Difference between revisions of "Dynamic Channel Model"

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(Created page with "Category:Block Docs Category:Stub Docs This is the template for the "Page-per-block Docs". This first section should describe what the block...")
 
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[[Category:Block Docs]]
 
[[Category:Block Docs]]
[[Category:Stub Docs]]
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The dynamic channel model is a hier block consisting of the following effects:
This is the template for the [[:Category:Block_Docs|"Page-per-block Docs"]].  This first section should describe what the block does and how to use it, using however many paragraphs necessary.  Note that the title of the wiki page should match the block's name in GRC, i.e. the one defined in the block's .grc file.  Look at the [[FFT]] Block for a good example.
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* Dynamic Frequency Selective Fading Channel
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* Dynamic Center Frequency Offset Model
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* Dynamic Sample Rate Offset Model
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* Additive White Gaussian Noise
  
As this is a basic template, it's also in the [[:Category:Stub_Docs|"Stub Docs category"]]. Please improve it.
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The desired power delay profile and max doppler frequency may be provided to achieve the desired Ricean or Rayleigh fading scenario.  For center frequency and sample rate offset models, a gaussian random walk process is conducted for each.  The single sample step variance and maximum deviation for these two processes is specified and may be modified to simulate various desired stability effects.  Lastly AWGN is added to simulate a typical receiver/thermal noise floor after propagation, and the variance may be modified here as desired.
  
 
== Parameters ==
 
== Parameters ==
 
(''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>
 
(''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>
  
; Param 1 (''R'')
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; samp_rate (''R'')
: Description of parameter, provide any tips or recommended values.  Note that the name of the parameter above should match the param's label that shows up in grc (e.g. Sample Rate).
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: Input sample rate in Hz
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; cfo_std_dev (''R'')
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: carrier frequnecy drift process standard deviation per sample in Hz
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; cfo_max_dev (''R'')
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: maximum carrier frequency offset in Hz
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; sro_std_dev (''R'')
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: sample rate drift process standard deviation per sample in Hz
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; sro_max_dev (''R'')
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: maximum sample rate offset in Hz
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; noise_amp (''R'')
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: Specifies the standard deviation of the AWGN process
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; N (''R'')
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: number of sinusoids used in frequency selective fading simulation
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; doppler_freq (''R'')
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: maximum doppler frequency used in fading simulation in Hz
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; LOS_model
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: defines whether the fading model should include a line of site component. LOS->Rician, NLOS->Rayleigh
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; K
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: (Only if Rician is chosen above) Rician K-factor, the ratio of specular to diffuse power in the model
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; noise_seed
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: A random number generator seed for the noise source.
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; delays
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: A list of fractional sample delays making up the power delay profile
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; mags
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: A list of magnitudes corresponding to each delay time in the power delay profile
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; ntaps_mpath
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: The length of the filter to interpolate the power delay profile over. Delays in the PDP must lie between 0 and ntaps_mpath, fractional delays will be sinc-interpolated only to the width of this filter.
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; Param 2
 
: blah blah blah
 
  
 
== Example Flowgraph ==
 
== Example Flowgraph ==

Revision as of 00:48, 18 August 2019

The dynamic channel model is a hier block consisting of the following effects:

  • Dynamic Frequency Selective Fading Channel
  • Dynamic Center Frequency Offset Model
  • Dynamic Sample Rate Offset Model
  • Additive White Gaussian Noise

The desired power delay profile and max doppler frequency may be provided to achieve the desired Ricean or Rayleigh fading scenario. For center frequency and sample rate offset models, a gaussian random walk process is conducted for each. The single sample step variance and maximum deviation for these two processes is specified and may be modified to simulate various desired stability effects. Lastly AWGN is added to simulate a typical receiver/thermal noise floor after propagation, and the variance may be modified here as desired.

Parameters

(R): Run-time adjustable

samp_rate (R)
Input sample rate in Hz
cfo_std_dev (R)
carrier frequnecy drift process standard deviation per sample in Hz
cfo_max_dev (R)
maximum carrier frequency offset in Hz
sro_std_dev (R)
sample rate drift process standard deviation per sample in Hz
sro_max_dev (R)
maximum sample rate offset in Hz
noise_amp (R)
Specifies the standard deviation of the AWGN process
N (R)
number of sinusoids used in frequency selective fading simulation
doppler_freq (R)
maximum doppler frequency used in fading simulation in Hz
LOS_model
defines whether the fading model should include a line of site component. LOS->Rician, NLOS->Rayleigh
K
(Only if Rician is chosen above) Rician K-factor, the ratio of specular to diffuse power in the model
noise_seed
A random number generator seed for the noise source.
delays
A list of fractional sample delays making up the power delay profile
mags
A list of magnitudes corresponding to each delay time in the power delay profile
ntaps_mpath
The length of the filter to interpolate the power delay profile over. Delays in the PDP must lie between 0 and ntaps_mpath, fractional delays will be sinc-interpolated only to the width of this filter.



Example Flowgraph

Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.

Source Files

C++ files
TODO
Header files
TODO
Public header files
TODO
Block definition
TODO