>Make sure both your radios are locked to the same clock source.
Any fsignificant requency offset between the two is going to ruin your
correlation peaks very quickly.
When the same clock source is not possible due to the distance between them, the carrier frequency offset can also be estimated and corrected at the initiating USRP and then the correlation can be applied. In this scenario, the quality of the result will depend on how good the CFO estimate is.
Message: 4
Date: Tue, 26 Feb 2019 10:07:51 +0100
From: Sylvain Munaut <address@hidden>
To: Jonathan Preheim <address@hidden>
Cc: GNURadio Discussion List <address@hidden>
Subject: Re: [Discuss-gnuradio] Distance Measurement by Correlation
Message-ID:
<CAHL+j0-D_THTOqoapb2N6VeLeR=BEkW9cyDHpt64=address@hidden>
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> Any ideas about how we can troubleshoot this more effectively? Or better model the channel?
Make sure both your radios are locked to the same clock source.
Any fsignificant requency offset between the two is going to ruin your
correlation peaks very quickly.
Frequency offset is going to end up as a progressive phase shift along
your PN sequence. If that phase shift is a non-negligibe part of the
unit circle during the time of your PN sequence, they won't 'add up'
to a peak anymore.
Cheers,
Sylvain
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