Satellite Digital Broadcasting Research Articles

Invasive weed optimization based compact hybridized fractal antenna design for RF energy harvesting and multifunctional wireless applications

This paper describes the optimal design and analysis of compact multiband Hybrid Fractal Antenna using Invasive Weed Optimization (HFAIWO). The configured structure involves the fusion of Minkowski, Sierpinski carpet and Giuseppe Peano in a coherent manner. The two-iterative conglomerated fractal antenna is realized physically by considering FR4 epoxy material (dielectric constant, εr = 4.4 and mass density = 1,900 kg/m3). The volumetric dimensions of the fabricated prototype are 36 x 36 x 1.6 mm3. In the designing process, the geometrical descriptors, namely, feedline width ‘WF’ and ground plane dimension ‘LG’ are optimized specifically using Invasive Weed Optimization (IWO) and Harmony Search Algorithm (HSA) strategies. The optimal solution is searched by changing the descriptor values under a set of practical constraints. The examined values of ‘WF’ and ‘LG’ using IWO and HSA are 3 and 31 mm, and 2.6 and 28.7 mm, respectively. Comparative results reveal that IWO offers superior solution quality and convergence than HSA. Afterwards, experimentation of the Projected HFAIWO is done to justify the recommended fractal hybridization approach. Measurements reveal that for VSWR ≤ 2, the fabricated structure produces nine resonance points (1.84, 3.99, 5.15, 5.55, 6.30, 6.58, 8.00, 9.29, and 12.01 GHz) with appreciable gain values. At the respective resonance points, the −10 dB impedance bandwidth is 3.9 %, 3.1 %, 2.1 %, 2.2 %, 1.4 %, 1.2 %, 6.9 %, 1.2 %, and 12.23 %. The provided radiation patterns are arbitrary bidirectional/omnidirectional. By applying the above-said approaches, the radiator size is reduced by 54 %. Importantly, the constructed structure covers two important bands i.e. 1.84 GHz (GSM 1800 band, downlink) and 5.55 GHz (WLAN (Lower) 5.150–5.725 GHz) associated with energy harvesting applications. The practical outcomes suggest that the introduced prototype is a proficient candidate for energy harvesting systems, Satellite communication for downlink, Long range tracking, Battlefield surveillance, Digital broadcast satellite service, Weather Radar, and Maritime navigation radar.

Efficient Multipath Clutter Cancellation for UAV Monitoring Using DAB Satellite-Based PBR

The increasing accessibility of unmanned aerial vehicles (UAVs) drives the demand for reliable, easy-to-deploy surveillance systems to consolidate public security. This paper employs passive bistatic radar (PBR) based on a digital audio broadcast (DAB) satellite for UAV monitoring in applications with power density limitations on electromagnetic radiation. An advanced version of the extensive cancellation algorithm (ECA) based on data segmentation and coefficients filtering is designed to improve the efficiency of multipath clutter suppression while retaining robustness, for which the effectiveness is verified by theoretical derivation and simulation. The detectability of small UAVs with DAB satellite-based PBR is validated with experimental results, with which the influence of target altitude and bistatic geometry are also analyzed.

Software Phase Correction Technique for Passive Radar

A traditional radar actively transmits pulses and receive the corresponding echoes. By computing the time taken to receive the echoes the system is able to detect targets and estimate their ranges. However, mainly for military applications, an active radar has a major drawback: it can be detected by the enemy since it radiates electromagnetic pulses. As such, there is currently high research and development activity in the field of passive radar systems. In this alternative scenario, the radar does transmit any signal. Instead, it uses signals already present in the environment, such as TV, radio broadcasts and satellite digital video broadcast as transmitters of opportunity. By measuring the time difference between the signal received by the transmitter of opportunity and the signal echoed by the targets, the radar can detect targets and estimate their ranges. In scenarios which use very low power illuminators of opportunity, such as satellite DVB-S or GPS, relatively long integration times are required in order to obtain reasonable values of signal to noise ratio. This implies that, besides frequency correction, the coherency of local oscillators in the receivers need to be maintained during long time intervals, which can be very difficult. The paper presents a novel phase correction technique for passive radar which uses targets of opportunity, already present in the target area, as references to maintain the coherency of the oscillators for all the integration interval. The proposed methodology is quite simple and enables the use of low-cost hardware with independent oscillators for the reference and surveillance channels which can be geographically distributed. The obtained results illustrate the effectiveness and applicability of the method.

