But my interface is in 1000Mbps mode and full duplex.
Why do I have dis problem?
With my configuration I have 15,35Mbps to the USRP2 (Tx) and 3.2Mbps from
the USRP2 (Rx). Is is by far less than the capacity of the Ethernet
interface which is in this state:
How?
> <key>decimation</key>
> <value>500</value>
> </param>
100e6/500 != 3.2Mbps
> <param>
> <key>interpolation</key>
> <value>104</value>
> </param>
100e6/104 != 15,35Mbps
-Josh
~$ sudo ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Link partner advertised link modes: Not reported
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: No
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X: off
Supports Wake-on: pumbag
Wake-on: g
Current message level: 0x00000001 (1)
Link detected: yes
Modulator chain by itself works fine and do the demudulator chain does. But
together I have this problem of Bandwidth?
Any ideas?
This is my new GRC code:
<?xml version='1.0' encoding='ASCII'?>
<flow_graph>
<timestamp>Thu Sep 23 09:18:32 2010</timestamp>
<block>
<key>options</key>
<param>
<key>id</key>
<value>top_block</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>title</key>
<value></value>
</param>
<param>
<key>author</key>
<value></value>
</param>
<param>
<key>description</key>
<value></value>
</param>
<param>
<key>window_size</key>
<value>1280, 1024</value>
</param>
<param>
<key>generate_options</key>
<value>wx_gui</value>
</param>
<param>
<key>category</key>
<value>Custom</value>
</param>
<param>
<key>run</key>
<value>True</value>
</param>
<param>
<key>realtime_scheduling</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(2, 384)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>note</key>
<param>
<key>id</key>
<value>Chain1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>note</key>
<value>MODULATOR</value>
</param>
<param>
<key>_coordinate</key>
<value>(233, 9)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>fm_freq_mod</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>FM frequency modulator</value>
</param>
<param>
<key>value</key>
<value>94000000</value>
</param>
<param>
<key>min</key>
<value>0</value>
</param>
<param>
<key>max</key>
<value>110000000</value>
</param>
<param>
<key>num_steps</key>
<value>300</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(0, 253)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>tune_filter</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>LPF Cutoff Freq</value>
</param>
<param>
<key>value</key>
<value>75000</value>
</param>
<param>
<key>min</key>
<value>15000</value>
</param>
<param>
<key>max</key>
<value>150000</value>
</param>
<param>
<key>num_steps</key>
<value>1000</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(0, 127)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>tune_osc_dem</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>Tunned frequency demodulator</value>
</param>
<param>
<key>value</key>
<value>94000000</value>
</param>
<param>
<key>min</key>
<value>88000000</value>
</param>
<param>
<key>max</key>
<value>108000000</value>
</param>
<param>
<key>num_steps</key>
<value>800</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(1, 1)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>note</key>
<param>
<key>id</key>
<value>Chain1_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>note</key>
<value>DEMODULATOR</value>
</param>
<param>
<key>_coordinate</key>
<value>(361, 500)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>gr_frequency_modulator_fc</key>
<param>
<key>id</key>
<value>gr_frequency_modulator_fc_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>sensitivity</key>
<value>0.980</value>
</param>
<param>
<key>_coordinate</key>
<value>(596, 297)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>gr_multiply_const_vxx</key>
<param>
<key>id</key>
<value>gr_multiply_const_vxx_1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>const</key>
<value>32000</value>
</param>
<param>
<key>vlen</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(797, 297)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>low_pass_filter</key>
<param>
<key>id</key>
<value>low_pass_filter_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>interp_fir_filter_fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>1</value>
</param>
<param>
<key>gain</key>
<value>1</value>
</param>
<param>
<key>samp_rate</key>
<value>240000</value>
</param>
<param>
<key>cutoff_freq</key>
<value>18e3</value>
</param>
<param>
<key>width</key>
<value>2e3</value>
</param>
<param>
<key>window</key>
<value>WIN_HAMMING</value>
</param>
<param>
<key>beta</key>
<value>6.76</value>
</param>
<param>
<key>_coordinate</key>
<value>(507, 44)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>usrp2_source_xxxx</key>
<param>
<key>id</key>
<value>usrp2_source_xxxx_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>interface</key>
<value></value>
</param>
<param>
<key>mac_addr</key>
<value></value>
</param>
<param>
<key>decimation</key>
<value>500</value>
