Rather than a simple bool type, convert the diversity switch
to the device interface specifer:
enum InterfaceType {
NORMAL,
RESAMP_64M,
RESAMP_100M,
DIVERSITY,
};
The more general specifier allows passing in special cases
other then selection diversity such as multi-ARFCN support.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Previous approach was to enable 4 SPS on the receive path only
for EDGE use, which is not a requirement for 4 SPS operation.
Make the 4 SPS configuration setting directly settable.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
OsmoTRX does not support the use of multiple TSC settings per
internal TRX instance. There should not be an error to modifiy
the TSC value after POWERON. Setting TSC value on TRX channels
other then 0 is a NOP operation that should only error if the
requested TSC differs from that of TRX channel 0.
Reported-by: Max <msuraev@sysmocom.de>
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Right now if you forget to send "POWER" control command, osmo-trx
will transmitt zeros. This is counter-intuitive and I've spent several
hours debugging this "issue". The issue may happen easily, because
osmo-bts doesn't send "POWER" command if there is no "power" setting
in the configuration file. Given that "POWER" command actually sets
attenuation, it's percieved as optional and in absence of it should
default to "POWER 0" (no attenuation), which translates to power
scale being 1.0.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
So we had the following define:
#define GSMRATE 1625e3/6
Now, I wanted to use it in the following expression:
3.0/GSMRATE
which turns into:
3.0/1625e3/6
while what I really wanted is:
3.0/(1625e3/6) = 3.0/1625e3*6
To avoid this, all macros with calculations must be enclosed in parentheses.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
When you build from an external path, compiler can't find convert.h
include, because it was specified relative to the current directory.
Change this to specify the include dit relative to the Makefile
location.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Slightly widen the search range to accommodate timing jitter
on certain classes of devices. The expanded range minimizes
the possibility of missing bursts that arrive too early or
too late due to timing error.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Create runtime version check for minimum supported UHD driver
when using USRP E3XX devices. The minimum version, 3.9.0, matches
supported version on current E3XX release images.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
The majority of GSM host platforms are capable of operating with
the 4x oversampled modulator, which justifies the new default
setting. The small number exceptions (e.g. Raspberry Pi) can still
use the lower complexity 1 sps modulator with the '-s 1' command
line option if required.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Tune timing values after testing on UHD 003.009.002 for E3XX.
Table value for 1 sps was off by 10 samples causing improper
operation. Table value for 4 sps was shifted by 1 sample for
more accurate timing.
Also update E3XX description string detection.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Current UDP receive reads up to MAX_UDP_LENGTH bytes into the
passed in buffer, which may lead to buffer overflow if the
write buffer is of insufficient size.
Add mandatory length argument to UDP socket receive calls.
Reported-by: Simone Margaritelli <simone@zimperium.com>
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
EDGE 8-PSK soft slicer was receiving input from the output of the
downsampler. Equalization and derotation were missing causing the
soft symbol output to be invalid.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Delay the EDGE downlink bursts by one symbol in order to match GMSK
pulse shaping group delay. The difference in group delay arises from
the dual pulse filter combination of the GMSK Laurent represenation
whereas 8-PSK uses a single pulse linear filter.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Previously MAXDLY value was applied to Normal Bursts, which was nice
when working with sloppy test equipment like CMD57, but useless for
real world usage. At the same time documentation and de facto usage
of MAXDLY in OsmoBTS and OpenBTS assumed that it actually applies to
Access Bursts (RACH). So this patch changes osmo-rx behavior to apply
MAXDLY to RACH bursts and introduces a new command MAXDLYNB for the
old behavior.
Commit 871b8782 "EDGE: Add support for UmTRX" disabled B210 support
using EDGE. Add B210 explicitly to the timing offset table to avoid
this issue.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Timing recovery and single tap channel compensation are identical
in both GMSK and EDGE receivers. This is the section ahead of and
including the optional 4-1 downsampler. GMSK and EDGE specific
sections operate at 1 SPS.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
When EDGE is enabled with the '-e' option, the random burst generator
switches from GMSK normal bursts to 8-PSK EDGE bursts.
$ ./osmo-trx -e -r 7
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Setup generators for empty, random, and dummy bursts. This moves error
prone burst length handling out of the Transceiver and into the signal
processing core.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
At 4 samples per symbol, we don't need to maintain the 156/157 sample
slot structure to account for the GSM 156.25 sample burst length.
Set the 4 SPS Laurent modulator to ignore the guard interval setting
and always output 625 sample sized bursts. The EDGE 8-PSK modulator
already has this behavior.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Create EDGE slot type in the Transceiver. When EDGE mode is enabled
for a particular slot, blind detection will be performed by
correlating against EDGE followed by normal bursts if no EDGE burst
is found.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Setup correlator and detection process similar to the GMSK
receiver chain. Require 4 SPS sampling on both Rx and Tx paths
as 1 SPS sampling adds too much distoration for 8-PSK recovery.
Core receiver operations still run at 1 SPS with the exception
of fractional delay filtering, which runs at the higher rate.
Perform linear equalization to handle the Gaussian pulse
induced ISI. The fixed impulse response used for equalizer tap
calculation consists of combined EDGE pulse shape filter and
effects of the downsampling filter. Note that the non-adaptive
equalizer corrects for modulation induced band limiting and
does not account for or compensate for fading channel effects.