THE CURRENT STATE AND TRENDS OF THE DEVELOPMENT OF DIGITAL TELE-RADIO BROADCASTING SYSTEMS IN THE WORLD

The object of the research is to make an analysis of the current state of the digital tele-broadcasting systems in the world and the transition trends from analogue to digital systems recommended by the International Telecommunication Union (ITU-R) for use in this area are considered. Therefore, the current trend of global transition to digital tele-broadcasting is due not only to the lack of a frequency resource, but also to society’s growing demands for up-to-date information, the need to introduce common global standards and systems for broadcasting systems. expansion of digital tele-broadcasting in the context of globalization, as well as the presence of this transmission technology. In this work, he is dedicated to considering the sustainable development trends of digital satellite broadcasting in the world in the phase of migration from analog to digital technologies in this area. In the final part, the results obtained based on the research and analysis made in recommendations and in the ITU-R database are presented.

Modernization of DVB-S2 Standard Using Signal-Code Constructions Based on Amplitude Modulation of Many Components

It is proposed to modernize the DVB-S2 standard by using AMMC (amplitude modulation of many components) signals instead of 8PSK (8-phase shift keying) and APSK (amplitude-phase shift keying) signals, and to modernize the DVB-S2 standard equipment by using the AMMC modulator and AMMC demodulator. Usage of AMMC makes it possible to reduce the symbol error rate in communication channel up to 52 times. The satellite digital video broadcast systems that apply signal-code constructions based on AMMC are characterized by a higher energy efficiency from 1 to 2.6 dB compared with signal-code constructions based on 8PSK and APSK.

A Soft Decoding Algorithm with Hard Decision Boundary Factor for High-Order M-APSK Signal

High-order amplitude phase shift keying is adopted in the latest digital satellite broadcasting system, which presents new challenges to the design of a receiver demodulation scheme. This study focuses on the soft decision decoding algorithm. Traditionally, maximum likelihood soft decision based on log likelihood ratio estimation is often used as a decoding scheme. Accordingly, a soft decision algorithm based on hard decision boundary is designed and the corresponding soft decision estimation formula is derived. Numerical analytical results show that the proposed soft decision algorithm can improve the error performance of a system and substantially reduce the complexity of implementation.

From Autonomy to Anonymity: Information Technology Policy and Changing Politics of the Media System in Indian Democracy

The prominence of information and communications technology (ICTs) in defining India’s media modernity can be gauged by the growing reach of online social media as well as continuing expansion of digital media channels and satellite broadcasting even in the early 21stCentury. Policies concerning information technologies, from telegraph to satellite networks, have also been central to media politics and with the rise of new media, internet related policies have similarly become pivotal to the interaction between the state and media system. Drawing from a comparative media system perspective, this paper argues that while there has been no major constitutional or legal overhaul, as yet, new ideas and information technology policy activism are reshaping the contours of state action and ‘autonomy’ of the press in India’s democracy. Comparing technology debates in an earlier era, when satellite networks swept across the media system, with the more recent deliberations around liabilities for digital intermediaries, the paper unpacks the nature of change and locates its origins in the revival of discursive institutions (Schmidt 2002, 2008) of technology policy since the early 2000s. Technology related ideas, I argue, now serve as institutions, able to function as a ‘coordinating discourse’ (ibid) that have revived ideals of an autonomous media. Technology inflected ideals of ‘anonymity’ also counter the ‘communicative discourse’ (ibid) of Hindutva and cultural nationalist politics of media which framed the issue of autonomy in the ascendant phase of print and electronic media capitalism until the 1990s.

Evaluation of Additive Manufacturing Techniques Applied to Ku-Band Multilayer Corporate Waveguide Antennas

In this letter, additive manufacturing technologies have been evaluated for waveguide antenna array prototyping at Ku band. Direct metal laser sintering (DMLS) and stereolithography have been assessed in terms of manufacturing limitations, electrical performance, accuracy, cost and weight, compared with traditional manufacturing methods. This assessment is performed on a corporate-fed waveguide array antenna for end-user digital broadcast satellite communications at Ku band. The objective is to manufacture this intricate multilayer structure as a single block, in order to prevent contact and leakage issues in the interface between antenna layers. This monolithic implementation is unfeasible with conventional milling in aluminum, renowned in the literature for its reliability in waveguide antenna implementation. A prototype has been machined with such technique as a reference for experimental results. A single block fabrication has been possible by DMLS, presenting a similar performance to the reference prototype. Experimental results, including impedance matching, realized the gain and axial ratio have been performed on the antenna prototypes. A 14.7% effective bandwidth has been obtained for the DMLS antenna.

