polarization mismatch. The work also discusses the vertical coverage diagram and radar propagation factor. The obtained results demonstrate that the PL increases with frequency and range, at a 90-degree roll angle, the attenuation approaches infinity, and as the altitude rises, the amount of attenuation caused by lensing decreases. The analysis of attenuation at 1 km vs. frequency variations, at roughly 60 GHz, indicated a high absorption owing to air gas. Lensing attenuations are also offered as secondary outputs for convenience, the wideband channels present higher performance crossways and a wide range of target height as expected. When the target height increases, the influence of multi-path fading approximately vanishes entirely due to the variation increasing in the spreading delay between the bounce and direct pathway signals. This will reduce the coherence sum between these two samples on receiving by the target

Задача управления сенсорной сетью на основе рандомизированного и многоагентного подходов и ее приложения

Tracking multiple targets is a classic signal processing problem that occurs in many applications such as air, maritime and traffic control. Autonomous sensor networks serve as desirable platforms for multipurpose tracking due to their redundancy and reconfigurability. However, the network implementation makes it impossible to use the classical centralized approaches to filtering, since each sensor has limited computing power and limited access to the measurements of other sensors. In addition to topological limitations (each sensor can only communicate with several neighboring network nodes), communication between sensors can be limited, for example, due to limited bandwidth of communication channels, delay and data distortion. This article proposes a new algorithm for distributed tracking of multiple targets in a sensor network, which is a combination of the SPSA algorithm and the local voting protocol. The algorithm is consolidated under conditions of unknown but limited noise, the algorithm step size is optimized, and simulation is carried out to confirm the algorithm’s performance. Possible applications for the algorithm are also described.

Performance evaluation of PDM-256-QAM inter-satellite optical wireless system (IsOWC) using DSP and different wavelength windows

Abstract For communication in space, information transmission lines are critical for reaching the whole world. A long delay and a poor data transfer rates have been observed in radio frequency (RF) communication and therefore inter-satellite communication has become more common in recent years and optical wireless communication has advanced dramatically. Owing to its multiple advantages, including large channel bandwidth, high-speed connectivity and economical operations, IsOWC technology is becoming popular among researchers. Uniphase modulations such as NRZ modulation does not have efficient spectrum for high speed inter-satellite communication. PDM-256-QAM at 160 Gbps over IsOWC channel is demonstrated in this work using matched filter and DSP. Proposed system is investigated for PDM-256-QAM at 850 and 1550 nm wavelength and results analyzed in terms of Q factor, log symbol error rate (SER) and error vector magnitude (EVM).

(Digital Presentation) Sub-THz Front Ends for Future Communication and Sensing Technologies in 130nm Sige Bicmos Technology

