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Flashcards

CPEN 80

Rey Genbert Legaspi Engineering English 137 cards

Cards in this deck (137)

  1. 1The communication that occurs in our day-to-day life is in the form of?signals
  2. 2The digital signals consist of1s and 0s
  3. 31s and 0s indicates what?High and Low values
  4. 4The elements which form a digital communication system is represented byBlocks
  5. 5this can be an analog signalSource
  6. 6takes a physical input and converts it to an electrical signal.Input Transducer
  7. 7A digital signal is generally represented by?binary sequence
  8. 8This compresses the data into minimum number of bitsSource Encoder
  9. 9It removes the redundant bits unnecessary excess bitsSource Encoder
  10. 10does the coding for error correction.Channel Encode
  11. 11due to the noise in the channel, the signal may get altered. How to avoid this?the channel encoder adds some redundant bits to the transmitted data
  12. 12The signal to be transmitted is modulated here by a carrierDigital Modulator
  13. 13The signal is converted to analog from the digital sequence, in order to make it travel through the channel or mediumDigital Modulator
  14. 14allows the analog signal to transmit from the transmitter end to the receiver end.Channel
  15. 15first step at the receiver endDigital Demodulator
  16. 16The received signal is demodulated as well as converted again from analog to digital. The signal gets reconstructed hereDigital Demodulator
  17. 17after detecting the sequence, does some error correctionsChannel Decoder
  18. 18How does the addition of bits help?It completes the recovery of the original signal
  19. 19The resultant signal is once again digitized by sampling and quantizing so that the pure digital output is obtained without the loss of informationSource Decoder
  20. 20it recreates the source output.Source Decoder
  21. 21the last block which converts the signal into the original physical formOutput Transducer
  22. 22It converts the electrical signal into physical outputOutput Transducer
  23. 23This is the output which is produced after the whole processOutput Signal
  24. 24Provides the necessary electrical power to operate the transmitterPower supply
  25. 25Creates alternating current at the frequency on which the transmitter will transmitOscillator
  26. 26generates the sine wave (carrier wave)Oscillator
  27. 27Adds useful information to the carrier wave. encoding info in a transmitted signalModulator
  28. 282 main ways to add info to the carrier wave- AM (Amplitude Modulation)
    -FM (Frequency Modulation)
  29. 29makes slight increases or decreases to the intensity of the carrier wave.AM (Amplitude Modulation)
  30. 30makes slight increases or decreases the frequency of the carrier wave.FM (Frequency Modulation)
  31. 31Amplifies the modulated carrier wave to increase its power.Amplifier
  32. 32The more powerful the _______, the more powerful the ________.amplifier, broadcast
  33. 33Converts the amplified signal to radio wavesAntenna
  34. 34opposite of a radio transmitterradio receiver
  35. 35It uses an _______ to capture radio wavesantenna
  36. 36simply a length of wireantenna
  37. 37amplifies the very weak radio frequency signal from the antenna so that the signal can be processed by the tunerRF amplifier
  38. 38A circuit that can extract signals of a particular frequency from a mix of signals of different frequenciesTuner
  39. 39The tuner usually employs the combination of what?inductor (coil) and capacitor
  40. 40resonates at a particular frequency, determined by the values chosen for the coil and the capacitorresonant
    frequency
  41. 41How can you adjust the resonant frequencyby varying the amount of inductance in the coil or the
    capacitance of the capacitor
  42. 42In simple radio receiver circuits, the tuning is adjusted byvarying
    the number of turns of wire in the coil
  43. 43More sophisticated tuners use a ____ to vary the frequencyvariable capacitor (also
    called a tuning capacitor)
  44. 44Responsible for separating the audio information from the carrier waveDetector
  45. 45This component’s job is to amplify the weak signal that comes from the detector so that it can be heard.Audio amplifier
  46. 46tools used by companies to establish a relationship and communicate with their audienceCommunication channels
  47. 47Usage of Communication Channel-build and establish your brand with your consumer
    -create a bridge between you and your audience
  48. 48what are the 7 channels?1. Social Media
    2. Blogs
    3. Email marketing
    4. Support
    5. Videos
    6. Discussion forums
    7. External complaint channels
  49. 49process of varying one or more parameters of a carrier signal in accordance with the instantaneous values of the message signalModulation
  50. 50the signal which is being transmitted for communication and the carrier signal is a high frequency signal which has no datamessage signal
  51. 51it is a pulse code modulated to convert its analog information into a binary sequencesignal
  52. 52The output of a PCM will resemble abinary sequence
  53. 53PCM produces a series of numbers or digits, and hence this process is called asdigital
  54. 54the message signal is represented by a sequence of coded pulsesPulse Code Modulation
  55. 55The transmitter section of a Pulse Code Modulator circuit consists ofSampling, Quantizing
    and Encoding
