Prior to this patch, osmo-trx relied totally on proper VTY configuration
being set in "rssi-offset" together with the RxGain set through TRXC in
order to provide correct Uplink RSSI measurements to bts-trx.
With this patch, RSSI is now by default calculated (in LMS and UHD
backends) based on the currently set RxGain, by providing empirically
discovered values. Still, for backward compatibility, the old
"rssi-offset" command will overwrite completely the per-default
calculated rssi offset.
A new optional parameter "relative" is added at the end of the
"rssi-offset" VTY command to flag the value as relative to the newly
per-default calculated value. This way specific setups (like adding a
LNA / RF fronted) can still be expressed while still keeping the
automatic per-default offset.
Related: OS#4468
Change-Id: I8ef78fd20c22c60d61bfb18d80a4a36df4fd6c20
All the Tx gain related APIs are left out of reach from radioInterface,
and in there we simply interact with radioDevice passing the attenuation
received from TRXC.
Prior gain logic is moved in base radiodevice class, with the idea that
the setTxGain() and related functions will be dropped over time in each
sublcass in favour of an specific implementation of the
SetPowerAttenuation API.
Change-Id: I4f8a1bcbed74aa9310306b97b0b1bfb02f7855e6
It allows the BTS to retrieve the nominal transmit output power value of
each TRX in order to compute attenuation later on and apply it through
SETPOWER or ADJPOWER TRXC commands.
Change-Id: I1d7efe56e008d8d60e23f9a85aa40809f7f84d9c
multi-arfcn feature uses a hardcoded disposition of logical channels on
a physical channel. Logical channels in the phisical channel are
separated by MCBTS_SPACING Hz, that is 4 GSM ARFCNs.
As a result, multi-arfcn restricts the TRX ARFCN setup to the following:
ARFCN(TRX0)=N, ARFCN(TRX1)=N+1*4, ARFCN(TRX2)=N+2*4, ...
Let's make sure radioInterfaceMulti verifies the requested Rx/Tx
frequencies for each logical channel over TRXC match the restriction
explained above. It will check freq going to be set is indeed separated
by MCBTS_SPACING from already set channels, making sure the ARFCN series
is consistent.
Otherwise, before this patch, one could set in osmo-bsc:
ARFCN(TRX0)=N, ARFCN(TRX1)=N+2
and osmo-trx would silently ack the related Rx/TxTUNE TRXC commands, but
actually still transmit on ARFCN N+4 instead. As a result, in this
scenario TRX!=0 were unusable with multi-arfcn.
Related: OS#4207
Change-Id: I2f3d66a611d3a489b3e4d9431994f4ec77b4460f
Otherwise, it could happen that underrun events are lost:
TxLower (isUnderrun): RxLower (pullBuffer):
read(underrun)
read(underrun)
write(underrun, |val) [maybe underrun becomes TRUE]
write(underrun, false)
Similary, it could happen the other direction if atomic was only applied
to isUnderrun:
TxLower (isUnderrun): RxLower (pullBuffer):
read(underrun) -> true
read(underrun)-> true
write(underrun, false)
write(underrun, true|val) where val=false
So in here isUnderrun would return true twice while it should only
return one.
Change-Id: I684e0a5d2a9583a161d5a6593559b3a9e7cd57e3
Only the radioDevice->getRxGain() is called from inside
radioInterfaceMulti, so the API in radioInterface is not used at all.
Change-Id: Icc4e9a7ebfdafe7c72c535752a5e379d12592c9a
Previous naming is ready confusing, because "Radio" is actually the
common term between radioInterface and radioDevice, and it looks like
it's referring to radioInterface rather than radioDevice. On the other
hand, mDevice cleary states it refers to the radioDevice item.