Introduction: Beyond the-5G technologies are targeting the available bandwidth (BW) in the D-band and J-band. This promises for very high speed communication and sensing accuracy. Although the advantages of operating beyond 100 GHz from the application point of view, it requires a lot of research and development to design a reliable and power efficient chipsets. In this presentation we will go through the design of wideband 240 GHz transmitter (Tx) and receiver (Rx). Firstly an overview about the link budget analysis will be given, then the design of the local carrier signal generator will be discussed. The wideband Txs and Rxs are to be presented with frequency channelizing concept. At the end the results of the wireless links will be demonstrated. Link Budget Analysis: Operating at sub-THz frequencies approaching the transistor fT put a lot of constraints on the system link budget. The elevated noise figure together with the limited maximum Pout of the transistors lead to solutions which might be limited in BW or power efficiency. Hence the design architecture need to be optimized taking into account the elevated power consumption and heat dissipation. Carrier Generation: Several approaches could be followed to generate the sub-THz carrier frequency. For a power efficient solution the fundamental oscillators promise for a power efficient solution but with limited phase noise performance and tuning range. Such a solution is more common for imaging systems operating at a single frequency. In order to achieve wider tuning ranges for multi-channel scenario or FMCW radar systems, the frequency multiplication chains are common, whereas the multiplication factor depends on the system parameters. Sub-THz Rx: Different approaches were followed to realize a wideband sub-THz Rx. For some technologies the transistors ft does not promise the realization of low noise amplifiers (LNA) with reasonable noise figure, gain and BW. Hence the mixer first approach were followed trying to optimize the noise figure of the down conversion mixer as much as possible. This also enhances the input compression point (IP1dB) of the Rx which is better for monostatic radar applications. On the other hand, if the technology in use allows the development of well performing LNA’s, the LNA first approach was followed to enhance the all over NF of the receiver and ease the implementation of IQ Rxs. In our work an LNA was implemented followed by IQ downconversion mixers and baseband chain as presented in [3]. Sub-THz Tx: The Tx main challenging performance parameter in the sub-THz frequency range is to achieve high output compression point across the required BW with as high efficiency as possible. Increasing the power handling capabilities of the power amplifiers (PA) by increasing the transistors sizes of the output stages, leads to low output impedance and hence higher impedance transformation ratios for the matching structures and eventually narrow band designs. Hence the power combining architectures were proposed as an alternative to increase the output power either by combining on-chip or combining in air. In this work a fully integrated IQ Tx is to be presented with on-chip LO chain and 4-way power combined power amplifier. Baseband Signal Generation and Processing The baseband topology depend on the application. For mobile communication or localization use cases a wideband channels are not available directly from the digital processors, a kind of channel bonding is required either in the digital domain or in the analog domain. As a proof of concept we present here 3-IQ frequency interleaving combiner. Wireless Link Demonstrator Two demonstrators are to be presented. The first demonstrator is transmitting a broadband IQ signal generated from an arbitrary wave generator wirelessly utilizing an IQ 240GHz Tx and Rx. Data rates up to 100 Gbps were demonstrated across a 1m of wireless link. The second demonstrator includes the implementation of 3-channel IQ channelizer to create the complex modulated signal at several intermediate frequencies (IFs) and then upconverted to the 240GHz carrier signal. On the Rx side the de-channelizer convert the down modulated signal to three IQ channels. Data rates up to 8Gbps were demonstrated wirelessly with the channelization with potential of further enhancements for more channels integration. Outlook The future of the sub-THz wireless links for high speed communication and localizations goes towards implementing phased array and MIMO systems. This requires the research community to develop novel architectures to develop large scale arrays with acceptable power consumptions and suitable packaging solution. On the baseband side also the channel bonding solutions are still in an early stage, requiring more work to bond modularly larger number of channels.

Investigation of an Information Leakage Channel in the Area of Optical Fiber Bending

An information leakage channel created on the basis of fiber bending when transmitting information over an optical fiber is studied. An increase in the bending diameter of an optical fiber is shown to lead to a decrease in the power of optical radiation proceeding from it. In a bending diameter range from 5 to 20 mm, the highest radiation power was observed for the optical fiber G.655, while the lowest corresponding figure was recorded for G.657. The information leakage channel bandwidth with changed bending diameter is determined for different types of optical fiber. The bandwidth of the information leakage channel is shown to depend on the location of the photodetector used to register optical radiation taken from the bend of the optical fiber.

Anticipative QoS Control: A Self-Reconfigurable On-Chip Communication.

A self-reconfigurable Network-on-Chip (NoC) architecture that supports anticipative Quality of Service (QoS) control with penetrative switch ability is proposed to enhance the performance of bidirectional-channel NoC communication while supporting prioritized packet transmission services. The anticipative QoS control not only allows each communication channel to be dynamically self-configured to transmit flits in either direction for a better channel utilization of on-chip hardware resources, but also enhances the latency performance for QoS services. The proposed anticipative control is based on penetratingly observing channel direction requests of routers that is two hops away from the current one. The added ability enables a router to allocate high-priority packets to a dedicated virtual channel and then rapidly bypass it to the next destination router. The provided flexibility of packet switch promises better channel bandwidth utilization, lower packet delivery latency, and furthermore guarantees the high-priority packets being served with a better QoS. Accordingly, in this paper, an enhanced NoC architecture supporting the hybrid anticipative QoS, penetrative switch, and bidirectional-channel control, namely Anticipative QoS Bidirectional-channel NoC (AQ-BiNoC) is presented. Tested with cycle-accurate synthetic traffic patterns, significant performance enhancement has been observed when the proposed AQ-BiNoC architecture is compared against conventional NoC designs.

