Digital Video Signals Research Articles

Modeling of Leaked Digital Video Signal and Information Recovery Rate as a Function of SNR

Substantial information leakage at PC monitors and TV systems arises in the form of unintentional emissions of high-speed digital video signals, such as DVI/HDMI. The information recovery rate from the emanated video signal varies depending on the SNR of the receiver system, which is placed a certain distance away. In this study, a situation in which the signal from a digital video system is intercepted is modeled using full-wave electromagnetic and circuit simulations. For a quantitative evaluation of the eavesdropping threat of display systems and the effect of its countermeasure, the readability of characters on a hypothetical screen as a function of the BER of the recovery signals is presented. It is clear that a decrease of the SNR of the received signal causes a deterioration of the digital video signal-recovery rate and consequently degrades the legibility of the characters on the intercepted screen. It is expected that these techniques can be useful for measurements and analyses of the effects of countermeasures, such as noise jamming or signal modulation, to prevent interceptions of digital video information.

ADT-Based UHDTV Transmission for the Existing ATSC Terrestrial DTV Broadcasting

In this brief, we propose an augmented data transmission (ADT)-based ultrahigh definition (UHD) television transmission system for the existing advanced television systems committee terrestrial digital television (DTV) broadcasting. The proposed system can support a rate of 12 Mb/s using a moving pictures expert group-2 (MPEG-2)-based DTV signal and a rate of 12.5 Mb/s using High Efficiency Video Coding (HEVC)-based DTV and ADT signals. By combining properly an MPEG-2-based DTV signal, an HEVC-based DTV signal and an HEVC-based ADT signal, 4K (3840 × 2160 ) UHD video can be served while providing backward-compatible high-definition video service.

Spectrum Sensing With Small-Sized Data Sets in Cognitive Radio: Algorithms and Analysis

Spectrum sensing is a fundamental component of cognitive radio. How to promptly sense the presence of primary users is a key issue to a cognitive radio network. The time requirement is critical in that violating it will cause harmful interference to the primary user, leading to a system-wide failure. The motivation of our work is to provide an effective spectrum sensing method to detect primary users as soon as possible. In the language of streaming based real-time data processing, short-time means small-sized data. In this paper, we propose a cumulative spectrum sensing method dealing with limited sized data. A novel method of covariance matrix estimation is utilized to approximate the true covariance matrix. The theoretical analysis is derived based on concentration inequalities and random matrix theory to support the claims of detection performance. Comparisons between the proposed method and other traditional approaches, judged by the simulation using a captured digital TV signal, show that this proposed method can operate either using smaller-sized data or working under lower SNR environment.

Experimental Investigation of Digital TV Signals with Multipath in Curitiba

Experimental Investigation of Digital TV Signals with Multipath in Curitiba

Digital TV Signal Reception Testing in a Device with Spatial Diversity

Digital TV Signal Reception Testing in a Device with Spatial Diversity

Passive Reception of Digital TV Signals with an Antenna

Passive Reception of Digital TV Signals with an Antenna

ATSC digital television signal detection with spectral correlation density

In this paper, we consider the problem of spectrum sensing for advanced television systems committee (ATSC) digital television (DTV) signal detection. To exploit the cyclostationarity of the ATSC DTV signals, we employ spectral correlation density (SCD) as the decision statistic and propose an optimal detection algorithm. The major difficulty is in obtaining the probability distribution functions of the SCD. To overcome the difficulty, we probabilistically model the pilot frequency location and employ Gaussian approximation for the SCD distribution. Then, we obtain a practically implementable detection algorithm that outperforms the industry leading systems by 2-3 dB. We also propose various techniques that greatly reduce the system complexity with performance degradation by only a few tenths of decibels. Finally, we show how robust the system is to the estimation errors of the noise power spectral density level and the probability distribution of the pilot frequency location.

Novel Fast Blind Channel Estimation and Hessian Analysis for Transmitter Identification of Digital Television Signals

The transmitter identification (Tx-ID) technique has been widely addressed in the modern advanced television systems committee digital television (DTV) standards. Kasami sequences are adopted as the Tx-ID sequences due to the favorable code capacity. However, the conventional cross-correlation based Tx-ID technique cannot combat the realistic multipath channel impairment. Therefore, in this paper, we propose a new least-square Tx-ID approach, which is demonstrated to be very robust when the multipath channels are encountered. We also establish the new Hessian analysis to provide the range for appropriate injection levels accordingly. Based on this new theoretical study, we design new efficient (fast) algorithms to determine the maximum allowable channel length given a particular Kasami Tx-ID sequence. These algorithms and theoretical results can be very useful for the future DTV technologies.

