The Space Communications and Navigation (SCaN) Testbed has a need to capture and analyze high-datarate (<2 Mbps required) baseband information sent over RF by the JPL Software-Defined Radio (SDR). An RF4425 front end, coupled with a MicroGate Synclink USB and custom C++ software back end, is being used to answer this need.

The RF4425 converts an S-band RF signal to an RS-422 differential baseband signal. The SyncLink samples the raw data stream and pipes it over USB2 into Linux. From here, C/C++ functions can be written to analyze the data such as frame synchronization, bit-error rate checking, file export, etc.

The SyncLink USB is a user-friendly, open-source, inexpensive data acquisition (DAQ) device that can stream either RS-232 or RS-422 raw data. This device can monitor a data stream according to the software written by the user, and thus be useful over a wide variety of applications.

This technology is currently supporting the development of delay-tolerant networking (DTN), as well as other cognitive radio capabilities, to be tested on the SCaN Testbed aboard the International Space Station (ISS). It has been demonstrated on both simulated and actual hardware in receive-only mode. Current efforts are focusing on the transmit link as well as establishing a remote node to the Near Earth Network (NEN), which will communicate with the SCaN Testbed through the TDRSS satellite constellation.

This work was done by Matthew D. Chase, Susan C. Clancy, James P. Lux, and Mazen M. Shihabi of Caltech for NASA’s Jet Propulsion Laboratory. This software is available for license through the Jet Propulsion Laboratory, and you may request a license at: https://download.jpl.nasa.gov/ops/request/request_introduction.cfm . NPO-49911

NASA Tech Briefs Magazine

This article first appeared in the May, 2016 issue of NASA Tech Briefs Magazine.

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