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This module prefaces the subsequent modules on differential pulse code modulation (DPCM). In this module, the standard technique known as pulse code modulation (PCM) is described.
  • PCM is the “standard” sampling method taught in introductory DSP courses. The input signal is
    1. filtered to prevent aliasing,
    2. discretized in time by a sampler, and
    3. quantized in amplitude by a quantizer
    before transmission (or storage). Finally, the received samples are interpolated in time andamplitude to reconstruct an approximation of the input signal. Note that transmission may employ the use of additionalencoding and decoding, as with entropy codes. PCM is the most widespread and well-understood digital coding systemfor reasons of simplicity, though not efficiency (as we shall see).
    This flowchart begins with an arrow, labeled x(t), pointing to the right at a box labeled anti-alias filter. The box is followed by a broken line pointed upward, and continuing down with an arc pointing back down to the main lines of the flowchart. The arc contains an arrow, and the expression t=nT is shown to the right of the arc. The arc is followed by a second arrow pointing to the right. This arrow is labeled x(n), and it points at a box labeled quantize. The quantize box is followed by another arrow pointing to the right, labeled y(n). This arrow points at a dashed box labeled encode, which is followed by an arrow pointing to the right at a rounded box labeled transmit/store. This box is followed by an arrow pointing at another dashed box, labeled decode. The decode box is followed by an arrow, labeled yhat(n), that points at a final box labeled interp. This final box is followed by a final arrow pointing to the right, labeled xhat(t). This flowchart begins with an arrow, labeled x(t), pointing to the right at a box labeled anti-alias filter. The box is followed by a broken line pointed upward, and continuing down with an arc pointing back down to the main lines of the flowchart. The arc contains an arrow, and the expression t=nT is shown to the right of the arc. The arc is followed by a second arrow pointing to the right. This arrow is labeled x(n), and it points at a box labeled quantize. The quantize box is followed by another arrow pointing to the right, labeled y(n). This arrow points at a dashed box labeled encode, which is followed by an arrow pointing to the right at a rounded box labeled transmit/store. This box is followed by an arrow pointing at another dashed box, labeled decode. The decode box is followed by an arrow, labeled yhat(n), that points at a final box labeled interp. This final box is followed by a final arrow pointing to the right, labeled xhat(t).
    Standard PCM system

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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Source:  OpenStax, An introduction to source-coding: quantization, dpcm, transform coding, and sub-band coding. OpenStax CNX. Sep 25, 2009 Download for free at http://cnx.org/content/col11121/1.2
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