Digital Television Receivers Research Articles

The Methods for Improving the Quality of Detection of Inconspicuous Aerial Objects Through the Use of External Radiation Sources

The article focuses on the methods for improving the quality of detection of inconspicuous aerial objects through the use of external radiation sources. It has been established that the existing methods for improving the quality of detection of airborne objects do not meet modern requirements for detection indicators. The energy potential of modern radars is limited. Therefore, the article proposes detection methods that combine active radar and nontraditional principles for detecting airborne objects. In the article, we will focus only on two main methods for improving the quality of detection of small airborne objects. This is the use of energy from digital television receivers (external radiation source) and the use of information from ADS-B receivers. Technically, this means introducing an additional receiving channel into the radar. The gain in the conditional probability of correct detection for bistatic signal reception (compared to monostatic) is due to the properties of the bistatic effective scattering surface. It is shown that with the additional use of digital television signals, the quality of detection of airborne objects is improved. It is shown that the additional use of information from the ADS-B receivers makes it possible to increase the accuracy of determining the coordinates of an air object up to 40-50%, depending on the parameters of the movement of an air object. The subject of advanced research is the development of methods for suppressing the penetrating signal when using digital television and the development of methods for detecting airborne objects not equipped with the ADS B system. Keywords— aerial object, detection, quality, third-party source, ADS-B, digital TV, radar

On Deploying Secondary Networks in Co-Channel Bands with DTV Networks

This paper explores the feasibility and scope of co-channel coexistence between a low data rate Orthogonal Frequency Division Multiplexing (OFDM) secondary network and a digital television (DTV) broadcast network operating in the same area. Since DTV receivers do not transmit, neither the presence nor the impact of interference from the secondary network on these DTV receivers can be known. Consequently, conventional spectrum sensing techniques cannot be employed effectively. This paper proposes to compensate the lack of feedback by combining the available information about population distribution in the region - ranging from coarse population density estimates to accurate geospatial maps - with better estimation of interference using a data-driven technique called Ordinary Kriging. Radio Environment Maps constructed using the Kriging method from field-reported observations from the secondary nodes are used to obtain better accuracy than the conventional statistical models. The estimates are then used to compute communication parameters for each secondary link in terms of power, number of active subcarriers, and active time slots, while keeping the average interference in the DTV network within threshold bounds. Thus, the viability of such co-channel license-exempt operation of secondary networks in the DTV black and grey spaces for low data rate applications in densely populated urban areas and higher data rate capabilities for sparsely populated rural areas is established.

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.

Analysis of Diameter Changes Effect on Radiation Element to Improve Characteristics of Fullwave Loop Antenna

The article explained about the analysis of effect changes the diameter of radiating elements to the improvement of antenna characteristics. The antenna radiating element studied was solid copper wire and the type of antenna observed was an antenna that had a circular contour called the Full Wave Loop antenna. This antenna is use for digital television broadcast receiver applications and has a circle radius of 16 cm. Improved antenna characteristics were analyze for 3 types of radiation element diameter, namely; 3.5 mm; 2.5 mm and 2.0 mm. The Antennas were operated in a working frequency of 586 MHz, which is for digital television receiver broadcast channels. Based on the test data on the 3 diameter antenna elements and calculation analysis, it is known that the improvement is characteristics VWSR occurs in the radiation element with 2.0 mm diameter, the VSWR value is 1.93, return loss is 7.6 dB, antenna impedance is 97 Ω, gain of 12.88 dBi and antenna bandwidth of 7,17% and gain of 12.86 dBi, while the antenna characteristics of the radiating elements that are 2.5 mm and 3.5 mm larger are worse, among others; for VSWR 2.7 and 3.63. Return loss is -6,9 dB and 4.9 dB.Antenna impedance was 135 Ω and 175 Ω. The antenna gain was 8.78 dBi and 7.1 dBi. The smaller the diameter of the radiating element in the Full Wave Loop antenna will improve the characteristics of VSWR, Return loss, input impedance, gain. On the other hand, the smaller the radiation element will reduce the antenna bandwidth, so it is necessary to look for other methods to improve bandwidth capacity without changing the four characteristics of the good antenna. Likewise, the equation for determining the physical size of the radiating element is redefined.

