Capacity Characterization of a MIMO-OFDM Wireless Channel with BLAST Implementation

Abstract

As the data rates and performance of current telecommunications technologies reach their limits, MIMO offers promising results allowing for higher spectral efficiencies (or capacities) through the use of multiple element antennas (MEAs). Conventional testing methods, however, cannot be used for multi-antenna systems due to the co-dependence of antenna and RF effects, and baseband hardware and software design. This dissertation specifies a novel MIMO-OFDM, BLAST-based testing design using a hybrid FPGA/DSP development platform from Lyrtech. The design allows for rapid implementation and a consistent indication of the channel impulse response. In addition, a multipath environment is further created to mimic a realistic high scattering scenario. A study of MIMO system capacity is performed along with measurements of an actual over-the-air (OTA) channel. Observations about capacity and the effect of MEA antenna separations are then drawn and conclusions made as to the overall ability to effectively test MIMO systems. The platform used is the result of efforts from several individuals within UW's CST group. My contributions and research are documented in this dissertation.