Senior Design and Graduate Projects Using Software Defined Radio (SDR)

Transcription

1 Senior Design and Graduate Projects Using Software Defined Radio (SDR) 1 PROF. SHARLENE KATZ PROF. JAMES FLYNN PROF. DAVID SCHWARTZ

2 Overview What is a Communications System? Traditional hardware radio versus Software Defined Radio What is SDR? Advantages and applications of SDR Projects Schedule for Summer/Fall 2

3 What is a Communications System? A communications system transfers an information bearing signal from a source to one or more destinations. Examples: Radio TV Telephone (landline or wireless) Computer Network (terminal-computer or computercomputer) Radar Wireless Microphone 3 July 16, 2008

4 Communications System Diagram 4 Information Source and Input Transducer Transmitter Channel Receiver Output Transducer July 16, 2008

5 Traditional Transceiver (Hardware) 5 Amplifiers Modulators Demodulators Mixers Filters Oscillators

6 Disadvantages of the Traditional Hardware Receiver Simple modulation / demodulation only Limited implementation of filters Alignment Aging Complexity Fixed design: frequency/mode Non linearity unwanted signals These are limitations of a hardware based system 6

7 What is Software Defined Radio (SDR)? 7 A new technology for implementing radio communications systems Art and science of building radios using primarily software Eliminating hardware and moving software as close to the antenna as possible Future direction of communications systems Encompasses many areas of EE: communications, signal processing, antennas, RF, digital design, software

8 Software Defined Radio 8 Analog to Digital Converter Software Radio is modified by changing the software. The hardware remains the same

9 Advantages of SDR 9 Makes communications systems reconfigurable (adapting to new standards) Flexibility (universal platform not special purpose) Hardware stays the same Upgradable, modifiable Filters/other hardware Cognitive/Smart Radio

10 Current Military Radio Astronomy Amateur Radio Future SDR Applications Personal Communications Cell phones Wi Fi Entertainment distribution Public Safety Broadcasting Digital Radio Digital Television 10

11 Components of a SDR System 11 Daughterboard (optional) Motherboard For development purposes ADC FPGA (Decimator, MUX, etc.) USB Controller PC Shifts the frequency of the desired signal Samples the analog signal Performs initial signal processing Software for Transmitter/ Receiver

12 USRP - Motherboard/Daughterboard 12

13 GNU Radio Software 13 Community-based project started in 1998 GNU Radio application consists of sources (inputs), sinks (outputs) and transform blocks Transform blocks: math, filtering, modulation/ demodulation, coding, etc. Sources: USRP, audio, file input, signal generator, Sinks: USRP, audio, file output, FFT, oscilloscope, Blocks written in C++ Python scripts used to connect blocks and form application

14 Previous SDR Projects Unmanned Air Vehicle (UAV) Telemetry Link 14 Two way communications link between a ground station and a UAV Transfers images, location, temperature, battery information Includes Automatic Target Recognition feature General Purpose Transceiver Multi-mode: AM/FM/ SSB/Digital, Voice/Data/CW Wide frequency spectrum: HF, VHF, UHF, + Signal processing Development of Hardware Platform for SDR FPGAs Amplifier and associated control and safety features

15 Future SDR Projects Continued work on the UAV link and HF transceiver Development of Hardware Platform for SDR Optical Link from Aircraft Cockpit to instrumentation on the wing Applications of Spread Spectrum in SDR systems Cognitive Radio Hardware for human/sdr interface Implementation of chirp radar system Front End for Transceiver 15

16 Demonstration Transceiver demonstration 16

17 Summer Schedule Introduction to Communications (for undergrads) Learning to use GNU Radio Preliminary project planning Accessing the lab with card Installing Ubuntu and GNU Radio Fall Semester Regular working meetings Sources of Information Project web page 17

18 Questions? 18