A description of channel coding using convolutional codes.
Convolutional codes are one type of code used for
channel coding .
Another type of code used is
block coding .
Convolutional codes
In convolutional codes, each block of
bits is mapped into a block of
bits but these
bits are not only determined
by the present
information
bits but also by the previous information bits. Thisdependence can be captured by a finite state machine.
A rate
convolutional coder
,
with memory length 2 and constraint length 3.
Since the length of the shift register is 2, there are 4
different rates. The behavior of the convolutional codercan be captured by a 4 state machine. States:
00,
01, 10, 11 ,
For example, arrival of information bit
0 transitions from state
10 to state
01 .
The encoding and the decoding process can be realized in
trellis structure.
If the input sequence is
1 1 0 0
the output sequence would be
11 10 10 11
The transmitted codeword is then
11 10 10
11 . If there is one error on the channel
11
0 0 10 11
Starting from state
00 the Hamming
distance between the possible paths and the receivedsequence is measured. At the end, the path with minimum
distance to the received sequence is chosen as the correcttrellis path. The information sequence will then be
determined.
Convolutional coding lends itself to very efficient trellis
based encoding and decoding. They are very practical andpowerful codes.
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?
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
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
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.
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
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?
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
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?
