Robust Data Transmission Research Articles

Robust data transmission and recovery of images by compressed sensing for structural health diagnosis

Digital cameras are cost-effective vision sensors and able to directly provide two-dimensional information of structural condition in monitoring and assessment applications. For example, digital cameras are essential components of unmanned aerial vehicles (UAVs) and robotic agents for mobile sensing and inspection of pipelines, buildings, transportation infrastructure, etc, especially in post-natural disaster and man-made extreme events assessment. Additionally, while surveillance cameras have been widely used for transportation systems (e.g., traffic monitoring), if appropriately mounted on the large-scale structures such as the bridges, they can continuously monitor the structural condition under operational loads and hazards, complementing the regular visual inspection and assessment conducted by experts. In these or other applications, efficiently and reliably transferring the structural images or videos, which are as such large-scale, are important and challenging, especially in wireless platform that is either required (e.g., UAVs and robotic agents) or more suitable (e.g., camera monitoring networks) with only limited power and communication resources. This paper studies the computational algorithms for efficient and reliable transmission of the structural monitoring images; in particular, the compressed sensing (CS) technique is explored for robust data transmission and recovery. The sparse representation or data structure of the structural images is exploited, leading to the CS based central strategy: on some sparse domain, randomly encode large-scale image data into few relevant coefficients, which are then transferred (robust to random data loss) and recovered (in base station) for subsequent structural health diagnosis. Image data of bench scale pipe structure, concrete structure and full scale stay cable are employed for validation of the CS based method. Its performance is also compared with traditional transform coding and low-dimensional encoding (sampling), and their advantages and drawbacks are discussed. Copyright © 2016 John Wiley & Sons, Ltd.

Robust Data Transmission through Video Watermarking under Noisy Environment

Watermarking is a process of embedding process. It is mainly proposed for copy right protection, data hiding and data security. Improving the robustness of video and image transmission is a critical importance in today's transmission control, video broadcasting and e-commerce because the robust data transmission is a key determinant of customer satisfaction. Secret key is important to transmit the embedded watermarked information in the original video file in the secured way. In the proposed method, the videofile is converted into frames and the watermark image or information is embedded into the one of the frame using secret key. The embedding process is done using SVD technique again the watermarked frames are combined to form video file and it is transmitted. In the receiver side the watermark image or information is extracted from the embedded video file using the secret key and its robustness is evaluated under various noisy environments. Finally the robustness of both video and watermark data is estimated by using metrics such as MSE, PSNR. All tests and experiments are carried out using MATLAB.

Implementation of multi-channel technology in ZigBee wireless sensor networks

This paper proposes a multi-channel ZigBee wireless sensor network (WSN) for robust data transmission. This study sought to increase the packet delivery ratio (PDR) through the application of multi-channel technology. Based on a cluster-tree construction protocol, we implemented a multi-channel time division multiple-access scheme using hardware devices. Furthermore, ZigBee and wireless LAN (WLAN) both operate on the 2.4 GHz band, referred to as the industrial, scientific, and medical unlicensed band. As a result, ZigBee faces severe interference problems in the presence of WLAN. In this study, we developed an interference avoidance method to improve conditions for the coexistence of ZigBee and WLAN and then conducted experiments using a practical network implementation to evaluate the resulting performance. Our experiment results demonstrate considerable improvements in the PDR of ZigBee transmission in an environment with interference from WLAN.

Piezoelectric transceiver matching for multiple frequencies

Abstract. Robust data transmission over long ranges with standard ultrasound devices is a challenge. Ultrasound indoor positioning systems in particular require long ranges and a robust data communication link. Fundamentally, a piezoelectric transducer has a narrow bandwidth for high sound pressure level and efficiency and is not suitable for broad-band applications. Moreover, ultrasound attenuation in the air increases quadratically within frequency, and thus ultrasound localization systems are restricted to low frequencies and low bandwidths. This work presents a novel method to match a piezoelectric transceiver for multiple frequencies by using the parallel and the series resonance of the transceiver. The aim is to adjust the amplitudes at different frequencies from different senders to the same level, which is important for orthogonal frequency division multiplex communication systems. Hence, an analog-to-digital converter (ADC) with low dynamic range (low voltage resolution) can be used to measure multiple frequencies with the same resolution. As a result, the optimization decreases the required dynamic range by 6 dB. Consequently, the ADC requires 1 bit fewer to ensure the same resolution for all carrier frequencies.

