Transcript Channel Sounding UsingUSRP2 & GNU-RADIO

Channel Impulse Response And Coherence Bandwidth
Estimation
Under :Prof S.N Merchant
SPANN LAB,IIT Bombay
By:Rohit Sharma
Jay Prakash
Why?:- Motivation
Increased Use of
Wireless Devices
Data-Intensive High
Bandwidth Services
Strain in capacity of
RF Spectrum
Most Communication becomes impractical above 10GHZ in Microwave Region.
Multipath Effects of Channel
Multiple propagation paths:
Line-of-Sight (LoS) and
NLoS Invites Multipath
invites:Scattering,
Reflection,
 Diffraction.
Channel Becomes:Frequency dependent,
Time dependent and
Position dependent.
Ultimately Coherence Bandwidth is adversely affected.
Flow Model
Apparatus
Our Transmitter side Flow-Design
Our Receiver side Flow-Design
Host PC(Tx) Flow-chart
Host Pc
(Transmitter)
Gb Ethernet
GNU-RADIO
USRP2
PN Sequence Vector Source
Unpack_to_pack
Digital_bert_tx.py
BPSK Differential gray
coded Modulation
Uhd_Transmitter
UHD-DRIVER
USRP2
Host PC(Rx) Flow-chart
USRP2
Gb Ethernet
Host Pc
(Receiver)
I
File Sink
Q
Data Processing I
File Sink(.dat)
Read
Complex_to_Binary
Windowing on Data-Stream Per
PnSequence
Window/Seq
Data Processing II
Cross Correlated Data
Window/Seq
Cross_Corr
Channel Impulse Response
Local Pn-Seq
Coherence Bandwidth Estimation
Averaged Over Windows
Frequency Correlation Function
Average
FFT
Power
Delay
Profile
CIR
Host PC(Rx) Flow-chart
Host Pc
(Receiver)
Uhd_Receiver
GNU-RADIO
Demodulator
Stream Converter
Digital_bert_rx.py
File Sink(.dat)
UHD-DRIVER
Octave Based
Post-Processing
Our Automated-Sounder APPLICATION
Requirements:Software
Gnu-Radio 3.6.0
Python
Octave
UHD_Driver (Latest stable)
Hardware
USRP2(Tx,Rx)
Two PCs
Gb Ethernet
Our Automated-Sounder APPLICATION
Impulse Response of a window
Power Delay of the window
Channel Impulse Response
Power Delay of the window
Power Delay Profile
Frequency Correlation Function