Change-Id: I708bb1992a156fb63334f5590f2c6648ca27495e
This code is not needed anymore since we are setting SCHED_RR scheduler
with a real time priority in main thread during startup, so all threads
will inherit same rt priority, which should be enough to keep the
process working reliably even on high system loads (from non rt
processes).
osmo-trx was tested to be reliable during test with stress-ng as
explained in related ticket below.
Related: OS#2344
Change-Id: I3a88946dd71e9aeeaac9d19d396e2236c302b608
This way code of radioInterface is independent of the device and doesn't
need to be rebuild for each device.
Change-Id: Id104e1edef02f863b6465ced5b4241050dc188f9
The 'diversity' option was an experimental 2 antenna receiver
implementation for UmTRX. The implementation has not been
maintained and current working status is unknown.
In addition to code rot, Coverity is triggering errors in the
associated code sections.
Removal of code cleans up many cases of special handling that
were necessary to accommodate the implementation.
Change-Id: I46752ccf5dbcffbec806081dec03e69a0fbdcdb7
Requires changing the radioInterface API to pass in Rx side SPS
value. Update the (deprecated) diversity configuration to match
as well.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Add new radio interface "radioInterfaceMulti" for multi-carrier
support.
Only USRP B200/B210 devices are supported because of sample
rate requirements (3.2 Msps).
Only 4 SPS operation Tx/RX is supported.
8-PSK is supported.
Other options may be added at a later time
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Two buffers, inner and outer, are used in the transceiver
implementation. The outer buffer interfaces with the device receive
interface to guarantee timestamp aligned and contiguously allocated
sample buffers. The inner buffer absorbs vector size differences between
GSM bursts (156 or 157 samples) and the resampler interface (typically
fixed multiples of 65).
Reimplement the inner buffer with a ring buffer that allows fixed size
segments on the outer (resampler) portion and variable lengths (GSM
side) on the inner side. Compared to the previous stack-like version,
this implementation removes unnecessary copying of buffer contents.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Allow setting the device to non single SPS sample rates - mainly
running at 4 SPS as the signal processing library does not support
other rates. Wider bandwith support is required on the receive path
to avoid 8-PSK bandlimiting distortion for EDGE.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Add stop and restart capability through the POWEROFF and POWERON
commands. Calling stop causes receive streaming to cease, and I/O
threads to shutdown leaving only the control handling thread running.
Upon receiving a POWERON command, I/O threads and device streaming are
restarted.
Proper shutdown of the transceiver is now initiated by the destructor,
which calls the stop command internally to wind down and deallocate
threads.
Signed-off-by: Tom Tsou <tom@tsou.cc>
This patch add support for dual channel diversity on the receive
path. This allows two antennas two shared antennas to be used for
each ARFCN handling channel in the receiver. This configuration
may improvde performance in multi-path fading environments,
however, noise andpotential interference levels are increased due
to the higher bandwidth used.
The receive path is oversampled by a factor of four for a rate
of 1.083333 Msps. If the receive paths are tuned within a
maximum channel spacing (currently set at 600 kHz), then both
ARFCN frequencies are processed by each channel of the receiver.
Otherwise, the frequency shifted diversity path is disabled and
standard non-diversity operation takes place.
Diversity processing is handled by selecting the path with the
higheset energy level and discarding the burst on the second
path. Selection occurs on a burst-by-burst basis.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
This patch primarily addresses devices with multiple RF front end
support. Currently device support is limited to UmTRX.
Vectorize transceiver variables to allow multiple asynchronous
threads on the upper layer with single downlink and uplink threads
driving the UHD I/O interface synchronously.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Move B100 to the resampling interface with default
clocking. This temporarily resolves undetermined
FPGA clocking issues. This also provides extensible
support for multiple clocking rates and resampling
ratios.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
This patch applies oversampling, when selected with 4 sps,
to the downlink only, while running the receiver with
minimal sampling at 1 sps. These split sample rates allow
us to run a highly accurate downlink signal with minimal
distortion, while keeping receive path channel filtering
on the FPGA.