</param>
<param>
<key>frequency</key>
<value>tune_osc_dem</value>
</param>
<param>
<key>lo_offset</key>
<value>float('inf')</value>
</param>
<param>
<key>gain</key>
<value>20</value>
</param>
<param>
<key>_coordinate</key>
<value>(180, 583)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_1_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>ccc</value>
</param>
<param>
<key>decim</key>
<value>5</value>
</param>
<param>
<key>interp</key>
<value>6</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(391, 591)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>low_pass_filter</key>
<param>
<key>id</key>
<value>low_pass_filter_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fir_filter_ccf</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>1</value>
</param>
<param>
<key>gain</key>
<value>20</value>
</param>
<param>
<key>samp_rate</key>
<value>240000</value>
</param>
<param>
<key>cutoff_freq</key>
<value>tune_filter</value>
</param>
<param>
<key>width</key>
<value>5000</value>
</param>
<param>
<key>window</key>
<value>WIN_HAMMING</value>
</param>
<param>
<key>beta</key>
<value>6.76</value>
</param>
<param>
<key>_coordinate</key>
<value>(613, 568)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_fm_demod_cf</key>
<param>
<key>id</key>
<value>blks2_fm_demod_cf_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>chan_rate</key>
<value>240000</value>
</param>
<param>
<key>audio_decim</key>
<value>5</value>
</param>
<param>
<key>deviation</key>
<value>75000</value>
</param>
<param>
<key>audio_pass</key>
<value>1000</value>
</param>
<param>
<key>audio_stop</key>
<value>16000</value>
</param>
<param>
<key>gain</key>
<value>20.0</value>
</param>
<param>
<key>tau</key>
<value>75e-6</value>
</param>
<param>
<key>_coordinate</key>
<value>(867, 417)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>audio_sink</key>
<param>
<key>id</key>
<value>audio_sink_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>samp_rate</key>
<value>48000</value>
</param>
<param>
<key>device_name</key>
<value>plughw:0,0</value>
</param>
<param>
<key>ok_to_block</key>
<value>False</value>
</param>
<param>
<key>num_inputs</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(945, 654)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>gr_wavfile_source</key>
<param>
<key>id</key>
<value>gr_wavfile_source_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>file</key>
<value>/home/thales/Desktop/outfile2.wav</value>
</param>
<param>
<key>repeat</key>
<value>True</value>
</param>
<param>
<key>nchan</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(195, 196)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>5</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(280, 68)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>usrp2_sink_xxxx</key>
<param>
<key>id</key>
<value>usrp2_sink_xxxx_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>interface</key>
<value></value>
</param>
<param>
<key>mac_addr</key>
<value></value>
</param>
<param>
<key>interpolation</key>
<value>104</value>
</param>
<param>
<key>frequency</key>
<value>fm_freq_mod</value>
</param>
<param>
<key>lo_offset</key>
<value>float('inf')</value>
</param>
<param>
<key>gain</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(1011, 265)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>4</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(756, 68)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<connection>
<source_block_id>blks2_rational_resampler_xxx_1</source_block_id>
<sink_block_id>gr_frequency_modulator_fc_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_multiply_const_vxx_1</source_block_id>
<sink_block_id>usrp2_sink_xxxx_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_frequency_modulator_fc_0</source_block_id>
<sink_block_id>gr_multiply_const_vxx_1</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_rational_resampler_xxx_0_0</source_block_id>
<sink_block_id>low_pass_filter_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>low_pass_filter_0_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_1</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_wavfile_source_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_fm_demod_cf_0</source_block_id>
<sink_block_id>audio_sink_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>low_pass_filter_0</source_block_id>
<sink_block_id>blks2_fm_demod_cf_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_rational_resampler_xxx_1_0_0</source_block_id>
<sink_block_id>low_pass_filter_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>usrp2_source_xxxx_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_1_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
</flow_graph>
On 22 September 2010 19:39, Nick Foster<n...@ettus.com> wrote:
Jorge,
Your sample rates do not match. The sample rates your USRP2 is operating
at is fixed for a given decimation/interpolation, and you must choose
sample rates in your upstream and downstream blocks to match.
