# I have a Question about channel model parameters

**URL:** <https://www.ruby-forum.com/t/i-have-a-question-about-channel-model-parameters/228668>\
**Category:** GNU Radio\
**Created:** [May 2, 2013, 1:15pm UTC](https://www.ruby-forum.com/t/i-have-a-question-about-channel-model-parameters/228668 "2013-05-02T13:15:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Irfan\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/57b2e6/32.png) [@Irfan\_U](https://www.ruby-forum.com/u/Irfan_U)\
**Post date:** [May 2, 2013, 1:15pm UTC](https://www.ruby-forum.com/t/i-have-a-question-about-channel-model-parameters/228668/1 "2013-05-02T13:15:00Z")

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hi all,

Now a days i am working on cooperative communication and i am  
simulating my communication on channel model block but i don’t know the  
purpose of the some parameters of channel model block like epsilon?,  
taps?, and frequency offset? can somebody tell me the purpose of these  
parameters

regards, Irfan U.

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**Author:** ![Irfan\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/57b2e6/32.png) [@Irfan\_U](https://www.ruby-forum.com/u/Irfan_U)\
**Post date:** [May 2, 2013, 3:34pm UTC](https://www.ruby-forum.com/t/i-have-a-question-about-channel-model-parameters/228668/2 "2013-05-02T15:34:03Z")

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Irfan,

epsilon: Simulates Sampling-Clock-Mismatch. It uses rational-resampling  
for  
interpolation/decimation. value=1 means no-mismatch i.e.  
in-samp-rate=out-samp-rate. value=1.00001 means receiver clock is  
fast(sample added). value=0.9999 means rcvr clock is slow  
(sample-skipped).  
useful for testing Timing-Synch. Algo’s

taps: Filter taps to simulate channel-response. Useful for testing  
Equalization Algo’s

frequency offset: Simulates Tx/Rx-Freq Mismatch. Useful for testing  
Freq-Synch. Algo’s

-Adeel

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<div class="post-metadata">

**Author:** ![Irfan\_U](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/i/57b2e6/32.png) [@Irfan\_U](https://www.ruby-forum.com/u/Irfan_U)\
**Post date:** [May 2, 2013, 3:52pm UTC](https://www.ruby-forum.com/t/i-have-a-question-about-channel-model-parameters/228668/3 "2013-05-02T15:52:45Z")

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On Thu, May 2, 2013 at 9:33 AM, Adeel A. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> > ```
> > Now a days i am working on cooperative communication and i am
> > 
> > ```
> > 
> > simulating my communication on channel model block but i don’t know the  
> > purpose of the some parameters of channel model block like epsilon?, taps?,  
> > and frequency offset? can somebody tell me the purpose of these parameters
> > 
> > regards, Irfan U.

They are also described in the manual:

[http://gnuradio.org/doc/doxygen/classgr\_1\_1filter\_1\_1channel\_\_model.html](http://gnuradio.org/doc/doxygen/classgr_1_1filter_1_1channel__model.html)

Tom