A DSSS receiver for dual-mode DSSS/OFDM wireless LAN systems

Abstract

This paper introduces a DSSS baseband receiver suitable for a dual mode DSSS/OFDM wireless LAN system. Packet synchronizer with a pair of ADCs with dynamic sampling is used for detecting both DSSS and OFDM packets. For differentially encoded symbols, frequency offset and phase offset can be compensated based on their inherent characteristics. For high data rate DSSS based modulations, channel estimation and equalization with receive diversity combining in frequency domain is applied to resolve the multipath distortions. With channel equalization and diversity combining of the DSSS receiver achieved in frequency domain the overall complexity of the dual mode DSSS/OFDM equalization can be realized.