BIDIRECTIONAL TURBO ISI CANCELLER-BASED DSSS RECEIVER FOR HIGH-SPEED WIRELESS LAN

摘要

A bidirectional turbo ISI canceller cancels precursor-ISI (94) as well as postcursor-ISI (90) in a received signal without incorporating a multiplicative feedforward equalization filter. This is accomplished by taki ng a three-step receiver design approach. In the first step, an optimal single- symbol RAKE receiver is 1 designed to comprise a CMF (9), a codeword correlator bank, and an energy bias EB (15) canceller under the assumption that no ISI is generated by preceding or trailing symbols. In a second step, a DFE (16) is included for suppressing postcursor-ISI (90) caused by a precedi ng symbol. Finally, a precursor-ISI (94) canceler is used to remove the remaini ng ISI caused by a trailing symbol. All three components may 10 be integrated into a BTIC-based receiver applying turbo-iteration processing.