usrp and gnuradio for prototyping radiofrequency ...2009.rmll.info/img/pdf/gnuradio-rmll09.pdfusrp...

USRP andGNURadio for

prototypingradiofrequencycommunication

algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses

Measurement ofacoustic sensor

Conclusion

USRP and GNURadio for prototypingradiofrequency communication algorithms

T. Retornaz1, J.M. Friedt1, G. Martin2 & S. Ballandras1,2

1Senseor, Besancon2FEMTO-ST/CNRS, Besancon

6 juillet 2009

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Radiofrequency circuitprototyping :

� basic blocks assembled : fragile and large, incompatible with use onthe field (outdoor)

� dedicated circuit : lengthy and costly manufacturing + hardwaredebug in parallel to software development

⇒ USRP (Universal Software Radio Peripheral) provides a flexible set ofhardware and software toolset

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Hardware vs Software DefinedRadio

SignalTransmitted signal

curves : http ://alexsoft.chez-alice.fr/cours/cm12.htm

electronics

versatile

Carrier frequency ∝ f(R,L,C)

Analog Radio

Digital Radio

Modulator

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Software Defined Radio

CNA

CAN

Python

C++

LISP, octave, shell...

Linux

USRP

Library of signal processing

Open-Hardware

Radio waves

Sof

twar

eH

ard

war

e

Hardware independant

Open-Source

USRP : http://www.ettus.com/

Gnuradio : http://gnuradio.org/trac

gnuradio

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http://www.ettus.com/

http://gnuradio.org/trac



algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

USRP & daughterboard

BasicRX : 0.1-300 MHz (75 $)

LFRX : 0.1-30 MHz (75 $)

TVRX : 50-870 MHz (100 $)

DBSRX : 0.8-2.4 GHz (150 $)

RFX400 : 400-500 MHz (275 $)

RFX900 : 800-1000 MHz (275 $)

RFX1200 : 1150-1450 MHz (275 $)

RFX1800 : 1.5-2.1 GHz (275 $)

RFX2400 : 2.3-2.9 GHz (275 $)

XCVR2450 : 2.4-2.5 GHz& 4.9-5.85 GHz (400 $)

Tra

nsm

itte

r

700 $ LFTX : 0.1-30 MHz (75 $)

picture : http://www.gnu.org/software/gnuradio/doc/exploring-gnuradio.html

64 MHz

128 MHz

IQ demodulator

IQ modulator

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http://www.gnu.org/software/gnuradio/doc/exploring-gnuradio.html



algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Graphical User Interface

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Equivalent Code

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

GNU Radio Applications� A TiVo equivalent for radio, capable of recording multiple stations

simultaneously.

� Time Division Multiple Access (TDMA) waveforms.

� A passive radar system that takes advantage of broadcast TV for itssignal source. For those of you with old TVs hooked to antennas,think about the flutter you see when airplanes fly over.

� Radio astronomy.

� Digital Radio Mundial (DRM).

� Software GPS.

� Distributed sensor networks.

� Distributed measurement of spectrum utilization.

� Amateur radio transceivers.

� Ad hoc mesh networks.

� RFID detector/reader.

� Multiple input multiple output (MIMO) processing.


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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

FM Radio

( Volume )

http://fr.wikipedia.org/wiki/Fichier:R%C3%A9cSuperH%C3%A9t.png

http://fr.wikipedia.org/wiki/R%C3%A9cepteur_radio

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http://fr.wikipedia.org/wiki/Fichier:R%C3%A9cSuperH%C3%A9t.png

http://fr.wikipedia.org/wiki/R%C3%A9cepteur_radio



algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Slider ≡ fast reconfiguration

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

FM Radio in use

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Spectrum Analyzer

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Spectrum Analyzer in use

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Acoustic Sensor

30 cm

Piezo-electric materials

Quality factor Q ≈ 104

Length (antenna) = λ4 ≈ 17 cm

5× 5× 3 = 75 mm3

T°sensor

f1 f2f (Hz)

∆(f ) ∝ ∆(T°)

Non-sensitive

resonatorSensitive

resonator

6= design :

6= types :

- delay line (wideband)

- resonator (narrowband)

T°,

Pressure,

pH, ...

S11

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

f /T°

f (Hz)

Hot

Cold

S11

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Radio frequency pulse

Amplitude (u.a)

t (s)

–am

plit

ud

e(%

)

–ton (s)

–tlook (s)

–tsw (s)

–freq (Hz)

Dead time (RF switch : 1.14 µs)

usrp radar mono.py

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Spectral distribution

Noise level

f (Hz)

Short pulse

Long pulse

Qsensor

f (u.a)f (u.a) foscfosc

Power (u.a)Power (u.a)

–ton = 25.10−6 s

–ton = 15.10−6 s

–ton = 5.10−6 s

–amplitude = 100 %

–amplitude = 46 %

–amplitude = 28 %

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Short Pulse = Frequency Sweep

fosc = 432.2 MHz fosc = 434.55 MHz

f (Hz) f (Hz)

fosc = 433.4 MHz

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Reception and Processing ofRadar-Echo

20000

0

5000

10000

15000

20000

25000

0 200 400 600 800 10000

5000

15000

25000

0 200 400 600 800 1000

10000

Noise level

Qsensor

Short pulse

Long pulse

Σ

Σ

Integration timeVoltage (u.a)

Time (s)Time (s)

fft(Echo)

f (Hz)

fft(Echo)

f (Hz)Integration time

Voltage (u.a)

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Sensitive mode

433 M∆(f ) ≡ ∆(T °)

434 M

0°C ≈ 23°C

f (Hz)

f23°Cf0°C

Σ (u.a)

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Time analysis

4

4

4

4

log

t (u.a)

f (Hz)fsample ≈ 10 Hz

fref−1 MHz

Burning

match

under

sensor

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Comparison of methods

Long pulse

Short pulse

Climatic chamber

t (u.a)

t (u.a)

T (°C)

fsensor (Hz)

≈ 2 hour

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Pattern of measurements

USB

Socket

Init –amplitude–ton

–freq

usrp radar mono.py

LUSH

USRP

Stop RADAR

Frequency tuning

Start RADAR

Pulse generation

Transmit Echo

<1 ms

Echo Request

FFT

fsensorTsample > 128 points ×50.10−3 > 6 s

50 ms

Short pulse

Σ

×128 ?

if fsample = 100 Hz : σ = 150 Hz

fsample > 800 Hz

Long pulse

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Conclusion : USRP prototyping

σ = 150 HzPower comsumption

<

ISM Band ISM Band

not allowed

noise level allowed

Mathematical complexity

<

>

Interval between antenna/sensor

FFT

fsample > 800 Hz

Short pulse

×128 Σ

fsample < 0.16 Hz

Long pulse

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algorithms

Retornaz & al.

Introduction

Soft Radio

Example ofUSRP uses


Conclusion

Conclusion and perspective

� Demonstration of the use of software defined radio for rapidprototyping of acoustic sensor interrogation algorithms

� Experimental measurements performed on resonators and delay linesusing USRP

Further work :

� move part of the processing from PC to FPGA (automaticfrequency tuning, received power detection)

� automatic gain control to tune emitted power as a function ofreceived signal strength

References :

� J.-M Friedt, T. Retornaz, G. Martin, T. Laroche, J.-P. Simonnet, E.Carry, S. Ballandras Surface Acoustic Wave Resonators as PassiveBuried Sensors 2009 EFTF/IFCS (April 2009).

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