Digital Tv

A

SEMINAR REPORT ON

DIGITAL TV PRESENTED BY : Pragnesh Bhimani

Dept. of Electronics & Comm. Engineering LDRP-ITR,Gandhinagar

INTRODUCTION

What is DTV? The DTV standard is a very flexible television system that will allow broadcasters to provide new and higher quality services. First, DTV will permit transmission of television programming in new wide screen, high resolution formats known as high definition television (HDTV). In addition, the new DTV television system allows transmissions in standard definition television (SDTV) formats that provide picture resolution similar to existing television service. Both the HDTV and SDTV formats will have significantly better color than the existing analog television system. DTV also will provide improved audio quality, similar to that of compact discs. Additional features and functions such as color, stereo sound, remote control, cable channels and others have been added. According to Allied Business Intelligence there would be 242 million TVs will be digital by 2005 from 40 million in 2000. The number of global TV installations as of today is exceeding 1 billion in number. The salient features of digital TV are, Channel compression (400% compression), Dolby Audio (5.1), High resolution viewing (1080 X 1920), 16:9 aspect ratio (wide picture).

In US all the commercial broadcasting will be digital by 2003. By 2006 there won’t be any along transmission.

Digital TV Vs Analog TV Analog TV has a resolution of 486 X 720 pixels, two-channel stereo and 4:3 aspect ratio of the screen compressed in a bandwidth of 6 MHz. The Analog signal is susceptible to noise, multi reflections resulting in quality degradation. Analog TV uses Amplitude modulation for video and frequency modulation for audio. Digital TV has a resolution starting from 486 X 720 to 1080 X 1290 pixels, 5.1 Dolby audio (two-channel stereo, two-channel surrounding, center channel and woofer channel) and 16:9 aspect ratio of screen.

The features of digital TV Channel compression (400% compression) Dolby Audio (5.1) High resolution viewing (1080 X 1920) 16:9 aspect ratio (vide picture) Clearer and sharper cinema-like pictures Multi-channel (up to five channels/program) Broadcasters have the ability to simultaneously transmit multiple video programs using a single TV channel. Multicasting: DTV signals are carried over a wider bandwidth and can be split into sub-segments of an original channel but of lower resolution programming. There are two types of digital TV systems: standard definition television (SDTV) and high definition television (HDTV). Both HDTV and SDTV formats will have significantly better color performance than the existing analog TV system.

The Benefits of the Digital TV are  Due to channel compression, more channels can be transmitted or utilization of entire channel results in high quality video.  Theatrical quality of sound due to 5.1 Dolby.  Finer details of the picture with true color.  Wider viewing due to improved aspect ratio.

Block Diagram of DTV

Architecture of Digital STB

Analog Video Transmission System

Digital Video Transmission System

The Components of a Digital Video Microwave Link

Application TV mail TV Chat TV interactive Games Video on Demand (VOD) Interactive TV (iTV)

 Different Standards used in DTV  Opportunities in Digital TV

CONCLUSION

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