The Smart Grid—State-of-the-art and Future Trends

This paper introduces Smart Grid and associated technical, environmental and socio-economic, and other non-tangible benefits to society, and articulates the need for the concept and the fact that it is a dynamic interactive, real-time infrastructure that responds to the challenges of designing and building the power system of the future, rather than being simply a marketing term. To illustrate the diversity of terminology, the paper compares an Electric Power Research Institute (EPRI) definition with that suggested by a study group of the International Electrotechnical Commission (IEC). Next, a paper sponsored by the Canadian Electricity Association (CEA) that cites three example definitions to highlight the diversity of views of Smart Grid is briefly reviewed. Early misconceptions and characterizations of Smart Grid are discussed as a prelude to addressing challenging issues that motivate developing and implementing related innovative technologies, products and services. The paper then discusses the potential promise of the Smart Grid, which is embedded in its often-cited attributes of efficiency, accommodating, quality focus, enabling and self-healing to name some. The paper then addresses some of the often-cited impediments to accepting Smart Grid which are based on concerns and issues confronting its forward progress, adoption and acceptance. Distribution Automation (DA) and embedded intelligence are discussed emphasising self-healing, optimizing operation and facilitating recreation and recovery from abnormal events. Functional and integration requirements of Distributed Energy Resources (DER,) are detailed. Smart Consumption Infrastructure elements of Distribution Management Systems (DMS,) Automated Metering Infrastructure (AMI,) Smart Homes (SH), and Smart Appliances (SA,) are discussed. Following the introductory section, this paper summarizes contributions included in the double issue 42(3–4) of the Electric Power Components and Systems Journal. To begin, papers are offered discussing smart grid activities in China, India, and the development of a Smart Grid roadmap for the US State of Kentucky. The approaches of each of these cases reflect the diversity of policy initiatives in these jurisdictions. Two state of the art reviews are given next. The first considers distribution network active management and future development trends in technologies and methods, where centralized and decentralized management frameworks and applying agent-based coordination are discussed. The second offers a review of smart home technologies and the goals of an energy management system (SHEMS). This section is concluded by a letter providing an overview of recent and expected advances nanotechnology applications in Smart Grid. Following the state of the art review section, ten papers offering new and innovative research approaches and results are included. These papers cover Smart Grid topics such as real-time energy control approach for smart home energy management systems, optimal operation of energy- efficient buildings with Combined Heat and Power (CHP) systems, energy management and control of Electric Vehicle (EV) charging stations, voltage-frequency control of a voltage source inverter (VSI) in a smart islanded microgrid, smart generation scheduling for wind-thermal-pumped storage systems, optimized power system restoration, robust data transmission upon compressive sensing, data fusion for wide-area oscillation monitoring, satellite based GPS synchronized monitoring systems, stability in Smart Grid with emerging renewable energy techno- logies.

Robust Data Transmission upon Compressive Sensing for Smart Grid

A huge amount of power system data are transmitted in the smart grid. If some data packets are lost during transmission, the received data quality will be affected or worsened. This article proposes a robust data transmission method upon compressive sensing technology for the smart grid. First, the original power system signals are transformed into wavelet domain coefficients by means of wavelet multi-resolution analysis. Then these coefficients are sampled by the compressive sensing algorithm. These compressive sensing sampling data are transmitted in communication channels. In the receiving end, the compressive sensing sampling data are reconstructed to obtain the wavelet domain coefficients, and then wavelet inverse transforms are applied to recover the power system signals. The compressive sensing transmission method can achieve higher rate-distortion performance compared with the direct data transmission method. The new method can be used for power system data communication in non-feedback communication systems.

An On-Time Power-Aware Scheduling Scheme for Medical Sensor SoC-Based WBAN Systems

The focus of many leading technologies in the field of medical sensor systems is on low power consumption and robust data transmission. For example, the implantable cardioverter-defibrillator (ICD), which is used to maintain the heart in a healthy state, requires a reliable wireless communication scheme with an extremely low duty-cycle, high bit rate, and energy-efficient media access protocols. Because such devices must be sustained for over 5 years without access to battery replacement, they must be designed to have extremely low power consumption in sleep mode. Here, an on-time, energy-efficient scheduling scheme is proposed that performs power adjustments to minimize the sleep-mode current. The novelty of this scheduler is that it increases the determinacy of power adjustment and the predictability of scheduling by employing non-pre-emptible dual priority scheduling. This predictable scheduling also guarantees the punctuality of important periodic tasks based on their serialization, by using their worst case execution time) and the power consumption optimization. The scheduler was embedded into a system on chip (SoC) developed to support the wireless body area network—a wakeup-radio and wakeup-timer for implantable medical devices. This scheduling system is validated by the experimental results of its performance when used with life-time extensions of ICD devices.

