| Multi-antenna transmission and reception (known as MIMO) is widely touted as the key technology for enabling wireless broadband services. Spectrally efficient, inexpensive cellular systems are by definition densely populated and interference-limited. But spatial multiplexing MIMO systems---whose principal merit is a supposed dramatic increase in spectral efficiency---lose much of their effectiveness in high levels of interference.;This dissertation first investigates the limitations of MIMO communications in interference-limited cellular environments by analyzing the outage capacity of cellular MIMO-CDMA systems. It is shown that even with spreading, that a low-complexity receiver loses the spatial multiplexing gain in a cellular context. These limitations of MIMO motivate interference mitigation techniques for multicell MIMO systems, which will generally operate at low signal to interference ratio. This dissertation overviews conventional approaches for handling interference in multicell MIMO systems. We argue that many of the traditional interference management techniques have limited usefulness (or are even counterproductive) when viewed in concert with MIMO.;The primary contribution of this dissertation is the development of three novel low complexity techniques to overcome the limitations of MIMO in an interference-limited environment: dynamic antenna partitioning, inter-cell scheduling, and distributed antenna architecture. We will quantify the system capacity and performance of these three techniques and show that from a practical standpoint, they are effective and potentially complementary solutions to the co-channel interference problem in interference-limited MIMO communications. |