Method for Determining Broadcaster Advised Emergency Wake-up Signal for ISDB-T Digital Television Receivers

There is a way to automatically wake up television receivers when a broadcaster sends out an emergency alert. In the Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) digital television standard, the emergency wake-up procedure is called an Emergency Warning System (EWS). In ISDB-T, the special signal is embedded in a control message known as transmission and modulation configuration control (TMCC). However, improper identification of the wake-up signal, often encountered in mobile reception, leads to unnecessary wake ups. In this paper, a method of reliably determining a wake-up signal is proposed by assuming that broadcasters will not change the TMCC message except for the wake-up signal when the broadcaster sends out an emergency alert. A change in the wake-up bit leads to variation parity, and the proposed method also relies on such variations. Mutual information to be obtained by the wake-up receiver is evaluated using the memoryless binary asymmetric channel model. Results showed that the proposed method provided mutual information even at a Eb/N₀ being lower than 10 dB. Mutual information of the proposed method with intermittent reception is also analyzed as a function of the duty ratio of the intermittent receiver.

A Graphical Method for LTE-A System and Digital Broadcasting Interoperability Studies

The co-primary basis operation between long term evolution-advanced (LTE-A) and current digital television (TV) receiver systems is a significant issue when working in cochannel or adjacent channel in the 800 MHz. This policy aims to efficient use of frequency spectrum, but leads to an intersystem interference phenomenon, which may disturb the Interoperability between LTE-A and digital TV receiver. In this paper, we propose an effective, simple and graphical approach based on the operating band unwanted emission technique to evaluate all possible intersystem interference scenarios. A variety of practical and substantial spectrum sharing elements that can seriously influence the coexistence situation of LTE-A and TV receiver have been studied. The findings show that co-channel sharing scenario will have much more coexistence difficulty for macro (urban/suburban/rural) areas without employing some interference mitigation techniques. However, in order to make the two systems interoperate in adjacent channel situation, the minimum frequency shift should be at least half of the interferer system bandwidth without mitigation technique. Additionally, the wider channel bandwidth of LTE-A system is preferable more than narrower bandwidth for peaceful compatibility, which helps to support high data rate for LTE-A system.

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.

Differential Electromagnetic Attacks on a 32-bit Microprocessor Using Software Defined Radios

Side-channel analysis has been used to successfully attack many cryptographic systems. However, to improve trace quality and make collection of side-channel data easier, the attacker typically modifies the target device to add a trigger signal. This trigger implies a very powerful attacker with virtually complete control over the device. This paper describes a method to collect side-channel data using a software defined radio (SDR) in real-time without requiring a collection device trigger. A correlation-based frequency-dependent leakage mapping technique is introduced to evaluate a 32-bit microprocessor, revealing that individual key bytes leak at different frequencies. Key byte-dependent leakage is observed in both SDR collected and triggered oscilloscope-based collections (which serve to validate the SDR data). This research is the first to demonstrate effective differential attack using SDRs. Successful attacks are presented using two SDRs, including a US$20 digital television receiver with modified drivers.

Using Broadcast Networks to Create On-demand Extremely Large Scale High-throughput Computing Infrastructures

A growing number of very simple parallel applications can benefit from the availability of very large computing resource pools that are exploited in an opportunistic way to considerably speed up the processing of these applications. In particular, many applications can scale out to take advantage of the availability of thousands, or even millions, of processors that can be simultaneously used. Some large-scale distributed computing infrastructures (DCI) have already been successfully assembled to this end. However, these DCI are normally designed to cater to specific kinds of applications, and their assemblage is not only costly, but also time consuming. We propose a novel architecture, named OddCI (On-demand DCI), for the cheap, fast and on-demand instantiation and dismantle of very large DCI. These characteristics allow application users to dynamically commission DCI that can cost-effectively be customized to their particular needs, and disposed after being used. Our approach leverages on broadcast communication as an efficient mechanism to enable aggregation of geographically distributed computing resources, including millions of non-traditional processing devices such as mobile phones, and digital television (DTV) receivers. We discuss how the proposed architecture can be implemented on top of a network of DTV receivers, providing evidences of both the technical, as well as the operational feasibility of the OddCI architecture.

