On spatial multiplexing in cellular MIMO-CDMA systems with linear receivers

In this paper, the effectiveness of spatial multiplexing in the forward link of cellular CDMA systems with linear (i.e. low complexity) receivers is investigated. General MIMO systems without spreading are a special case of our analysis when the spreading gain is unity. Through the development of new closed-form results on outage probability and capacity for MIMO-CDMA, we show that cellular MIMO outage capacity is severely degraded by the enhancement of other-cell interference by the linear spatial receiver, and that a large number of transmit and receive antennas is required to simply break even with a SISO system. The results indicate that for practical cellular MIMO systems, which will be interference-limited and have low complexity receivers, future research is required on feasible methods for reducing the impact of other-cell interference. The framework presented in this paper can be used for future analysis of multicell MIMO systems.