Unified digital front end for IEEE 802.11g WLAN system

摘要

A unified digital front end filtering circuit is described for IEEE 802.11g protocol compliant systems. The front end uses polyphase rate conversion filters cascaded with channel extraction and pulse shaping filters to accommodate the different sampling rate requirements for orthogonal frequency division multiplexing (OFDM) and direct sequence spread spectrum (DSSS) modulation, which have to be supported simultaneously, without using separate analog front ends.