Transcription
Introduction toSoftware Defined RadiosSteven Bible, N7HPRTucson Amateur Packet Radio, Inc.
Agenda!!!!!!Why Software Defined Radios?What is a Software Defined Radio?Block DiagramsTechnical ChallengesAmateur ContributionsHow to Build A SDR– The DSP-10 As a SDR!!Supporting DocumentationConclusion
Why Software Defined Radios?!Comments of ARRL:“ARRL is most interested in this proceeding, not onlybecause of the utility of the Amateur Radio Service as atesting ground for different configurations of SDRs, butalso because of the potential long-term opportunities forSDRs to effect substantial changes, even conceptualchanges, in traditional frequency assignment and spectrumallocations decision making in all services.”ARRL comments to the Notice of Inquiry Regarding Software Defined Radiosdated June 14, 2000 (ET Docket No. 00-47 released March 21, 2000).http://www.fcc.gov/searchtools.html
Why Software Defined Radios?!Dale Hatfield, WØIFO,Chief, Office of Engineering and Technology,Federal Communications Commission“This could stimulate a whole new generation ofamateur innovation that not only includes themore spectrally efficient systems I mentionedearlier, but also radios that could adapt to theirenvironment as well.”Speech to AMRAD’s 25th Anniversary Dinner June 17, l
What Is a Software Defined Radio?Software Defined Radio (SDR)Performs the majority of signal processing in thedigital domain using programmable DSPs andhardware support, but some signal processing is stilldone in the analog domain, such as in the RF and IFcircuits.
What Is a Software Defined Radio?Software Radio (SW)The ultimate device, where the antenna is connecteddirectly to an A-D/D-A converter and all signalprocessing is done digitally using fullyprogrammable high speed DSPs. All functions,modes, applications, etc. can be reconfigured bysoftware.
Benefits of SDR! Flexible! ReducedObsolescence! Enhances Experimentation! Brings Analog and Digital World Together
New Breed of ableSimultaneous voice, data, and videoFull convergence of digital networks and radioscience.
Block DiagramSoftware Defined cy OscillatorOscillator (fixed)BasebandADC/DACDSP
Block DiagramSoftware Defined DACDSP
Block DiagramSoftware RadioAntennaRFADC/DACIFBasebandDSP
Smart RadiosThe positive control over the transmitter’s use of thespectrum has traditionally been the purview of theradio operators, who were guided and trained tofollow the rules of engagement carefully craftedduring the course of decades to prevent harmfulinterference to other users.The control of radio functions by softwarealgorithms embedded into the future “smart”communications device will directly affect themanner in which that device uses the spectrum.
Smart Radio!When combined with the software radio’s abilityto monitor the RF environment and preciselysense its location, the software radio opens thepossibility of sharing spectrum among vastlydifferent users.
What Is a Software Defined Radio?Cognitive RadioAs radios embed increasingly complex and realisticmodels of their environments, users, and networks,they begin to approach what an outside observermight call rational, or common-sense behavior.
Technical Challenges! DynamicRadio! ADC/DAC Speed! Smart Radio Algorithms
Amateur Contributions
How to Build a SDR!DSP-10 by Bob Larkin, W7PUAQST - Sep, Oct, Nov 1999http://www.proaxis.com/ roj.html!R2-DSP by Rob Frohne, KL7NAQST - Apr 1998http://www.wwc.edu/ frohro/R2 DSP/R2-DSP.html!A Panoramic Transceiving System for PSK31by Skip Teller, KH6TY and Dave Benson, NN1GQST - Jun 2000http://www.arrl.org/tis/info/psk31.html
The DSP-10 As a SDR
DSP-10Constructed byErnie Manly, W7LHL
143 - 149 MHzReceiveRF AmpSynthesizer124.3 to 128.4 MHz5 kHz StepsSynthesizer19.680 MHz10 MHzExt. Ref.(Optional)U1,U2RANT orXVRTRTR SW(D2)J211J212T2-PoleLC Filter32 dB150 MHzTransmitRF Amp143 - 149 MHzRTR SW(D1)T4-PoleLC FilterJ213FirstMixerU4,U5Low-PassFilterRReceiver Second IF10-20 kHzTR SW(U11A,U11C)(U15)TU109B,Q5,Q610-20 kHzAudioPower AmpAudioFilterso90TRSW(U11B)DACRADCo90SSB and CWDetector /-AGCRLMSDenoiseSinewave BFO12.5 -17.5 kHzJ102FFT SpectrumAnalyzerPTTCW KeyLow-Pass FilterIF Driver50 dBMicrophoneSecondMixer40 dBQ1,U10AT4-PoleCrystal Filter(U3)IF AmpTR SW(U12A,U12B)28 kHz19.665 MHzJ103Arc TangentFM DetectorSWFMSquelchAnalog Devices EZ-Kit Lite1024 PointsJ201Serial Datato PCU14J204Speaker
Supporting Documentation!Signals, Samples and Stuff: A DSP Tutorialby Doug Smith, KE6DXQEX - Mar, May, Jul, Sep 1998http://www.arrl.org/tis/info/dsp.html!Basics of Digital Receiver Designby Brad Brannon, N4RGIQEX – Sep/Oct 1999!A DSP-Based Audio Signal Processorby Johan Forrer, KC7WWQEX – Sep 1996http://www.peak.org/ forrerj/ASP/article.html
Conclusion
What Is a Software Defined Radio? Software Radio (SW) The ultimate device, where the antenna is connected directly to an A-D/D-A converter and all signal processing is done digitally using fully programmable hi
