An improved decision feedback equalization technique is provided that may
be used in data communications receivers such as those in WLAN (Wireless
Local Area Network) systems. The decision feedback equalizer comprises a
feedforward filter that is connected to receive an input data signal and
output a filter representation thereof. The feedforward filter has a
filter characteristic that depends on filter coefficient data. The
decision feedback equalizer further comprises a filter coefficient
computation unit for generating the filter coefficient data and
outputting the generated data to the feedforward filter. At least one
data processing circuit is provided that receives a mode switch signal
for switching its operational mode. The data processing circuit is
arranged for performing a feedforward filter function in one operational
mode and a filter coefficient computation function in another operational
mode.