Characterization of rain heights due to 0° isotherm in tropical and subtropical climates: implication on rain-induced attenuation prediction

In this paper, the dynamics of the structure of the rain profile as related to the zero-degree isotherm height and the implications for attenuation prediction along the Earth-space propagation links at locations in Nigeria, a tropical region, and South Africa, a subtropical region, are presented. Five-year (January 2010–December 2014) precipitation data on board the Tropical Rainfall Measuring Mission (TRMM) satellite have been analyzed over some selected locations in the two regions. The influences of the zero-degree isotherm height on some observed weather parameters are also discussed. The result on the influence of air temperature on rain height hr shows a significant increase in the tropical environment as compared with those in the subtropics. However, when hr results are compared with those obtained using rain height as recommended by the International Telecommunication Union (ITU), there is a significant difference at the 0.01% unavailability of the signal in a year particularly at higher frequencies. Further comparison with the slant path attenuation at 0.01% unavailability of the signal in a year shows a slight deviation (between 1.04 and 2.13 dB) in rain height than those acquired using the measured rain height in the tropical locations. Nevertheless, the result is slightly less than those obtained using the measured rain height in the subtropical locations with the differences in dB between − 0.49 and − 1.18. The overall results will be useful for estimating the link budgeting for digital radio satellite broadcasting. It will also be applicable for radar propagation systems at higher-frequency bands in Nigeria and South Africa.

BSデジタル放送 エンジニアリングストリーム・ダウンロード設備

BSデジタル放送 エンジニアリングストリーム・ダウンロード設備

MIMO for Mobile Satellite Digital Broadcasting: From Theory to Practice

This paper presents the detailed design and the key system performance results of a comprehensive laboratory demonstrator (testbed) for a hybrid satellite/terrestrial S-band mobile digital broadcasting system. The physical layer is based on an enhanced version of the digital video broadcasting—satellite to handheld (DVB-SH) standard, exploiting dual-polarization multiple-input–multiple-output (MIMO) technology. This complete digital MIMO demonstrator, which is the first of its kind, allows for an in-depth verification and optimization of the MIMO techniques applied to satellite broadcasting networks. Moreover, this demonstrator allows for complementing and confirming the theoretical or simulation-based findings published thus far. It is shown that dual-polarization MIMO diversity is able to provide remarkable gains in terms of satellite/terrestrial transmit power reduction and/or capacity increase compared with more conventional non-MIMO solutions. It is also demonstrated that the adoption of a relatively simple spatial multiplexing MIMO technique represents the best way to grasp these gains. This paper provides an extensive set of laboratory measurement results for existing stochastic satellite and hybrid MIMO channels, as well as results based on an S-band satellite-measured dual-polarization time series recently collected during a campaign sponsored by the European Space Agency. Results obtained using MIMO techniques are also compared with a dual- and single-polarization single-input–single-output (SISO) DVB-SH benchmark system and with computer simulation results.

Ku-대역 광대역 디지탈 위성방송용 저 잡음하향변환기 개발

본 논문에서는 디지털 위성방송을 수신하기 위하여 Ku-대역 광대역 하향변환기를 설계하였다. 설계된 저 잡음 하향변환기는 잡음 정합에 의한 3단 저 잡음 증폭회로와 10.7~12.75 GHz의 입력신호를 VCO-PLL에 의한 저 위상잡음을 나타내는 4개의 국부발진주파수(9.75, 10, 10.75 및 11.3 GHz)를 형성하고, 디지털 제어에 의하여 4-대역의 IF 주파수 채널을 선택할 수 있도록 설계하였다. 개발한 저 잡음 하향 변환기의 전체 변환이득 64 dB, 저 잡음 증폭기의 잡음지수는 0.7 dB, 출력신호의 P1dB는 15 dBm, band 1 반송주파수 9.75 GHz에서 위상잡음은 -85 dBc@10 kHz를 나타내었다. 설계한 광대역 디지털 위성방송용 하향변환기(LNB)는 국제적으로 이동하는 선박 등의 위성방송용으로 사용가능하다. In this paper, wideband Ku-band downconverter was designed to receiver digital satellite broadcasting. The low-nose downconverter was designed to form four local oscillator frequencies(9.75, 10, 10.75 and 11.3 GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75 GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select intermediate frequency bands by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64 dB, and the noise figure of low-noise amplifier was 0.7 dB, the P1dB of output signal 15 dBm, and the phase noise -85 dBc@10kHz at the band 1 carrier frequency of 9.75 GHz. The low noise block downconverter(LNB) for wideband digital satellite broadcasting designed in this paper can be used for global satellite broadcasting LNB.

