MPEG-2 Test Stream with Static Test Patterns in DTV System

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.

In this paper, we analyze the coexistence between the International Mobile Telecommunications (IMT) system and the digital television (DTV) system in the 700MHz band. The 700MHz band is now called the "digital dividend" and is expected to be allocated to IMT services. This plan could cause mutual interference between existing broadcasting and the IMT services. The members in the Asia-Pacific Telecommunity Wireless Group are currently discussing the coexistence issues associated with the 700MHz band. In order to allocate this band to the IMT services without harming the DTV system, coexistence problems should be solved. This paper presents the simulation methodology for analyzing the mutual interference between the IMT and DTV system and provides the results of the performance degradation of the two systems.

In a Single Frequency Network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences induced by the multiple transmitters and/or repeaters using same frequency are unavoidable. To ease the interference handing in the SFN for ATSC DTV system, transmitter identification (TxID) signal is recommended in the ATSC terrestrial DTV system. The TxID signal is embedded in the ATSC DTV signal and transmitted from each transmitter and repeater within the SFN and in ATSC recommended practice (RP) A/111, Kasami sequence is recommended as the TxID signal. In this paper, we propose an additional data transmission scheme using the TxID signal. In the proposed scheme, the Kasami sequence not only acts as the conventional TxID of the SFN for ATSC terrestrial DTV system but also carriers the additional data bits on its polarity and the code phase.

The rapid progress in digital transmission technology has spurred demand for developing a technology that supports monitoring of video transmissions. Automating the picture quality assessment process is in particular demand because it currently depends on subjective assessments by human operators and places a heavy burden on them. The authors therefore propose an objective picture quality measurement method that works without reference pictures. In this proposed method, invisible markers are embedded into original pictures by use of the spread spectrum data hiding method. Since the markers are widely spread over the frequency domain, the degradation caused by MPEG compression can be estimated by detecting the extent of marker degradation. Our method is usable regardless of the kind of picture, bitrate, and number of stages of tandem codec connections. The degradation in picture quality caused by the embedded markers is quite small and not perceivable by the human eye. The proposed method is therefore applicable to a wide range of visual transmission services.

Video watermarks must maintain picture quality and withstand image processing, and resolving the tradeoff between these conflicting requirements has been one of the central problems in research on video watermarking. This paper shows that watermarks are less perceptible where picture contents are moving and proposes a new criterion for measuring watermark imperceptibility from motion vectors and deformation quantities. It also proposes a watermarking method that uses this criterion to allocate watermarks to picture areas adaptively. Experimental evaluation showed that the proposed method reduces degradation in picture quality and that, for the same picture quality after MPEG encoding and decoding, between 30% and 40% more watermarks can be embedded, improving detection reliability after MPEG processing by an average of 9.5%. The proposed method would be most effective when used with MPEG encoders because they already have the necessary motion estimation functions.

In this paper, simulation is conducted to study the interference to digital television (DTV) system due to the introduction of Long Term Evolution (LTE) system. Access coverage loss curves and capacity performance of DTV system are plotted with Adjacent Channel Interference Ratio (ACIR). The results indicate that minimum interference effects on DTV system can be achieved when deploying LTE system on its adjacent channels if proper separation is kept.

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).

This paper presents design, implementation and field trial of terrestrial DTV (digital television) system made in ETRI, Korea. The DTV system is ATSC compliant and under field trial in Korea.

MPEG-2 is an international standard specifying a normative bitstream syntax that decoders must recognize and that allows flexible selection of detailed coding parameters at the encoder. The compression performance is therefore largely dependent on the encoder design and the difference in coded picture quality is present even among encoders developed by different codec makers at identical bit-rates. Conventional MPEG-2 encoders were also designed for high picture quality transmission at an adequate bit-rate, and the overhead portion occupancy in a coded bitstream can be ignored in the final picture quality. However, the unexpected increase in overhead portion occupancy might cause fatal picture quality degradation at extremely low bitrates. To overcome this problem, we investigated an optimal design for an MPEG-2 encoder for use in HDTV digital terrestrial broadcasting where the available bit-rate is limited to less than 0.2 bit/pixel. In our study, advanced key technologies which have not been clearly recognized until now were introduced into possible optimization points, picture type selection macroblock coding mode selection and rate control, and a significant coding gain versus conventional encoding schemes was confirmed in coding experiments.

