Digital Communication Puzzles

8/10/2019 Digital Communication Puzzles

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PUZZLES1.

C E A Y T G L E S M S P P P L

O I F F C A N I S Y T O U A E

D D I F T N L I S A L E Y R R

E H S I I L E T M Y H R H I R

S I G F E C E U N M A P T T O

K I E R Y M I O Q N A I S Y RD N T G A + M E I E + H Y + +

+ + + T + I D B N + R + N + +

+ + I + A + + E + C + F D + +

+ C + L + + + + C + Y + R + +

C I L C Y C + + + O + + O + +

Y C N A D N U D E R D + M + +

L A R T C E P S + + + I E + +

E C N A M R O F R E P + N + +

+ + + + + + + + + + + + + G +

(Over,Down,Direction)

BINARY(8,8,NE)

CODE(1,1,S)

CYCLIC(6,11,W)

DECODING(7,8,SE)

DIGITAL(1,7,NE)

EFFICIENCY(2,1,SE)

ERROR(15,2,S)

FREQUENCY(12,9,NW)

HAMMING(12,7,NW)

PARITY(14,1,S)

PERFORMANCE(11,14,W)

PHASE(12,5,NW)

POLYNOMIAL(13,1,SW)

REDUNDANCY(10,12,W)

SHIFT(1,5,NE)

SPECTRAL(8,13,W)SYNDROME(13,6,S)

SYSTEMATIC(11,1,SW)

TRELLIS(3,7,NE)

AMPLITUDE SHIFT KEYING

2. SPREAD SPECTRUM MODULATION


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3.

4.


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5.

6.

7.


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8.


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9.Fill in the blanks

10.

11.Find the missing block:

12. FIND


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13) The figure below shows an example of a modulation system used in digital communication.What is that modulation system?

a. PCM Modulation.b. Delta Modulation.c. Sigma Modulation.

d. Differential Modulation.

14) JUMBLED words

Nhcnale

rues

oucsre

cervrei

emasgse

15. Match the followingModulation Technique Applications

a. Amplitude Modulation 1. audio transmission

b. Frequency Modulation 2. Digital synthesizers

c. Vestigial Side band modulation 3. video and image transmission

d. Phase modulation 4. Television signals

16) Pick the odd man out:

a. ratio detector

b. slope detector

c. balanced slope detector

d. envelope detector

17)Find the missing letters

a) Di- -r- - - - -tr


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b) _ _ S _ o _ _i _ _

c) O _ _ _l _ _ t _ r

18.Copy the letters in the numbered cells to other cells with the same number.

Thwie

Woehinntn

Guasinsa

Kpin

Wobrnr

ensio

19. Which is Discrete signal

20.

21.

22.


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23.Match the following:

Modulation Technique Applications

e. Amplitude Modulation 1. audio transmission

f. Frequency Modulation 2. Digital synthesizers

g. Vestigial Side band modulation 3. video and image transmission

h. Phase modulation 4. Phase Constant

i. Balanced Modulator 5. Television signalsj. FM and PM 6. DSB-SC

Ans: a-3, b-1, c-5, d-2, e-6, f- 4

24. DOUBLE PUZZLE

UNIT 2

25. UNSCRAMBLE THE TITLE TO FIND THE WORD


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26.

27.

28. CRISSCROSS


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ANS:

29.Fallen phrase

30. What does figure a. and b. represents?

a. b.

31) Double Puzzle


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32..

33. Rearrange

ONLY NEEDS TEXT DIGITIZING THE ENCODING

34. Hints developing:

Filteranalog signalsamplecalledprefiltering

35. sampleanalog signalfiltercalledpostfiltering

36. sampling frequency can be ____________

Hint :

37. Quantization levels can be ___________

Hint:

38. Rearrange:

IS ERROR DIFFERENCE QUANTIZATION THE BETWEEN SIGNAL SIGNAL QUANTIZED MESSAGE AND


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39. FIND

40. FIND

41. Rearrange

BE SHOULD POSITIVE INFORMATION (I) I >=O

42. REDUNDANCY RECTIFICATION MORE OF NEEDS ERROR

43. Match

44. HINTS DEVELOPING:

PARITY CHECK CODENUMBER OF CHECK BITS1EVENEVEN NUMBER OF 1S INFORMATION

BITSODDODD NUMBER OF 1S

45. FIND

FORWARD ERROR

CORRECTION

ERROR CORRECTING CODES

AUTOMATIC REPEAT

REQUEST

DOES BOTH DETECTION AND

CORRECTION OF ERROR

NEEDS MORE OVERHEAD

COMPUTER

COMMUNICATION


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48. DELTA MODULATION DISADVANTAGES:

HINT: 1. HINT: 2.

