Patent ID: 7260360

Claim:
A multi-band ZigBee transceiver for supporting IEEE 802.15.4 wireless communications, comprising: a Multi-Mode Modem (MMM) for selecting any one of a European version standard using 860 MHz band, a US version standard using 920 MHz band, and a worldwide version standard using 2.4 GHz Industrial, Scientific and Medical (ISM) band among IEEE 802.15.4 standards in response to a received signal, and performing digital modulation/demodulation in a BaseBand (BB) according to the selected transmission standard and a transmission channel; a frequency synthesizing unit for variably adjusting a carrier frequency according to the transmission standard selected by the MMM, and outputting the carrier frequency; a transmission unit for receiving a digital modulated signal output from the MMM, low-pass-filtering the digital modulated signal with a bandwidth thereof being variably adjusted according to the selected transmission standard, and up-converting the filtered digital modulated signal into a Radio Frequency (RF) modulated signal corresponding to the selected transmission channel using the carrier frequency; a receiving unit for down-converting the RF modulated signal into a BB modulated signal using the carrier frequency, low-pass-filtering the BB modulated signal with a bandwidth thereof being variably adjusted according to the selected transmission standard, converting the filtered BB modulated signal into a digital modulated signal, and outputting the digital modulated signal to the MMM; and a transmission/reception switch unit for outputting the RF modulated signal from the transmission unit to an antenna, or outputting the RF modulated signal received from the antenna to the receiving unit; wherein the MMM comprises an intelligent channel selection block comprising a channel power measuring unit, a channel list storage unit, a channel selection data generation unit coupled to the channel power measurement unit and the channel list storage unit and a channel selection unit coupled to the channel selection data generation unit, wherein the channel power measuring unit measures received power in each of a plurality of channels and stores the same, the channel list storage unit generates a channel list by arranging all channels unoccupied on at least one network to which the transceiver belongs, and stores the channel list, the channel selection data generation unit generates channel selection data on the basis of channel power data measured by the channel power measurement unit and the frequency offsets of channels in the channel list generated by the channel list storage unit, and the channel selection unit selects a channel from the channels in the channel list based on the channel selection data.