NASHUA AREA RADIO CLUB TECH NIGHT –SOFTWARE DEFINED RADIOS MARCH 8 TH , 2016
NASHUA AREA RADIO CLUB
TECH NIGHT – SOFTWARE
DEFINED RADIOSMARCH 8TH,2016
• WhatisanSDR?Whyuseone?• Howdotheywork?• SDRDemo– FlexRadio6000Series• InterfacingToOtherEquipmentandSoftware
• Amps,BandDecoders,etc.• Loggers,CWandDigitalModeswithSDRs
• SDRDongleDemo– Aninexpensivewaytogetstarted
• SDRAdd-onforConventionalRadios
SoftwareDefinedRadios(SDRs)
Topicsfordiscussion
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SoftwareDefinedRadios
Examples
ManyHardwareOptions ManySoftwareOptions3
TheComputerRevolution
• Off-lineapplications– Calculators– Logbooks
• “User-definedRadio”– e.g.,HTmemoryandmodeuploads
• “User-controlledRadio”– Readstatusfromrig– Read/write (statusandcontrol)– e.g.,HamRadioDeluxe,CT,N1MM,RoverLog, …
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MoreComputerRevolution
• DigitalSignalProcessing– Filters– PSK,RTTYdemodulators– Skimmers
• “Software-DefinedRadio”– Allnonfrequency-determining processes
doneaslogicorequations
“There is a distinct difference between a radio that internally uses software for some of its functions and a radio that can be completely redefined in the field through modification of software. The latter is a software-defined radio.”
AC5OG (now K5SDR), QEX Jul/Aug 2002
MOST
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SoftwareDefinedRadioWhat’sItBuyMe?
• Moreidealfunction– Betterperformance
• Expandedfunctionalcapability– Was:selectable.Now:continuouslyvariable– Was:sweptdisplay.Now:continuousdisplay
• ImprovedSituationAwareness– Understandwhatisonabandandwhereitis
• Updatesequalnewcapability– Newmodes– Newfiltertypese.g.,TrackingNotchFilters
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SituationAwarenessIntegratedBandscopesofthe2000s
• “Nearreal-time”style• Swept“secondaryreceiver”
• Displaysareaaroundtunedfrequency– ± 12.5/25/50/100kHz
• Mediumresolution• Sweptatmoderaterate
IcomIC-756PRO
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SituationAwarenessDigitalSampling/Processing/Display
• Goal:continuous,real-timedisplay
• PhysicalaccessoryorsoftwareGUI
• Stillcaptures“IF”spectrum
8ElecraftK3andP3Panadapter
SituationAwareness- SDRDigitalSampling/Processing/Display
• Continuous,real-timedisplayviaFouriertransformofentire“IF”bandwidth
• Highresolution– Inbothfrequencyandtime
• Waterfallprovidesactivityhistory• Adjustableintensity
– “VisualEnhancement” allowspullingsignalsoutofthenoise
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SoftwareDefinedRadioArchitectureVariants
RFDown-
Convert,Detect
SoundCard Software
RF Down-convert
D/AConvert Software
RF Down-convert
D/AConvert Software
SingleConversionDesigns
Flex-3000,Flex-5000,ApacheLabs,RFSPACE,
Dongles
RF D/AConvert Software PC
Client
RF D/AConvert Software Buttons
& Knobs
DirectSamplingDesigns
Flex-6000Series,IcomIC-7300
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BasebandAudio
Firewire
Ethernet
It’saBlackBox(notreally)
• What’sinthere?(hardware)– RFinput-output switching– Filtering– LOandfrequencyselection– A-DandD-Aconversion– Computer interface
• Where’stherest?(software,that’swhere)– Firmwareinthebox– Drivers toconnect theboxtothecomputer
viaFireWire(IEEE1394),USBorEthernet– Softwareapplicationorclientprogramincomputerperforms“radio”
and“knobs”functions
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FlexRadio 6000SeriesDirectConversionArchitecture
FlexInsiderAugust2012
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WhyAllThatMath?
• Adiodedetects
• Butarealdiodeisn’tperfect
• Themathdescribeswhat’ssupposedtogoonVo=0,(Vi<1)Vo=1,(Vi>=1)
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What’sThisI/QThing?
• IandQbothsampleincomingsignals
• QChannel isshifted90o fromIchannel
• Effectivelyseparatesfrequencies aboveandbelowLO
• Doublesradio“passband”foragivensampling rate
• Makessideband“demodulation “asnap
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Filtering intheDigitalDomain
• SimplestdesignisFiniteImpulseResponse orFIR
• Implemented byaddedscaled&delayedversionsofasignal
• Softwareapplicationsexisttodetermine coefficients
• Withtoday’sdigitalprocessors, digitalfilterscanbeverycloseto“ideal”
– Roll-off”sharpness”– Passbandripple– Phaseshift
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SoftwareDefinedRadiosKeyElementsEffectingPerformance
• Architecture– Minimizeuseofanalogcomponents– SingleConversionvs.DirectSampling
• A/DConverterResolution,RangingandSpeed– 12-bit,16-bit,24-bit,….Resolution– Converter rangingalgorithms– Samplingspeed determines radio“bandwidth”– PanadapterBandwidth (96KHz– 14MHz)
• PrecisionandAccuracyofDigitalClock– Stable,temperature compensated clocks– Determines phasenoiseperformance– GPSDisciplinedOscillatorsorGPSDO’s(especially forUHFandabove)
• Processingpowerin“box”– NumberofsimultaneousPanadpaters (1– 8)andreceivers
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SoftwareDefinedRadiosInterfaceBetweenthe“Box”andthe“Computer”
• Informationontheinterfacecaninclude:– I/Qdigitaldatastreams– Radiocontrolinterface (e.x.CATInterface)
• Interfacespeedcanlimitpanadapterbandwidthinmanydirectcoversiondesigns
• NativeinterfacesupportonPCishighlydesirable• Thin-clientdesignsusingethernetmaybea“sweetspot”
Interface Bandwidth Distance Remotable?
