Hi!
I’m trying to use Channel Sounder based on PN sequences with:
GNU Radio 3.2.2.1
and USRP1 REV:4.5 with XCVR2450 REV 849 2.4GHz and 5 GHz Transceiver on
board.
Measurement environment - quite small room with balcony, distance
between Tx and Rx ~ 3m, LOS. Seqeunce - maximum length - 12.
I’ve founded this topic here Gr-sounder using xcvr2458 daughterboard - usrpsounder.py - GNU Radio - Ruby-Forum, but
what I got wasn’t the same as there.
Details:
At the TX side
lordu@ubuntu:~$ sudo usrp_sounder.py -f 2.4G -R B -t -v -D
Using PN code degree of 12 length 4095
Sounding frequency range is 2.384G to 2.416G
Using XCVR2450 Tx for sounder transmitter.
Asserting reset.
Writing mode register with: 0x1
Setting transmitter frequency to 2.4G
Setting PN code degree to 12
Disabling digital loopback.
Writing mode register with: 0x1
De-asserting reset.
Writing mode register with: 0x0
Enabling transmitter.
Writing mode register with: 0x2
Press return to exit.
Disabling transmitter.
Writing mode register with: 0x0
Comparing this code with code from link above I can’t found this part in
code:
“db_xcvr2450_tx: init
Creating new xcvr2450 instance
xcvr2450: init with 47a50364: 0”
Rest’s the same.
At the RX side:
tommecki@laptok:~/testy$ sudo usrp_sounder.py -f 2.4G -R B -r -v -D -F
output2.dat
Using PN code degree of 12 length 4095
Sounding frequency range is 2.384G to 2.416G
Logging impulse records to file: output2.dat
Using XCVR2450 Rx for sounder receiver.
Setting receiver gain to None
Generating impulse vectors of length 4095 byte length 32760
Using smoothing alpha of 1.0
Asserting reset.
Writing mode register with: 0x1
Setting receiver frequency to 2.4G
Setting PN code degree to 12
Disabling digital loopback.
Writing mode register with: 0x1
De-asserting reset.
Writing mode register with: 0x0
Writing mode register with: 0x4
Starting receiver flow graph.
gr_buffer::allocate_buffer: warning: tried to allocate
4 items of size 32760. Due to alignment requirements
512 were allocated. If this isn’t OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
gr_buffer::allocate_buffer: warning: tried to allocate
4 items of size 32760. Due to alignment requirements
512 were allocated. If this isn’t OK, consider padding
your structure to a power-of-two bytes.
On this platform, our allocation granularity is 4096 bytes.
Enter CTRL-C to stop.
Received impulse vector of length 32760
Received impulse vector of length 32760
… (many of them) …
Received impulse vector of length 32760
Received impulse vector of length 32760
Received impulse vector of length 32760
Received impulse vector of length 32760
^Z
[1]+ Stopped
so where is:
“db_xcvr2450_rx: init
Creating new xcvr2450 instance
xcvr2450: init with 48571832: 1
xcvr2450: Setting reg 2 to 030072
xcvr2450: Setting reg 5 to 038885
xcvr2450: Setting reg 6 to 004006
xcvr2450: Setting reg 7 to 000627
xcvr2450: Setting reg 8 to 01C218
xcvr2450: Setting reg 9 to 0068B9
xcvr2450: Setting reg 10 to 003C0A
xcvr2450: Setting reg 11 to 00010B
xcvr2450: Setting reg 12 to 0003FC
RF=2.45G VCO=3.26667G R=1 PHD=21.3333M DIV=153.12500 I=153 F= 8192
ACT=2.45G
GPIO: RXRX=6000 RXTX=4000 TXRX=E010 TXTX=A810
xcvr2450: Setting reg 3 to 000993
xcvr2450: Setting reg 4
to 008004
xcvr2450: Setting reg 5 to 038825
lock detect: True
Using for sounder receiver.”
?
We were trying to start usrp_sounder.py on two laptops at the same time,
measure took maybe 2 minutes. Earlier we measured 3 sec, 30 sec, 1 min -
no changes in results.
After that we used a=read_complex_binary(‘output2.dat’) and plot(abs(a))
and we get this:
http://www.bankfotek.pl/view/624066
I’m sure that is not ok 
Why we have problems with “Creating new
xcvr2450 instance” and we can’t get the same code line as
Gr-sounder using xcvr2458 daughterboard - usrpsounder.py - GNU Radio - Ruby-Forum. Is it connected with not correct
set up of usrp_sounder.py or to small distance between transmitter and
receiver side ?