Development of a Hyperspectral System with Controlled Spectral, Spatial, and Radiometric Resolution

An approach to the construction of a hyperspectral system is proposed and justified, providing control of spectral, spatial, and radiometric (brightness) resolution, which opens up the possibility of hyperspectral monitoring of objects with limited computing resources and bandwidth of the video data transmission channel. Spectral resolution control is supposed to be carried out on the basis of tuneable, software-controlled acousto-optic filters, spatial resolution control – based on modern CMOS matrix technologies with the “active pixel” function, digitalization control of the images obtained – based on the developed analogy-to-digital converter with tuneable quantization level. Modelling using experimental data has shown the possibility of implementing a sufficiently reproducible classification of hyperspectral images with a decrease in their spectral, spatial, and radiometric resolutions.

A Collision-Avoided MAC Protocol With Time Synchronization and Power Control for Underwater Sensor Networks

In recent years, there has been a great deal of interest in underwater sensor networks (UWSNs) because they can effectively monitor the submerged environment. However, due to the long delay, high bit error rate, and limited propagation bandwidth of underwater acoustic channels, the media access control (MAC) protocol cannot function effectively in underwater acoustic sensor networks, particularly in offshore waters. To solve these issues, an MAC protocol with time synchronization and power control (TSPC) is proposed for a particular scenario. In addition, the proposed protocol is a joint channel access scheme, and the central nodes are deployed on an offshore seabed, which can be used as a synchronization reference standard time. A power control strategy is also implemented to limit the communication range of nodes. In brief, integrating TSPC with layered concepts and distributed clustering algorithms can effectively prevent communication collisions and reduce the energy consumption of UWSNs. The simulation results indicate that the TSPC MAC protocol performs well with regard to packet transmission rate, synchronization error, collision-free operation, and energy consumption.

CMOS System-on-Chip Spectrometer Processors for Spaceborne Microwave-to-THz Earth and Planetary Science and Radioastronomy

This article presents development of CMOS system-on-chip spectrometer processor for Spaceborne Earth Science, Planetary Science and Astronomy. The developed chip is intended for use in rotational emission spectroscopy observations from microwave to sub-millimeter wavelengths performed from Earth orbiting or deep space exploration spacecraft. The article first provides an overview of rotational spectroscopy for space sciences and highlights some of the important results achieved in Earth science, planetary science, and astronomy. The article then discusses the need for smaller and more compact spectrometer instruments across these three space science areas, which motivates this work. Then key considerations in development of spectrometer processors for space science are discussed including the significance including bandwidth, quantization efficiency and spectral channel shapes. The article then highlights detailed design of the developed spectrometer processor focusing on the many calibration techniques included to allow the chip to adapt to operations in space environments where large temperature ranges and high radiation levels are encountered. Presented measurements demonstrate the spectrometer processor operates up to 12.8 GS/s to provide up to 6.4 GHz of processing bandwidth with a frequency resolution of 8192 spectral channels and an analog resolution of 4 bits while consuming only 3960 mW of total DC power.

Galvanic-coupled Trans-dural Data Transfer for High-bandwidth Intra-cortical Neural Sensing.

A digital-impulse galvanic coupling as a new high-speed trans-dural (from cortex to the skull) data transmission method has been presented in this paper. The proposed wireless telemetry replaces the tethered wires connected in between implants on the cortex and above the skull, allowing the brain implant to be "free-floating" for minimizing brain tissue damage. Such trans-dural wireless telemetry must have a wide channel bandwidth for high-speed data transfer and a small form factor for minimum invasiveness. To investigate the propagation property of the channel, a finite element model is developed and a channel characterization based on a liquid phantom and porcine tissue is performed. The results show that the trans-dural channel has a wide frequency response of up to 250 MHz. Propagation loss due to micro-motion and misalignments is also investigated in this work. The result indicates that the proposed transmission method is relatively insensitive to misalignment. It has approximately 1 dB extra loss when there is a horizontal misalignment of 1mm. A pulse-based transmitter ASIC and a miniature PCB module are designed and validated ex-vivo with a 10-mm thick porcine tissue. This work demonstrates a high-speed and miniature in-body galvanic-coupled pulse-based communication with a data rate up to 250 Mbps with an energy efficiency of 2 pJ/bit, and has a small module area of only 26 mm2.

