Teaching Real-time Beamforming With The C6211 DSK and MATLAB

This paper describes our efforts to teach hardware-based beamforming at the undergraduate level. A DSP based beamformer is at the heart of numerous military systems, including active and passive sonars, RF direction finding equipment, and phased-array radars. While the military has needed engineers capable of designing and enhancing these and other systems, civilian applications of these same technologies have recently made beamforming an important topic for many engineers. High interest topics include E911 mobile position location, space division multiple access (SDMA), cellular/PCS base station antenna design, and low Earth orbit (LEO) satellite communications within a densely packed constellation. Beamforming is routinely discussed in a course on multidimensional signal processing but an actual hardware system to design or enhance is often not available. The use of powerful software, such as MATLAB, to simulate the geometries and techniques necessary to learn about beamforming has become standard. However, proceeding beyond MATLAB simulation to a realtime hardware implementation has been impeded by a very expensive and abrupt transition, in terms of both cost and the learning curve of unfamiliar systems and software. By developing a software bridge between MATLAB and the C6211 DSK, we make it possible to smoothly and incrementally transition from simulation to full hardware implementation, all while retaining the impressive capabilities of the MATLAB display engine. Using this approach, students can develop and enhance their own sonar system. Initially, a student works with MATLAB generated data files to develop an understanding of various beamforming techniques. Then, they proceed to non-real-time processing of actual data acquired directly into MATLAB from the DSK, then incrementally move the processing into C code running on the DSK, and finally, using MATLAB only for display of the real-time results. The software development cycle of algorithm and display development in MATLAB, followed by real-time implementation with a C6X DSK, can be iterated as many times as the semester will allow. The paper describes in detail the software and inexpensive multichannel ADC daughtercard that facilitate this pedagogical process. The software is freely distributed by the authors for educational use.