Digital television systems - (DTS) Lectures Broadcast TV systems Digital television standards 2 Technical Univ. of Kosice Faculty of Electrical Engineering and Informatics Lˇ. Maceková, 2017

DVB DVB-S,C,T Fig. - source: Hewlett Packard

Content DTV transmissions systems - modulations, ... DVB – T, T2, S, S2, C others world DTV systems

Main principles: 1. Formation of DVB signal Step by step: digitization of video and audio signals reduction / compression of data stream – MPEG2, MPEG4, etc. (exploitation of the correlation between adjacent image elements in the frame and in the neighboring frames, , removing of the redundancy and irelevancy|) integrating of the program and services into 1 bouquette (multiplexing) anti-error protection /coding - different coding methods, interleaving of the data OFDM transmission technology (digital modulation of the thousands orthogonal carriers - optional „2k“ – 1705 carrieres, or „8k“ – 6817 carriers); each OFDM carrier is modulated by digital modulation (QPSK or QAM), protecting (Guard) interval embedding between 2 adjacent OFDM symbols broadcasting

Fig. Formation of DVB transmission signal [1]

2. Common principles of DVB-S,C,T systems Main principles: 2. Common principles of DVB-S,C,T systems Video and audio data are compressed by MPEG2 or MPEG 4 compression FEC1 channel coding (block Reed –Solomon code – external error protection FEC2 channel coding (internal error protection / convolutional code + interleaving) - only at DVB-S, T Common cryptography system for conditional (payed) access to DVB services Data Scrambling - multiplication of the data by pseudonoise sequence (PNS)  for equalizing of the spectra (the power and PAPR question) the common system of the service information (SI) about actually broadcasted programm

2. Differencies between DVB-S,C,T Main principles: 2. Differencies between DVB-S,C,T External modulation methods: QPSK (Quaternary Phase Shift Keying) – DVB-S QAM (Quadrature Amplitude Modulation) - DVB-C OFDM (Orthogonal Frequency Division Multiplexing)-DVB-T Because of (the reasons of the differencies): different bandwidths different types and levels of the interferences and distortions in the transmission channel different limits of the radiated power

Tab. Modes and features of latest DVB-x2 system standards in comparison Wikipedia

The DVB Multimedia Home Platform (DVB-MHP) defines a Java-based platform for the development of consumer video system applications. In addition to providing abstractions for many DVB and MPEG-2 concepts, it provides interfaces for other features like network card control, application download, and layered graphics. DVB has standardised a number of return channels that work together with DVB(-S/T/C) to create bi-directional communication. RCS is short for Return Channel Satellite, and specifies return channels in C, Ku and Ka frequency bands with return bandwidth of up to 2 Mbit/s. DVB-RCT is short for Return Channel Terrestrial, specified by ETSI EN 301958.

in India http://www.dthnews.com/2013/12/dvb-t2-technology-entering-in-23.html

Delivering 3DTV to Viewers good pages : https://www.dvb.org/resources/public/factsheets/DVB-3DTV_Factsheet.pdf DVB-3DTV is the first delivery format for ‘Plano-stereoscopic’ 3D television developed by the DVB Project. It enables the left and right images needed to be delivered over existing HDTV infrastructures, including to viewers with existing HDTV set top boxes. DVB-3DTV can be used for cable, terrestrial and satellite broadcast and broadband channels. The 3DTV channel has approximately the same bit rate requirements as a compression-artefact-free HDTV channel. To watch in 3D, viewers need a 3D display that provides the functionality required by the specification. DVB-3DTV is independent of the type of technology in the viewer’s 3D display (polarisation-plane discrimination, display time-multiplexing, or autostereoscopic). The specification offers the option of signalling independent depth positioning for the sub-titles of different scene characters. This can be used with new set top boxes, or existing set top boxes that can be appropriately software-upgraded. The DVB specifications relating to 3DTV form a suite of the following documents: • DVB-3DTV specification (DVB BlueBook A154) • DVB-SUB addendum for 3D subtitles (DVB BlueBook A156) • DVB-SI service information (DVB BlueBook A38). How does it work? the addition of depth or volume to television pictures. Today’s systems provide two images (the ‘left image’ and the ‘right image’), which are arranged to be seen by the corresponding left and right eyes of the viewer. The brain is ‘tricked’ to interpret the differences (‘binocular disparity’) in the images as depth in the picture, because it would see the same two images if the depth were really present. The full colour 3D-TV broadcast in DVB-3DTV arranges for the left and right colour images to be geometrically compressed so that the two images fill the frame of a broadcast HDTV image – this is a ‘spatial multiplex’. Two general forms of geometrical compression are used, called ‘Side-by-Side’ and ‘Top-and Bottom’. This is called ‘Frame Compatible

2nd Generation Cable The World’s Most Advanced Digital Cable TV System DVB-C2 is a digital cable transmission system developed by the DVB Project. It uses the latest modulation and coding techniques to enable highly efficient use of cable networks where, up to now, in many cases downstream transmission capacity is already being used to its limit. DVB-C2 will initially be used for the delivery of innovative new services, such as video-on-demand (VOD) and high definition television (HDTV), helping digital operators to remain competitive and also to meet retransmission requirements; in the longer term the migration of current DVB-C services to DVB-C2 is also foreseen. April 2010 saw the publication of the DVB-C2 specification (EN302769. An updated version is already available as DVB BlueBook A138) and the Implemention Guidelines Document (DVB BlueBook A147). In the same month, the Technical University of Braunschweig performed the first live DVB-C2 transmission, which validated the strong expected performance boost of the new system. A successful Plugfest was held in February 2012 and there are silicon and TV solutions in mass production. By using state of the art coding and modulation techniques it offers greater than 30% higher spectrum efficiency under the same conditions as today’s DVB-C deployments.

Tab. Comparing DVB-C and DVB-C2

Referencies [1] N.Pickford:Dig. Televisionbradcasting, Comm.Laboratory, Univ. of Camberra, Australia