A wireless local area network receiver having separate automatic gain
control (AGC) loops for providing a radio frequency AGC and a baseband
frequency AGC, as well as a DC offset cancellation circuit. The AGC loops
control a low noise amplifier amplifying the received RF signal, and the
baseband signal or signals from a mixer of I and Q mixers. The DC offset
compensation loop is also responsive to the baseband AGC signal to
maintain a substantially fixed gain in the DC offset compensation
feedback. Details of various embodiments are disclosed, including
embodiments for orthogonal frequency division multiplexing (OFDM) that
provide the AGC operation and the DC offset cancellation to the desired
levels within the relatively short period of a preamble that precedes the
data transmission.