A CMOS RF Programmable-Gain Amplifier for Digital TV With a $+$9-dBm IIP3 Cross-Coupled Common-Gate LNA

A CMOS RF programmable-gain amplifier (RFPGA) is designed for a digital television receiver. In order to obtain high linearity with wide bandwidth, a common-gate (CG) low-noise amplifier (LNA) with transconductance nonlinearity cancellation is proposed for the RFPGA. The proposed LNA achieves high linearity while maintaining low-noise and low-power characteristics by applying a g" <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> nonlinearity cancellation technique to the cross-coupled CG configuration. The proposed RFPGA is designed with a 0.13-μm CMOS process and measured. The measurement result at maximum gain mode shows a gain of 17.5-19.8 dB, a noise figure of 1.9-3.9 dB, an input-referred third-order intercept point of 6-9.1 dBm, an input-referred second-order intercept point of 22.4-25 dBm, and an input impedance matching of less than -10 dB over the range of 48-860 MHz with 5.4-mW power consumption at a 1.8-V supply voltage. The total gain range of the proposed RFPGA covers 55 dB with a 1-dB resolution.

Antennas for Digital Television Receivers in Mobile Terminals

The incorporation of new services in handheld devices, such as the Digital Video Broadcast-Handheld (DVB-H) operating at the lower ultrahigh-frequency (UHF) band poses a challenge for antenna designers. Wideband small antennas or electrically tunable narrowband small antennas are needed to fulfil the performance requirement. It is well known that below 900 MHz the operation of embedded mobile terminal antennas is based on utilizing the whole structure of the terminal as a radiator. However, even this way reaching the whole required impedance bandwidth of about 46% at about 0.61-GHz center frequency is possible only either with clamshell-type terminals used as thick dipoles by feeding them from the hinge or with “large tablet”-sized terminals. With the popular smartphone-sized terminals with a monoblock structure the available bandwidth with good total efficiency is clearly smaller. We study the options to implement antennas for smartphone-type mobiles for receiving digital TV broadcasts at about 0.47-0.75-GHz frequencies. The mainly studied technology is the nonresonant capacitive coupling element (CCE)-type antennas having one of the smallest achieved volume-to-bandwidth ratios. We show that for a fixed-frequency antenna with a volume of less than a few cubic centimeters the total efficiency will become rather low due to moderate matching level, but the requirement of the DVB-H standard for the realized gain can easily be met. Additionally, we show that by having switching between two bands, one can implement a dual-antenna configuration with small total volume and significant multiple-input-multiple-output (MIMO) gain. Furthermore, we study the very important effect of the user's hands on the antenna performance and find that the effect can range from some increase of the total efficiency due to improved matching to significant losses caused by the hands. Finally, we propose some possible ways ahead in solving this very challenging antenna design problem.

Remote health monitoring for elderly through interactive television

BackgroundProviding remote health monitoring to specific groups of patients represents an issue of great relevance for the national health systems, because of the costs related to moving health operators, the time spent to reach remote sites, and the high number of people needing health assistance. At the same time, some assistance activities, like those related to chronical diseases, may be satisfied through a remote interaction with the patient, without a direct medical examination.MethodsMoving from this considerations, our paper proposes a system architecture for the provisioning of remote health assistance to older adults, based on a blind management of a network of wireless medical devices, and an interactive TV Set Top Box for accessing health related data. The selection of TV as the interface between the user and the system is specifically targeted to older adults. Due to the private nature of the information exchanged, a certified procedure is implemented for data delivery, through the use of non conditional smart cards. All these functions may be accomplished through a proper design of the system management, and a suitable interactive application.ResultsThe interactive application acting as the interface between the user and the system on the TV monitor has been evaluated able to help readability and clear understanding of the contents and functions proposed. Thanks to the limited amount of data to transfer, even a Set Top Box equipped with a traditional PSTN modem may be used to support the proposed service at a basic level; more advanced features, like audio/video connection, may be activated if the Set Top Box enables a broadband connection (e.g. ADSL).ConclusionsThe proposed layered architecture for a remote health monitoring system can be tailored to address a wide range of needs, according with each patient’s conditions and capabilities. The system exploits the potentialities offered by Digital Television receivers, a friendly MHP interface, and the familiar remote control, to make the service effective and easy to use also for elderly people.

