Digital Terrestrial Television Reception Research Articles

Portable Wideband Directional Antenna Scheme with Semicircular Corrugated Reflector for Digital Television Reception.

This research proposed a portable wideband horizontally-polarized directional antenna scheme with a radome for digital terrestrial television reception. The operating frequency band of the proposed antenna scheme is 470–890 MHz. The portable antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of a folded bowtie radiator, a semicircular corrugated reflector, and a V-shaped director. Simulations were carried out, and an antenna prototype was fabricated. To validate, experiments were undertaken to assess the antenna performance, including the impedance bandwidth (|S11| ≤ −10 dB), gain, and unidirectionality. The measured impedance bandwidth was 75.93%, covering 424–943 MHz, with a measured antenna gain of 2.69–4.84 dBi. The radiation pattern was of unidirectionality for the entire operating frequency band. The measured xz- and yz-plane half-power beamwidths were 150°, 159°, 160° and 102°, 78°, 102° at 470, 680, and 890 MHz, with the corresponding cross-polarization below −20 dB and −40 dB. The radome had a negligible impact on the impedance bandwidth, gain, and radiation pattern. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (−70.4 dBm) with a carrier-to-noise ratio (C/N) of 11.6 dB. In addition, the power obtained for the indoor test was 26.6 dBµV (−82.2 dBm) with a C/N of 10.9 dB. The novelty of this research lies in the concurrent use of the Yagi-Uda and bowtie antenna technologies to improve the impedance bandwidth and directionality of the antenna for digital terrestrial television reception.

Aggregate interference from white space devices into digital terrestrial television receivers

The cognitive radio devices operating in the digital terrestrial television (DTT) frequency band, known as white space devices (WSDs), use the free DTT channels under the condition that they do not cause interference above the limit set by the regulator. In 2015, the UK regulatory authority, Office of Communications (Ofcom), published the first European regulation allowing WSD systems to operate in the DTT band. It defines a methodology to calculate the maximum WSD transmission power based on single-entry interference. It does not guarantee, however, that the co-channel aggregate interference produced by the WSDs operating in the same region satisfies the intersystem interference limit. In addition, to define the maximum intersystem interference, the Ofcom methodology does not use the same criterion as that used in DTT system planning for the intrasystem interference. This work develops a new methodology for calculating the WSD transmission powers that solve the problems identified in the Ofcom regulation. Based on this methodology, a new WSD admission procedure that guarantees the protection of the DTT receivers from the WSD aggregate interference is proposed. It is compared to two other admission procedures based on the Ofcom regulation and Electronic Communications Committee report 186, respectively.

Coexistence of DTT and Mobile Broadband: A Survey and Guidelines for Field Measurements

This article provides a survey and a general methodology for coexistence studies between digital terrestrial television (DTT) and mobile broadband (MBB) systems in the ultra high frequency (UHF) broadcasting band. The methodology includes characterization of relevant field measurement scenarios and gives a step-by-step guideline on how to obtain reliable field measurement results to be used in conjunction with link budget analyses, laboratory measurements, and simulations. A survey of potential European coexistence scenarios and regulatory status is given to determine feasible future use scenarios for the UHF television (TV) broadcasting band. The DTT reception system behavior and performance are also described as they greatly affect the amount of spectrum potentially available for MBB use and determine the relevant coexistence field measurement scenarios. Simulation methods used in determining broadcast protection criteria and in coexistence studies are briefly described to demonstrate how the information obtained from field measurements can be used to improve their accuracy. The presented field measurement guidelines can be applied to any DTT-MBB coexistence scenarios and to a wide range of spectrum sharing and cognitive radio system coexistence measurements.

Performance analysis of IEEE 802.22 wireless regional area network in the presence of digital video broadcasting – second generation terrestrial broadcasting services

In Cognitive Radio (CR) networks unlicensed secondary users aim at transmitting in licensed bands while preserving primaries from harmful interference. CR communications have been especially studied in the white spaces of TV band (TVWS), defined as the TV free channels left unused in each territorial area by the reallocation of TV services as a direct consequence of the switchover plans. The first full CR standard, the IEEE 802.22 Wireless Regional Area Network (WRAN), has been developed to bring wireless broadband access to remote, rural areas where other wireless networks are not present due to low revenue impact or critical network deployment. IEEE 802.22 WRAN devices are designed to operate in the range of frequencies between 54MHz and 862MHz alongside digital terrestrial television (DTT) operation. In this work we perform a complete analysis to evaluate the performance of IEEE 802.22 WRAN devices coexisting with DVB-T2 adjacent channel transmission in the TV bands in a rural environment. The link budget analysis for IEEE 802.22 WRAN in different coexistence scenarios, such as fixed DTT reception with indoor/outdoor IEEE 802.22 WRAN reception shows that its robustness is comparable to long term evolution (LTE) which represents the state-of-the art of cellular networks in rural scenario.

