with ur valuable information i have implemented
a viterbi decoder with k=7,1/2 decoder with
puncturing capability satidfactorily.... . i have also
implemented a puncturing unit which punctures the
1/2 code to rate 2/3 and 3/4 rate... using fifo ram and state
machine.. and it is working... but i have a problem
with the output data rate of the clock in 2/3 that is .If iam
giving the encoded output at 1 Mhz to the 2/3 punctuer
unit that is 2 bits for each clock cycle i have to output 3 bits for
every two clock cyclesss...
that if input to puncture unit is 1 mhz output data should go
serially at 1.5 mhz that is 3/2 of master clock
frequency from the puncture unit..
and the same case with the depuncture unit it should sample
the data serially at 3/2 of the master clock frequency
and given to decoder.
and the same case with 3/4 puncturing if input i need clock with 3/4
frequency of the master clock ;
so how can we achieve this clock in the punturing unit and
as the clock will be changing for the rate 1/2 , 2/3 and 3/4
smilarly for 3/4 for an input clock of 3 mhz outpu clock or data
transmission shuld happen at 4 mhz or
4/3 of the master clock frequency. how can we change that clock..
kindly throw some light on this....