discuss-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Extracting raw samples after binary slicing and C


From: Vipin Sharma
Subject: Re: [Discuss-gnuradio] Extracting raw samples after binary slicing and Correlate Access Code block
Date: Wed, 9 May 2018 18:36:04 -0700

Can anyone help with the question below?

Thanks,
Vipin

On May 4, 2018, at 12:35 AM, Vipin Sharma <address@hidden> wrote:

Hi,

I have a question about the Rx section of the flow graph here: http://aaronscher.com/GNU_Radio_Companion_Collection/Audio_Modem_loop_back_test_FSK.html.

The Rx section has a Binary Slicer block which feeds the Correlate Access Code - Tag Stream block. If I understand correctly, once the predetermined access code is detected in the data stream, the Correlate Access Code - Tag Stream tags the Payload start with len_key2 tag so that downstream blocks now only operate on Payload packet. 

My application needs a similar functionality but I would like the Payload to be the input of the Binary Slicer block (as opposed to the output of the Binary Slicer block in the link above). 

I basically don't want the sliced payload but the non-sliced version. But if I don't slice the output of Polyphase Clock Sync block in Rx section, then there isn't a binary (soft decision) value for Correlate Access Code - Tag Stream to work with? What happens if I change the IO type of Correlate Access Code - Tag Stream block to "float" type? Would it still be able to match the access code?

My application basically has some preamble, header and payload information. I simply want to implement some form of basic frame synchronization mechanism so that I can precisely define where the payload (or the frame) starts. Without frame synchronization I am unable to do frame based (or packet based) processing. However, note that, I want the raw I/Q samples (in float value) to be extracted for the payload instead of the soft decision outputs as described in the flow graph of Rx in the link above.

How do I achieve this?

Vipin


reply via email to

[Prev in Thread] Current Thread [Next in Thread]