Interference Analysis Between Digital Terrestrial Television (DTT) and 4G LTE Mobile Networks in the Digital Dividend Bands

With the introduction of digital terrestrial television (DTT) and the analogue television switch-off, terrestrial broadcast spectrum in the UHF band is being released for mobile communications, in particular for fourth generation (4G) long term evolution (LTE) mobile services. This spectrum is known as digital dividend. An impending problem when deploying 4G LTE mobile networks in the digital dividend bands is that interferences may appear in the adjacent radio frequency channels used for DTT. In this paper, we analyze the adjacent coexistence of DTT and 4G LTE networks in the digital dividend bands at 700 MHz and 800 MHz. A generic framework is adopted such that results can be easily extrapolated to different scenarios and bands. Results are presented as a function of the guard band between technologies, for both LTE uplink and downlink adjacent to the DTT signals, and for fixed outdoor and portable indoor DTT reception. Also, the effect of using anti-LTE filters is studied.

Polarization and Effects on Hidden Node/Shadowing Margin for TVWS

Dual polarized measurements comparing the received power of a line of sight broadcast signal in the ultra-high frequency band with received power in suburban streets and indoors including high rise buildings are presented in this paper. Both the co-polarized and cross-polarized fades are therefore measured in the different locations. Their purpose is twofold: 1) to identify the importance of using polarization when considering hidden node margins in spectrum sensing of television white spaces and 2) to indicate how polarization can be beneficial in improving the shadowing margin to increase the path loss from the secondary to primary user and thus further protect digital terrestrial television receivers from harmful interference. The impact of polarization in open environments with low clutter or near windows inside high rise buildings is more significant than in densely cluttered spaces experiencing strong multipath.

Enhanced the Accuracy of Specification of Maximum Permitted Emission Levels for TV White Space Devices

In this paper, we present a proposed geo-location database calculations which needs to perform in order to obtain high accuracy of maximum permitted emission levels for TV white space devices (WSDs) operating in the digital terrestrial television (DTT) frequencies. The study is mainly aimed at to analuze the impact of channel power condition in band ( ) and power out band ( ) for WSD for DTT reception in hilly environment under different altitudes. The proposed methodology for the calculation of such emission levels considers the effect of environment and hight of DTT reception. Both theoretical study and mathematical investigations are conducted in order to model and characterize such complex communication medium for WSDs. The propagated maximum permitted emission levels varies from one place to another due to time varying channel condition as a result of obstacles and distance between the transmitter and receiver. The study achieved according to the methodologies, results and recommendations addressed by the European Conference of Postal and Telecommunication administration CEPT. The comparison between proposed model and traditional one has been done by CEPT. The result shows that the proposed model with various altitudes in the hilly terrain environment obtain more accurate maximum permitted emission levels for WSDs, Which increase by 25.609 dBm and 25.61 dBm for and respectively at 100 altitude accordingly.

A cognitive radio indoor HDTV multi-vision system in the TV white spaces

Wireless multi-vision applications for home entertainment are becoming an important trend in consumer electronics domain. Currently, most of the existing applications rely on the 802.11g/n standards, capable to seamlessly stream HD video contents. These standards are operating in the license-free ISM band, which, due to the rapid revolution in wireless communication in past years, is becoming overexploited and experiences serious coexistence problems. The spectrum overcrowding in the free bands puts in a new light the VHF and UHF bands that are currently seen as a promising alternative spectrum resource, especially in the perspective of the worldwide switchover from analog to digital TV and in the light of the new emerging dynamic spectrum access techniques. Within this framework, this paper presents an unlicensed cognitive radio indoor multi-vision system operating in the UHF TV band for short-range indoor transmission of high definition TV contents. The system relies on a combined exclusive approach of spectrum sensing and geo-location database and is compliant with the DVB-T2 broadcasting standard. A proof-of-concept digital terrestrial television (DTT) compliant prototype has been implemented on a test-bed based on commercial DTT receivers in combination with software defined radio hardware devices. Extended measurements performed in a real indoor environment assessed the feasibility of the proposed system in terms of coverage and protection of the incumbent users.

DTT switchover accomplished in most areas of Japan

Digital terrestrial television (DTT) broadcasting in Japan began in 2003. It was planned to accomplish total switchover on 24 July 2011, simultaneously throughout the country. DTT broadcasts have come to cover nearly 100 per cent of households in a rather short time, but the penetration of DTT receivers was very slow in the beginning. The Government then introduced various assistance systems to promote the sale of DTT receivers and the installation of aerials, and the prices of DTT receivers have dropped considerably. The penetration rate of DTT receivers was improved, but on 11 March 2011, the Great East Japan Earthquake added a last hazard to the total switchover, and in the most affected three prefectures the switchover was postponed. In the other areas of the country switchover has been accomplished as scheduled without any major trouble.

