應用在IEEE 802.11g上頻域等化與資料解碼的結合

Abstract

A procedure against heavy multipath is developed in this thesis, which combines equalization with CCK codewords demapping and is based on conditioned maximum likelihood (ML) criterion in frequency domain by means of only one DFT. These techniques is applied to dual mode system IEEE 802.11g so that ERP-DSSS/CCK mode can share DFT and point by point multiplier of ERP-OFDM mode and reach the purpose of hardware saving, instead of huge DFE in most solutions of IEEE 802.11g ERP-DSSS/CCK mode. However, 802.11g systems are now being used in home, office and warehouse environments where the multipath delay can be much greater on the order of about 150ns. Such environments require the use of equalization for acceptable performance. According to simulation results under IEEE 802.11g and JTC indoor multipath models, the concepts of joint equalization and CCK demapping not only provide acceptable accomplishment but also improve the performance of the system substantially over separate equalization and demapping.