OQPSK modulator designing: when to do the pulse shape ?

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salam2000

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[question] OQPSK

I want design a OQPSK modulator. in some reference the pulse shape is done after T/2 delay section, while in some reference pulse shaping (exmple Square Root Rised Cosine) done before T/2 delay.
what of these are correct?
introduce reliable reference!!
Thanks a lot.
 

Re: [question] OQPSK

Asslamo 3likom

It doesn't matter if pulse shaping is after the delay or before the delay
because the delay is effective only when summing the I & Q components .
the delay is made just to make the I change in phase not at the same time of Q change of phase.
you can find an example in the 2.4GHz phy of IEEE 802.15.4 with drawing

Salam
Hossam Alzomor
www(.)i-g(.)org
 

Re: [question] OQPSK

I think it is difference in receiver design. If pulse shaping done after delay the receiver design is similar to the other demodulation receiver in matched filter, timing & ... . but if it be before delay the receiver is difference and isn't general.
Please Help, I Wait. :|
 

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