For instance, in your receiver chain, you are using a decimation rate of
64. This means that your USRP2 will provide samples to the rest of your
flowgraph at 1.5625Msps. This is connected to an FFT sink operating at
200ksps -- this is not correct. If you want to operate at 200ksps you
must provide a resampling block to get there. Likewise, your rational
resampler at (32/25) outputs a sample rate of (1.5625e6 * (32/25)) = 2e6
samples per second. Your low pass filter which follows is expecting a
sample rate of 256k. This will cause the filter coefficients to be
incorrectly calculated, and eventually will cause over/underruns when
you finally get to a block which operates at a fixed sample rate, like
your audio sink.
The "SSSSSSSSSSSS" you are seeing is caused by the audio sink being
overrun by providing it with 250ksps when it is expecting 32ksps.
Nick
On Wed, 2010-09-22 at 08:30 +0200, Jorge Miguel wrote:
Sorry, in my previous email the code was corrupted.. This is the right
code of my GRC:
<?xml version='1.0' encoding='ASCII'?>
<flow_graph>
<timestamp>Wed Sep 22 08:14:26 2010</timestamp>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>tune_filter</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>LPF Cutoff Freq</value>
</param>
<param>
<key>value</key>
<value>75000</value>
</param>
<param>
<key>min</key>
<value>15000</value>
</param>
<param>
<key>max</key>
<value>150000</value>
</param>
<param>
<key>num_steps</key>
<value>1000</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(0, 127)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>gr_frequency_modulator_fc</key>
<param>
<key>id</key>
<value>gr_frequency_modulator_fc_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>sensitivity</key>
<value>0.980</value>
</param>
<param>
<key>_coordinate</key>
<value>(454, 315)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>5</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(233, 68)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>note</key>
<param>
<key>id</key>
<value>Chain1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>note</key>
<value>MODULATOR</value>
</param>
<param>
<key>_coordinate</key>
<value>(233, 9)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>note</key>
<param>
<key>id</key>
<value>Chain1_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>note</key>
<value>DEMODULATOR</value>
</param>
<param>
<key>_coordinate</key>
<value>(181, 427)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>4</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(699, 122)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>wxgui_fftsink2</key>
<param>
<key>id</key>
<value>wxgui_fftsink2_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>title</key>
<value>FFT Plot</value>
</param>
<param>
<key>samp_rate</key>
<value>200000</value>
</param>
<param>
<key>baseband_freq</key>
<value>2000000</value>
</param>
<param>
<key>y_per_div</key>
<value>10</value>
</param>
<param>
<key>y_divs</key>
<value>10</value>
</param>
<param>
<key>ref_level</key>
<value>50</value>
</param>
<param>
<key>fft_size</key>
<value>512</value>
</param>
<param>
<key>fft_rate</key>
<value>50</value>
</param>
<param>
<key>peak_hold</key>
<value>False</value>
</param>
<param>
<key>average</key>
<value>False</value>
</param>
<param>
<key>avg_alpha</key>
<value>0</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(370, 568)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>audio_sink</key>
<param>
<key>id</key>
<value>audio_sink_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>samp_rate</key>
<value>32000</value>
</param>
<param>
<key>device_name</key>
<value>plughw:0,0</value>
</param>
<param>
<key>ok_to_block</key>
<value>True</value>
</param>
<param>
<key>num_inputs</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(607, 648)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>usrp2_sink_xxxx</key>
<param>
<key>id</key>
<value>usrp2_sink_xxxx_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>interface</key>
<value></value>
</param>
<param>
<key>mac_addr</key>
<value></value>
</param>
<param>
<key>interpolation</key>
<value>104</value>
</param>
<param>
<key>frequency</key>
<value>fm_freq_mod</value>
</param>
<param>
<key>lo_offset</key>
<value>float('inf')</value>
</param>
<param>
<key>gain</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(874, 283)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>usrp2_source_xxxx</key>
