ICI equalizer in a CCK based DSSS communication system

In a typical indoor wireless environment, multipath channels are often encountered which introduce inter symbol interference (ISI). Multipath delay spread also cause interchip interference (ICI) in a direct sequence spread spectrum (DSSS) system. ISI arises from the past symbols whereas ICI is caused by the past chips within the same symbol. In this paper, we present two ICI equalization schemes, namely, deconvolution and gain scaling and compare their performance in the presence of Rayleigh faded multipath channels having different delay spread. These ICI equalizers are used in IEEE 802.11b based WLAN receivers to study the performance improvement. We present simulation results with delay spread channels yielding significant improvement in packet error rate performance.