Multiuser Detection in Large-Dimension Multicode MIMO-CDMA Systems With Higher-Order Modulation
In this paper, the authors are interested in high spectral efficiency multi-code CDMA systems with large number of users employing single/multiple transmit antennas and higher-order modulation. In particular, they consider a local neighborhood search based multiuser detection algorithm which offers very good performance and complexity, suited for systems with large number of users employing M-QAM/M-PSK. They apply the algorithm on the chip matched filter output vector. They demonstrate near-Single User (SU) performance of the algorithm in CDMA systems with large number of users using 4- QAM/16-QAM/64-QAM/8-PSK on AWGN, frequency-flat, and frequency-selective fading channels.