Stub- and Capacitor-Loaded Folded Dipole Antenna for Digital Terrestrial TV Reception

A bandwidth enhancement method for a folded dipole antenna is proposed for digital terrestrial television (TV) reception. The antenna has a pair of stubs inside a folded dipole and a capacitor loaded on the folded dipole. A cylindrical wire model with a lumped element capacitor is analyzed by the commercial simulator ldquoFEKO.rdquo The analysis shows the effect of the stubs and capacitor on bandwidth enhancement, using current distributions and a comparison of dipoles without stubs and/or capacitor. A prototype antenna printed on polyethylene terephthalate (PET) film has dimensions of 15 mm by 280 mm with a line width of 1 mm. The capacitor is implemented with a slit on the line for ease of fabrication. The antenna in free space exhibits a voltage standing wave ratio (VSWR) of less than 2.6, and figure-of-eight radiation patterns with gain from 0.7 to 2.5 dBi in a frequency range from 470 to 950 MHz. The antenna attached to flat dielectric plates of materials that are typically used in automotive body parts, maintains a VSWR of less than 2.7 from 470 to 710 MHz for digital terrestrial TV reception.

Analysis, realization, and measurement of broadband miniature antennas for digital TV receivers in handheld terminals

AbstractHandheld terminals for digital terrestrial television reception and their possible integration in GSM or 3G convergence terminals using the digital video broadcasting–handheld standard (DVB‐H) [ETSI EN 302 304, Digital Video Broadcasting (DVB); Transmission System for Handheld Terminals (DVB‐H), V1.1.1, June 2004] must support the UHF band (470–702 MHz or 470–860 MHz) as specified in the EICTA radio specification. Beside the required new receiver concepts for such battery‐powered and small terminals, there is also the request for broadband integrable antennas, which cover the mentioned frequency band. This article depicts a possible antenna structure and simulation results for the antenna performance and compares these findings with measurement results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 293–297, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23082

Study of On-Glass Mobile Antennas for Digital Terrestrial Television

Digital Terrestrial Television (DTV) services began in Japan in December 2003. This paper proposes a novel on-glass antenna for mobile reception of terrestrial television. The gain of the proposed antenna is 4.7 dB higher than commercial monopole antennas when installed on a vehicle. Other merits of this antenna are a broad input impedance bandwidth across the UHF band (470-710 MHz), and the fact that it does not spoil vehicle appearance. Field experiments have confirmed that a diversity system using four of the proposed antennas is capable of mobile DTV reception.

Field Measurement Based Characterization of the Wideband Urban Multipath Channel for Portable DTV Reception in Single Frequency Networks

This paper presents a study developed to obtain several parameters of the small scale fading of the wideband propagation channel applied to the portable and mobile reception of Digital Terrestrial Television (DTV) services in an urban Single Frequency Network (SFN) environment. The study is focused on the calculation of some relevant parameter values related to the multipath behavior of the channel, using field data collected in a real network. Mean values for the Root mean square Delay Spread (RDS) and the frequency domain Level Crossing Rate (LCR) are given, together with an analysis of the influence of the specific environment and network (SFN) features.

Antenna diversity for improved indoor reception of US digital terrestrial television receivers

Antenna diversity algorithms are presented and are shown to improve the reception performance of an ATSC A/53 compliant digital terrestrial TV receiver. A maximum ratio combining algorithm is outlined and the results of field tests of a prototype are presented. An improved beamforming algorithm is described and computer simulation results on captured data are presented. Antenna diversity (in many forms) provides many gains over current single antenna digital terrestrial TV receivers, in particular for indoor use.

Joint VSB terrestrial digital TV indoor reception project

The reliability and efficacy of indoor reception of 8VSB digital terrestrial television (DTV) in four major U.S. cities was studied in an initial field measurement survey program and a subsequent data capture and processing program. Measurements from the initial survey identified problem sites for reliable DTV reception using currently available 2nd generation DTV receivers. Subsequent field dual channel data captures made at the identified problem sites provided data for testing and verification of new antenna diversity receiver algorithms destined for future generation DTV receivers. From data captures at selected problem sites of sufficient signal strength, but where currently available 2nd generation DTV receivers failed, it was found that in 70% of the cases DTV reception performance was satisfactory when using new antenna diversity receiver algorithms. These measurements and data captures corroborate the claim that the VSB DTV indoor reception problem may be less severe than implied from surveys using less advanced current 2nd generation receivers with a single antenna. For sites with severe multipath, 8VSB DTV reception could be potentially superior to NTSC, which would experience an unwatchable picture.

A DTV reception technology using software data streaming on a personal computer

This paper describes a new DTV (digital terrestrial television) reception technology relying primarily on software to receive, process and display DTV signals, which realizes an integrated DTV reception add-on card, and real-time MPEG-2 data streaming by software on a PC (personal computer). In addition to the real-time DTV reception, this technology can be also applied to a HDD (hard disk drive) based video recorder with time-shift function, where the DTV signal is stored onto the HDD and played back. Utilization of PC assets enables cost-effectiveness and rich functionality.