Re: [Discuss-gnuradio] USRP2 missing Quadrature samples

[Leslie Choong]

I was able to compile the firmware with Eric's suggestion but it made
no difference on the performance. I tested this out on another USRP2
to see if it was a hardware issue but again got the same results.

I noticed something interesting though: Using a RFX 2400 board if I
try to tune to 2.45G (my original freq), 2.4G or 2.5G I get similar
behaviour (Q samples are 0). If I tune away from them I start to
receive Q samples!

I sampled at 2.425G and compared it to the USRP1. I noticed 2 things:
1. The IQ samples at 2.425G seem like complete noise compared to the
USRP1 samples.
2. The Amplitude of the USRP2 IQ samples is much lower than the USRP1

I have posted these results at: http://www.cs.ucla.edu/~septikus/usrp2.html

Am I setting something up wrong? Why are the IQ samples I'm getting
just noise? This is using my own compiled firmware and the latest FPGA
image off the GNURadio website.

Any further help or comments would be great! Thanks again for all your help!
-Leslie

On Fri, Jan 30, 2009 at 4:41 PM, Eric Blossom <address@hidden> wrote:
> On Fri, Jan 30, 2009 at 04:24:55PM -0800, Leslie Choong wrote:
>> So I've pulled down the most recent trunk and re-built gnuradio. One
>> thing I noticed that I forgot about was that running make in
>> gnuradio/usrp2 does not produce a txrx.bin under usrp2/firmware/apps.
>> I must have copied the latest one sitting in the trunk which is dated
>> Dec 31st (same date as the FPGA binary blob).
>>
>> I looked into it and it seems like ./configure did not find mb-gcc
>> (the microblaze toolchain). I installed the pre-compiled binary from
>> instructions here:
>> http://gnuradio.org/trac/wiki/USRP2UserFAQ
>>
>> And then after configuring and running make I get this error:
>> make[3]: Entering directory `/home/leslie/gnuradio/usrp2/firmware/lib'
>> if gcc -DHAVE_CONFIG_H -I. -I. -I..  -DHAL_IO_USES_UART  -I../include
>> -I../lib  --std=gnu99 -Wall -Werror-implicit-function-declaration
>> -mxl-soft-div -msoft-float -mxl-soft-mul -mxl-barrel-shift -g -O2 -MT
>> abort.o -MD -MP -MF ".deps/abort.Tpo" -c -o abort.o abort.c; \
>>       then mv -f ".deps/abort.Tpo" ".deps/abort.Po"; else rm -f
>> ".deps/abort.Tpo"; exit 1; fi
>> cc1: error: unrecognized command line option "-mxl-soft-div"
>> cc1: error: unrecognized command line option "-mxl-soft-mul"
>> cc1: error: unrecognized command line option "-mxl-barrel-shift"
>> make[3]: *** [abort.o] Error 1
>
> Run ./configure from top directory.  Otherwise you get gcc instead of mb-gcc.
>
> Eric
>