Method of Common View Based on Digital Satellite Television

This paper apply satellite digital television signal for common view based on the DVB-S standard. By choosing some information from the signal as timing signal, we can get the arriving time of timing signal on local time scale. At last, we use the arriving time and some necessary correct massage to get the time difference between two locations.

Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms

In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far-field low-power-density energy-harvesting technology is thoroughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capabilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

Sniffing the city: issues of sousveillance in inner city London

This article reflects on a series of workshops run by the art/media/hacktivist collective Deptford.TV in collaboration with the Centre for Urban and Community Research (CUCR), Goldsmiths, University of London in 2009–2010 and in 2012. The aim of the workshops was to create short films using hacked CCTV material. Participants, equipped with digital video signal receivers, were led through the city by incoming surveillance camera signals. Receivers cached surveillance camera signals making a range of city spaces visible. The material was then stored on a shared video platform and reshuffled in personal narratives and montages of the city. Hackers and media artists call it ‘sousveillance’ and frame it as a critique of the ‘panopticon society’. I argue that this practice reveals an unusually realistic portrait of inner city London and its working-class population at their everyday work. My contention is that the absence of such activities in narratives of gentrification and the presumed end of manual work make this portrait particularly valuable. The article evaluates this emerging and ethically controversial practice of video recording, asking to what extent it can become a useful tool for urban scholars, visual sociologists and media artists. In conclusion, I argue that the exercise provides moments of self-discovery for the urban stroller, who – while practicing a sort of heroic immersion in inner city London – paradoxically becomes a watcher of scenes from life fabricated at a ‘safe’ distance; a middle way between urban ethnographer and flâneur.

Experimental Results of an X-Band PARIS Receiver Using Digital Satellite TV Opportunity Signals Scattered on the Sea Surface

A bistatic radar at X-band (11 GHz) using opportunity signals (Passive Reflectometry and Interferometry System (PARIS) concept implementing the interferometric technique) has been developed and tested in a coastal-based experimental setup. Digital satellite TV signals broadcast from geostationary orbit have been used as sources of opportunity, and correlation waveforms have been collected at different receiver bandwidths. Calibration algorithms to compensate instrumental errors have improved our observables and allowed us to obtain delay measurements with a precision of about 10 cm for wind speeds in the range of 3 m/s. A statistical analysis of the measurement noise is used to determine the quality of the obtained observables. This paper also discusses the opportunities of the PARIS concept applied at higher frequency band and with stronger signals.

Energy-Saving Driver Design for Full-Color Large-Area LED Display Panel Systems

This paper demonstrates how the multilevel pulsewidth modulation (PWM) (MPWM) driving method can be implemented on a full-color large-area light-emitting diode (LED) display panel system through a low-cost modification of the existing hardware configuration. The method employs multiple LED driver modules connected in parallel which are combined to deliver MPWM current to individual LED pixels. For a three-level driving scheme, the criterion for selecting the midlevel current in order to maximize the luminous efficacy gain is derived mathematically. The algorithm for video signal conversion required for deriving the subvideo signals from the original high-definition multimedia interface or digital visual interface video signal for activating multiple LED driver modules is also discussed.

Minimum Eigenvalue Detection for Spectrum Sensing in Cognitive Radio

Spectrum sensing is a key task for cognitive radio. Our motivation is to increase the probability of detection for spectrum sensing in cognitive radio. In this paper, we proposed a new semi blind method which is based on minimum Eigenvalue of a covariance matrix. The ratio of the minimum eigenvalue to noise power is used as the test statistic. The method does not need channel and signal information as prior knowledge. Eigenvalue based algorithm perform better than energy detection for correlated signal. Our proposed method is better than the maximum eigenvalue and energy detection for correlated signal. We perform Simulation which is based on digital TV signal. In all tests, our method performs better than maximum eigenvalue detection and energy detection. DOI: http://dx.doi.org/10.11591/ijece.v4i4.6226

Kernel Feature Template Matching for Spectrum Sensing

Feature template matching (FTM) was proposed by Zhang and Qiu in 2011 for spectrum sensing in cognitive radio. Theoretical analysis for FTM is, however, missing in the literature. This paper will address this issue. Another new direction suggested by this paper is a nonlinear version of FTM, which is called kernel FTM (KFTM). The proposed nonlinear algorithm is performed on data mapped to a kernel space usually with higher dimension by a general nonlinear mapping. The high-dimensional data are cheaply operated with the so-called kernel trick. Furthermore, higher order statistics is considered in the proposed algorithm. Simulations using the real-world measurements of digital television (DTV) signal show that a gain of more than 4 dB can be achieved for KFTM over its linear counterpart FTM. Theoretical analysis is conducted for KFTM (that can be directly applied to FTM). For the first time, a theoretical justification is also performed for FTM. The concentration inequalities of KFTM, which are valid for arbitrary dimensions, are established as a result of concentration of measure phenomenon. The closed-form expressions of the probability distributions (under null hypothesis) are derived for both FTM and KFTM under different kernel functions. The obtained closed-form results agree with simulations. The closed-form expressions of the decision thresholds for a target false-alarm probability are obtained as well. The thresholds are noise power independent; thus, the proposed algorithm overcomes the difficulty of noise uncertainty.

