UCLA Extension

Design of JTRS /SCA Waveforms and Applications for Software Radios

The software radio allows software re-use, customization and upgradeability simultaneously using a general-purpose radio platform, thereby maximizing the use of open-architecture general-purpose PC software and hardware. The concept and expectations of the software radio are continually changing as new ideas and hardware/software technology promote a more desirable product. At the same time, the software radio is a highly complex engineering design, embedding RF, DSP, computer, software, and networking technologies into a single integrated component. Although the system architecture actually decouples the hardware, software, and networks from each other, the interaction requires a much broader knowledge base of distributed computing, RF design, and network design than the previous generation of software radios. A successful design should be less expensive to develop and produce while providing flexibility and extensibility to the consumer, with the “glue” for integrating the required technologies being the constantly evolving distributed computing techniques.

Complete Details

To promote the development and deployment of the software radio, the U.S. Department of Defense (DOD) has funded the Joint Tactical Radio System (JTRS) program for the past four years. A product of this program is the Software Communications Architecture (SCA) that defines a plug-and-play architecture for commercial and DOD radios. This course has two goals: first, to provide a working knowledge of the various disciplines applicable to the software radio; and second, to prepare participants for the development of SCA-compliant waveforms and applications. The course begins by presenting all aspects of a software radio, from antenna to the digital output port or speaker, including traditional radio RF architectures, and discusses the latest commercial RF architectures encompassing zero-IF, wide-IF, and low-IF designs. Design notes for A/Ds and channelizers are examined to allow participants to design or specify optimum front-ends for their software radio. A review of legacy software radios helps participants to better understand the evolution of the product and anticipate future architectural improvements. Because software technology has advanced so rapidly, participants may require a short review of enabling software technologies. An introduction to the Unified Modeling Language (UML) establishes the technical base necessary to read and graphically model the software elements of a radio. This introduction uses Rational Rose models from the Joint Tactical Radio System (JTRS), making examples relevant to radio system design, as well as introducing various aspects of the software radio architecture. Distributed computing is the enabling software technology of JTRS and SDR radios, and the two competing distributed computing technologies, Common Object Request Broker (CORBA) and Distributed Component Object Model (D-COM), are analyzed in the context of their application to the software radio. Specific software radio examples let participants learn simultaneously both CORBA/D-COM and software radio design. Simple code examples are reviewed and executed in class examples that illustrate the concepts of distributed processing for radio designers. For system designers and programmers, the course shows how to read and write the Interface Definition Language (IDL) that defines the interfaces between CORBA and D-COM objects, and because most software radio components are specified in IDL format, this skill is necessary to design and integrate software radio components from different suppliers. Specific radio application examples also are demonstrated.

To meet the second objective of the course, the SCA is presented in depth with discussions on all interfaces and meta-data files. The SCA’s Core Framework is discussed in detail, including working examples of Core Frameworks. Simple examples on developing SCA software components are presented, the first example addressing the SCA-compliant component that inherits only the Resource interface, and other examples describing the complete development of a waveform using ports and XML files.

It is recommended that participants also take the companion course, Design of Wireless Modems, to obtain an in-depth review of the DSP technology used in software radios.

Course Materials

Lecture notes are distributed on the first day of the course. The notes are for participants only and are not for sale.

Coordinator and Lecturer

Donald R. Stephens, PhD, President and Chief Scientist, CommLargo, Inc., St. Petersburg, Florida. Dr. Stephens has recently been involved with designing and developing three software radios: the Digital Modular Radio (DMR), the Joint Tactical Terminal (JTT), and the Airborne Integrated Terminal Group (AITG). He has acquired extensive experience in multiple communications and radar receiver systems including CPM, spread spectrum waveforms, wavelet video compression, and multi-spectral signal processing with companies such as Raytheon E-Systems, McDonnell Douglas, Emerson Electric, and Scientific Atlanta. He has participated in all technology facets of software radio design such as RF, DSP, distributed computing, security, and networking.

Dr. Stephens has taught electromagnetic theory and digital signal processing as an adjunct professor at Southern Illinois University, Edwardsville. He is the author of Phase-Locked Loops for Wireless Communications: Digital, Analog, and Optical Implementations, (Kluwer Academic Publishers, 2001), and has a new title forthcoming this year. Dr. Stephens is currently a member of the JteL—a DOD organization chartered to test waveforms and applications for SCA compliance—and he has participated in a joint government/industry MILSATCOM working group.

Daily Schedule

Day 1

General introduction and brief description of class topics. Introduction to current expectations and configurations of software radios. Discussion of legacy software radios and their architectures and implementations. Review of the Unified Modeling Language (UML) used throughout the course to describe the requirements, functionality, and implementation of a radio. Discussion of software programmable radio architectures and the various forums defining software radio specifications.

Discussion of radio fundamentals (antenna to analog-to-digital converter). Introduction to hardware architectures–both receiver and processor platforms. Comments on physical implementations such as VME, Compact PCI, etc., and discussion of high-speed data paths. Introduction to distributed computing and its application in the software radio. Introduction to wireless networks and implementations within the software radio architecture. Discussion of virtual radios (radios implemented on standard PCs and workstations). Review of industry Application Program Interfaces (APIs) for software radios.

Day 2

Introduction to CORBA as applied to software radio domain. Review of TCP-IP and performance considerations within the radio and within a wireless network. Discussion of communications and transmission security within the radio. Review of GSM and North American Cellular/PCS systems. Discussion of current cellular security architectures and Public Key Infrastructure (PKI).

Introduction to D-COM for software radios. Discussion of the differences between CORBA and D-COM in the software radio. Review of software design patterns typically deployed in software radios. Review of Simple Network Management Protocol (SNMP) (often used to manage/control software radios).

Introduction to the Joint Tactical Radio System (JTRS). Discussion of the Software Communications Architecture (SCA) developed by the DOD.

Day 3

Presentation on the Core Framework for the SCA. Working examples of Core Frameworks shown and discussed.

Development of SCA-compliant components and waveforms, beginning with simple resource-only interfaces and ending with the development of an SCA-compliant waveform.

For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu | (310) 825-3344 | fax (310) 206-2815