High performance frequency division MC-CDMA system via carrier interferometry codes

ABSTRACT

This paper proposes a novel multi-carrier CDMA scheme, namely FD-CI/MC-CDMA (frequency division carrier interferometry multi-carrier code division multiple access), to combine the benefits of previously developed FD-MC-CDMA with CI/MC-CDMA together to provide higher BER performance in multipath fading channels. FD-MC-CDMA is capable of exploiting the available frequency diversity benefits in multipath fading channels while reducing MAI. Specifically, instead of transmitting all users' information bits over all carriers, FD-MC-CDMA employs a subset of non-contiguous carriers to support a subset of users (while maintaining the same overall system capacity and throughput as in MC-CDMA). However, since the length of Hadamard-Walsh codes only exists for certain integers, FD-MC-CDMA lacks the flexibility to accurately divide all subcarriers into subsets according to the channel condition. On the other hand, CI/MC-CDMA offers good BER performance while providing any length of orthogonal spreading codes. By combining these two systems together, the proposed FD-CI/MC-CDMA system significantly outperforms FD-MC-CDMA (as well as MC-CDMA) in multipath fading channel at similar complexity.

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INDEX TERMS

Primary Classification:
  H. Information Systems
  H.4 INFORMATION SYSTEMS APPLICATIONS

Keywords:
FD-MC-CDMA, MUD, carrier interferometry, communication