Syndrome Calculation
Cyclic code
is extremely well suited for error detection. Error detection can be
implemented by simply adding an additional flip flop to the syndrome
calculator. If the syndrome is non zero, the flip flop sets an indication of
error is provided (indicates that transmission error have occurred). If the
syndrome is zero the received vector is dividable by the generator polynomial
and hence is a code vector.
Block Diagrams
The operation of the block diagram
·
The
received vector is directly entered to division circuit which consists of
flip-flop & control gate. As the received vector is 7 bit , then we need
7clocks to insert all data to circuit.
· The control gate will be on during first 7 cocks
, which allow the all received vector to entered the division circuit and
processed.
·
We
can get syndrome vector in two forms.
·
Parallel:
If we connect the output of S0, S1, S2 to LEDS,
then once the received vector is inserted (after 7’clocks) and during clock number
8 we can read the syndrome at out of each flip-flop.
·
Serial:
After the received vector is inserted the control gate will be off 2’clocks to
get the syndrome vector out in serial. in this case the content of the
flip-flops will be zero.
x(t) = 5 ∙ sin (20 ∙ π ∙ t −
ردحذفπ
2
) + 3 ∙ sin (400 ∙ π ∙ t +
π
4
) − 0, 7 ∙ cos(40 ∙ π ∙ t)