I had forgotten to enclose the code, here it goes!
# USRP2 sinks
#####################################################################################################
# slave USRP2
self.usrp2_sink_slave = uhd.single_usrp_sink(
device_addr="addr=192.168.20.3",
io_type=uhd.io_type_t.COMPLEX_FLOAT32,
num_channels=1,
)
_config = uhd.clock_config()
_config.ref_source = uhd.clock_config.REF_MIMO
_config.pps_source = uhd.clock_config.PPS_MIMO
self.usrp2_sink_slave.set_clock_config(_config, 0)
self.usrp2_sink_slave.set_samp_rate(self.output_samp_rate)
self.usrp2_sink_slave.set_center_freq(self.center_frequency, 0)
self.usrp2_sink_slave.set_gain(self.tx_gain, 0)
# master USRP2
self.usrp2_sink_master = uhd.single_usrp_sink(
device_addr="addr=192.168.10.4",
io_type=uhd.io_type_t.COMPLEX_FLOAT32,
num_channels=1,
)
self.usrp2_sink_master.set_samp_rate(self.output_samp_rate)
self.usrp2_sink_master.set_center_freq(self.center_frequency, 0)
self.usrp2_sink_master.set_gain(self.tx_gain, 0)
2012/2/22 Jorge Hernandez <jorge.gnura...@googlemail.com>
> Hi,
>
> Actually what I'm trying to do is a 2x1 MIMO, but I was trying to run the
> benchmark with its default set up to see if I had success with the merging.
> As you said, this segmentation fault must appear somewhere when trying to
> implement 2 receivers, when you adjust the parameters for 2 tx antennas and
> 1 rx antennas there is no problem to run it.
>
> So, now I think I have this benchmark_ofm_mimo prepared to work I'm
> finding another problems...I am using two USRP2 with XCVR2450daughterboards
> in the transmitter side and another one in the receiver side
> (less than 1 meter of distance between tx and rx). My first problem comes
> when setting the sample rate, I don't know if I should set the sample rate
> in the rx usrp as the sum of the two sample rates of the tx usrps, or it
> has nothing to do...Also, I've been reading the UHD/USRP2 application notes
> and I think I've got how to configure the slave usrp but I am not sure. I
> enclose my code so anyone who has any adviece can have a look at it. Appart
> from this issues, my heaviest problem is how to introduce an input into the
> transmission chain. I see how packets are made and sent in the
> benchmark_ofmd_mimo, but how should I proceed if I want to use my own
> source block (in my case it would be a wavfile source)? Thank you for your
> support, I will appreciate any help!
>
>
> 2012/2/20 Tom Rondeau <t...@trondeau.com>
>
>> On Mon, Feb 20, 2012 at 5:48 AM, Jorge Hernandez <
>> jorge.gnura...@googlemail.com> wrote:
>>
>>> Hi all,
>>>
>>> I've been working lately to get to work the mimo files from trondeau's
>>> branch. After some trials, I thought I've successfully merged the master
>>> branch into this branch so I could use the mimo files. However, when
>>> trying to run the benchmark_mimo_ofdm.py file a segmentation fault is
>>> happening. I've been reading about this error but I don't know yet where it
>>> comes from. I've checked the "How do I debug GNU Radio in Python" from the
>>> FAQ to see what to do in this case. I've followed the 2 steps suggested in
>>> this point but I don't understand the results coming from the (gdb)
>>> backtrace. If anyone has experience with this problem or knows how to
>>> understand this message I would really appreciate any help. I enclose the
>>> messages I'm getting.
>>>
>>> This is what it shows when trying to run benchmark_ofdm_mimo.py:
>>>
>>> ./benchmark_ofdm_mimo.py
>>> linux; GNU C++ version 4.4.1 [gcc-4_4-branch revision 150839];
>>> Boost_103900; UHD_003.004.000-122b947
>>>
>>> 27435
>>> Press Enter to continue
>>> Noise voltage: 4.472135955
>>> Frequency offset: 0
>>> Symbols per Packet: 16.0
>>> Samples per Packet: 11520.0
>>> >>> gr_fir_ccf: using 3DNow!
>>> >>> gr_fir_ccc: using 3DNow!Ext
>>> >>> gr_fir_fff: using 3DNow!
>>> Transmitter using 1
>>> Receiver using 2
>>> x
>>>
>>> After following the steps suggested it shows:
>>>
>>> (gdb) backtrace
>>> #0 gr_ofdm_alamouti_frame_acquisition::calculate_equalizer
>>> (this=0x1137c40, channel=<value optimized out>, symbol=<value optimized
>>> out>,
>>> zeros_on_left=<value optimized out>) at
>>> gr_ofdm_alamouti_frame_acquisition.cc:210
>>> #1 0x00007f4b40673f67 in
>>> gr_ofdm_alamouti_frame_acquisition::general_work (this=0x1137c40,
>>> noutput_items=<value optimized out>,
>>> ninput_items=<value optimized out>, input_items=std::vector of
>>> length 3, capacity 3 = {...}, output_items=<value optimized out>)
>>> at gr_ofdm_alamouti_frame_acquisition.cc:245
>>> #2 0x00007f4b40702c65 in gr_block_executor::run_one_iteration
>>> (this=0x7f4b187d7f20) at gr_block_executor.cc:378
>>> #3 0x00007f4b407235c2 in gr_tpb_thread_body::gr_tpb_thread_body
>>> (this=<value optimized out>, block=...) at gr_tpb_thread_body.cc:49
>>> #4 0x00007f4b4071c20c in
>>> boost::detail::function::void_function_obj_invoker0<gruel::thread_body_wrapper<tpb_container>,
>>> void>::invoke(boost::detail::function::function_buffer&) () from
>>> /usr/local/lib64/libgnuradio-core-3.4.2git.so.0
>>> #5 0x00007f4b4010cd64 in boost::function0<void>::operator()
>>> (this=<value optimized out>) at
>>> /usr/include/boost/function/function_template.hpp:989
>>> #6 0x00007f4b3fce1010 in thread_proxy () from
>>> /usr/lib64/libboost_thread.so.1.39.0
>>> #7 0x00007f4b415d665d in start_thread () from /lib64/libpthread.so.0
>>> #8 0x00007f4b40ce9ecd in clone () from /lib64/libc.so.6
>>> #9 0x0000000000000000 in ?? ()
>>>
>>> Thanks in advance,
>>>
>>> Jorge
>>>
>>
>> Hi Jorge,
>> So what that backtrace is telling you is on the #0 line that the seg
>> fault is occurring here:
>> gr_ofdm_alamouti_frame_acquisition.cc:210
>>
>> So it's that file, line 210.
>>
>> All that does is narrow your search down for where it's going wrong, but
>> this one isn't going to tell you what's wrong with it.
>>
>> So you're doing a 1x2 code. I know when Matt and I left off with this
>> branch, there were some definite issues, and this might just be one of
>> them. Have you tried to do a 2x1 MIMO? I'm pretty sure we had that working.
>> I can't really remember...
>>
>> I'm afraid I can't help you more right now, yo're going to have to look
>> into that file and try to figure out why it's segfaulting one you. But,
>> thanks for reading over the FAQ and posting the back trace! And you figured
>> out how to merge those two branches, so it sounds like you're heading in
>> the right direction!
>>
>> Tom
>>
>>
>
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