Physical layer security in wireless smart grid

The smart grid is characterized by the two-way flow of electric power and information. For the information flow implementation and support, several wireless communication technologies and standards are being considered. Although there is no doubt that using wireless communications offers significant benefits over wired connections, the wireless technology introduces additional vulnerability in terms of network security. This work addresses physical layer security, a topic that has been hardly investigated in the smart grid domain. To understand new types of threats, we review fundamentals of wireless communication and examine physical attack models in depth. As a promising solution to physical security, we describe a random spread-spectrum based wireless communication scheme that can achieve both fast and robust data transmission. We expect that the work presented here will advance the research on wireless smart grid security.

Multiple Descriptions Coinciding Lattice Vector Quantizer for Wavelet Image Coding

Multiple description (MD) coding has been a popular choice for robust data transmission over the unreliable network channels. Lattice vector quantization provides lower computation for efficient data compression. In this paper, a new MD coinciding lattice vector quantizer (MDCLVQ) is presented. The design of the quantizer is based on coinciding 2-D hexagonal sublattices. The coinciding sublattices are geometrically similar sublattices, with the same index but generated by different generator matrices. A novel labeling algorithm based on the hexagonal coinciding sublattices is also developed. Performance results of the MDCLVQ scheme, together with the new labeling algorithm applied to standard test images, show improvements of the central and side decoders, as compared with the renowned techniques for several test images.

Deterministic and stochastic channel models implemented in a physical layer simulator for Car-to-X communications

Abstract. This paper presents a physical (PHY) layer simulator of the IEEE 802.11p standard for Wireless Access in Vehicular Environments (WAVE). This simulator allows the emulation of data transmission via different radio channels as well as the analysis of the resulting system behavior. The PHY layer simulator is part of an integrated simulation platform including a traffic model to generate realistic mobility of vehicles and a 3D ray-optical model to calculate the multipath propagation channel between transmitter and receiver. Besides deterministic channel modeling by means of ray-optical modeling, the simulator can also be used with stochastic channel models of typical vehicular scenarios. With the aid of this PHY layer simulator and the integrated channel models, the resulting performance of the system in terms of bit and packet error rates of different receiver designs can be analyzed in order to achieve a robust data transmission.

An Efficient Receiver Structure for Robust Data Transmission using TxID Signal in the ATSC DTV System

In a single frequency network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences due to the multiple transmitters and/or repeaters using same frequency is inevitable. This interference problem can be solved by adjusting transmit power and time of each transmitter and repeater within a SFN. To assist this process, a transmitter identification (TxID) signal, which is embedded in the transmit signal from each transmitter or repeater, is recommended in the ATSC terrestrial DTV system. In this paper, we investigate the previous proposed robust data transmission schemes using the TxID signal and propose an efficient receiver structure for detection of the embedded data in TxID signals. Based on the laboratory test, we verify that the proposed scheme offers an additional reliable communication link supporting up to 160 bps data rate, which is at least 13 dB robust compared to the conventional DTV system.

Detection of Aperiodically Embedded Synchronization Patterns on Rayleigh Fading Channels

Correct reception of synchronization patterns aperiodically embedded in random data is vital for robust data transmission. In this letter, we derive general metrics and high-signal-to-noise ratio approximations to the metrics for random-length frames transmitted over Rayleigh fading channels. Simulation results are presented for commonly used modulation schemes with coherent and noncoherent demodulation

