DMWTCS BASED STBC-MC-DS-CDMA in Fast-Fading Multipath Channel

Wireless digital communications is rapidly expanding resulting in a demand for systems that are reliable and have a high spectral efficiency, to fulfill these demands, the Multicarrier modulation scheme, often called Orthogonal Frequency Division Multiplexing (OFDM), has drawn a lot of attention. On the other hand (CDMA) techniques have been considered to be a candidate to support multimedia services in mobile radio communications. In this work, STBC-OFDM block have been studied extensively, and proposed a new structure for STBC-OFDM that based on Multifilters called Multiwavelets using Critically-Sampled (DMWTCS), it has two or more lowpass and highpass filters, the purpose of this multiplicity is to achieve more BER performance than the conventional STBC-OFDM using FFT and DWT. The proposed STBC-OFDM systems have been examined in different channel models AWGN, flat fading and selective fading. After a study made to the STBC-OFDM systems and evaluated their BER performances with channels models. Several structures of STBC-MC-DS-CDMA systems will be studied, these structures based on FFT, DWT and DMWTCS. The simulation results are presented for a simulated AWGN, Flat fading and Selective fading channels. Index Terms —OFDM, DWT, DMWTCS, STBC, MC-DS-