49. NOISE IN PCM SYSTEM

HINT: 1. 2. 3. 4.

50. MATCH

UNITS OF INFORMATION:

51.------- is the interface device that maps the digital information.

HINT : Answer is in shuffled form

O D U A T R M L O

NO BASE OF LOG IS SPECIFIED

BASE e

BASE 10NAT

BINIT

HARTLEY


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52. Linearity of a modulation requires the principle of

HINT : S---R----T-O-

53. Fill The Remaining Letters

s G L L N G

T

Which is known as set of all these signal waveforms .

Answer:

54. The modulated waveform carries imprint of --- information

Hint:

The waveform contains the answer

55. An waveform is distinguished by its ------, -----and-----

Hint: This waveform contain the answer

56. The rate at which the data sequence enters the modulator is ----

Hint: One of the character in the name of the picture contains the answer


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S

E

B

O R P D N A

63.Bandpass transmitter usually called as-----

64.ISI ALONG with-----poses considerable difficulty in detecting modulated signal

Hint:Intermediate between transmitter and receiver

65.Modulator have a ----


a)PCM - ADAPTIVE

b)DM - LINEAR

c)ADPCM - BINARY

67.Telephone companies are normally provided a voltage of ----------to power telephones.

A)+24volt DC B)-24volt DC

C)48 volt DC D)-48 volt DC

68. That a waveform transmitted in any time interval depends on one or more previous -----symbol

Hint:

69.The baseband processor whose job is to imbibe-----

Hint:ISI - - - - - -

70.In-----bandpass processor usually the pulseshaper block is omitted

Hints:It is important while running


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71. What Does Mp Denotes In A-Law?

Hint:

72.What type of modulation is given by the following figure

73.Optimum baseband detector _ _ _ _ _ the detection error probability

Hint: the answer is used in computer if any files open this option will display

74. The optimum receiver can be implemented in either of two popular ways.

Hint: 1. One method is kind of filter. The before word is we use comparison.

2. Another one is we use in probability.

75.Different signal waveforms are generally derived from a signal pulse waveforms differing only in amplitude.

That in

__ __S__ __AN__

76.Match the following;

Analog signal - audio

Wired - electromagnetic wave

Storage - optical fibre

Wireless - telephone lines.


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87.The function which obeys orthogonal property is ?

B S F C

88.Find the missing letter ?

Hint:Collection of basis function.

B I E

89.Pick the odd one out:

Most manmade electro-magnetic noise occurs at frequencies below 500 MHz the most significant of these include:

A. Hydro lines

B. Ignition systems

C. Fluorescent lights

D. Thunder storms

90.Pick the odd one out:

A. Atmospheric noise

B. Industrial noise

C. Extraterrestrial noise

D. Transit time noise

91.Is it true that power of sum of two noise wave forms is equal to sum of individual powers?

92.------ Similar to pink noise, but with different spectral content and different relationships, -------

noise has power density decreasing in logarithmic frequency space at 6 dB per octave, for --------

noise it increases at 3 dB per octave, for -------- it increases at 6 dB per octave rate, for ------noise

it reduces first and then increases.

Choose the appropriate colour noise in the

93.How is this train of impulses also referred as?


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94.

95.Fill in the blank box

96. What does this picture represent ?

97. Fill the box

Hint:In a QAM signal, there are two _______(1)_, each having the ______(2)_ frequency but

differing in _______(3) by 90 degrees.


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98.


100. Match the following.

a.Two different phases are used to - QPSK

represent two binary values.

b.Four different phases are used to - BPSK

represent two binary values.

c.Each signal element represents - QPSK

only one bit.

d.Each signal element represents - BPSKtwo bits

101.Types of digital modulation

`

Hint:Across Down

1.AM comes at the back 2.Also called as on-off keying3.It has four points in signal space diagram 4.0 and 180 degree phase shift5.It uses two frequencies.

64

16

32


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102.

103.

104. Match:

(i)Rs>2W = possible to remove ISI but practically it has disadvantages.

(ii)Rs


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108.Find Adaptive M output binary stream for the following waveform. Use only two levels; 1=1 and 2=2.A binary 0 at the output represents a decrement and a binary 1 represents an increment.

What will be the output

a.1111100101000101 b.1100010101011101 c.111111111010101

109.Given the sequence S={1,1,1,0,1,0,1,0,1,0,0,0,0,0} generated by adaptive delta modulation of two

increment/decrement values (let them be 1 and 2), draw the demodulator output.Find the best match.

a. b. c.