Assessment of Interference to the DTT Service Generated by LTE Signals on Existing Head Amplifiers of Collective Distribution Systems: A Real Case Study

The increasing market interest for broadband services led the World Radiocommunication Conference (WRC-07) to allocate the upper part of the UHF band (the so called “digital dividend”) to mobile services. The coexistence of broadcasting and mobile telephony services, i.e., long-term evolution (LTE) in contiguous frequency bands can generate interferences to the reception of digital terrestrial television (DTT) signals; in particular, in the case of collective antenna systems, there is the risk of saturation of the wideband head-end distribution amplifier, due to the high level of the new LTE signals. This paper analyzes such situation in a real environment by means of extensive computer simulations and exploits specific techniques that must be adopted to mitigate such interference.

Non-conformance and problems related to the digital TV signals transmitted in Brazil and their impact on the Users and Application Developers

Non-conformance and problems related to the digital TV signals transmitted in Brazil and their impact on the Users and Application Developers

Experimental investigation of accuracy time-frequency synchronization by using digital television signals

The results of studying the model of passive time-frequency synchronization system are given in the paper. The algorithm of general coverage is taken as a basis. Brief description and mathematical analysis of the algorithm of general coverage were conducted. The laboratory bench, used in this work was described. Digital terrestrial television signal is used as a general signal source. Correlation and spectral signal properties of the digital terrestrial television were shown. Sources of errors, arising in the receive and signal processing paths and their influence were estimated. An algorithm for digital processing of measurement results of scale shifts was developed. It includes spectral analysis, correlation processing, as well as mathematical methods, allowing to improve the scale difference calculation accuracy. The results of experimental investigations and their statistical analysis are shown. The graphs and bar charts, showing statistical processing results, which reflect positive trends for using the digital terrestrial television signal as a common source for comparison of time and frequency scales according to the algorithm of general coverage.

Improved Compression Performance of H.264/MPEG4-AVC for Digital Video Using DVDP

Digital video sequences in uncompressed form require huge storage and high transmission bandwidth for multimedia communication. The increasing number of Video over Wireless (VoW) services is creating greater thrust for higher coding efficiency for digital video signals. Efficient coding and transmission control techniques are required to meet the needs of Quality of Service (QoS). H.264/MPEG4-advanced video coding (AVC) video enCOder/DECoder (CODEC) is the latest coding and compression standard from the International Telecommunications Union-Telecommunication (ITU-T). This standard is currently dominating the field by offering a flexible architecture and compression gain for video coding. Due to its high compression efficiency with low compression delay, it is used in many real time VoW transmission applications. Modern wireless networks provide many different means to adapt QoS like low end-to-end delay, efficient bandwidth-utilization and lower bit-rate. This paper presents a design of integrated CODEC scheme with relatively lower bit-rate and improved edge peak signal-to-noise ratio (EPSNR). Several important factors of video sequence are analyzed for achieving lower bit-rate. A new scheme is proposed at Application (APP) layer for video compression, called as Enhanced Intra Prediction (EnIP). This algorithm uses picture structure without B-pictures for real time VoW application. The proposed algorithm is implemented on TMS320DM6437; a multimedia processor, using Digital Video Development Platform (DVDP). The superior performance of the proposed EnIP algorithm is validated by experimental results. It shows that the implementation of EnIP using digital multimedia processor lowers the bit-rate and improves EPSNR significantly.

Feasibility of Guard Band Utilization for Cognitive Radio Using TV White Space

In cognitive radio systems using TV white space, it is desirable to secure a control channel to exchange the wireless network control information and to secure minimum frequency resource for secondary user communications if TV white space is unavailable. In order to satisfy these requirements, this paper proposes guard band utilization, which aggregates the multiple guard bands between digital TV signals and uses them for a control channel and/or a communication channel. To investigate the feasibility of the proposed scheme, this paper evaluates the performance degradation of the digital TV signals when the guard band is used. Furthermore, it discusses the permissible transmitting power and occupied bandwidth of the guard band signals to avoid the harmful interference to the digital TV signals.