Developing Adaptive Antennas for High-Capacity Communication Systems and Tracking Multiple Cellular Phones

In the lower microwave region, researchers are looking into solutions to overcome the problem of a crowded spectrum and limited accessible bandwidth. Researchers have recently devised systems that use directional antennas to overcome the problem of restricted channel bandwidth by combining sector beams from multiple directional antenna elements. By boosting channel capacity, enhancing spectral efficiency, extending range coverage, customizing beam shapes, and allowing multiple beams to steer to detect and track numerous mobile users, this strategy increases system performance. This study assumes and discusses a strategy for creating numerous beams. The goal is to build a physical representation of the cellular phone network. It is suggested that a beam guiding algorithm be used.

Cavity-enhanced two-photon source emitting narrow linewidth telecommunication wavelength photons for improved quantum memory-coupling efficiency enabling long-distance quantum communications

In long-distance quantum communication using quantum repeaters with quantum memories, entangled photons at telecommunication wavelengths that can be coupled to quantum memory with high efficiency are required. Typically, entangled photons are generated via spontaneous parametric down conversion (SPDC). However, the phase-matching bandwidth of SPDC is more than 100 GHz, which is much broader than the bandwidth of a Pr3+:Y2SiO5 quantum memory (with overall bandwidth of ∼10 GHz while the bandwidth of each frequency channel is ∼10 MHz) suitable for frequency-multiplexed quantum repeaters. In this study, nondegenerate SPDC (1550 nm and 995 nm) inside an optical cavity is used to obtain a narrow linewidth and cluster width of SPDC to match the Pr3+:Y2SiO5 bandwidth. We also developed a cavity control mechanism that can fulfill the doubly resonant condition. The developed two-photon source can maximize the coupling efficiency with Pr3+:Y2SiO5 by introducing wavelength conversion and is promising for use in a quantum repeater.

Cross-World Covert Channel on ARM Trustzone through PMU.

The TrustZone technology is incorporated in a majority of recent ARM Cortex A and Cortex M processors widely deployed in the IoT world. Security critical code execution inside a so-called secure world is isolated from the rest of the application execution within a normal world. It provides hardware-isolated area called a trusted execution environment (TEE) in the processor for sensitive data and code. This paper demonstrates a vulnerability in the secure world in the form of a cross-world, secure world to normal world, covert channel. Performance counters or Performance Monitoring Unit (PMU) events are used to convey the information from the secure world to the normal world. An encoding program generates appropriate PMU event footprint given a secret S. A corresponding decoding program reads the PMU footprint and infers S using machine learning (ML). The machine learning model can be trained entirely from the data collected from the PMU in user space. Lack of synchronization between PMU start and PMU read adds noise to the encoding/decoding ML models. In order to account for this noise, this study proposes three different synchronization capabilities between the client and trusted applications in the covert channel. These are synchronous, semi-synchronous, and asynchronous. Previously proposed PMU based covert channels deploy L1 and LLC cache PMU events. The latency of these events tends to be 100–1000 cycles limiting the bandwidth of these covert channels. We propose to use microarchitecture level events with latency of 10–100 cycles captured through PMU for covert channel encoding leading to a potential 100× higher bandwidth. This study conducts a series of experiments to evaluate the proposed covert channels under various synchronization models on a TrustZone supported Cortex-A processor using OP-TEE framework. As stated earlier, switch from signaling based on PMU cache events to PMU microarchitectural events leads to approximately 15× higher covert channel bandwidth. This proposed finer-grained microarchitecture event encoding covert channel can achieve throughput of the order of 11 Kbits/s as opposed to previous work’s throughput of the order of 760 bits/s.

The Statistical Analysis of the Security for a Wireless Communication System with a Beaulieu-Xie Shadowed Fading Model Channel

The paper considers the problem of a wireless communication system’s physical level security for a multipath signal propagation channel and the presence of a wiretap channel. To generalize the propagation effects, the Beaulieu-Xie shadowed channel model was assumed. To describe the security of the information transfer process, such a metric as the secure outage probability of was considered. An analytical expression of the secure outage probability was obtained and analyzed depending on the characteristics of the channel and the communication system: the average value of the signal-to-noise ratio in the main channel and the wiretap channel, the effective path-loss exponent, the relative distance between the legitimate receiver and the wiretap and the threshold bandwidth, normalized to the bandwidth of a smooth Gaussian channel. The analysis considers the sets of parameters that cover all practically important scenarios for the functioning of a wireless communication systems: both deep fading (corresponding to the hyper-Rayleigh scenario) and small fading, both in the case of a significant line-of-sight component and a significant number of multipath clusters, and with significant shadowing of the dominant component and a small number of multipath waves, as well as all intermediate options. It is found out that the value of the energy requirements for guaranteed secure communication at a given speed is determined primarily by the power of multipath components, as well as the existence of an irreducible secure outage probability of a communication session with an increase for channels with strong overall shadowing of the signal components, which from a practical point of view is important to take into account when imposing requirements for the values of the signal-to-noise ratio and the data transfer rate in the direct channel, providing the desired degree of security of the wireless communication session.