Availability on
RecentPCs
Analog Audio ~1.5Mbps Few Feet No Sound cardusingI/Q
Firewire 400– 800Mbps FewFeet No Not native
Ethernet 100Mbps– 1Gbps
WorldwideviaInternet
Excellent Native
USB3.0 Upto5Gbps FewFeet No Native
PCInternal Limitedbybus Same Box No CustomPC
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RemoteOperatingWithAnSDROfficeDesktop
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Flex-6700SDROperationDemoScenarios
• PhoneQSO
• MultiplePanadapters(“slices”andreceivers)
• TrackingNotchFilters
• CWQSO
• DigitalQSO
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Flex-6700
SDR
PCRunning
SmartSDR
Remotevia
theInternet
Flex-6700 inOperationPhoneQSOs,SplitOperation,MultiplePanadapters,Filters
USPhoneQSOon20m 5J0PDXpedition SplitQSO
Multiple PanadaptersandReceivers21
TrackingNotchFilter(TNF)
Flex-6700 inOperationCWQSOs,CWSkimmer,DigitalQSO
2015CWSweepstakes Contest
VK9WADXpedition Pileupon30mCW22
DigitalDXQSO
PAPort A Port
A1-6
BandData,PTT&INH
PTT&INH
TomicroHAMControlBus
ToAntennaSwitching
1GBpsSwitchedLANWAN GW
(100/5
MBps)
WiFi GW
802.11g/n
microHAMSNDBandDecoder
Flex-6700SDR
FlexRadioMaestro
HeilPR781/USBQ
BoseBluetoothHeadset
ShackRemote
Site
SoftwareAppsRemote:• RotatorControl• Power/SWRMeter• Amp/TunerControl• AntennaSelection (custom)
LANRemotes Audio,CW,CAT,UIandCOMPorts
ElecraftW2Power/SWRMeter
LocalaudioviaPC
Elecraft500WAmp&Tuner
FilterMaxBPF
SoftwareDefinedRadiosInterfacingtotheOtherEquipment
DDUtil Creates
PhysicalCAT
Interface
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PTT&INH
Flex-6700SDR
LocalaudioviaPC
CWOperationCWSkimmer
LANCarriesAudio,CW,AT,UIandCOMPorts
VirtualAudioCableReceive I/QStream
DAX(Digital
AudioExchange)
SDR-Bridge
ConnectsDAX
andCWSkimmer
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PTT&INH
Flex-6700SDR
LocalaudioviaPC
DigitalOperationandLoggerInterfaceDXLabSuite
LANCarriesAudio,CW,AT,UIandCOMPorts VirtualAudioCable
Tx&RxAudioStream
DAX(Digital
AudioExchange)
SDR-Bridge
ConnectsDAX
andCWSkimmer
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DXLabCommander
DXLabWinWarbler
RTL-SDRDongleOperationDemoScenarios
• OverviewoftheHardwareandSoftware– RTL-SDRDongleandAntennaPackage– HaminUpUpconverter– SDR-RadioSoftware
• ReceiveFMBroadcastRadio• 2mSimplexFM• 2mRepeaterMonitoring• WeatherBandRadio• PagerChannelReception• …
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Setupguide- http://www.rtl-sdr.com
SDRAdd-onforConventionalRadiosExample- RFSPACESDR-IQ
• SDRConnectstoIFoutputofconventionalradio• UseSDR-RADIOsoftwaretodisplayIFinSDRformaton
computer• SDR-RADIOusesCATinterfacetotuneconventionalradio
baseduponSDRinputs27
IFOutput
USBIQ+Control
AdditionalTopicsforDiscussion
• OpenSourceSDRProgramsavailable
• NewIcomIC-7300DirectSamplingRadio
• ContestingPossibilitieswithSDRs
• AdvancedDigitalModeswithSmartSDR
• SDRPerformanceMeasurementsReciprocalMixingDynamicRange(RMDR)andPhaseNoise
• …
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2:00,5:00,8:45,12:30,28:15mins
UsefulLinks
• FlexRadio- http://www.flexradio.com/amateur-products/
• RTL-SDR- http://www.rtl-sdr.com
• RFSPACE- http://www.rfspace.com
• SDR-RADIO- http://sdr-radio.com
• SignalIDWiki- http://www.sigidwiki.com
• SherwoodRadioPerformanceComparisons-http://www.sherweng.com/table.html
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