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Amplitude Modulation and Demodulation

Rebecca Perriment 9 questions

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Questions in this quiz (9)

  1. 1CODEC TRANSMITTER
    1. [blank_start]ADC[blank_end] - [blank_start]sampler[blank_end] , [blank_start]quantiser[blank_end] , [blank_start]coder[blank_end]
    2. [blank_start]Source[blank_end] [blank_start]coding[blank_end] - take [blank_start]binary[blank_end] signal and removes [blank_start]redundant[blank_end] bits
    3. [blank_start]Encryption[blank_end] - ensures only user with the [blank_start]correct[blank_end] [blank_start]key[blank_end] can access
    4. [blank_start]Error[blank_end] [blank_start]control[blank_end] [blank_start]coder[blank_end] - encodes signal by [blank_start]adding[blank_end] [blank_start]redundant[blank_end] bits, lengthening the binary signal therefore errors can be [blank_start]corrected[blank_end] at the [blank_start]receiver[blank_end]
    1. Asampler
    2. BADC
    3. Cquantiser
    4. Dcoder
    5. ESource
    6. Fcoding
    7. Gbinary
    8. Hredundant
    9. IEncryption
    10. Jcorrect
    11. Kkey
    12. LError
    13. Mcontrol
    14. Ncoder
    15. Oadding
    16. Predundant
    17. Qcorrected
    18. Rreceiver
  2. 2MODEM TRANSMITTER
    From CODEC to MODEM [blank_start]multiplexing[blank_end] takes place
    1. [blank_start]Line[blank_end] [blank_start]coding[blank_end] - maps [blank_start]binary[blank_end] stream to a sequence of [blank_start]voltage[blank_end] levels so information has [blank_start]electrical[blank_end] representation
    2. [blank_start]Modulator[blank_end] - converts [blank_start]binary[blank_end] stream to a form that can be [blank_start]transmitted[blank_end], usually [blank_start]band[blank_end] [blank_start]pass[blank_end] [blank_start]waveform[blank_end]
    1. Amultiplexing
    2. BLine
    3. Ccoding
    4. Dbinary
    5. Evoltage
    6. Felectrical
    7. GModulator
    8. Hbinary
    9. Itransmitted
    10. Jband
    11. Kpass
    12. Lwaveform
  3. 3MODEM RECIEVER
    1. [blank_start]Demodulator[blank_end] - coverts received [blank_start]band[blank_end] [blank_start]pass[blank_end] [blank_start]waveform[blank_end] to a [blank_start]baseband[blank_end] [blank_start]signal[blank_end]
    2. [blank_start]Detector[blank_end] - converts [blank_start]baseband[blank_end] [blank_start]signal[blank_end] to [blank_start]binary[blank_end] stream
    [blank_start]Demultiplexing[blank_end] occurs between the MODEM and CODEC
    1. ADemodulator
    2. Bband
    3. Cpass
    4. Dwaveform
    5. Ebaseband
    6. Fsignal
    7. GDetector
    8. Hbaseband
    9. Isignal
    10. Jbinary
    11. KDemultiplexing
  4. 4CODEC RECIEVER
    1. [blank_start]Error[blank_end] [blank_start]control[blank_end] [blank_start]decoding[blank_end]
    2. [blank_start]Decryption[blank_end]
    3. [blank_start]Source[blank_end] [blank_start]decoder[blank_end]
    4. [blank_start]DAC[blank_end] - [blank_start]PCM[blank_end] [blank_start]decoder[blank_end], [blank_start]reconstruction[blank_end]
    1. AError
    2. Bcontrol
    3. Cdecoding
    4. DDecryption
    5. ESource
    6. Fdecoder
    7. GDAC
    8. HPCM
    9. Idecoder
    10. Jreconstruction
  5. 5Need of modulation
    1. to increase [blank_start]operating[blank_end] [blank_start]range[blank_end] the signal energy must be increased, therefore a greater [blank_start]frequency[blank_end] is needed as [blank_start]E=hf[blank_end]
