This patch fixes some confusion in gain vs. attenuation
setting. The UHD device is controlled through gain
settings but OpenBTS represents gain in terms of
attenuation relative to maximum - 0 dB attenuation.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2662 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Commit e161523c (transceiver: simplify transmit power control)
changed transmit gain control to RF setting only. This was
appropriate for a WBX board with 25 dB of gain control, but
inappropriate for an RFX with fixed transmit gain.
RFX boards will regain the ability to set transmit
attenuation. Since gain is set on the RF side first,
reintroducing digital gain settings should have limited
overall effect on non-RFX daughterboards.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2660 19bc5d8c-e614-43d4-8b26-e1612bc8e597
UHD will internally accept floats with a range of +/-1.0,
which corresponds to a 16-bit signed integer range of
apporximately +/- 32000. Set the default amplitude to .3,
which is a safe value agaist saturation elsewhere in the
transmit chain.
The non-UHD maximum amplitude is unchanged at 13500.
Remove digital gain control because it's unnecessary and
causes extra load on enbedded systems.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2654 19bc5d8c-e614-43d4-8b26-e1612bc8e597
The output of the modulator or resampler is scaled and
converted from floating point to fixed point. The scaling
factor is the leftover dB in RF attention (relative to max
transmit power), which is handled prior to the integer
conversion. This should work across all daughterboards and
non-UHD installations.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2650 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Previously this was referenced off the the ad9862
PGA with a range from 0 to -20 dB. Instead base
the attenuation factor on the maximum total RF
gain returned by the device.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2649 19bc5d8c-e614-43d4-8b26-e1612bc8e597
