ZigBee over IEEE 802.15.4 standard for wireless technology, developed in 2003 were designed for interconnection of data communication using low data rate, low power and low complexity short range communication in a wireless personal area network (WPAN). Later in 2006, it was enhanced for market applicability to remove ambiguities in implementation for low data rate and short range wireless networks with high battery life. This technology supports cost effective, low power, wireless network monitoring and control products based on open global standard. ZigBee along with IEEE 802.15.4 combined forms the protocol suit, in which the upper layer or the application layer devices are ZigBee enabled devices and the lower layer such as PHY and MAC are defined by IEEE 802.15.4 standard. In this book the complete baseband processing of ZigBee transceiver over IEEE 802.15.4 is analyzed and verified. Later a new method of baseband processing is also described here.