![Page 1: Working with programmable radios Hariharan Rahul](https://reader035.vdocument.in/reader035/viewer/2022072006/56649f4d5503460f94c6dd3a/html5/thumbnails/1.jpg)
Working with programmable radios
Hariharan Rahul
![Page 2: Working with programmable radios Hariharan Rahul](https://reader035.vdocument.in/reader035/viewer/2022072006/56649f4d5503460f94c6dd3a/html5/thumbnails/2.jpg)
Our Group’s Experience
• USRP
• USRP2
• WiGLAN
• WARP
• Lyrtech
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What have we used programmable radios for?
• Network-oriented PHY design– Flexible layering• SOFT, MIXIT, Softcast
– New technologies: UWB, MIMO• SWIFT, FARA, IAC
– Dealing with Interference• ANC, ZigZag
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Peeling the Onion• Changing the PHY interface– Soft information
• Changing the PHY algorithms– Interference cancellation and Interference
alignment• Timing-sensitive PHY algorithms– Adaptive sensing
• Bandwidth limited– Wide frequency bands
Host
FPGA
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USRP and USRP 2• What’s good?– Affordable– Stable algorithms– Large community– Easy to use– USRP had narrow bandwidth; better with USRP2
• What’s bad?– No room for additional FPGA logic– Bandwidth only up to 20 MHz even in USRP2– High latency
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WARP• What’s good?– Close to our ideal board– Large FPGA– Relatively fast host interface– Rich development platform • Onboard processor cores
• What’s bad?– Cost– Relatively narrow bandwidth (FPGA code does 10 MHz,
radio can support 40 MHz)– Calibration
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WiGLAN• What’s good?– Very high bandwidth (128 MHz)– Large FPGA to deal with high bandwidth– Calibrated
• What’s bad?– Development process• Form factor
– Out of print
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Learnt Lessons• A programmable radio is a package– Hardware– Software
• SNR-BER curve is the proof of the pudding
4 5.5 7 8.5 1011.5 13
14.5 1617.5 19
20.5 2223.5 25
26.5 2829.5
00.5
11.5
22.5
33.5
44.5
5BPSK,1/2BPSK,3/44-QAM,1/24-QAM,3/416-QAM,1/216-QAM,3/464-QAM,2/364-QAM,3/4
SNR (dB)
Thro
ughp
ut (M
bps/
MH
z)