  56. 56This filter eliminates the high frequency components present in the input analog signal which is greater than the highest frequency of the message signal, to avoid aliasing of the message signal.Low Pass Filter
  57. 57This is the technique which helps to collect the sample data at instantaneous values of message signal, so as to reconstruct the original signalSampler
  58. 58is a process of reducing the excessive bits and confining the data.Quantizer
  59. 59The sampled output when given to Quantizerreduces the redundant bits and compresses the values
  60. 60The digitization of analog signal is done byEncoder
  61. 61It designates each quantized level by a binary codeEncoder
  62. 62What is the sampling done in the encoder?sample-and-hold process
  63. 63______minimizes the bandwidth usedEncoding
  64. 64This section increases the signal strengthRegenerative Repeater
  65. 65decodes the pulse coded waveform to reproduce the original signalDecoder
  66. 66After the digital-to-analog conversion is done by the regenerative circuit and the decoder, a low pass filter is employed, called asReconstruction Filter
  67. 67This circuit digitizes the given analog signal, codes it and samples it, and then transmits it in an analog form.Pulse Code Modulator
  68. 68The process of measuring the instantaneous values of continuous-time signal in a discrete formSampling
  69. 69This discretization of analog signal is called asSampling
  70. 70piece of data taken from the whole data which is continuous in the time domainSample
  71. 71the gap between the samples is calledsampling period
  72. 72reciprocal of sampling periodSampling frequency
  73. 73sampling frequency can be called assampling rate
  74. 74denotes the number of samples taken per second, or for a finite set of values.sampling rate/ sampling frequency
  75. 75the minimum rate (sampling rate) at which a signal can be sampled without introducing errors, which is twice the highest frequency present in the signal.Nyquist rate
  76. 76Nyquist rate is also called asSampling theorem
  77. 77the phenomenon of a high-frequency component in the spectrum of a signal, taking on the identity of a low-frequency component in the spectrum of its sampled version.Aliasing
  78. 78The digitization of analog signals involves the rounding off of the values which are approximately equal to the analog valuesQuantization
  79. 79is representing the sampled values of the amplitude by a finite set of levels, which means converting a continuous-amplitude sample into a discrete-time signal.Quantization
  80. 80The discrete amplitudes of the quantized output are called asrepresentation levels or reconstruction levels
  81. 81The spacing between the two adjacent representation levels is calledquantum or step-size
  82. 82two types of Quantizationuniform and non-uniform quantization
  83. 83quantization levels are uniformly spaced is termedUniform Quantization
  84. 84quantization levels are unequal and mostly the relation between them is logarithmicNon-uniform Quantization
  85. 85two types of uniform quantizationMid-Rise type and Mid-Tread type
  86. 86origin lies in the middle of a raising part of the stair-case like graph. The quantization levels in this type are even in numberMid-rise type
  87. 87origin lies in the middle of a tread of the stair-case like graph. The quantization levels in this type are odd in numbermid-tread
  88. 88The difference between an input value and its quantized value is calledQuantization Error
  89. 89is a logarithmic function that performs Quantization rounding off the value. An analog-to-digital converter (ADC) works as thisQuantizer
  90. 90It is a type of quantization error, which usually occurs in analog audio signal, while quantizing it to digitalQuantization Noise
  91. 91The word _________ is a combination of Compressing and Expanding, which means that it does bothCompanding
  92. 92This is a non-linear technique used in PCM which compresses the data at the transmitter and expands the same data at the receiver.Companding
  93. 93two types of Companding techniques- A-law Companding Technique
    - µ law Companding Technique
  94. 94- Uniform quantization is achieved at A = 1, where the characteristic curve is linear and no compression is done. -has mid-rise at the origin. Hence, it contains a non-zero value. -used for PCM telephone systemsA-law Companding Technique
  95. 95-Uniform quantization is achieved at µ = 0, where the characteristic curve is linear and no compression is done -has mid-tread at the origin. Hence, it contains a zero value. -used for speech and music signals -used in North Americaµ law Companding Technique
  96. 96process of converting the data or a given sequence of characters, symbols, alphabets etc., into a specified format, for the secured transmission of data.Encoding
  97. 97reverse process of encoding which is to extract the information from the converted format.Decoding
  98. 98is the process of using various patterns of voltage or current levels to represent 1s and 0s of the digital signals on the transmission link.Encoding
  99. 99common types of line encodingUnipolar, Polar, Bipolar, and Manchester
  100. 100data encoding technique is divided into the following types-Analog data to Analog signals
    -Analog data to Digital signals
    -Digital data to Analog signals
    -Digital data to Digital signals
  101. 101The modulation techniques such as Amplitude Modulation, Frequency Modulation and Phase Modulation of analog signals, fall under this category.Analog data to Analog signals