110.Draw 2-level Adaptive -Modulation-Demodulation output for the following waveform on the same grid. Let=1 and 2=2. Zero is at the lower-left corner. Determine the binary stream when 0 represents a decrement and 1represents an increment.

a. 111100010110101 b. 100100010110101 c. 111100010000101

111.What would be the matched filter response for the given waveform


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a. b. c.

112.What would be the impulse response of the matched filter for the given waveform.

113.If The Number Of Step Size Increases,The Quantisation Noise------------

Hint:As The Stones Are Thrown In A Vessel Containing Water ,What Will Happen?

114. In Uniform Quantisation,The Characteristics Of Step Size Is-----------

Hint:

S - -S - -S - -S- -S- -

This Option Depicts The Answer

115.What Type Of Conversion Takes Place In Quantisation?

Hint:

116.More Number Of Levels Requires -----------------------Bandwidth For The Transmission Of The QuantisedSignal.

Hint:


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117. The main aim of the Non Uniform Quantisation is to--------------------

Hint:

118.Quantisaton Is An--------------------Process

Hint:This Figure Contains The Answer

119. -----------------------and quantized signals is transmitted through the channel at the receiver.

Hint:This Figure Contains The Answer

120.What Does Mp Denotes In A-Law?

Hint:

121.Non Uniform Quantisation shows the---------------properties of human speech.

Hint:It Is Used In Probability


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128. The Non Uniform Quantization can be used for real time application like_________________

Hint:

129. The mid tread and mid raiser are under the classification of ________________Quantisation.

Hint:

130. The A-Law and Mu-Law are purely based on __________________Function.

Hint:

131.The Aim Of Non-Uniform Quantization Is To _____________Over All Snr By Reducing Quantizatoin Noise

For The Weak Signal.

Hint:


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A Student Secured 65% In His First Semester And 85% In Second Semester.The Action Depicts??

132.In Non Uniform Quantization Step Is Made ___________For Smaller Signal And -----------------For Larger

Signal.

Hint:

Llll Ssss.133.Type of modulation with 4 phases of carrier

134. Arrange the following picture based on cut shape and type of waveform

135.Arrange the following picture based on cut shape and the basic communication model


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136. Puzzle: its a type of error checking codes and algorithm

137.Replace the & symbol

& I G N A LP

A

C

E

Which is known as minimum number of basis function (or) set of signals.

138.Replace @ Symbol

B

A

@ E T

I

@

Which is known as collection of basis function.

ANSWER: S

139. Replace the $ symbol


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That is the view of the signal wave from that is highly useful for detection of transmitted signals.

ANSWER: E

140.Fill The Remaining Letters

s G L L N G

T

Which is known as set of all these signal waveforms .

141.Find Out The Word

2 1 19 9 19

Function.It is a collection of the minimum number of function .

ANSWER: 2B,1A,19S,9I,19S.(ALPHABETIC ORDER NUMBER )

BASIS.

142.Suppose we have a set of finite

Signal waveforms a set of orthonormal

Function.

ANSWER: ENERGY &BASIS.

143.Give The Correct Sentence .

Fi the dimensionality fo the signal ecaps corresponding to eht given M langis waveforms is osla M.

ANSWER: if the dimensionality of the signal space corresponding to the given M signal waveform is

also M.

144.Give The Correct Sentence

Noitcelloc of eht minimum rebmun of noitcnuf is dellac basis noitcnuf.

ANSWER: collection of the minimum number of function is called basis function.

145.Types of noise:

G O $ T I

$ M N R C

5 14 5 18 7 25

2 1 19 9 19


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Across3. He ___ a man with a gun

4. Heat energy5. The name of a baby soap brandDown1. An alien2. A colorSOLUTION:

1. Extraterrestrial2. White3. Shot4. Thermal5. Johnson

146.Fill the blanks

147.Unscramble each of the clue words.

Copy the letters in the numbered cells to other cells with the same number.


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Solution:White

NonwhiteGaussian

ExternalPinkBrown

NOISE

148.Unscramble each of the clue words.

Take the letters that appear in boxes and unscramble them for the final message.