<param>
<key>id</key>
<value>usrp2_source_xxxx_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>interface</key>
<value></value>
</param>
<param>
<key>mac_addr</key>
<value></value>
</param>
<param>
<key>decimation</key>
<value>64</value>
</param>
<param>
<key>frequency</key>
<value>tune_osc_dem</value>
</param>
<param>
<key>lo_offset</key>
<value>float('inf')</value>
</param>
<param>
<key>gain</key>
<value>20</value>
</param>
<param>
<key>_coordinate</key>
<value>(162, 521)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>fm_freq_mod</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>FM frequency modulator</value>
</param>
<param>
<key>value</key>
<value>94000000</value>
</param>
<param>
<key>min</key>
<value>0</value>
</param>
<param>
<key>max</key>
<value>110000000</value>
</param>
<param>
<key>num_steps</key>
<value>300</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(0, 253)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>variable_slider</key>
<param>
<key>id</key>
<value>tune_osc_dem</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>label</key>
<value>Tunned frequency demodulator</value>
</param>
<param>
<key>value</key>
<value>94000000</value>
</param>
<param>
<key>min</key>
<value>88000000</value>
</param>
<param>
<key>max</key>
<value>108000000</value>
</param>
<param>
<key>num_steps</key>
<value>800</value>
</param>
<param>
<key>style</key>
<value>wx.SL_HORIZONTAL</value>
</param>
<param>
<key>converver</key>
<value>float_converter</value>
</param>
<param>
<key>grid_pos</key>
<value></value>
</param>
<param>
<key>notebook</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(1, 1)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>gr_wavfile_source</key>
<param>
<key>id</key>
<value>gr_wavfile_source_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>file</key>
<value>/home/thales/Desktop/outfile2.wav</value>
</param>
<param>
<key>repeat</key>
<value>True</value>
</param>
<param>
<key>nchan</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(223, 186)</value>
</param>
<param>
<key>_rotation</key>
<value>180</value>
</param>
</block>
<block>
<key>gr_multiply_const_vxx</key>
<param>
<key>id</key>
<value>gr_multiply_const_vxx_1</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>complex</value>
</param>
<param>
<key>const</key>
<value>32000</value>
</param>
<param>
<key>vlen</key>
<value>1</value>
</param>
<param>
<key>_coordinate</key>
<value>(645, 315)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_rational_resampler_xxx</key>
<param>
<key>id</key>
<value>blks2_rational_resampler_xxx_1_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>ccc</value>
</param>
<param>
<key>decim</key>
<value>25</value>
</param>
<param>
<key>interp</key>
<value>32</value>
</param>
<param>
<key>taps</key>
<value>[]</value>
</param>
<param>
<key>fractional_bw</key>
<value>0</value>
</param>
<param>
<key>_coordinate</key>
<value>(371, 467)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>low_pass_filter</key>
<param>
<key>id</key>
<value>low_pass_filter_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>fir_filter_ccf</value>
</param>
<param>
<key>decim</key>
<value>2</value>
</param>
<param>
<key>interp</key>
<value>1</value>
</param>
<param>
<key>gain</key>
<value>10</value>
</param>
<param>
<key>samp_rate</key>
<value>256000</value>
</param>
<param>
<key>cutoff_freq</key>
<value>tune_filter</value>
</param>
<param>
<key>width</key>
<value>5000</value>
</param>
<param>
<key>window</key>
<value>WIN_HAMMING</value>
</param>
<param>
<key>beta</key>
<value>6.76</value>
</param>
<param>
<key>_coordinate</key>
<value>(583, 443)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>blks2_fm_demod_cf</key>
<param>
<key>id</key>
<value>blks2_fm_demod_cf_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>chan_rate</key>
<value>128000</value>
</param>
<param>
<key>audio_decim</key>
<value>4</value>
</param>
<param>
<key>deviation</key>
<value>75000</value>
</param>
<param>
<key>audio_pass</key>
<value>1000</value>
</param>
<param>
<key>audio_stop</key>
<value>16000</value>
</param>
<param>
<key>gain</key>
<value>20.0</value>
</param>
<param>
<key>tau</key>
<value>75e-6</value>
</param>
<param>
<key>_coordinate</key>
<value>(784, 443)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>low_pass_filter</key>
<param>
<key>id</key>
<value>low_pass_filter_0_0</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>type</key>