DTV에 대한 WiFi의 간섭영향 분석

TV White Spaces (TVWS) are freed up after transition from analog television to Digital Television (DTV). Some wireless communications are allowable to operate in TVWSs, such unlicensed Wireless Fidelity (WiFi). Because TVWSs are located in the VHF and UHF bands, TVWSs can provide significantly better coverage and wall penetration inside buildings and other structures than the 2.4 GHz and 5 GHz WiFi frequencies currently in use. Therefore, this paper assumes that WiFi will be deployed in TVWSs. However, the interference impact of WiFi on DTV has to be taken into account. The interference probability in DTV receiver was evaluated by using Spectrum Engineering Advanced Monte-Carlo Analysis Tool (SEAMCAT). As a result, when 20 WiFi UEs are simultaneously operating at the maximum transmit power of 23 dBm and the guard band is 22 MHz, the protection distance should be at least 6 km to meet the interference probability of 5% in DTV receiver.

Effect of the User's Hands on the Operation of Lower UHF-Band Mobile Terminal Antennas: Focus on Digital Television Receiver

This paper deals with the effect of the user's hands on the performance of lower UHF-band antennas in handheld terminals. It is studied that how the input impedance, efficiency, and far-field directional pattern of the internal broadband digital television antenna are affected by the presence of the user's hands. The main part of the study has been carried out by applying finite-difference time-domain simulations. Measurements have been performed to support the results obtained by simulations. In the worst case, as much as 7-11 dB decrease of the antenna efficiency compared to free space case is shown. The results also indicate that the power absorption to the hand(s) is generally a more severe problem for the total efficiency than the change of the matching. On the other hand, it is also shown that in certain cases, the total efficiency of the antenna can even be improved due to the hands of the user. The results of this paper increase the understanding of the effect of the user's hands on the operation of the lower UHF-band antennas, whose operation is based on the radiation of a finite ground plane.

Position determination using the DTV segment sync signal

As a supplement to the Global Positioning System (GPS) in an urban center and indoor environment, the digital television (DTV) segment sync signal can be employed to obtain a mobile user’s position. Two DTV receivers and a counter are integrated to measure the time difference of arrival (TDOA) for a pair of received signals from a transmitter and its corresponding repeater (DTVR). Using the measurements from a transmitter and its multiple corresponding DTVR pairs, the mobile user position can be estimated using the recursive least square method. An experiment done in Seoul using two low-grade high resolution digital television (HDTV) receivers and a two-channel universal counter demonstrates that the mean value of the mobile user position measurement is accurate to 42.58 meters circular error probability (CEP).

RF Watermark Backward Compatibility Tests for the ATSC Terrestrial DTV Receivers

In a single frequency network (SFN) for the Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, co-channel interference induced by the multiple transmitters and/or repeaters which use the same output channel is inevitable. Since the presence of interference results in the performance degradation of the SFN, it is crucial to manipulate the interference by adjusting the transmit power and the emission time of each transmitter and repeater within the SFN. In the ATSC terrestrial DTV system, in order to facilitate the interference manipulation process, a transmitter identification (TxID) signal which is embedded in the transmit signal from each transmitter and repeater is recommended. However, such an embedded signal may degrade the DTV signal quality even though the injection level of the TxID signal is very low compared to the DTV signal. Hence, the effect of the TxID signal on the DTV signal needs to be investigated before deploying the SFN with TxID signal. In this paper, the effect of the TxID signal on the performance of legacy DTV receivers is investigated not only with extensive computer simulation but also with laboratory and field tests. According to the various test results, the average performance loss of the conventional DTV receiver due to the TxID signal is less than 0.2 dB when the TxID signal is injected at 30 dB below the DTV signal power.

