Network Design and Field Application of ATSC Distributed Translators
ABSTRACT In this paper, a design method for a distributed translator network considering the equalization window of commercial receivers is presented and compared with the field application results with three distributed translators in an urban area of Seoul, Korea. Proper transmission timing to minimize pre-ghost can be derived from the proposed design method. With designed timing information and the measured TxID (Transmitter Identification) information, the transmission timings of translators can be adjusted. Three types of receivers with different chipset generations were used for this field test. Several combinations of translators were applied for the analysis of the effect of operating multiple translators. Field test results are analyzed and discussed for the evaluation of the target distributed translator network and its design method.
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ABSTRACT: A transmitter identification system for DTV distributed transmission network using embedded pseudo random sequences is investigated. Different orthogonal pseudo random sequences and their suitability for transmitter identification are discussed. Code generators are developed to study the auto-correlation and cross-correlation properties of the Kasami sequences. To speed up the identification process, the embedded pseudo random sequence is preferred to be time-synchronized with the DTV frame structure. Therefore, the length of the identification code has to be truncated before it is fitted into each field of the ATSC DTV signal. The impact of truncation noise and in-band DTV interference on transmitter identification is also investigated. It is shown that the auto-correlation and cross-correlation properties are only slightly affected by truncation. It is also found that the dominant interference to the transmitter identification is the in-band DTV signal. The signal to truncation noise ratio and signal to DTV interference ratio in the correlation output are derived, and verified via simulation. It is further recognized that in-band DTV interference can only be mitigated by increasing the code length or by time-domain averaging technique to smoothen out the in-band interference.IEEE Transactions on Broadcasting 10/2004; · 2.09 Impact Factor
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ABSTRACT: This paper presents the implementation procedures and field test results of a Distributed-Transmission Network (also referred to as "DTx network" or "DTxN" throughout the paper) consisting of three coherent translators. As will be explained later in the text, a network of coherent translators, which is called "distributed translator network", is one of the three methods of implementing a DTxN. The performance of such distributed translator network was tested in a strong static and dynamic multipath environment. The target area of the distributed-translator network under consideration was selected to be a small part of the coverage area of a distant single transmitter. This provided the possibility of taking the reception quality of the distance transmitter as a reference, and evaluating the reception quality of distributed-translator network in its target area. Two types of ATSC receivers, a new prototype and an older generation one, were used for this study. This in turn made it possible to compare the performance of the two receivers under tough conditions, and to investigate the impact of DTxN on the older generation receiver. As an application of the Distributed-Transmission Network, the possibility of changing a number of low-power (LP) existing DTV assignments into a DTxN was also investigated in a case study. The existing LP assignments, the candidates for changing into DTxN, were all part of a provincial network that is broadcasting the same program on different channels across the province of Ontario-Canada. Using DTxN can improve the quality of service of the LP assignments and reduce the spectrum congestion within the existing allotment planIEEE Transactions on Broadcasting 10/2006; · 2.09 Impact Factor
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ABSTRACT: To analyze numerous field test data of digital broadcasting systems efficiently, field measurement systems have been integrated and become more intelligent. In this paper, we present the Integrated Measurement and Analysis System (IMAS) which manages DTV and TDMB (Terrestrial Digital Multimedia Broadcasting) test data very efficiently. This system can measure various parameters of DTV, T-DMB as well as analog TV (ATV) and FM broadcasting in fixed or mobile measurement mode. All the test equipments are connected through the local area network and managed by the system controller with an open device interface. Every test result can be converted into specific standard formats and stored in the main data base which can be accessed with a web graphical user interface through the intranet.IEEE Transactions on Consumer Electronics 03/2009; · 1.09 Impact Factor