Solution:

RandomMovementElectronsHolesJunction

NoiseSHOT NOISE

149.With sinusoidal carrier, the feature that is used by the modulator to distinguish one signal from another is

step change in frequency this is called----


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CLUE:

Starting letter of a fruit

Answer:FSK

150.Which signal is mostly used

CLUE: 1) starting letter of the row is FLOWERand column is POWER

Ending letter of the column and row is KEY

Ans : PSK &FSK

151.In a binary fsk system, symbol __ & __ are distinguished from each other by transmitting one of two sinusoidal

waves

CLUE: the answers are hide in the two pictures out of three

pictures

Ans: 0 & 1

152. Average probability of signal error is

S


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for__ __ ___binary fsk

CLUE: arrange the letters you get the answer

ANS: coherent

153) Wave forms having __ __ __amplitude but different frequencies this is called FSK

CLUE: The answer is hide in this picture

154) All the FSK waveforms have equal -----

CLUE:

Without this cant do anything

__ __E__ __Y

Ans : Energy

155. Frequency deviation 2*2fats=2p for binary FSK & p=1 this continuous phase FSK signal is called-----FSK

__ __ N __ E `s FSK

CLUE:

E

SU

T H

E

C E O

RN


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Arrange letters from this circles

Ans: sunde`s FSK

156. Prime application of multioscillator FSK is------

Hint: 1) It is a type of telephoney

2) It is also called as another name of mobile

Ans: cellular telephoney

157.Optimum baseband detector _ _ _ _ _ the detection error probability

Hint: the answer is used in computer if any files open this option will display

ANS: minimize

158. The optimum receiver can be implemented in either of two popular ways.

Hint: 1. One method is kind of filter. The before word is we use comparison.

2. Another one is we use in probability.

159. Different signal waveforms are generally derived from a signal pulse waveforms differing only in amplitude.

That is

D

MINIMIZE

MAXIMIZE

NORMALIZEEQUALIZE


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CLUE: Using identity matrix you get a answer

ANS: baseband

160.The correlation or matched filter filters need to be completely different waveforms in.

Hint: It is type of filter

CLUE: Starting letter is from nose and ending letter is placed in mouth

Ans : Bandpass

161. The code bits are converted into -------- waveforms

Hint: a. It is measured from our heart beats.

162.If the signal m(t) changes so fast that the predicted signal m^q(t) cannot follow it, the systemnoise.

Hint:

a. if one end is higher than the another, what will you say?

b. the things are so heavy to carry.

If you join this, you will get the answer.

163. ------------------------------ is a more powerful parameter for digital waveform.

Hint:boost

164. Energy signal has --------------average power

B A L L O X Z L

S A E U C D H Q

R O S E M O A P

P Q F E O Y L I

I W R U B P X N

G J P R F A O Y

W K R V Y C N O

X V B J F I P D

N

A A D

B P

s S


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Hint: 1. 2)it is also represented in binary

165.I am the receiver block with an ability to tackle ISI , guess who I am?

Equalizing filter_

166. It is vital in delivering information about ISI and noise impairments of the system?

Eye pattern


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ANSWERS

1. BINARY(8,8,NE)CODE(1,1,S)

CYCLIC(6,11,W)

DECODING(7,8,SE)

DIGITAL(1,7,NE)

EFFICIENCY(2,1,SE)

ERROR(15,2,S)

FREQUENCY(12,9,NW)HAMMING(12,7,NW)

PARITY(14,1,S)

PERFORMANCE(11,14,W)

PHASE(12,5,NW)

POLYNOMIAL(13,1,SW)

REDUNDANCY(10,12,W)

SHIFT(1,5,NE)

SPECTRAL(8,13,W)

SYNDROME(13,6,S)

SYSTEMATIC(11,1,SW)

TRELLIS(3,7,NE)

AMPLITUDE SHIFT KEYING

2. SPREAD SPECTRUM3. MIDPOINT QUANTIZATION

4. PERFORMANCE, WIRELESS, TWISTED PAIR, SPECTRAL EFFICIENCY, COAXIAL , OPTICAL FIBRE, LINEAR,

COMMUNICATION

5. ANSWER

6. DELTA MODULATION

7.

8.


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9.

Bit valueAmplitudePhase shift

000 1 None

001 2 None

010 1 1/4

011 2 1/4

100 1 1/2

101 2 1/2

110 1 3/4

111 2 3/4

10.CONVOLUTIONAL CODING, BLOCK CODES, HAMMING ERROR CORRECTING

11.SOURCE ENCODER, SOURCE DECODER

12. BIT ERROR RATE

13.DELTA MODULATION.

14.CHANNEL, USER, SOURCE, RECEIVER, MESSAGE15.a-3 , b-1, c-4 and d-2

16.envelope detector. It is AM detection technique whereas all the others are FM detection

technique.