DeepWiVe: Deep-Learning-Aided Wireless Video Transmission

We present <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DeepWiVe</i> , the first-ever end-to-end joint source-channel coding (JSCC) video transmission scheme that leverages the power of deep neural networks (DNNs) to directly map video signals to channel symbols, combining video compression, channel coding, and modulation steps into a single neural transform. Our DNN decoder predicts residuals without distortion feedback, which improves the video quality by accounting for occlusion/disocclusion and camera movements. We simultaneously train different bandwidth allocation networks for the frames to allow variable bandwidth transmission. Then, we train a bandwidth allocation network using reinforcement learning (RL) that optimizes the allocation of limited available channel bandwidth among video frames to maximize the overall visual quality. Our results show that <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DeepWiVe</i> can overcome the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cliff-effect</i> , which is prevalent in conventional separation-based digital communication schemes, and achieve graceful degradation with the mismatch between the estimated and actual channel qualities. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DeepWiVe</i> outperforms H.264 video compression followed by low-density parity check (LDPC) codes in all channel conditions by up to 0.0485 in terms of the multi-scale structural similarity index measure (MS-SSIM), and H.265+ LDPC by up to 0.0069 on average. We also illustrate the importance of optimizing bandwidth allocation in JSCC video transmission by showing that our optimal bandwidth allocation policy is superior to uniform allocation as well as a heuristic policy benchmark.

Downlink Wideband Channel Estimation for Asymmetrical Full-Digital System

This letter considers downlink wideband channel estimation in an asymmetrical full-digital system where the number of uplink receive radio frequency chains is less than that of the downlink. This channel inconsistency will reduce downlink channel estimation accuracy. To deal with this problem, we adopt the coprime array topology in uplink receive antennas. Then, two iterative algorithms which are based on alternating direction method of multipliers and block-sparsity orthogonal matching pursuit, respectively, are developed to rebuild downlink channel. Simulation results demonstrate the effectiveness of the proposed scheme in the asymmetrical full-digital system.

Flow Entry Timeouts Optimization over Software Defined Networks Supporting Elephant Flow Classification

&lt;p&gt;Elephant flow (elephant) classification is significant for network performance management and resource optimization. Classifying elephants over Software Defined Networks (SDNs) often relies on statistics counted by switches and transferred to controllers, leading to a huge control channel bandwidth occupation that degrades network latency and user experience. Classifying elephants using flow packets forwarded to controllers completely avoids moving statistics from switches to controllers, but couples flow entry timeouts to elephant classification accuracy, time efficiency, flow table size, control channel bandwidth usage, and network latency. This paper aims to find the best flow entry timeouts to optimize the objectives by modeling the objectives and formulating a multi-objective optimization problem. The number of objectives is further reduced to 3 and the problem is solved by Machine Learning (ML) approaches. Extensive evaluations are made over real packet traces. To the best of our knowledge, this work is the first effort that explores all the objectives related to flow entry timeouts when using flow packets forwarded to controllers to classify elephants over SDNs.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

A 0.4–6 GHz Receiver for Cellular and WiFi Applications

A wideband RF receiver employs a multi-loop architecture to ease the tradeoff between noise and linearity, a new method of harmonic rejection that relaxes gain and phase matching requirements, and a new op amp topology to achieve a wide bandwidth with low power consumption. Furthermore, multiple techniques are introduced to improve the out-of-band and in-band linearity, input matching, and stability. Fabricated in 28-nm CMOS technology, the prototype accommodates channel bandwidths from 200 kHz to 160 MHz and exhibits a noise figure of 2.1–4.42 dB while drawing 23–49 mW. It demonstrates an out-of-band IIP3 of 2.8–9.8 dBm and provides more than 60 dB of rejection for blockers at the third and fifth harmonics of the LO.