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Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey.

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Presentation on theme: "Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey."— Presentation transcript:

1 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Chapter 17 Television Modern Electronic Communication Beasley & Miller

2 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Television Digital Television (DTV) High Definition TV (HDTV)  Began transmission in 1999  All stations on the air in 2009  Old NTSC (analog) signal is no longer transmitted National Television System Committee (NTSC)

3 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 17-1 The (a) HDTV screen ratio and (b) NTSC screen ratio format, shown for comparison.

4 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Advanced Television System Committee (ATSC)  Came up with 16 by 9 format  Also defined standard definition television (SDTV)

5 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Video Signal ITU-R 601 4:2:2 format International standard for digitizing component video Base sampling frequency of MHz

6 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Video Signal Luminance [Y]:Red-luminance [R-Y]:Blue-luminance [B-Y] Video signal composed of red, green, and blue (RGB) Luminance is the black and white detail Y, R-Y, and B-Y are converted to digital signal using Pulse Code Modulation (PCM) at MHz base rate. 10-bit sampling is used Luminance is sampled at 4 times the base rate Red-luminance and Blue-luminance at 2 times the base rate They are time-division-multiplexed (TDM) together at 270 Mbps

7 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Video Signal ChannelSample RateBit Rate Luminance Channel 4 X MHz = 13.5 MHz x 10 bits/sample = 135 Mbps R-Y channel 2 X MHz = 6.75 MHz x 10 bits/sample = 67.5 Mbps B-Y channel 2 X MHz = 6.75 MHz x 10 bits/sample = 67.5 Mbps Serial data bit rate of 270 Mbps = MPEG2 is used for data compression to fit in 6 MHz bandwidth Motion Pictures Expert Group (MPEG)

8 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Audio Signal Digital Audio Compression (AC-3) developed by Dolby Laboratories Provides five full-bandwidth audio channels (3 Hz to 20 kHz) Left, center, right, and left-right surround-sound channels Also one low-frequency enhancement channel at 3 Hz to 120 Hz 5.1 Channel Input (5 full and 1 reduced) 6 channels are multiplexed together to Mbps Compressed to 384 kbps

9 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 17-2 A block diagram of the ATSC digital transmission system.

10 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Transmission 8VSB – 8–level vestigial-sideband modulator I (In-phase) and Q (Quadrature) Exciter has 6 parts  Frame synchronizer to synchronize the MPEG2 data packets  Data randomizer to make data appear random to make the RF spectrum be flat across the channel so data will fit in 6 MHz bandwidth  REED Solomon Encoder for error correction  Data Interleaver – interleaves data to reduce interference  Trellis Encoder – more error correction  Pilot/Sync Insertion

11 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 17-3 (a) The 8VSB and (b) the 64-QAM constellations. (Courtesy of Harris Broadcast.)

12 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 17-4 The 8VSB segment sync. (Courtesy of Harris Broadcast.)

13 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure 17-5 The 8VSB frame sync. (Courtesy of Harris Broadcast.)

14 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The display of the 8VSB constellation and the 8VSB eye diagram as displayed in the modulation detail screen.

15 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The RF spectrum for a DTV signal.

16 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Simplified TV system.

17 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure An example of a CCD imaging device. (Courtesy of Hamaqmatsu Corp.) CCD – Charge Coupled Device

18 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Simplified scanning representation.

19 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Interlaced scanning.

20 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Video Signal Horizontal Retrace - Time to move from end of one line back to start of next lower line Vertical Flyback or retrace – time to move from bottom line to the start of the top line FCC stipulates that NTSC broadcasts have 525 horizontal scanning lines. 40 lines are lost as result of vertical retrace interval, so only 485 visible lines

21 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Frame frequency – number of times per second that complete set of 485 lines is traced.  30 times per second Flicker – need 60 frames per second so human eye does not perceive difference Interlaced scanning is used to trick the eye.

22 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. First set of lines (first field) is traced in 1/60 second Second set of lines (second field) is then traced 485 lines are displayed, even lines first, then the odd lines Horizontal sync between every line of video signal Horizontal sync for each of 525 lines in 1/30 second So 525 X 30 = kHz is frequency of pulses

23 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Horizontal sync pulses.

24 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Vertical retrace interval video signal.

25 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Transmitted TV signal.

26 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure TV receiver block diagram.

27 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure VHF/UHF tuner block diagram.

28 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Stagger tuning.

29 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure SAW filter.

30 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Ideal IF response curve.

31 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Wavetraps.

32 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Video section block diagram.

33 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Sync separator.

34 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Horizontal deflection block diagram.

35 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Nonlinear horizontal scanning. (From Bernard Grob, Basic Television Principles and Servicing, 4th ed., 1977; Courtesy of McGraw-Hill, Inc., New York.)

36 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Horizontal system schematic.