Generalised finite radon transform for N× N images

This paper extends the domain of the finite radon transform (FRT) to apply to square arrays of arbitrary size. The FRT is a discrete formalism of the Radon transform that assumes the image is periodic over the finite array Z N 2 and requires only arithmetic operations for both forward and exact inverse transformation. The FRT is useful in image processing applications such as tomographic reconstruction [I. Svalbe, D. van der Spek, Reconstruction of tomographic images using analog projections and the digital Radon transform, Linear Algebra and Its Applications 339 (15) (2001) 125–145.], image representation [M. Do, M. Vetterli, Finite ridgelet transform for image representation, IEEE Transactions on Image Processing 12(1).] image convolution [D. Lun, T. Chan, T. Hsung, D. Feng, Y. Chan, Efficient blind image restoration using discrete periodic Radon transform, IEEE Transactions on Image Processing 13(2) (2004) 188–200.], image watermarking and encryption [A. Kingston, I. Svalbe, Projective transforms on periodic discrete image arrays, to appear in P. Hawkes (Ed), Advances in Imaging and Electron Physics (2006).], and robust data transmission [A. Kingston, I. Svalbe, Geometric shape effects in redundant keys used to encrypt data transformed by finite discrete Radon projections, In: Proc. 8th Int. Conf. on Digital Image Computing: Techniques and Applications (2005).]. The original definition by Matúš and Flusser in 1993 [F. Matúš, J. Flusser, Image representation via a finite Radon transform, IEEE Transactions on Pattern Analysis and Machine Intelligence 15(10) (1993) 996–1006.] was restricted to apply only to square arrays of prime size, p× p. Hsung, Lun and Siu developed an FRT that also applied to dyadic square arrays, 2 n ×2 n , called the discrete periodic radon transform (DPRT) [T. Hsung, D. Lun, W. Siu, The discrete periodic Radon transform, IEEE Transactions on Signal Processing 44(10) (1996) 2651–2657.]. Kingston further extended this to define an FRT that applies to prime-adic arrays, p n × p n . This paper defines a generalised FRT that applies to square arrays of arbitrary size, N× N for N ∈ N The Fourier slice theorem and convolution property (two important properties of the classical Radon transform) are established for this FRT. The original image can be reconstructed exactly from the FRT projections using Fourier inversion and back-projection. New methods are identified to correct for the over-representation of pixels due to the compositeness of N. A remarkable result is established that enables 2D sampling patterns to be corrected by an angle invariant 1D filter prior to back-projection.

Hardcopy image barcodes via block-error diffusion

Error diffusion halftoning is a popular method of producing frequency modulated (FM) halftones for printing and display. FM halftoning fixes the dot size (e.g., to one pixel in conventional error diffusion) and varies the dot frequency according to the intensity of the original grayscale image. We generalize error diffusion to produce FM halftones with user-controlled dot size and shape by using block quantization and block filtering. As a key application, we show how block-error diffusion may be applied to embed information in hardcopy using dot shape modulation. We enable the encoding and subsequent decoding of information embedded in the hardcopy version of continuous-tone base images. The encoding-decoding process is modeled by robust data transmission through a noisy print-scan channel that is explicitly modeled. We refer to the encoded printed version as an image barcode due to its high information capacity that differentiates it from common hardcopy watermarks. The encoding/halftoning strategy is based on a modified version of block-error diffusion. Encoder stability, image quality versus information capacity tradeoffs, and decoding issues with and without explicit knowledge of the base image are discussed.

Robust data transmission using the transmitter identification sequences in ATSC DVT signals

Transmitter identification (TxID, or transmitter fingerprinting) technique is used to detect, diagnose and classify the operating status of radio transmitters. Due to an ever-increasing number of transmitters, the need for transmitter identification is becoming an urgent issue, since it enables the broadcast authorities and operators to identify the source of interference. As a result, transmitter identification has been recognized as an important feature in the ATSC synchronization standard for distributed transmission. A new robust data transmission technique using the transmitter identification (TxID) sequences in the digital TV (DTV) signals is proposed in this paper. The major advantage of this low data transmission system is its robustness and extremely large coverage. The principle of the proposed data transmission system is presented. The modulation technique and throughput of the data transmission system is also evaluated.

Implementation of a two-dimensional barcode in the preanalytic phase

The automation process in the preanalytic phase of the laboratory is of increasing interest since there is an increasing discrepancy between the enormous advances in the automation process of the analytical/ postanalytical and the preanalytical phase of the central laboratory. Besides there is need of a secure transmission of the test requests from the clients to the central laboratory. We started a project together with other supra-regional laboratories in Germany in order to develop and establish a secure and robust data transmission system for the transmission of clinical data and laboratory information to the central laboratory. Based on common standards for laboratory data transmission and using a two dimensional barcode we developed an offline usable open source standard. Our project and the members of our project group may be a basis for the development and establishment of a standardized catalogue of laboratory methods and laboratory analyses in Germany in the near future.

