Separate Linear Receiver Interfaces for MIMO Multiple-Access Channels

We address the design of a receiver for the uplink of a direct sequence code division multiple access wireless communication system, endowed with multiple transmit and receive antennas and affected by multiple-access interference (MAI) for the presence of multiple transmitting users. The receiver is assumed to keep separate the tasks of mitigating the spatial and MAI in order to be implementable in two options: a baseline option accommodating the MAI mitigation interface only and an enhanced option accommodating the spatial interference mitigation interface as well. The MAI mitigating interface is based on standard linear multiuser detectors. The spatial interference mitigating interface is derived according to a linear minimum mean-square error criterion, which assumes the MAI mitigating interface to be given.