Fichas
CPEN 80
Fichas del conjunto (137)
- 1The communication that occurs in our day-to-day life is in the form of?signals
- 2The digital signals consist of1s and 0s
- 31s and 0s indicates what?High and Low values
- 4The elements which form a digital communication system is represented byBlocks
- 5this can be an analog signalSource
- 6takes a physical input and converts it to an electrical signal.Input Transducer
- 7A digital signal is generally represented by?binary sequence
- 8This compresses the data into minimum number of bitsSource Encoder
- 9It removes the redundant bits unnecessary excess bitsSource Encoder
- 10does the coding for error correction.Channel Encode
- 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
- 12The signal to be transmitted is modulated here by a carrierDigital Modulator
- 13The signal is converted to analog from the digital sequence, in order to make it travel through the channel or mediumDigital Modulator
- 14allows the analog signal to transmit from the transmitter end to the receiver end.Channel
- 15first step at the receiver endDigital Demodulator
- 16The received signal is demodulated as well as converted again from analog to digital. The signal gets reconstructed hereDigital Demodulator
- 17after detecting the sequence, does some error correctionsChannel Decoder
- 18How does the addition of bits help?It completes the recovery of the original signal
- 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
- 20it recreates the source output.Source Decoder
- 21the last block which converts the signal into the original physical formOutput Transducer
- 22It converts the electrical signal into physical outputOutput Transducer
- 23This is the output which is produced after the whole processOutput Signal
- 24Provides the necessary electrical power to operate the transmitterPower supply
- 25Creates alternating current at the frequency on which the transmitter will transmitOscillator
- 26generates the sine wave (carrier wave)Oscillator
- 27Adds useful information to the carrier wave. encoding info in a transmitted signalModulator
- 282 main ways to add info to the carrier wave- AM (Amplitude Modulation)
-FM (Frequency Modulation) - 29makes slight increases or decreases to the intensity of the carrier wave.AM (Amplitude Modulation)
- 30makes slight increases or decreases the frequency of the carrier wave.FM (Frequency Modulation)
- 31Amplifies the modulated carrier wave to increase its power.Amplifier
- 32The more powerful the _______, the more powerful the ________.amplifier, broadcast
- 33Converts the amplified signal to radio wavesAntenna
- 34opposite of a radio transmitterradio receiver
- 35It uses an _______ to capture radio wavesantenna
- 36simply a length of wireantenna
- 37amplifies the very weak radio frequency signal from the antenna so that the signal can be processed by the tunerRF amplifier
- 38A circuit that can extract signals of a particular frequency from a mix of signals of different frequenciesTuner
- 39The tuner usually employs the combination of what?inductor (coil) and capacitor
- 40resonates at a particular frequency, determined by the values chosen for the coil and the capacitorresonant
frequency - 41How can you adjust the resonant frequencyby varying the amount of inductance in the coil or the
capacitance of the capacitor - 42In simple radio receiver circuits, the tuning is adjusted byvarying
the number of turns of wire in the coil - 43More sophisticated tuners use a ____ to vary the frequencyvariable capacitor (also
called a tuning capacitor) - 44Responsible for separating the audio information from the carrier waveDetector
- 45This component’s job is to amplify the weak signal that comes from the detector so that it can be heard.Audio amplifier
- 46tools used by companies to establish a relationship and communicate with their audienceCommunication channels
- 47Usage of Communication Channel-build and establish your brand with your consumer
-create a bridge between you and your audience - 48what are the 7 channels?1. Social Media
2. Blogs
3. Email marketing
4. Support
5. Videos
6. Discussion forums
7. External complaint channels - 49process of varying one or more parameters of a carrier signal in accordance with the instantaneous values of the message signalModulation
- 50the signal which is being transmitted for communication and the carrier signal is a high frequency signal which has no datamessage signal
- 51it is a pulse code modulated to convert its analog information into a binary sequencesignal
- 52The output of a PCM will resemble abinary sequence
- 53PCM produces a series of numbers or digits, and hence this process is called asdigital
- 54the message signal is represented by a sequence of coded pulsesPulse Code Modulation
- 55The transmitter section of a Pulse Code Modulator circuit consists ofSampling, Quantizing
and Encoding - 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
- 57This is the technique which helps to collect the sample data at instantaneous values of message signal, so as to reconstruct the original signalSampler
- 58is a process of reducing the excessive bits and confining the data.Quantizer
- 59The sampled output when given to Quantizerreduces the redundant bits and compresses the values
- 60The digitization of analog signal is done byEncoder
- 61It designates each quantized level by a binary codeEncoder
- 62What is the sampling done in the encoder?sample-and-hold process
- 63______minimizes the bandwidth usedEncoding
- 64This section increases the signal strengthRegenerative Repeater
- 65decodes the pulse coded waveform to reproduce the original signalDecoder
- 66After the digital-to-analog conversion is done by the regenerative circuit and the decoder, a low pass filter is employed, called asReconstruction Filter
