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bastibl / gr-ieee802-15-4

IEEE 802.15.4 ZigBee Transceiver
https://www.wime-project.net
GNU General Public License v3.0
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Another question about o-qpsk demodulation in UCLA-ZigBee #12

Closed SUSTC2013 closed 8 years ago

SUSTC2013 commented 8 years ago

Thanks a lot for your advice about the block function in UCLA-ZigBee, but there is another question about the demodulation part. I know UCLA-ZigBee treats the o-qpsk modulation as MSK, and I know the reason why this is reasonable. But I referred to the textbook, that there will a delay in I-component to counteract the delay in Q-component in modulation part. I cannot find any delay in the demodulation part. Can you give me more advice? Thanks a lot. Regards Marx

bastibl commented 8 years ago

I know UCLA-ZigBee treats the o-qpsk modulation as MSK, and I know the reason why this is reasonable.

Then you know that QPSK with an offset in combination with the pulse-shape makes it MSK. Thinking in MSK, there is no offset.