Universal set-top box: a simple design to provide accessible services

This paper presents the design of a low cost accessible digital television set-top box. This set-top box was designed and tested to the International ISDB-T system and considered the adoption of solutions that would provide accessible services in digital television in the simplest digital television receiver. The accessible set-top box was evaluated regarding the processing and memory requirements impacts to provide the features for accessible services. The work presents also the access services bandwidth consumption analysis.

VHF 및 UHF 대역의 DTV 수신기 전계강도 예측

본 논문에서는 30 MHz ~ 3000 MHz 대역에서 1 kW ERP에 대해 점-대-지역 전파특성 예측에 이용되는 ITU-R 권고 P.1546 전파 모델을 이용하여 DTV 수신기의 전계강도 예측을 위한 방법을 제안한다. DTV 수신기의 유도된 전계강도 수식과 권고에서 기술된 절차를 이용하여 수치계산을 통한 결과를 제시한다. 또한 산출된 결과의 적절성 검증을 위해 Okumura-Hata 모델과 비교하였으며, 수신 전계강도가 약 6.9 ~ 11.5 % 범위 내에 오차가 있음을 확인할 수 있었다. 제시된 방법은 DTV 수신지역의 전계강도 예측을 통한 송신된 신호의 품질 분석은 물론, 양호한 전파환경 구축을 위한 적절한 국소 선정을 제공한다. 또한 동일 대역의 주파수 공유를 위한 보호비 또는 이격 거리 분석에도 직접 활용이 가능하다. In this paper, we propose the methodology of prediction of field strength for a digital television (DTV) receiver by virtue of Recommendation ITU-R P.1546. The curves shown in this recommendation represent the point-to area field strength for 1.0 kW effective radiated power in the 30 MHz ~ 3000 MHz. Based upon the procedures described in this Recommendation, computation results are presented here from the derived formulation of field strength for DTV receiver. To show the validity of this method, some results are compared with the analysis by Okumura-Hata model and it was shown that the error of field strength is in the range of 6.9 ~ 11.5 %. The presented method provides not only the predicted values of field strength for DTV receiving area to check the quality of transmitted signal, but also an appropriate site selection for obtaining good propagation environment. In addition, it can be directly used for analyzing the protection ratio or separated distance for frequency sharing in the same band.

An efficient iterative frequency domain equalization for ATSC DTV receiver

In this paper, we present an efficient single carrier frequency domain equalization for Advanced Television Systems Committee (ATSC) digital television receiver. The proposed scheme employs iterative cyclic prefix reconstruction (CPR) combined with block-overlapping process to reduce inter-carrier interference (ICI) component caused by the absence of cyclic prefix in multipath fading channel. In addition, trellis decoder aided iterative decision feedback frequency domain equalizer is derived to further mitigate inter-symbol interference (ISI). Finally, low-complex iterative frequency domain channel estimation is proposed to predict and track the time-varying multipath fading channel coefficients. The computer simulation results reveal that the proposed scheme has a significant performance improvement in multipath fading channel with respect to the previous time domain equalization (TDE) and frequency domain equalization (FDE).

Internal Broadband Antennas for Digital Television Receiver in Mobile Terminals

The Implementation of internal broadband antennas for digital television receiver (DTV) in mobile terminals operating at the lower UHF band is studied comprehensively. Certain challenges such as inherently narrow impedance bandwidth of electrically small antennas and limited volume available for the antennas inside mobile terminals are identified and handled. The proposed design principle for DTV antennas is to decrease the total efficiency of the antenna to a level which is just good enough to ensure a sufficient signal-to-noise ratio and that way make the size of the antenna sufficiently small. The limits for the size of broadband capacitive coupling element-based DTV antenna structures inside handsets of different sizes are studied. In the end, a manufactured prototype and simulated design are presented and compared with the limits studied earlier in the paper. The results show that the studied antenna concept is a promising candidate for broadband DTV antennas in mobile terminals. The work also increases general understanding on the implementation of antennas based on the radiation of the finite ground plane.