- 67This circuit digitizes the given analog signal, codes it and samples it, and then transmits it in an analog form.Pulse Code Modulator
- 68The process of measuring the instantaneous values of continuous-time signal in a discrete formSampling
- 69This discretization of analog signal is called asSampling
- 70piece of data taken from the whole data which is continuous in the time domainSample
- 71the gap between the samples is calledsampling period
- 72reciprocal of sampling periodSampling frequency
- 73sampling frequency can be called assampling rate
- 74denotes the number of samples taken per second, or for a finite set of values.sampling rate/ sampling frequency
- 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
- 76Nyquist rate is also called asSampling theorem
- 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
- 78The digitization of analog signals involves the rounding off of the values which are approximately equal to the analog valuesQuantization
- 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
- 80The discrete amplitudes of the quantized output are called asrepresentation levels or reconstruction levels
- 81The spacing between the two adjacent representation levels is calledquantum or step-size
- 82two types of Quantizationuniform and non-uniform quantization
- 83quantization levels are uniformly spaced is termedUniform Quantization
- 84quantization levels are unequal and mostly the relation between them is logarithmicNon-uniform Quantization
- 85two types of uniform quantizationMid-Rise type and Mid-Tread type
- 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
- 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
- 88The difference between an input value and its quantized value is calledQuantization Error
- 89is a logarithmic function that performs Quantization rounding off the value. An analog-to-digital converter (ADC) works as thisQuantizer
- 90It is a type of quantization error, which usually occurs in analog audio signal, while quantizing it to digitalQuantization Noise
- 91The word _________ is a combination of Compressing and Expanding, which means that it does bothCompanding
- 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
- 93two types of Companding techniques- A-law Companding Technique
- µ law Companding Technique - 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-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
- 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
- 97reverse process of encoding which is to extract the information from the converted format.Decoding
- 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
- 99common types of line encodingUnipolar, Polar, Bipolar, and Manchester
- 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 - 101The modulation techniques such as Amplitude Modulation, Frequency Modulation and Phase Modulation of analog signals, fall under this category.Analog data to Analog signals
- 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
- 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
- 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
- 105has 1 for High voltage level and 0 for Low voltage level. the voltage level remains constant during bit intervalNon Return to Zero (NRZ)
- 106Two variations of NRZLevel NRZ and Inverted NRZ
- 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
- 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
- 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
- 110two types of Bi-phase Encoding- Bi-phase Manchester
- Differential Manchester - 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
- 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
- 1134 bits of code is mapped with 5 bits, with a minimum number of 1 bits in the group.4B/5B Encoding
- 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
- 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
- 116represents the binary data in the form of variations in the amplitude of a signal.Amplitude Shift Keying (ASK)
- 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)
- 118T or F Any modulated signal has a high frequency carrierT
- 119The frequency of the output signal will be either high or low, depending upon the input data applied.Frequency Shift Keying
- 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)
- 121The binary 1s and 0s are calledMark and Space
frequencies - 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
- 123The phase of the output signal gets shifted depending upon the input.Phase Shift Keying
- 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)
- 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 - 126also called as 2-phase PSK (or) Phase Reversal KeyingShift Keying
- 127In this technique, the sine wave carrier takes two phase reversals such as 0° and 180°Shift Keying
- 128BPSK is basically a _________ modulation scheme, for message being the digital information.DSB-SC (Double Sideband Suppressed Carrier)
- 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)
- 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)
- 131communication at a distanceTelecommunication
- 132means fartele
- 133information presented in whatever formdata
- 134exchange of data between two devicesdata communication
- 135collection of computers operating autonomously and interconnected to provide computing or data servicesdata communication network
- 1362 main categories of Network-LAN (Local area network)
-WAN (Wide area network) - 137—
Información
- Descripción
- Engineering Fichas sobre CPEN 80, creado por Rey Genbert Legaspi el 27/11/2022.
- Creado por
- Rey Genbert Legaspi
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