Paper Title
UWB Modulation Scheme “Sc-CFDMA” For Multi-User Communications

Abstract
Abstract: A very high-speed wireless access of 100Mbps to 1Gbps is required for the 4th generation (4G) mobile communications systems. However, for such high-speed data transmissions the channel is severely requency-selective due to the presence of many interfering paths with different time delays. A promising wireless access technique that can overcome the channel frequency-selectivity and even take advantage of this selectivity to improve the transmission performance is code division multiple access (CDMA). There may be two approaches in CDMA technique: direct-sequence (DS)-CDMA and multi-carrier (MC)-CDMA. A lot of attention is paid to MC-CDMA. However, recently it has been found that DS-CDMA can achieve a good performance comparable to MC-CDMA if proper frequency-domain equalization is adopted. The modulation method adopted with frequency omain equalization to CDMA is called SCCFDMA. The motivation was to combine the advantages of multicarrier transmission with the ability of CDMA to accommodate a greater number of users