Commercial Communications Products Development

Tools and Systems to Analyze Communication System Components, Channels, and Spectra
Computer modeling programs enable us to predict the performance of communication links, networks, and antennas. We have also designed, built, and fielded numerous radio systems, several of which incorporate advanced waveform technology such as direct-sequence, spread-spectrum, and code-division channel access.

SimCard
SimCard, a general-purpose communication signal generator, was developed in response to the cellular telephone industry's need to emulate CDMA (IS-95) systems. The SimCard can simultaneously generate the four base station signals identified in the IS-95 standard, as well as four reverse link signals, thus emulating multiple mobile transmitters. It can be configured to generate many modulations including binary FSK, M-ary FSK, M-ary PSK, and QAM, and can emulate virtually any data protocol including signal spreading, framing, and scrambling. The SimCard has been embedded in a variety of systems to emulate INMARSAT, Intelsat, and various TDMA signals.

Atrium
Atrium is a custom, general-purpose card that represents the next-generation SimCard's capabilities. Built on a C-PCI card, the Atrium board incorporates FPGA technology, which enables it to be configured as a single transmitter or receiver for many modulations and data protocols including signal spreading, framing, and scrambling. Its plug-in, modular analog front end enables the user to tailor it easily for specific frequency bands. The Atrium board is currently being incorporated into a GPS simulator, a CDMA base station, and a mobile phone system prototype. (more information)

Cable Modem
For a commercial client, SRI developed transmitter and receiver cards that implemented protocol specifications for the physical and link layers and part of the network layer. The transmitter card supports bidirectional communication for reservation and contention access; uses channel control filtering and QPSK demodulation; and sends TDM data at 1.544 or 3.088 Mbps and 70—400 MHz (or, optionally, 70—800 MHz). The receiver card implements TDMA access at 1.544 Mbps and 256 kbps; 5—65 MHz receiver channels can be assigned. It supports all physical-layer specifications including burst detection, filtering, QPSK demodulation, descrambling, and R/S decoding; and implements timing measurements and burst power measurements.