An adaptive 2.4 GHz low-IF receiver in 0.6 /spl mu/m CMOS for wideband wireless LAN

High bit-rate communications require wideband channels and complex modulation schemes, such as QAM, to convey multiple bits per symbol. Available bandwidth (BW) and desired user density per cell together determine the BW allocated per channel. In short-range applications like indoor wireless LAN where transmitted power is limited to 1 mW, FCC rules allow channel BW higher than 1 MHz. This system adapts to channel bandwidths ranging from 0.625 MHz to 10 MHz, and modulations spanning 4-QAM to 64-QAM. The carrier frequency is slowly hopped across the 2.4 GHz ISM band.