A novel MC DS-CDMA system scheme with high spectral efficiency

This paper presents a novel multicarrier DS-CDMA scheme based on the loosely synchronous (LS) codes (D. Li, 1999) which can achieve very high spectral efficiency. Instead single subcarrier modulation in conventional multicarrier DS-CDMA scheme, this novel scheme introduces the non-orthogonal subcarrier-group modulation, whose interferences caused by the non-orthogonal spacing in a subcarrier-group can be reduced by a multi-code detector. We provide the detailed analysis for this system architecture and also give a MIMO multicarrier DS-CDMA solution to satisfy the requirement of beyond 3G mobile communications system. Simulated results demonstrate this scheme can obtain excellent bit error rate (BER) performance, as well as achieve high spectral efficiency