글로벌형 다중대역 디지털 위성방송용 Ku-대역 LNB 개발

In this paper, a Multi-Band Ku-band down converter was designed for reception of multi-band digital satellite broadcasting. The Multi-band low-nose down converter was designed to form four local oscillator frequencies (9.75, 10, 10.75 and 11.3GHz) representing a low phase noise due to VCO-PLL with respect to input signals of 10.7 to 12.75GHz and 3-stage low noise amplifier circuit by broadband noise matching, and to select an one band of intermediate frequency (IF) channels by digital control. The developed low-noise downconverter exhibited the full conversion gain of 64dB, and the noise figure of low-noise amplifier was 0.7dB, the P1dB of output signal 15dBm, and the phase noise -73dBc@100Hz at the band 1 carrier frequency of 9.75GHz. The low noise block downconverter (LNB) for receiving four-band digital satellite broadcasting designed in this paper can be used for satellite broadcasting of vessels navigating international waters.

Behavioral characteristics of composite-antenna-structure covering three bands under compression load

A composite-antenna-structure covering three bands of global positioning system (1.575 GHz), digital multimedia broadcasting (2.62 GHz) and direct broadcast satellite (11.7–13.5 GHz) was designed and fabricated as a part of the structure surfaces. A new concept of antennas integrated into a composite sandwich structure provides a design that is an electrically and structurally effective multi-functional antenna structure. We designed two types of antennas. One is an annular ring patch antenna for global positioning system and digital multimedia broadcasting. The other is a microstrip patch antenna for direct broadcast satellite. In the design process, the effects of the composites and adhesive films are considered for in the design processes, because structural materials affect the antenna performance. Additionally, the composite-antenna-structure was designed by considering the coupling effect in a strict substrate. The measured results of buckling tests have provided useful information regarding not only the compression behavioral characteristics but also its degradation in electrical performance before and after the test. The experimental results have shown good results for compressive tolerance, though the specimens after compression loading returns to their original shape before failure. Additionally, an acoustic emission system is implemented in the buckling test system to study the inner behavior of the composite-antenna-structure for the reliability of secure mechanical performance. The antenna performance, as measured by the return loss and radiation pattern, remained excellent after the compression tests. These electrical performance results suggest that antennas with composite laminates will function well despite damage.

Simulation of Satellite Digital Video Broadcasting via Variable Frequency Based on Simulink

The traditional cable television broadcasting, digital mobile television broadcasting and the direct satellite video broadcasting ensure the television services of people’s daily life. Owing to digital broadcast satellite, also known as the digital video broadcasting (DVB) protocol applying terminal, direct-to-home television services with an outdoor dish of one meter come true. In order to accommodate the requirements of various broadcasting services, the DVB-S.2 protocol provides more efficient technology details. The LDPC codes concatenated with BCH codes achieve high performance near the Shannon limit and have low encoding and decoding complexity. Some high efficiency modulation methods are introduced into theDVB-S.2, such as QPSK, 8PSK, 16APSK and 32APSK. The adaptive coding and modulation (ACM) according the channel performance (E s /N 0 ) is applied in the DVB-S.2 technology. In order to preventing the burst disturbance, satellite broadcasting via variable frequency band is presented in this paper to ensure the quality of services. The DVB-S.2 via variable frequency is simulated based on Matlab/Simulink in this paper, and the simulation implements the video streams coding and modulation, ACM and frequency change with the channel performance.

