Hi, guys,
One issue got me stumped these days, I hope you guys could help me out here.
My confuse lies in the modulation scheme and demodulation scheme used in the chip-CC2420
As you may know, IEEE 802.15.4 standard specifies O-QPSK modulation with half-sine shaping, which actually is equal to MSK. My humble opinion is that we may have four options to design transceiver in terms of modulation and demodulation.
1. O-QPSK modulation (with half-sine shaping) + O-QPSK demodulation
2. O-QPSK modulation (with half-sine shaping) + MSK demodulation
3. MSK modulation + O-QPSK demodulation
4. MSK modulation + MSK demodulation
If my analysis is right, I am wondering which option is applied in CC2420 or other serial chips, and if possible, please explain a little bit the reason for your choice. I checked it's specification, and it seems that transmitted signal can be set up as O-QPSK with half-sine shaping or as MSK, but doesn't which demodulation is applied.
Thank you very much for your time.
Regards,
Allerson