  102. 102This process can be termed as digitization, which is done by Pulse Code Modulation PCM. Hence, it is nothing but digital modulation. Delta Modulation gives a better output than PCMAnalog data to Digital signals
  103. 103The modulation techniques such as Amplitude Shift Keying ASKASK, Frequency Shift Keying FSKFSK, PhaseShift Keying PSKPSK, etc., fall under this category.Digital data to Analog signals
  104. 104here are several ways to map digital data to digital signals. Some of them are Non Return to Zero, Bi-phase Encoding, Block Coding, etc.Digital data to Digital signals
  105. 105has 1 for High voltage level and 0 for Low voltage level. the voltage level remains constant during bit intervalNon Return to Zero (NRZ)
  106. 106Two variations of NRZLevel NRZ and Inverted NRZ
  107. 107There is a change in the polarity of the signal, only when the incoming signal changes from 1 to 0 or from 0 to 1. It is the same as NRZ, however, the first bit of the input signal should have a change of polarityLevel NRZ
  108. 108If a 1 occurs at the incoming signal, then there occurs a transition at the beginning ofthe bit interval. For a 0 at the incoming signal, there is no transition at the beginning of the bit interval.Inverted NRZ
  109. 109The signal level is checked twice for every bit time, both initially and in the middle. Hence, the clock rate is double the data transfer rate and thus the modulation rate is also doubled. The clock is taken from the signal itselfBi-phase Encoding
  110. 110two types of Bi-phase Encoding- Bi-phase Manchester
    - Differential Manchester
  111. 111In this type of coding, the transition is done at the middle of the bit-interval. The transition for the resultant pulse is from High to Low in the middle of the interval, for the input bit 1. While the transition is from Low to High for the input bit 0.Bi-phase Manchester
  112. 112In this type of coding, there always occurs a transition in the middle of the bit interval. If there occurs a transition at the beginning of the bit interval, then the input bit is 0. If no transition occurs at the beginning of the bit interval, then the input bit is 1Differential Manchester
  113. 1134 bits of code is mapped with 5 bits, with a minimum number of 1 bits in the group.4B/5B Encoding
  114. 114We have used two voltage levels to send a single bit over a single signal. But if we use more than 3 voltage levels, we can send more bits per signal.8B/6T Encoding
  115. 115provides more information capacity, high data security, quicker system availability with great quality communication. have a greater demand, for their capacity to convey larger amounts of data than analog ones.Digital Modulation
  116. 116represents the binary data in the form of variations in the amplitude of a signal.Amplitude Shift Keying (ASK)
  117. 117The amplitude of the resultant output depends upon the input data whether it should be a zero level or a variation of positive and negative, depending upon the carrier frequency.Amplitude Shift Keying (ASK)
  118. 118T or F Any modulated signal has a high frequency carrierT
  119. 119The frequency of the output signal will be either high or low, depending upon the input data applied.Frequency Shift Keying
  120. 120is the digital modulation technique in which the frequency of the carrier signal varies according to the discrete digital changes. is a scheme of frequency modulationFrequency Shift Keying (FSK)
  121. 121The binary 1s and 0s are calledMark and Space
    frequencies
  122. 122T or F The output of a FSK modulated wave is high in frequency for a binary HIGH input and is low in frequency for a binary LOW input.T
  123. 123The phase of the output signal gets shifted depending upon the input.Phase Shift Keying
  124. 124is the digital modulation technique in which the phase of the carrier signal is changed by varying the sine and cosine inputs at a particular timePhase Shift Keying (PSK)
  125. 125types of PSK-BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying), according to the number of phase shifts.
    -DPSK (Differential Phase Shift Keying)
    which changes the phase according to the previous value
  126. 126also called as 2-phase PSK (or) Phase Reversal KeyingShift Keying
  127. 127In this technique, the sine wave carrier takes two phase reversals such as 0° and 180°Shift Keying
  128. 128BPSK is basically a _________ modulation scheme, for message being the digital information.DSB-SC (Double Sideband Suppressed Carrier)
  129. 129This is the phase shift keying technique, in which the sine wave carrier takes fourphase reversals such as 0°, 90°, 180°, and 270°Quadrature Phase Shift Keying (QPSK)
  130. 130the phase of the modulated signal is shifted relative to the previous signal element. No reference signal is considered here. The signal phase follows the high or low state of the previous element. doesn’t need a reference oscillator.Differential Phase Shift Keying (DPSK)
  131. 131communication at a distanceTelecommunication
  132. 132means fartele
  133. 133information presented in whatever formdata
  134. 134exchange of data between two devicesdata communication
  135. 135collection of computers operating autonomously and interconnected to provide computing or data servicesdata communication network
  136. 1362 main categories of Network-LAN (Local area network)
    -WAN (Wide area network)
  137. 137—

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Engineering Flashcards on CPEN 80, created by Rey Genbert Legaspi on 27/11/2022.
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