This paper presents a research of current practices in audio description broadcast in Spanish television channels. The results of this research show that in some television channels the audio description is broadcasted in 'receiver mix audio description' mode while in other channels the alternative used is 'broadcaster mix audio description' mode. In both cases, correct signalling and correct audio description coding is crucial so that digital television receivers can recognize audio description in the broadcast signal and reproduce it upon user request. The current practice of audio description broadcast in Spanish television channels only partially fulfils DVB standard. In addition, not all digital television receivers are able to reproduce appropriately the wide range of options defined in DVB to convey audio description in the television channels. The consequence for the users is less availability of audio description services than expected. Some of the problems detected for the activation of audio description in users' receivers can be solved by applying some enhancement to signalling information used by broadcasters in their DVB television channels. Finally, some recommendations for the users are included to present the key aspects for audio description activation in their digital television receivers.

Physical Unclonable Function (PUF) is recently used in modern electronic systems for device authentication and secret key generation. SRAM PUF is a popular memory-based PUF because it is a standard component for most electronic devices. Previously only strongly stable RAM bits are selected as PUF bits in order to achieve high reliability, hence requiring relatively large SRAM. Furthermore, SRAM PUF might suffer from PUF clone attack for using stable bits. Attackers may use Photon Emission Analysis (PEA) to observe the behavior of the stable bits and conducted Focused Ion Beam circuit edit (FIBCE) to produce an identical physical response. In this paper, we propose a new method that employs unstable bits as PUF bits in addition to the stable bits to increase the SRAM bit usage rate. We also show that this method can efficiently resist the PUF clone attack. Experimental results show that even though our proposed method uses unstable bits as PUF bits, it can still achieve high reliability. It can reach an average 2% intra-HD without Error Correction Code (ECC) under various conditions and an average inter-HD of 49.33%.

Broadcasting has always been limited by interference between signals. With the introduction of digital terrestrial television broadcasting (DTTB) in the existing analog TV channels, interference remains a limiting factor in the post-transition era after analog signals are turned off and the spectrum is repacked. The use of first adjacent channels and the "UHF taboo channels" in the same community without transmitter spacing limits is unprecedented, and is a challenge to digital television (DTV) receiver designers. This paper discusses the nature of interference between DTV signals on adjacent and UHF taboo channels, and propose some solutions to receiver designers to mitigate the problem.

“In 1927, Gray, Honon and Mathes [1J gave the first full theoretical discussion of the inflUence of waveband restriction on the quality of television pictures, and were able to.fix the minimum waveband requirements in advance, long before the first high-definition system was realized.” D. Gabor, “Theory of Communication,” Journal of the IEE, 1946 [2] Multiresolution decompositions for video coding are reviewed. Both nonrecursive and recursive coding schemes are considered. In nonrecursive schemes, it is shown that pyramid structures have certain advantages over subband or wavelet techniques, and a specific spatiotemporal pyramid coding of HDTV is discussed in some detail. It is shown that recursive, DPCM like schemes will incur a slight loss of optimality due to a restricted form of prediction if multiresolution decomposition with compatible decoding is required. Compatibility and transmission issues are also discussed. Multiresolution transmission for digital broadcast TV is introduced. This, when combined with multiresolution source coding, achieves spectrum efficiency, robustness and graceful degradation under channel impairments.Key WordsDigital televisionmultiresolution codingvideo compression

We propose the methodology of field strength prediction for a digital television (DTV) receiver by virtue of Rec. ITU-R P.1546. The curves shown in this Rec. represent the point-to area field strength for 1kW effective radiated power in the 30 MHz ∼ 3000 MHz. Some computed results are illustrated here from the formulation of field strength for DTV receiver. It was shown that the error of field strength value for dense urban area (R = 30 m) is in the range of about 6.8 ∼ 11.5 % compared with the Okumura-Hata model under some conditions. In addition comparison of service distance between analog and digital TV receivers has been also illustrated. The presented method provides the predicted values of field strength for TV receiver whether transmission quality can be assured or not, and it can be also used to get the protection ratio or separated distance for frequency sharing in the same or adjacent band.

Over the past several years we have investigated viewer response to temporal fluctuations in the quality of digital television pictures, which occur when video is coded into relatively low bit rates. Three phenomena of interest have been identified: (1) a forgiveness effect, (2) a recency effect, and (3) a negative-peak (duration-neglect); these are described and discussed in the paper. In collaboration with our partners in European projects MOSAIC and TAPESTRIES, we have developed a three-stage method of measuring time-variant quality, which has been accepted by the ITU-R. The first stage is a Single Stimulus Continuous Quality Evaluation (SSCQE) of instantaneous quality; the second a calibration stage to link SSCQE with conventional DSCQS, and the third stage a numerical procedure for relating continuous and overall quality. Some of the factors we have identified as being important in producing good overall quality judgements have relevance to the design of optimal coding strategies for digital television.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.