Re: [Discuss-gnuradio] How to minimize Spillage of energy in neighboring frequencies while transmission

[abhinav narain]

Hi Sylvain,

 

> You can see the spectrogram at the receiver. I want to do narrowband(1 kHz)
> transmission hence I am keeping the sampling freq at transmitter at 1k.

That sentence is just wrong. It's actually quite the opposite.

By keeping the sample rate at the transmitter at 1k, you're basically
leaving all the alias filtering to the hardware and it's just not that
good.

What is alias filtering ? I have hear about anti-alias filters. Apologies as I am a CS student

but interested in radios and hence working on the project. I might be missing something 

obvious.

 

You would be much better off oversampling the TX by like 10 and then
do digital filtering to make sure you filter out anything in the
higher freq.

You mean at 400k center freq, I have a sample_rate of 400k X 10 = 4M ?

Isn't this going to increase my transmisson BW ? 

Sure, I can do that with low pass filter at the receiver, but I don't want a massive frequency 

spectrum signature on the channel itself. My priority/requirement is to keep my transmission detectability

in the spectrum as low as possible.

Looking for your comments,

Abhinav

Cheers,

   Sylvain

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio