RRC frequency_response missing about komm

[mbe9a]

Also if I wanted to incorporate oversampling into the filter design, how would I do that?

[rwnobrega]

Thanks for the feedback! This is indeed a bug. I'm working on it.

[rwnobrega]

I just saw you fixed this on 188b094. So I merged into master. Thank you!

[mbe9a]

No problem my man!

I think I figured out what you are doing to design the pulses too. I like it!

The 't' array you provide the pulse function defines everything -- the spacing between time points does actually. The way I incorporated 4X oversampling was making the spacing between points in 't' 0.25. Essentially making 4 points for every '1' unit of time/samples. This is how you intended it yes? It took me a while to figure that out because I've only ever used matlab filter design before.

[rwnobrega]

Also if I wanted to incorporate oversampling into the filter design, how would I do that?

Oversampling can be accomplished with komm.TransmitFilter. For example:

In [1]: import komm                                                                                                                                                                           

In [2]: pulse = komm.RectangularPulse()                                                                                                                                                       

In [3]: tx_filter = komm.TransmitFilter(pulse=pulse, samples_per_symbol=4)                                                                                                                    

In [4]: tx_filter([1, -1, 0.5])                                                                                                                                                               
Out[4]: array([ 1. ,  1. ,  1. ,  1. , -1. , -1. , -1. , -1. ,  0.5,  0.5,  0.5,  0.5])

In [5]: tx_filter([1])                                                                                                                                                                      
Out[5]: array([1., 1., 1., 1.])

The example above uses komm.RectangularPulse, but should work with other pulses.

The 't' array you provide the pulse function defines everything -- the spacing between time points does actually. The way I incorporated 4X oversampling was making the spacing between points in 't' 0.25. Essentially making 4 points for every '1' unit of time/samples. This is how you intended it yes? It took me a while to figure that out because I've only every used matlab filter design before.

Yes, you are right, you could also do that. Perhaps the docs should be improved (e.g., pointing to komm.TransmitFilter).

[mbe9a]

Oh very cool. I will use that from now on.

[rwnobrega]

By the way, maybe length_in_symbols should be a property of TransmitFilter instead of SincPulse, RaisedCosinePulse, RootRaisedCosinePulse, and GaussianPulse. Opinions are welcome.