17.a) discriminator b) distortion c) oscillator d) broadband18.White, Nonwhite, Gaussian, Pink, Brown, NOISE

19.

20.

21. TIME DIVISION MULTIPLEXING

22. SIGNAL TO NOISE RATIO

23. a-3, b-1, c-5, d-2, e-6, f- 4


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24. SOURCE, TRANSMITTER, CHANNEL, RECEIVER, MODULATION, AMPLITUDE, FREQUENCY, PHASE,

BANDWIDTH, POSITION

25.ANS: BALANCED MODULATOR

26.ANS: THRESHOLD EFFECT

27.ANS: PRE EMPHASIS

28. 6. COMMUNICATION

1. WIDEBANDFM

2. MODULATION

3. PHASEMODULATION

4. CHANNEL

5. DIGITAL

7. ANALOG

29.Transmission bandwidth in vestigial sideband modulation is twice the modulating frequency

30.Ans: a. Represents time domain representation of an impulse signal

Represents frequency domain representation of an impulse signal31.Ans:

GRANULAR

SLOPEOVERLOAD

DELTA

AMPLITUDE

POSITION

SAMPLING

QUANTISATION

THRESHOLD

DIGITAL

32.ANSWER: PHASE SHIFT KEYING

33.Ans: Digitizing the text needs only encoding

34.Ans: Filtering the analog signal before sampling is called prefiltering

35.Sampling the analog signal before filtering is called postfiltering

36. INFINITE

37.LLEVELS38.Ans: Quantization error is the difference between message signal and quantized signal.

39.Ans: Continuously variable slope delta modulation

40.Quadrature mirror filter

41.Ans: Information (I) should be positive I >=0

42.Ans: Rectification of error needs more redundancy

43.


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44.PARITY CHECK CODE WITH EVEN NUMBER OF 1S IS CALLED EVEN AND IF IT HASODD NUMBER OF

1S IT IS CALLED ODD PARITY BITS.

45.LONGITUDINAL REDUNDANCY CHECK

46.

47.BLOCK CODES, CONVOLUTIONAL CODES

48.SLOPE OVERLOAD AND GRANULAR NOISE

49.ALIASING, QUANTISATION, CHANNEL, INTERSYMBOL

50.


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51.MODULATOR

52.SUPERPOSITION

53.Signalling set

54. INPUT SIGNAL

55.AMPLITUDE AND TIME PERIOD

56.BIT RATE

57.OS OR 1S

58.Rb

59.Rs

60.ASK,PSK & FSK

61.LINEAR AND NON-LINEAR

62.BASEBAND

63.MODULATED SIGNAL

64.CHANNEL

65. INPUT AND CARRIER

66.a)PCM - BINARY

b)DM - LINEAR

c)ADPCM - ADAPTIVE

67. ANS:D

68.TIME

69. ISI IMMUNITY

70.LINE CODERS

71.Answer: Peak

72.QPSK

73.MINIMIZES

74.MATCHED FILTER, CORRELATOR FILTER

75. ANS: baseband

76. Analog signal - OPTICAL FIBRE


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Wired - TELEPHONE LINE

Storage - AUDIO

Wireless - ELECTROMAGNETIC WAVES

77.Telephony -256 kbps

PCM -64kbps

ISDN -2 KHz

DSL -52Mbps

78. Simple model - additive noise channel

Band limit the signals - linear filter channel

Under water acoustic channel - linear time variant filter channel

79. a)NRZ-L= 1 goes high for half the bit period.0 does nothing

b)NRZ-M =1 forces to high level.0 forces to low level.

c)NRZ-S=1 does nothing.0 forces transistion

d)RZ =1 forces transistion.0 does nothing.

80. d) unipolar NRZ


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93. IMPULSE TRAIN

94.

95. SERIAL TO PARALLEL CONVERTOR

96. SIGNAL SPACE DIAGRAM

97. CARRIERS, SAME, PHASE

98.

99. 16, 64, 32

100. A. BPSK, B. QPSK, C. BPSK, D. QPSK

101. 1. PAM, 2. ASK, 3. QPSK, 4. PSK, 5. FSK102.

103.

104. i)Rs>2W = more immune to ISI.

. (ii)Rs


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151. 0 & 1

152. coherent

153. SAME

154. Energy

155. sunde`s FSK

156. cellular telephoney

157. minimize

158. MATCH, STATISTICAL

159. baseband

160. Bandpass

161. PULSE

162. INCREASES

163. ENERGY

164. 0

165. EQUALIZING FILTER

166. EYE PATTERN


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Documents

Digital Communication Puzzles