Blind space-time equalization/decoding with carrier frequency synchronization in multicarrier CDMA systems

Diversity technology is an effective technique to combat channel fading. Multicarrier Modulation Code Division Multiple Access (MCM-CDMA) technique or Orthogonal Frequency Division Multiplexing Code Division Multiple Access (OFDM-CDMA) scheme can sufficiently utilize the subcarrier diversity; therefore it is broadly considered as an effective approach for future wireless multimedia communications. But it is very sensitive to a carrier frequency offset, while the orthogonal property between the subcarrier is lost with carrier drifts. In this paper a Space-Time Constant Modulus Algorithm (ST-CMA) is implemented for equalization and decoding of MC-CDMA signals in the frequency domain with the carrier frequency synchronization at the same time. The proposed method has faster convergence rate, less computational complexity, and without requiring the periodic transmission of training blocks. Numerical simulations can illustrate the effectiveness of this algorithm.