<value>interp_fir_filter_fff</value>
</param>
<param>
<key>decim</key>
<value>1</value>
</param>
<param>
<key>interp</key>
<value>1</value>
</param>
<param>
<key>gain</key>
<value>1</value>
</param>
<param>
<key>samp_rate</key>
<value>160000</value>
</param>
<param>
<key>cutoff_freq</key>
<value>1.5e3</value>
</param>
<param>
<key>width</key>
<value>2e3</value>
</param>
<param>
<key>window</key>
<value>WIN_HAMMING</value>
</param>
<param>
<key>beta</key>
<value>6.76</value>
</param>
<param>
<key>_coordinate</key>
<value>(458, 44)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<block>
<key>options</key>
<param>
<key>id</key>
<value>top_block</value>
</param>
<param>
<key>_enabled</key>
<value>True</value>
</param>
<param>
<key>title</key>
<value></value>
</param>
<param>
<key>author</key>
<value></value>
</param>
<param>
<key>description</key>
<value></value>
</param>
<param>
<key>window_size</key>
<value>1280, 1024</value>
</param>
<param>
<key>generate_options</key>
<value>wx_gui</value>
</param>
<param>
<key>category</key>
<value>Custom</value>
</param>
<param>
<key>run</key>
<value>True</value>
</param>
<param>
<key>realtime_scheduling</key>
<value></value>
</param>
<param>
<key>_coordinate</key>
<value>(2, 384)</value>
</param>
<param>
<key>_rotation</key>
<value>0</value>
</param>
</block>
<connection>
<source_block_id>low_pass_filter_0_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_1</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_rational_resampler_xxx_0_0</source_block_id>
<sink_block_id>low_pass_filter_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_rational_resampler_xxx_1</source_block_id>
<sink_block_id>gr_frequency_modulator_fc_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_frequency_modulator_fc_0</source_block_id>
<sink_block_id>gr_multiply_const_vxx_1</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_multiply_const_vxx_1</source_block_id>
<sink_block_id>usrp2_sink_xxxx_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>gr_wavfile_source_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>usrp2_source_xxxx_0</source_block_id>
<sink_block_id>blks2_rational_resampler_xxx_1_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>usrp2_source_xxxx_0</source_block_id>
<sink_block_id>wxgui_fftsink2_0_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_fm_demod_cf_0</source_block_id>
<sink_block_id>audio_sink_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>blks2_rational_resampler_xxx_1_0_0</source_block_id>
<sink_block_id>low_pass_filter_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
<connection>
<source_block_id>low_pass_filter_0</source_block_id>
<sink_block_id>blks2_fm_demod_cf_0</sink_block_id>
<source_key>0</source_key>
<sink_key>0</sink_key>
</connection>
</flow_graph>
On 21 September 2010 18:59, Rafael Diniz<raf...@riseup.net> wrote:
Hi Jorge,
Can you copy the .grc file you created?
> Hello community!
>
> I initiated myself in GNU radio two weeks ago and I am
learning as fast as
> I
> can. To begin with, I decided to play with GRC and my URSP2.
> I successfully built a FM modulator that works fine.
> I successfully built a FM demodulator that works fine.
> But there are still several things I do not understand.
>
> While building the FM modulator:
> 1)Wave file source
> 2)Rational resampler
> 3)LPF
> 4)Rational resampler
> 5)Frequency Mod
> 6)Multiply const
> 7)USRP2 sink
>
> Why is block 6 necessary? I tried with lots of values over 2
and all of
> them
> are ok. I realized that the smaller the number, the higher
the noise in my
> receiver (my mobile phone). Is it related to the amplitude
of the
> modulated
> signal?
>
> Another thing very strange is that if I create a GRC file
with both,
> transmitter and receiver with exactly the same blocks and
the same
> parameters I cannot hear any demodulated signal. I can see
information
> with
> a FFT block connected to the receiver chain, and I am able
to demodulate
> the
> signal with my mobile phone when the example is running but
in my computer
> I
> do not hear anything else besides noise mixed with some sort
of
> non-understandable signal. Thus, I guess I have to change
something in the
> receiver chain although it works alone in my FM demodulator.
I changed
> every
> single parameter but I cannot get any improvement.
>
> Any suggestions?
>
> Many thanks in advance,
> Jorge.
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