Linear and nonlinear techniques for multibeam joint processing in satellite communications

Existing satellite communication standards such as DVB-S2, operate under highly-efficient adaptive coding and modulation schemes thus making significant progress in improving the spectral efficiencies of digital satellite broadcast systems. However, the constantly increasing demand for broadband and interactive satellite links emanates the need to apply novel interference mitigation techniques, striving towards Terabit throughput. In this direction, the objective of the present contribution is to investigate joint multiuser processing techniques for multibeam satellite systems. In the forward link, the performance of linear precoding is investigated with optimal nonlinear precoding (i.e., dirty article coding) acting as the upper performance limit. To this end, the resulting power and precoder design problems are approached through optimization methods. Similarly, in the return link the concept of linear filtering (i.e., linear minimum mean square error) is studied with the optimal successive interference cancelation acting as the performance limit. The derived capacity curves for both scenarios are compared to conventional satellite systems where beams are processed independently and interbeam interference is mitigated through a four color frequency reuse scheme, in order to quantify the potential gain of the proposed techniques.

Satellite digital broadcast services to handheld DVB‐SH: The complementary ground component

AbstractDVB‐SH introduces into the portfolio of standards for broadcasters, a hybrid system that provides TV services to handheld devices by means of satellite transmission coverage, complemented by terrestrial components for locations like dense urban areas, not reachable by the satellite signal.Among the articles devoted to DVB‐SH in this special issue of the International Journal of Satellite Communications and Networking, this article reports in particular on the researches performed on the Complementary Ground Component of the DVB‐SH hybrid transmission system.The article discusses the key technology elements used in the SH terrestrial transmission, provides an extensive range of performance results based on laboratory measurements, reports on the field trials performed in South‐West of France, and concludes with a DVB‐SH frequency planning exercise performed over a fictitious 3G network in the German city of Hannover. Copyright © 2009 John Wiley & Sons, Ltd.

高度衛星デジタル放送方式のARIB実証実験

Three channels, which will cease to be used for analog satellite broadcasting in July 2011 and 4 channels of the BS-17 19, 21, and 23ch, which were assigned to Japan at the WRC-2000, will be used for new digital broadcasting services after 2011. In these channels, a new broadcasting system called "Advanced Digital Satellite Broadcasting System" will be available as well as the current ISDB-S one. The new system can increase transmission bit rate by 30%compared with the current ISDB-S system by using LDPC codes and a roll-off factor of 0.1. The Association of Radio Industries and Businesses (ARIB) conducted evaluation tests to acquire its C/N-BER and synchronous performance as well as confirm how well the TMCC signal functions. Demonstrative tests to transmit Super Hi-Vision were also performed. The tests were done using a satellite simulator and a real satellite transponder. The tests showed that the system performed very well, and the details are reported here.

Channel Estimation and Code Word Inference for Mobile Digital Satellite Broadcasting Reception

This paper proposes a method of improving reception of digital satellite broadcasting in a moving vehicle. According to some studies, the antennas used for mobile reception will be smaller in the next generation and reception will be more difficult because of a fading multipath channel with delays in a low carrier-to-noise ratio. Commonly used approaches to reduce the inter symbol interference caused by a fading multipath channel with delays are pilot sequences and diversity reception. Digital satellite broadcasting, however, does not transmit pilot sequences for channel estimation and it is not possible to install multiple antennas in a vehicle. This paper does not propose any change to the broadcasting standards but discusses how to process currently available digital satellite signals to obtain better results. Our method does not rely on the pilot sequences or diversity reception, but consists of channel estimation and stochastic inference methods. For each task, two methods are proposed. The maximum likelihood estimation and higher order statistics matching methods are proposed for the estimation, and the marginal with the joint probability inference methods are proposed for the stochastic inference. The improvements were confirmed through experiments with numerical simulations and real data. The computational costs are also discussed for future implementation.

A new transmission system for the advanced satellite broadcast

Current satellite digital broadcasting transmission system "ISDB-S" employs digital modulation schemes, BPSK, QPSK, and 8PSK combined with a concatenated code consists of convolution code and Reed-Solomon code. While, in recent years, transmission systems adopted LDPC codes have been developed. Multi-level digital modulation schemes combined with LDPC codes can achieve more efficient transmission. In this paper, we propose a new transmission system employed LDPC, multi-level modulation and advanced TMCC signal <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> .