(Georgia Institute of Technology, 2006-08-31)
Durkin, Christopher J.; Pirkl, Ryan J.; Trzecieski, Alexander J.; Durgin, Gregory D.
This report documents the continuing research efforts of the Propagation Group at Georgia Tech
towards the construction of a broadband spatio-temporal channel sounder for the Aerospace Corp.
The channel sounder, a valuable research tool in radio frequency (RF) channel and direction finding
(DF) measurement, was constructed from the 8-element antenna array receiver setup on loan from
Aerospace Corporation to support this collaborative project. Upon completion of the 2006 portion of this on-going collaboration, the following contributions
were made to the system: The broadband pseudo-random noise generator was modified for improved operation and wider
bandwidth.
The vector RF signal generator was improved to be cleaner, more stable, and include onboard
programming firmware, obviating the need for an external computer and allowing better transmitter
portability.
An autonomous self-powered transmitter platform was constructed. Extensive improvements were made to the RF receiver signal chain in order to compensate for
near out-of-band interference and amplifier noise.
Software improvements included an SQL database interface for captured data and associated
metadata in order to facilitate storage and retrieval. In addition to these improvements, field measurements were taken to demonstrate channel sounding
operation and direction finding in environments with copious noise and interference. Collectively,
these outputs fulfill the research deliverables for the year 2006 collaborative project between
Aerospace Corporation and Georgia Tech. Future work for this ongoing collaboration will likely involve more measurements and further
miniaturization of the array channel sounder. The ultimate goal of the research should be a single
compact receiver box containing all RF components and analog-to-digital conversion hardware. This box could then be plugged into a network or laptop computer and an arbitrary array manifold
for portable direction-finding and channel measurement. When coupled with the array processing
software developed during the 2004 and 2005 phase of this collaborative project, the end result
will be a dynamic, portable unit capable of both spatio-temporal channel sounding and/or accurate
DF location of 2.4 GHz radios in a complicated radioscape. Temporal and spatial analysis of the
measurements should be able to yield detailed data to assist in detailed channel characterization.