MIMO Communications Testbed
Whilst demonstrating the basic functionality of the testbed here, it only represents the first stages of development and usage. The testbed will be used for a hardware implementation of orthogonal frequency division multiplexing (OFDM) MIMO and this requires more stringent firmware development.
CFO estimation must be implemented in real-time, as OFDM is sensitive to transmitter and receiver mismatch in oscillator frequency. Voltage controlled oscillators (VCOs) are provided with simple control to deliberately misalign the CFO for testing purposes. Typical hand-held device oscillator characteristics can be evaluated as well with stability in the order of +/-20ppm.
Algorithms currently used in off-line processing will be implemented in the FPGA. This will allow implementation aspects of MIMO algorithms to be evaluated in terms of complexity and performance. The expansion bus will be utilised to expand the processing capabilities of the testbed. Initially this will be a TI development kit, with later work to include additional FPGA support such as Altera Stratix III or ASIC devices. Finally to support research across different frequency bands, additional radio modules may be developed.