Re: Question on Gnuradio Polyphase Channelizer Block?

Hello Joao,

It works (caveat to a point)!

I have tested it with QPSK Modulated signals. It works to a point, but the Channelized output is not completely correct. Channel-0 time series (real and imaginary components) are good, but the time series from the other channels are a little distorted. I have written the code for a channelizer in Matlab and the output modulated time series is perfect on all channels.

I may have to write one, which I was not planning on doing.

George

On Tue, Dec 22, 2020 at 10:18 AM <joao@phygitall.rio> wrote:

Here you are!

I just downloaded the .xml file and renamed it to .grc. It seems to work, but I am using GNU Radio 3.8.2.0. See if it works for you.

Cordially,

João

On December 22, 2020 at 1:35:29 pm -03:00, George Edwards <gedwards.eng@gmail.com> wrote:

Hi Ron,

That is good! I have Gnuradio 3.7.13.4 on one of my computers. Please send me the grc file as an attachment as soon as you can.

This way, I can learn how to use the Gnuradio Polyphase Channelizer block.

Thank you!

Respectfully,

George

On Tue, Dec 22, 2020 at 8:58 AM Ron Economos <w6rz@comcast.net> wrote:

It's a GNU Radio 3.7 flow graph. It can be converted by GNU Radio 3.8.

Ron

On 12/22/20 07:47, George Edwards wrote:

  Hi Ron,

Thanks again for your help.

When I click on the link you provided, I get the XML file. Please send me the actual grc file as a standalone.

Thank you!

Regards,

George

On Mon, Dec 21, 2020 at 2:47 PM Ron Economos <w6rz@comcast.net> wrote:

You should probably use an add block instead of Streams to Stream.

Here's an example flow graph.

http://www.w6rz.net/pfb-filter-10.grc

Ron

On 12/21/20 11:20, George Edwards wrote:

> Hello,

>

> I have three signals routed to the Gnuradio Polyphase Channelizer

> Block. The system operates at a sample rate of 90 kHz with 3 channels

> spaced 25 kHz apart. One channel is centered around DC and the other

> two at +/-25 kHz. The 3 waveforms are routed into a Gnuradio Streams

> to Stream Block, so that a simple concatenated stream flows into the

> Gnuradio Polyphase Channelizer. I also set the Channelizer Block to

> use 120 Taps and provide 3-outputs. Here are my questions on observing

> the outputs

>

> Q1. I was expecting each output (block set to 3 outputs) to be at the

> sample rate (90 kHz/3 =) 30 kz in each of the 3-plots. The plots show

> a sample rate based on the original rate of 90 kHz. Why is this?

>

> Q2. I expected each output waveform to be centered around DC, but they

> were instead centered around -25 kHz. Why?

>

> Q3. The output bandwidth for each waveform seems a little bigger than

> the input, why?

>

> I will appreciate any help that assists to point me in the right

> direction.

>

> Regards,

> George