Modulation & Demodulation in Zigbee

This Model has covered most of the physical layer blocks which is used in Zigbee Protocol.

In the transmitter, spreading is done using a PN Sequence at chip rate of 2 Mcps and then the spreaded bits are modulated using OQPSK modulator. In the receiver side, OQPSK demodulation is done first,then the spreaded bits are despreaded using the delayed version of PN chip sequence. The delay in transmitted and received bits is 4us.