37 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. 28-Sep

38 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Composite video Composite video is the format of an analog television (picture only) signal before it is combined with a sound signal and modulated onto an RF carrier Contains four information groups  Video Brightness information  Horizontal Line Sync  Vertical Line Sync  Sound (Audio)

39 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Composite Video A composite video signal combines on one wire the video information required to recreate a color picture, as well as line and frame synchronization pulses. The color video signal is a linear combination of the luminance of the picture, and a modulated subcarrier carries the chrominance or color information. Chrominance is a combination of hue and saturation. Hue is a pure color like red, green, or blue without tint. Saturation is the amplitude of a given color Tint is the shade of a color

40 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Composite Video Video > 7.5 IRE Sync Pulses < 0 IRE 0 IRE

41 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Color TV Color TV started in 1953 Compatible with monochrome Uses same 6 MHz bandwidth Needed to be displayed on monochrome Can use unused spaces in spectrum by interleaving

42 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Interleaving process.

43 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Color Camera Uses 3 cameras in one – one for each color  Red, Green, Blue  3 cameras scan in unison  Can create any color with these 3 primary colors

44 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Generating the electrical color signals (color camera).

45 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. The 3 color signals are fed into a transmitter processing circuit called the matrix Creates the Y (luminance) and the chroma or color signal (I and Q) Y signal has proportions of Red, Green, and Blue to create a monochrome signal for use on Black/White screens. The I and Q signals will contain the color information.

46 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Composite color TV transmission.

47 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The composite color modulating signal.

48 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Color receiver block diagram.

49 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Color burst.

50 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Color CRT construction.

51 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. To build a jumbo TV, you take thousands of these LED modules and arrange them in a rectangular grid. For example, the grid might contain 640 by 480 LED modules, or 307,200 modules. The computer system looks at the incoming TV signal and decides which LEDs it will turn on and how brightly. The computer samples the intensity and color signals and translates them into intensity information for the three different LED colors at each pixel module.samples

52 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Plasma TV

53 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. What is Plasma? The central element in a fluorescent light is a plasma, a gas made up of free-flowing ions (electrically charged atoms) and electrons (negatively charged particles). In a plasma with an electrical current running through it, negatively charged particles are rushing toward the positively charged area of the plasma, and positively charged particles are rushing toward the negatively charged area. In this mad rush, particles are constantly bumping into each other. These collisions excite the gas atoms in the plasma, causing them to release photons of energy.

54 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Plasma TV To ionize the gas in a particular cell, the plasma display's computer charges the electrodes that intersect at that cell. It does this thousands of times in a small fraction of a second, charging each cell in turn.computer

55 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Plasma TV When the intersecting electrodes are charged (with a voltage difference between them), an electric current flows through the gas in the cell. The current creates a rapid flow of charged particles, which stimulates the gas atoms to release ultraviolet photons.voltage The released ultraviolet photons interact with phosphor material coated on the inside wall of the cell. Phosphors are substances that give off light when they are exposed to other light. When an ultraviolet photon hits a phosphor atom in the cell, one of the phosphor's electrons jumps to a higher energy level and the atom heats up. When the electron falls back to its normal level, it releases energy in the form of a visible light photon.

56 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. LCD Screens

57 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. LCD The combination of four facts makes LCDs possible: Light can be polarized. Liquid crystals can transmit and change polarized light. The structure of liquid crystals can be changed by electric current. There are transparent substances that can conduct electricity.

58 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. If we apply an electric charge to liquid crystal molecules, they untwist. When they straighten out, they change the angle of the light passing through them so that it no longer matches the angle of the top polarizing filter. Consequently, no light can pass through that area of the LCD, which makes that area darker than the surrounding areas

59 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Digital TV Aspect ratio - Standard television has a 4:3 aspect ratio -- it is four units wide by three units high. HDTV has a 16:9 aspect ratio, more like a movie screen. Resolution - The lowest standard resolution (SDTV) will be about the same as analog TV and will go up to 704 x 480 pixels. The highest HDTV resolution is 1920 x 1080 pixels. HDTV can display about ten times as many pixels as an analog TV set. Frame rate - A set's frame rate describes how many times it creates a complete picture on the screen every second. DTV frame rates usually end in "i" or "p" to denote whether they are interlaced or progressive. DTV frame rates range from 24p (24 frames per second, progressive) to 60p (60 frames per second, progressive).

60 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. When you hear someone mention a "1080i" HDTV set, they're talking about one that has a native resolution of 1920 x 1080 pixels and can display 60 frames per second, interlaced.

61 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Color convergence yoke.

62 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Enhanced Audio Zenith / dbx Similar to FM, but better signal

63 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure Zenith/dbx stereo system.

64 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The Electronics Workbench TM Multisim circuit used to simulate the frequency spectra for a UHF television signal.

65 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The Electronics Workbench TM simulation of the frequency spectra for a channel 22 television signal.

66 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The Electronics Workbench TM Multisim circuit of a high-Q bandstop circuit, or wavetrap.

67 Modern Electronic Communication 9th edition Jeffrey S. Beasley and Gary M. Miller Copyright ©2008 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Figure The Bode plotter output for the wavetrap filter.


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