    2. [blank_start]antenna[blank_end] [blank_start]length[blank_end] is proportional to wavelength of the signal
    3. [blank_start]wireless[blank_end] [blank_start]communication[blank_end] can only be done with a modulated singal
    1. Aoperating
    2. Brange
    3. Cfrequency
    4. DE=hf
    5. Eantenna
    6. Flength
    7. Gwireless
    8. Hcommunication
  6. 6Amplitude Modulation
    vs(t) = (Vdc + (1) [blank_start]Vm.cos(2*pi*fm*t)[blank_end]) * (2)[blank_start]cos(2*pi*fc*t)[blank_end]
    [blank_start]Message[blank_end] signal = (1)
    [blank_start]Carrier[blank_end] signal = (2)
    The carrier signal is [blank_start]high[blank_end] frequency
    Modulation depth, m =[blank_start]Vm[blank_end]/[blank_start]Vdc[blank_end] = [blank_start]Vmax[blank_end] - [blank_start]Vmin[blank_end]/[blank_start]Vmax[blank_end] + [blank_start]Vmin[blank_end]
    m<1 [blank_start]DSB-AM[blank_end]
    m=1 [blank_start]DSB-AM[blank_end]
    m>1 [blank_start]DSB-DimC[blank_end]
    m=infinite [blank_start]DSB-SC[blank_end]
    1. AVm.cos(2*pi*fm*t)
    2. Bcos(2*pi*fc*t)
    3. CMessage
    4. DCarrier
    5. Ehigh
    6. FVm
    7. GVdc
    8. HVmax
    9. IVmin
    10. JVmax
    11. KVmin
    12. LDSB-AM
    13. MDSB-AM
    14. NDSB-DimC
    15. ODSB-SC
  7. 7Power
    P = [blank_start](V/sqrt(2))^2[blank_end]
    Plsb and Pusb = [blank_start]((Vm)^2)/8[blank_end]
    Psb = Plsc + Pusb = [blank_start]((Vm)^2)/4[blank_end]
    Pc = [blank_start]((Vdc)^2)/2[blank_end]
    Ptotal = [blank_start]Pc[blank_end] + [blank_start]Psb[blank_end]
    1. A(V/sqrt(2))^2
    2. B((Vm)^2)/8
    3. C((Vm)^2)/4
    4. D((Vdc)^2)/2
    5. EPc
    6. FPsb
  8. 8Amplitude Demodulation
    Envelope/non-coherent/diode detection:
    RsC<<[blank_start]1/fc[blank_end]
    1/fc<<[blank_start]RlC[blank_end]<<1/fm
    AM input must have m[blank_start]>1[blank_end]
    For large signal inputs, forward bias [blank_start]on[blank_end], reverse bias [blank_start]off[blank_end] and the circuit acts as a [blank_start]half[blank_end] [blank_start]wave[blank_end] [blank_start]rectifier[blank_end]
    [blank_start]RC[blank_end] part acts as smoothing circuit
    Output is [blank_start]m(t)[blank_end] + [blank_start]distortion[blank_end]
    1. A1/fc
    2. BRlC
    3. C>1
    4. Doff
    5. Eon
    6. Fhalf
    7. Gwave
    8. Hrectifier
    9. IRC
    10. Jdistortion
    11. Km(t)
  9. 9Synchronous/ coherent demodulation:
    More [blank_start]complex[blank_end] and [blank_start]expensive[blank_end] than envelop detection
    Am input -> [blank_start]local[blank_end] [blank_start]oscillator[blank_end] -> v(x) -> [blank_start]low[blank_end] [blank_start]pass[blank_end] [blank_start]filter[blank_end] -> m(t)
    LO must be at the same [blank_start]frequency[blank_end] and in [blank_start]phase[blank_end] with the input signal therefore LO = [blank_start]cos(2*pi*fc*t)[blank_end]
    v(x) = [blank_start]AM input[blank_end] * [blank_start]LO[blank_end]
    Low pass filter ensure only [blank_start](Vdc+m(t))/2[blank_end] gets through
    1. Acomplex
    2. Bexpensive
    3. Coscillator
    4. Dlow
    5. Epass
    6. Ffrequency
    7. Gphase
    8. Hcos(2*pi*fc*t)
    9. IAM input
    10. JLO
    11. K(Vdc+m(t))/2
    12. Llocal
    13. Mfilter

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Description
Signals and Communications 1 (Amplitude Modulation and Demodulation) Quiz on Amplitude Modulation and Demodulation, created by Rebecca Perriment on 22/05/2018.
Language
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