Duality

Wednesday was my last research meeting. Made a few final edits to the documentation before turning in my work. And so ended my direct involvement with the MCMA project at BWRC. I doubt that will be the last time I go there though. Artem—the guy who will be taking over my position—will probably need at least a little help understanding my work. There wasn’t really anyone to help me when I took over Artem’s work (well, I took over for Ted, who really didn’t do much; long story), so it took me forever to get going. Yeah, I took over Artem’s work and he’ll be taking over mine.

The goal of the MCMA project is to create a multi-carrier, multi-antenna system. As far as I know, the theory behind using multiple carrier frequencies and multiple antennas for communication networks is well-established, but so far, no one has created a system that makes use of it. The MCMA hardware consists of multiple, single-antenna boards. Each board has an FPGA, an ADC/DAC chip (analog-to-digital, digital-to-analog), various input connectors, and an RF daughter-card with an antenna and PLL. (Thank you, Wikipedia, though don’t think I don’t know what each of those do =)). My job was to program the FPGA to handle all of those components and do basic testing.

Artem left me a bunch of different files. Each file was tailored for a single test: one file to test the ADC, one file to test the DAC, etc. So each time I wanted to test something else, I had to load a different bit file onto the board. Not very elegant. He also chose to program the ADC/DAC by repeatedly sending commands. Not very elegant either.

I integrated the functionality of all the different files into a single file and created a user interface (using buttons and jumpers) to change settings on-the-fly. I also changed the way the ADC/DAC was programmed to a state-machine-based system (hello, CS majors =)). Instead of repeatedly sending commands, it would only send commands in reponse to user input.

Screenshots from Simulink

• System overview (same as above)
• Signal subsystem and jumper interface
• My pride and joy: ADC/DAC control subsystem
• Individual state machines within the ADC/DAC control