scholarly journals Very High-Performance Echo Canceller for Digital Terrestrial Television in Single Frequency Network

Author(s):  
El Miloud Ar-Reyouchi ◽  
Yousra Lamrani ◽  
Kamal Ghoumid ◽  
Salma Rattal
2021 ◽  
Vol 16 (2) ◽  
pp. 31-40
Author(s):  
A.O Gbenga-Ilori ◽  
O. I. Ladipo

The transition from analogue to digital television promises an enormous digital dividend that can translate to spectrum resource provision for other services. In this work, the size of the spectrum that can be released as dividend after digital switchover in some selected States of Nigeria is estimated. First, the present analogue television (ATV) network coverage is compared with predicted digital terrestrial television (DTTV) network coverage during a simulcast period, and after ATV switch-off. The predicted DTTV network is initially planned with a multi-frequency network (MFN) and analysis showed that DTTV had a 12.5% improvement in spectrum utilization compared to ATV while achieving a better coverage probability of 95.3%. This work predicted further spectrum savings with the use of a single-frequency network (SFN) design for DTTV network planning. The analysis done showed that 87.5% of the ATV spectrum could be saved for other services after the transition to DTTV using SFN. Keywords: Digital television, SFN, MFN, Spectrum, dividend


Telecom IT ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 7-12
Author(s):  
А. Buchatsky ◽  
O. Guzenko ◽  
S. Kulikov

Continuous monitoring of the status of the television network is necessary to ensure uninterrupted and high-quality broadcasting of digital air television signals. This report considers the method of measuring the single-frequency network of standard DVB-T2, presents the results of theoretical calculation of the coverage area of several single transmitting stations of digital air television of Leningrad region and shows the results of practical measurements of the total coverage area of DT-TV stations, as well as recommendations on the selection of the location of the control equipment.


Author(s):  
Chandrakala K. ◽  
Jaya Kumari J. ◽  
Sreeja T. K.

Digital multimedia broadcasting is a technology for transmitting multimedia signals to devices like mobile phones, PC, laptops, etc. This allows everyone to watch TV on mobile devices. With the fifth-generation network, one can download a movie in a few seconds. Mobile TV offers round-the-clock participation in communication and broadcasting around the globe. This has become possible by watching a live TV program on handheld devices, as it facilitates real-time updates. Digital terrestrial television broadcasting aimed at transmitting two types of information: global and local content. The global content aims at broadcasting over the entire network, and the local content is location specific. Broadcasting the local content using multiple transmitters at different frequencies in multifrequency network requires additional spectrum. Global content can be transmitted through single frequency network. Therefore, if both global and local information are transmitted in a single frequency network (SFN), the system will become highly spectrally efficient and cost-effective.


Alloy Digest ◽  
2017 ◽  
Vol 66 (12) ◽  

Abstract Alloy C688 is a high-performance copper alloy with very high conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming and joining. Filing Code: Cu-867. Producer or source: Gebr. Kemper GmbH + Company KG Metallwerke.


Alloy Digest ◽  
2017 ◽  
Vol 66 (10) ◽  

Abstract Alloy KHP 7025 (UNS C70250) is a high-performance copper alloy with very high conductivity. Uses include connector springs, tabs, contact springs, switches, relays, and leadframes. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Cu-865. Producer or source: Gebr. Kemper GmbH + Company KG Metallwerke.


2017 ◽  
pp. 96-103 ◽  
Author(s):  
Gillian Eggleston ◽  
Isabel Lima ◽  
Emmanuel Sarir ◽  
Jack Thompson ◽  
John Zatlokovicz ◽  
...  

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.


2021 ◽  
Vol 11 (2) ◽  
pp. 699
Author(s):  
Worapol Tangsopa ◽  
Jatuporn Thongsri

At present, development of manufacturer’s ultrasonic cleaning tank (UCT) to match the requirements from consumers usually relies on computer simulation based on harmonic response analysis (HRA). However, this technique can only be used with single-frequency UCT. For dual frequency, the manufacturer used information from empirical experiment alongside trial-and-error methods to develop prototypes, resulting in the UCT that may not be fully efficient. Thus, lack of such a proper calculational method to develop the dual frequency UCT was a problem that greatly impacted the manufacturers and consumers. To resolve this problem, we proposed a new model of simulation using transient dynamics analysis (TDA) which was successfully applied to develop the prototype of dual frequency UCT, 400 W, 18 L in capacity, eight horn transducers, 28 and 40 kHz frequencies for manufacturing. The TDA can indicate the acoustic pressure at all positions inside the UCT in transient states from the start to the states ready for proper cleaning. The calculation also reveals the correlation between the positions of acoustic pressure and the placement positions of transducers and frequencies. In comparison with the HRA at 28 kHz UCT, this TDA yielded the results more accurately than the HRA simulation, comparing to the experiments. Furthermore, the TDA can also be applied to the multifrequency UCTs as well. In this article, the step-by-step development of methodology was reported. Finally, this simulation can lead to the successful design of the high-performance dual frequencies UCT for the manufacturers.


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