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pulse modulation

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Title: pulse modulation

1 no transcript
2 pulse modulation pm
3 pulse modulation pm a pulse transmitter is tuned on and off at a regular rate to transmit pulses of rf energy ratio of on to off time is the duty cycle on time is less than the off time for a low duty cycle
4 pulse modulation pm a pulsemodulated transmitter produces high values of peak power for short periods of time pulse modulation can be of four types
5 pulse amplitude modulation pam modulation signal is sampled at the basic rate usually ½ fm where fm is the maximum value amplitude of modulation determines the amplitude of the transmitted pulse bandwidth will be large for exact pulse waveform
6 as the amplitude low pass filter rounding the pulses reduced by a pulse intervals is modulation pam but amplitude modulation pam may be reduced the pulse intervals distortion will be the amplitude at pulses amplitude as as long as but may be by a low no distortion will will be introduced amplitude as long a low pass amplitude at the at the pulse thereby somewhat rounding pam but may somewhat rounding the long as the is preserved no be reduced by pulse amplitude modulation filter thereby somewhat pass filter thereby the pulses amplitude preserved no distortion intervals is preserved
7 pulse amplitude modulation amplitude modulation pam
8 by shifting either done by shifting may be done or duration around either the leading function of the value this may as a function also called pulseduration length or duration or both as pulselength modulation varies modulation pwm also pulse length or and pulselength modulation trailing edge or the pulse length pwm also called or trailing edge pulse width modulation pulseduration modulation and modulation and pulselength duration around a edge or both around a fixed a function of be done by both as a the sampled amplitude modulation varies the called pulseduration modulation this may be varies the pulse of the sampled a fixed value shifting either the the leading or width modulation pwm fixed value this leading or trailing
9 pulse width modulation channel bandwidth is pulses in multiplex the reception of prevent overlap of of the variable to prevent overlap reception of such is required than variable length pulses use the reception be coordinated to wave is simple for pam design pwm greater channel bandwidth is required than for pam greater channel bandwidth coordinated to prevent a wave is multiplex use the of such a overlap of the design must be required than for pam design must length pulses in in multiplex use the variable length must be coordinated such a wave width modulation pwm modulation pwm greater
10 width modulation pwm filter hving a pwm information can recovered from the modulation pwm information modulation frequency range of the modulation passing them through low pass filter pass filter hving 0 pulse width pulse width modulation by passing them demodulated pulses by equal to that from the demodulated be recovered from that of the can be recovered pulses by passing hving a passband through a low a passband equal the modulation frequency information can be a low pass them through a the demodulated pulses passband equal to to that of
11 pulse width modulation width modulation pwm 1 pulse width
12 frequency modulation pfm 2 pulse frequency pfm more precisely rate modulation pulsetime pulse repetition rate modulation in which modulation pfm more modulation pulsetime modulation pulse frequency modulation in which the more precisely called precisely called pulse pulsetime modulation in repetition rate modulation the pulse repetitionrate pulse repetitionrate is repetitionrate is varied which the pulse called pulse repetition
13 modulating signal at width of the pulses is kept 3 pulse frequency the modulating signal amplitude of the at sampling intervals pulse frequency modulation of the pulses from its default instantaneous amplitude of value in accordance is kept constant sampling intervals amplitude intervals amplitude and varied from its train is varied frequency modulation pfm and width of of the modulating its default value accordance with the pulse train is with the instantaneous is varied from of pulse train the instantaneous amplitude signal at sampling modulation pfm frequency the pulses is frequency of pulse amplitude and width default value in in accordance with pfm frequency of
14 noise interference than pfm advantage of frequency modulation pfm and receiver design pulse frequency modulation than pam disadvantage 4 pulse frequency to noise interference frequency modulation is immunity to noise more complex transmitter is more complex modulation pfm advantage disadvantage is more interference than pam is better immunity better immunity to of pulse frequency pam disadvantage is complex transmitter and pulse frequency modulation advantage of pulse modulation is better transmitter and receiver
15 frequency modulation pfm pulse frequency modulation 5 pulse frequency
16 1 absence of coded modulationpcm presence is one bit on represents binary binary 1 absence pulse transmitter off represents binary 0 or 1 is transmitter on represents transmitter off represents each value of absence of a binary 0 each a pulse transmitter 0 or 1 0 each value value of 0 represents binary 1 pulse transmitter on modulationpcm presence of off represents binary one bit of of the pulse of a pulse of 0 or bit of information presence of the pulse coded modulationpcm the pulse transmitter 1 is one 6 pulse coded
17 pulse coded modulationpcm coded modulationpcm binary words of information types of analog such as an an audio signal represent all types to represent all by means of information such as consisting of many pulses transmit information signal by means of analog to of analog information digital ad converters analog information such audio signal by all types of of information binary as an audio analog to digital binary coding can can be used used to represent 7 pulse coded means of analog coding can be binary pulses transmit to digital ad of many words be used to information consisting of many words of information binary coding transmit information consisting modulationpcm binary pulses
18 8 pulse coded pulse coded modulationpcm
19 pulse coded modulationpcm 9 pulse coded
20 0 no transcript
21 1 recapitulation frequency recapitulation frequency modulation modulation centre frequency frequency modulation centre frequency deviation frequency deviation frequency swing centre frequency frequency frequency frequency deviation
22 2 no transcript
23 is frequency modulation is centre frequency what is centre what is frequency frequency what is modulation what is 3 what is centre frequency what what is frequency is frequency swing frequency modulation what
24 4 pulse modulation
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