Sum capacity of CDMA systems with multiple transmit antennas

The use of multiple antennas at the transmitter (and receiver) is considered for a synchronous CDMA system. The spreading sequences are assumed to be random and independent across users, but could be dependent across the transmit antennas of each user. The effect of various system parameters, especially sequence correlation across transmit antennas, on the spectral efficiency of the optimum receiver is studied.