1 Software Defined Radio GNU Radio and the USRP 2 Overview What is Software Defined Radio? Advantages of Software Defined Radio Traditional versus SDR Receivers SDR and the USRP Using GNU Radio 3 Introduction What is Software Defined Radio (SDR)? Getting code as close to the antenna as possible Replacing hardware with software for modulation/demodulation Advantages: Makes communications systems reconfigurable (adapting to new standards) Flexible (universal software device - not special purpose) Filters/Other Hardware Cognitive Radio
11
Embed
Software Defined Radio - California State University ...skatz/katzpage/sdr_project/sdr/sdr_intro.pdf · 1 Software Defined Radio GNU Radio and the USRP 2 Overview What is Software
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Software DefinedRadio
GNU Radio and theUSRP
2
Overview
What is Software Defined Radio?
Advantages of Software Defined Radio
Traditional versus SDR Receivers
SDR and the USRP
Using GNU Radio
3
Introduction What is Software Defined Radio (SDR)?
Getting code as close to the antenna as possible Replacing hardware with software for
modulation/demodulation Advantages:
Makes communications systems reconfigurable(adapting to new standards)
Flexible (universal software device - not specialpurpose)
Filters/Other Hardware Cognitive Radio
2
4
Traditional Receiver
LocalOscillator
RF Amplifier
IF Amplifier
x Demod-ulator
fc
fLO
|fLO-fc|fLO+fc
f (KHz)530 1700980
10 KHz
f (KHz)530 1700980
10 KHzf (KHz)
455
10 KHz
fLO=1435 KHz
455f (KHz)
10 KHzf (KHz)
5
5
Traditional vs. SDR Receiver
RF Amplifier
IF Amplifier
x Demod-ulator
LocalOscillator
Receiver Front End
Traditional/ HardwareReceiver
SoftwareReceiver Front End ADCCurrentSDRReceiver
SoftwareADC
FutureSDRReceiver ?
6
SDR Receiver Using the USRP
Receiver Front End ADC USB
ControllerFPGA PC
Daughterboard Motherboard
similar to traditionalfront end with fIF = 0
Decimation,MUX, +
Interface to PC
GNU Radiosoftware
USRP: Universal Software Radio Peripheral
3
7
Quadrature SignalRepresentation
The received signal, S(t), may be represented as follows:
S(t) = I(t)cos(2! fct) +Q(t)sin(2! fct)
fc = carrier frequency
I(t) = in-phase component
Q(t) = quadrature component
Contain amplitudeand phaseinformation ofbaseband signal
•GNU Radio software uses I and Q components todemodulate signals•USRP front end translates the signal to zero frequencyand extracts I and Q