Re: [Discuss-gnuradio] Trouble with SSB demod of real signal

[Louis Brown]

Tom,

OK I got it fixed after looking at your link.  See diagram below:

https://dl.dropboxusercontent.com/u/49570443/test.grc_fixed.png

I was using the Delay block to give me a 65 sample delay to account for the 
delay in the Hilbert.  This will not work as I assume there is more delay in 
the Hilbert than just the 65 taps.  The real output of the Hilbert is a 
properly delayed version of the input, so I replaced the delay with that.  It 
now works well  What's shown in the diagram is LSB though, not USB.

Thanks,
Lou KD4HSO



On Feb 16, 2014, at 11:19 AM, Tom McDermott <address@hidden> wrote:

> Hi Lou - the diagram you sent isn't going to perform a single-signal 
> conversion.
> Taking just the real part of the received signal (and throwing away the 
> imaginary part)
> gets rid of information that distinguishes negative frequency components from
> positive frequency components. After that point there is no possibility to 
> separate out
> the LSB components from the USB components.
>  
> You will need a bit more complicated design, I've used the following 
> configuration for
> implementing a phasing type receiver. There are other ways as well, the 
> Weaver method,
> and a filter method (using complex taps to a filter).
>  
> http://www.tapr.org/~n5eg/index_files/DCC_2013_Gnuradio_Presentation%20-%20Rev%205.pdf
>  
> Look at about slide 14.
>  
> -- Tom, N5EG
>  
> 
> 
> 
>