SUN
Tutorial on USRP
Xiuzhen Guo
2016.03.23
1
Make it comprehensive
Intro to Software-Defined Radio
Intro to Universal Software Radio Peripheral
Intro to GNU Radio
Applications
SDR
Software——GNU Radio
Hardware——USRP
2
Part 1
Using software to realize the radio functions
Joe Mitola of MITRE
In IEEE National Telesystems Conference
3
Structure of SDR
ADC
DAC
RF Section
Radio
Frequency
Digital
Downconverter
Digital
Upconverter
IF Section
Intermediate
Frequency
Baseband
processing
Baseband
Section
4
Advantages of SDR
Function
Performance
Re-configurability
Strengthen the possible
potential applications
Evolve to a new standard
conveniently
Multifunctional devices
Multi-mode
Multi-band
Shorter time-to-market
compatibility
Lower hardware cost
hardware module
widespread applications
Different hardware
Different demand
Improve development
efficiency
 open architecture
5
Part 2
USRP: Universal Software Radio Peripheral
PC
RF
6
Overall architecture
Mother board
Rx
Daughter board
120 MHz Data Clock
I
Your Host Code
Here
DMA
FIFO
Your
Code
Here
Fractional
Decimator
Frequency
Shift
Basic DC
Offset &
IQ Balance
DMA
FIFO
Your
Code
Here
Fractional
Interpolator
Frequency
Shift
Basic DC
Offset &
IQ Balance
Q
ADC
ADC
Tx
I
Your Host Code
Here
Q
DAC
FPGA
CPU
LabVIEW (Host PC)
Host PC
DAC
Fixed Personality (FPGA)
PCIe x4 Cable
USRP N210
NI USRP
RIO
RF
7
History of USRP
duplexing
40MHz
最高支持
120MHz
Lower latency
Performance
USRP RIO
120MHz
bandwidth
accuracy
speed
USRP N210
16MHz
16MHz
USRP 1
Simplex
20M
Millisecond
USRP 2
频率范围
应用
50MHz-2.2GHz
FM、雷达、GSM、ISM
70MHz-6GHz
FM、蓝牙、GSM、ISM
…
…
Price
8
USRP N210
Multiple Device
Synchronization
MIMO Expansion
Improved Freq
Accuracy w/ GPS
Clock Option
RF1/RF2
Gigabit Ethernet
Interface to Host
A:transmitting
B:mimo cable link
C:receiving
D:firmware loaded
E:reference lock
F:CPLD loaded
Power
6v/DC/3A
9
Compositions
Daughter Board：
RF front end
Cover different frequency range
Convertible
Mother Board：
high-speed signal processing
ADC/DAC/FPGA/I/O
10
Features of USRP N210
Use with GNU Radio, UHD
 Gigabit Ethernet Interface to
 Modular Architecture: DC-6 Host
GHz
 2 Gbps Expansion
 Dual 100 MS/s, 14-bit ADC 1 MB High-Speed SRAM
 Dual 400 MS/s, 16-bit DAC  Auxiliary Analog and Digital
 DDC/DUC with 25 mHz
I/O
Resolution
 2.5 ppm TCXO Frequency
 Up to 50 MS/s Gigabit
Reference
Ethernet Streaming
 0.01 ppm w/ GPSDO Option
https://www.ettus.com/application/category/general/applications
11
But it is not enough to achieve
several functions with only USRP
12
Part 3
A free & open-source software
development toolkit that provides
signal processing blocks to
implement software radios.
http://gnuradio.org/redmine/projects/gnuradio/wiki
13
The Installation of GNURadio
Attention:
1> Updata Ubuntu
2>UHD failed——Network problems
3>IP:192.168.10.1;255.255.255.0;192.168.10.2
4>Wait quite a while (15:10~18:05)
5>_uhd_find_devices
14
GRC
$ gnuradio-companion
Toolbar
Library
Searching for blocks
Workpalce
Terminal
15
Throttle
Make sure it does not consume 100% of your CPU cycles
and make your computer un responsive
16
Example
waveform display
（a）complex
（b）float
（a）
（b）
17
Modifying block properties
Parameters list
18
Blocks
Help
Types
Different color represents different data types
19
Make blocks
How to
make our own blocks?
Take
QPSK_demod as an example
20
QPSK(4QAM)
（-1+1j）10
00（1+1j）
（-1+1j）11
00（1+1j）
（-1-1j）11
01（1-1j）
（-1-1j）10
01（1-1j）
With Gray coding
Without Gray coding
21
How to make our own blocks?
1. Using gr_modtool
22
Block:qpsk_demod
Four types of block
Three types of block file
Synchronous (1:1)
Decimation (N:1)
Interpolation (1:M)
General/Basic (N:M)
23
Modifying the python block file
24
QA tests
25
QA tests
Test result
26
XML files
27
Installation
What should we do?
success
new block
28
Running
Take an example to achieve the function of qpsk_demod
29
Part 4
What can we do
with USRP and GNU Radio?
 operations related with the waveform
Modulation
Demodulation
Spreading spectrum
Despreading
Coding
decoding
Sample
FFT
Digital up convert
Digital down convert
 high speed processes
30
Uhd_fft(2.4GHz)
Observe signals in 2.45GHz with USRP
31
Uhd_fft(2.4GHz)
Results
32
mzig
mZig: Enabling Multi-Packet Reception in ZigBee
（MobiCom 2015）
33
Collisions
Examples of collisions
With chip-level time offset(CTO)
Without CTO
34
Decomposing
RX
Alice
Bob
Cross Interference
Cancellation(CrossIC)
L1
1
1
L2
1
0
L3
0
1
L4
0
0
L4
0
0
Amplitude Combination
based Decomposition
(AmpCoD)
35
Flow chart
Flow chart in Dmzig module
36
Physical layer
Physical layer of TX and RX with mZig
37
Testbed
TX: USRP B210*6 + Laptop*6 + iRobots*6
RX: USRP X310 + PC
Why we choose USRP instead of other devices?
38
More
DVB - T real-time communication
system(the University of Pisa, Italy）
http://www.mailarchive.com/discussgnurad
[email protected] /msg11639.html
SmartRadio, a cognitive radio program
( Virginia Tech University , USA)
http://www.cognitiveradio.wireless.vt.edu/
dokuwiki/doku.php?id=home
Tests of MIMO and multi-hop network
(University of Texas, USA)
http://hydra.ece.utexas.edu/testbed/
39
SUN
Thanks
Question & Answer
40