Re: [Discuss-gnuradio] SSB demodulation

[Johnathan Corgan]

cswiger wrote:

> Hi All - I'm making wild stabs are writing modules to demod SSB
> with REAL+IMAG or REAL-IMAG for upper and lower sideband, simply
> by cloning David Carr's gr_complex_mag module:

You have to phase delay the IMAG (Q) symbol stream by 90 degrees 
(Hilbert transform all-pass filter) prior to the addition or subtraction 
with the REAL (I) symbol stream.  (And don't forget to keep them in time 
sync; that is, whatever the sample propagation delay through the Hilbert 
filter is for the Q stream must be accounted for in the I stream prior 
to addition or subtraction.)

This is the "phasing" method of SSB modulation/demodulation, Google has 
many references.

73 de Johnathan, AE6HO