Ber Performance of HARQ MIMO-CDMA Systems in Multi User Environment
A new method for designing the spreading permutations based on space time block code matrices for MIMO-CDMA systems has been proposed. In Code Division Multiple Access (CDMA) systems, the calculated parity bits are used to select a spreading sequence from a set of mutually orthogonal spreading sequences. This paper focuses on wireless systems using Hybrid Automatic Repeat Request (HARQ) with emphasis on the Multiple-Input Multiple-Output paradigm. MIMO-HARQ offers new opportunities because of the additional degrees of freedom introduced by the multiple antennas at the transmitter and receiver.