Foveation-Based Error Resilience and Unequal Error Protection over Mobile Networks

By exploiting new human-machine interface techniques, such as visual eyetrackers, it should be possible to develop more efficient visual multimedia services associated with low bandwidth, dynamic channel adaptation and robust visual data transmission. In this paper, we introduce foveation-based error resilience and unequal error protection techniques over highly error-prone mobile networks. Each frame is spatially divided into foveated and background layers according to perceptual importance. Perceptual importance is determined either through an eye tracker or by manually selecting a region of interest. We attempt to improve reconstructed visual quality by maintaining the high visual source throughput of the foveated layer using foveation-based error resilience and error correction using a combination of turbo codes and ARQ (automatic reQuest). In order to alleviate the degradation of visual quality, a foveation based bitstream partitioning is developed. In an effort to increase the source throughput of the foveated layer, we develop unequal delay-constrained ARQ (automatic reQuest) and rate compatible punctured turbo codes where the punctual pattern of RCPC (rate compatible punctured convolutional) codes in H.223 Annex C is used. In the simulation, the visual quality is significantly increased in the area of interest using foveation-based error resilience and unequal error protections (as much as 3 dB FPSNR (foveal peak signal to noise ratio) improvement) at 40% packet error rate. Over real-fading statistics measured in the downtown area of Austin, Texas, the visual quality is increased up to 1.5 dB in PSNR and 1.8 dB in FPSNR at a channel SNR of 5 dB.

Equal-Norm Tight Frames with Erasures

Equal-norm tight frames have been shown to be useful for robust data transmission. The losses in the network are modeled as erasures of transmitted frame coefficients. We give the first systematic study of the general class of equal-norm tight frames and their properties. We search for efficient constructions of such frames. We show that the only equal-norm tight frames with the group structure and one or two generators are the generalized harmonic frames. Finally, we give a complete classification of frames in terms of their robustness to erasures.

A new multichannel spatial diversity technique for long-range acoustic communications in shallow water

A new multichannel spatial diversity technique has been developed for underwater acoustic communications in very shallow waters. This technique combines a novel synchronization method with maximum-likelihood symbol estimation. It was tested with a multichannel Mills-Cross receiver using various numbers of elements. The FAU general purpose acoustic modem source transmitted messages using four types of frequency-hopped multiple-frequency-chirp-keying (FH-MFSK) modulation: 4 hops at 221 coded bits per second (cps), 2 hops at 442 cps, or no hopping at 1172 cps. These types of modulation allowed for robust data transmission in adverse environment. The modem operated between 16 and 32 kHz at 192-dB source level, at ranges from 1 to 5 km in 40 ft of water. Using only four channels of the Mills-Cross receiver array, messages coded at 1172 cps were received with a frame error rate (FER) of 0% at a range of 3 km. In the same four-channel configuration, messages coded at 221 cps were received with no frame error at 5 km. The experimental results matched the performance predictions from the Crepeaus model. This reliable and computation-efficient method can be implemented on new generations of embedded acoustic modems, such as the four-channel FAU acoustic modem, and can provide significant improvements in communication performance.

Analysis and design of a frequency-hopped spread-spectrum transceiver for wireless personal communications

Personal communications services (PCS) require low-power radio technologies. One such transceiver architecture employing frequency-hopped spread-spectrum techniques is presented. System features such as antenna diversity with equal-gain combining and sequential hop combining are incorporated into the transceiver design to achieve robust wireless digital data transmission over fading channels. A direct-conversion architecture from radio frequency (RF) to baseband reduces the overall power consumption by eliminating intermediate frequency (IF) components. High-rate frequency hopping with frequency-shift keying (FSK) modulation is implemented using a direct digital frequency synthesis technique. A multiplierless correlation FSK detector, suitable for direct-conversion receivers, has been designed for quadrature noncoherent detection. Robust acquisition algorithms based on energy detection and pattern matching and tracking architectures using digital phase-locked loops are also described for system synchronization. The proposed transceiver is well-suited for low-power PCS applications and other portable wireless communications.