Multiple antenna wireless systems: capacity and user performance limits

Multiple antenna wireless systems are those that have multiple transmit and/or multiple receive antennas, and are often referred to as multiple input multiple output (MIMO) wireless systems. Significant gains in the data rate for point-to-point systems was shown in [1, 2] by employing multiple antennas at both the transmitter and the receiver. This rate gain results from the creation of multiple parallel, possibly decorrelated, spatial channels between the transmit and receive antennas. The MIMO point-to-multipoint system naturally occurs as the downlink of a cellular system where there is a multiple antenna central transmitter and multiple users each with multiple receive antennas. An understanding of the MIMO point-to-multipoint system involves fundamental advances in multiuser information theory and raises many new issues. Understanding these issues, which range from characterizing the theoretical rate gain associated with point-to-multipoint MIMO systems to devising joint transmit strategies and scheduling policies that may exploit this theoretical rate gain, is the primary focus of this research.