Download Direct Sequence Spread Spectrum (DSSS) Receiver

DSSS Receiver User's Manual (U)
Executive Summary
The Direct-sequence spread-spectrum (DSSS) Receiver program is a multi-faceted
contribution to Defence wireless communications capability – it provides an alternative
modulation scheme for special-purpose link scenarios as well as an advanced,
reconfigurable, wideband signal processing engine that lends itself to multiple
applications, with inherent functional and logistic advantages.
Physically, a single receiver unit consists of the signal processing platform (designated the
Digital Processor Card, or DPC) hosted in a computer chassis on the industry-standard
PCI bus. The DPC digitises its input signal and provides reconfigurable logic circuits in
which a wide variety of digital signal processing algorithms can be implemented.
Functionally, the unit also requires both the signal processing code for the reconfigurable
logic (known as firmware) and the application software which lets the host computer
communicate with, control and monitor the DPC. Both the firmware and software for the
DSSS application are parameterised and run-time configurable.
To exploit this capability then, an operator needs to connect, configure and dynamically
control the DSSS Receiver in such a way as to achieve the expected performance. It is the
purpose of this manual to adequately define the interfaces and operation of the Receiver to
allow this.
Accordingly, this manual includes: definitions of hardware and firmware interfaces; the
typical sequence of control and monitoring events following system power-up that lead to
valid demodulation in the presence of a continuously transmitted signal; a file-level
review of the DSTO DSSS graphical user interface (GUI) and driver software, which
includes an example of fully automated set-up and operation; and receiver operating
characteristics, in the form of bit error rate (BER) versus signal-quality curves, that indicate
the expected performance levels in benign (white noise) channels.
Dissemination of this document will facilitate uptake of the DSSS Receiver capability by
Defence personnel and Defence contractors.