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RF Upsampling (Read 3876 times)
Aomeen
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RF Upsampling
Jun 22nd, 2005, 4:58am
 
Hello all,

I'm a new designer in the field of RF system design..

I'm designing an RF system on ptolemy , in order to improve the accuricy , I had to perform RF upsampling with raised cosine filtration "intterpolation filter"

Two problems exists,first upsampling causes the constallation of my received signal "64 QAM" to be completely destroyed , even after down sampling , second the signal level at RF  is changed when compared to no upsampling case.

Sorry for the long topic.
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pancho_hideboo
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Re: RF Upsampling
Reply #1 - Aug 2nd, 2005, 3:23am
 
Hi.

Which Upsampler do you use, TSDF_USampleRF or SDFUpSample ?
We can use both timed and numeric components, but I think timed components is easier for RF engineer.

Even though you insert FIR interpolation filter(Raised Cosine Filter), there still exist unnecessary image.
So you have to insert continuous time LPF or increase up-sampling ratio.

And about amplitude issue after decimation, do you set compensation gain for interpolation filter ?
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