Without this patch, we oversample the receive path and
require a steep receive filter to get similar adjacent
channel suppression as the FPGA halfband / CIC filter
combination, which comes with a high computational cost.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Provides substantially improved transmit phase error
performance when enabled. Requires use of 4 samples
per symbol, and is enabled by default when set.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Replace the polyphase filter and resampler with a separate
implementation using SSE enabled convolution. The USRP2 (including
derived devices N200, N210) are the only supported devices that
require sample rate conversion, so set the default resampling
parameters for the 100 MHz FPGA clock. This changes the previous
resampling ratios.
270.833 kHz -> 400 kHz (65 / 96)
270.833 kHz -> 390.625 kHz (52 / 75)
The new resampling factor uses a USRP resampling factor of 256
instead of 250. On the device, this allows two halfband filters to
be used rather than one. The end result is reduced distortial and
aliasing effecits from CIC filter rolloff.
B100 and USRP1 will no be supported at 400 ksps with these changes.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Because repeatedly typing mSamplesPerSymbol is giving me
carpal tunnel syndrome. Replace with the much shorter,
easier to type, and just as clear name of 'sps'.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Remove the built time resampling selection and link both options.
Move the normal push/pullBuffer() calls back to the base class and
overload them in the inherited resampling class.
USRP2/N2xx devices are the only devices that require resampling so
return that resampling is necessary on the device open(), which is
the point at which the device type will be known.
The GSM transceiver only operates at a whole number multiple of
the GSM rate and doesn't care about the actual device rate and
if resampling is used. Therefore GSM specific portion of the
transceiver should only need to submit the samples-per-symbol
value to the device interface.
Then, the device should be able to determine the appropriate
sample rate (400 ksps or 270.833 ksps) and if resampling is
appropriate.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
The transceiver only uses a single integer oversampling value,
which is more simply referred to as samples-per-symbol.
mRadioOversampling --> mSPS
mTransceiverOversampling (removed)
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Periodic timing alignment should never be required for UHD devices,
though the mechanism was used as a fallback mechanism should UHD
not properly recover after an underrun - as may occur in old
003.003.000 based revisions. This issue is not a concern in more
recent UHD releases and deprecates this code for legacy USRP1
use only.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
UHD device type was previously detected, but only categorized in
terms of bus type, USB or Ethernet, and sample rate capability.
With the number of supported device increasing, we can no longer
easily group devices since we need to handle more and more
device-specific peculiarities. Some of these factors are managed
internally by the UHD driver, but other factors (e.g. timing
offsets) are specific to a single device.
Start by maintaining an enumerated list of relevant device types
that we can use for applying device specific operations. Also
rename the USB/Ethernet grouping to transmit window type because
that's what it is.
enum uhd_dev_type {
USRP1,
USRP2,
B100,
NUM_USRP_TYPES,
};
Signed-off-by: Thomas Tsou <tom@tsou.cc>
With the introduction of the B100, there is USB support
using UHD devices. The characteristics of the trasmit
side burst submissions are more reflective of the bus
type than the device or driver.
Use a fixed latency interval for network devices and the
adaptive underrun approach for USB devices - regardless
of driver or device type.
The GPMC based transport on the E100 appears unaffected
by either latency scheme, which defaults to network.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2677 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Move push and pull of buffers into a dedicated file. This will
allow us to swap out resampling, non-resampling, and possibly
floating point device interfaces while presenting a single
floating point abstration in the interface itself.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2670 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Remove radio clock and vector interfaces into their own
files. This clears up and simplifies the radio interface
and, additionaly, prepares for a further split of the I/O
portion for optional resampler use.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2669 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
Push the ability to set thread priority out to the 52M
Transceiver interface, because that's where the thread
control exists.
Signed-off-by: Thomas Tsou <ttsou@vt.edu>
git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2644 19bc5d8c-e614-43d4-8b26-e1612bc8e597
Pau Espin
Martin Hauke
Tom Tsou