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>
DFE equalizer is unused and has been experiencing code rot for
multiple years. The effect is a significant amount of baggage being
carried in the Transceiver and interfaces.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Samples per symbol used by the transceiver is not configurable through
the socket interface once running, so stop pretending like it could be.
Initialize all tables and midambles at start.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Patch f147b174 "sigproc: Make convolution and convert input buffers
immutable" changed the internal conversion interface with the addition
of the const type qualifier. This change was not reflected on ARM builds
which led to build failure. Add const qualifier to resolve build issue.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Certain pre-release versions of the B200mini used the B205 naming, which no
longer exists. Update device naming and detection to reflect current UHD
product names.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
UHD handles built in tick and floating point timestamp conversion
since version 003.005.004. This removes the need for separate UHD
timespec to tick conversion.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Commit 90f7a01d lost "return" statement. We also should account the fact that
offset can be negative.
We should return the tuning request immediately after
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Rounding error introduced oscilating timing advance error by regularly
overwriting one bit and then skipping one bit.
This commit also adds an error message to show up in logs if this ever
happens again.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
As a side change - get rid of passing toa and amp arguments as pointers and use
references instead.
The commit doesn't change behaviour, but makes the code cleaner.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
We can't rely on an assumption that if we can't decode a burst - it's noise.
There are many rasons why we can't decode a burst even if it's well above the
noise level. Just one example is a RACH burst which can be overlapped with
another RACH burst up to a level both are completely unrecognizable. Another
example is when a burst is destroyed by bad multi-path.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
It does more harm than good. the current noise calculation is too error
prone, so we can't trust it. And we end up loosing perfectly good bursts
because of that.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
There are two primary changes in this commit:
1) Return values of detect functions changed form bool to int to actually pass
the return value from the inner function and notify higher levels about clipping.
Previously the information was lost due to conversion to bool.
2) Clipping level is not the final verdict now. We still try to demod a burst
and mark it as clipped only if the level is above the clipping level AND we can't
demod it. The reasoning for this is that in real life we want to do as much as
possible to demod the burst, because we want to get as much from our dynamic
range as possible. So a little bit of clipping is fine and is expected. We just
don't want too much of it to break our demod.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
R&S CMD57 complains about the start phase of bursts, particularly it shows
-15 to -30 deg of error for the bit 0.5 position (start tail bit). This patch
makes it happy. ETSI TS 145 004 section 2.2 describes this: "Before the first
bit of the bursts as defined in 3GPP TS 45.002 enters the modulator,
the modulator has an internal state as if a modulating bit stream consisting
of consecutive ones (di = 1) had entered the differential encoder."
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Receive thread receives data from the device, which is a more stable source of
clocking than the transmit side. If transmit side has a hiccup, osmo-trx doesn't
send the clock indication, and transmit side is getting completely lost in time.
With this patch we ensure that clock indication keeps coming.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Filler types was of "bool" type, which prevented it from taking values greter
than 1. And RAND filler type has integer value of 2, which was casted to 1 on
assigning, which led to a normal filler table being used instead of the RAND
one.
Previous behaviour used UHD command line args string for device search,
but did not apply the values to the device constructor. Now use the user
passed args string for both find and device construction.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
New UHD versions support split configuration of Tx gain stages.
We utilize this to set the gain configuration, optimal for
the Tx signal quality. From our measurements, VGA1 must be
18dB plus-minus one and VGA2 is the best when 23dB or lower.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Alert user of overdriven burst input indicated by a positive
threshold detector result. This indication serves as notification
that the receive RF gain level is too high for the configured
transceiver setup.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Non-zero buffer indices may lead to uplink/downlink timing offset
during repeated start/stop cycles. Mainly affects USRP2 and other
resampled devices that rely on the buffer to absorb sample block
sizes that are not multiples of the burst size.
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Commit 8e17df7374 "Add option for baseband frequency offset",
modified the base device API to allow for RF tuning, which was never
updated for the USRP1.
Update the implementation to match the API, however, note actual offset
in the USRP1 remains unsupported.
Signed-off-by: Tom Tsou <tom@tsou.cc>
Frequency tuning is a multi-step process with RF and DDC/DUC protoimns
that can be corrupted if both channels attempt to tune at the same time.
Signed-off-by: Tom Tsou <tom@tsou.cc>
Treat X300 similar to N200 and resample with 100 MHz base clocking,
which provides some amount of oversampling for reduced phase error
compared to the 1 sample per symbol receiver. Treat E310 similar to 13
MHz rate devices for the lowest computational use.
Signed-off-by: Tom Tsou <tom@tsou.cc>
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>
Existing implementation outputs sample buffer parameters, but it is
helpful to know the submitted timestamp that led to the errant
condition.
Signed-off-by: Tom Tsou <tom@tsou.cc>
An errant shuffle register value used in complex-complex convolution
causes distorted correlation peak-to-average values for certain TSC
values. The error effect varies for different TSC sequences with the
most noticeable effect of degraded detection on TSC 1 and no effect on
TSC 7.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Commit 15d743efaf "Disable filler table
retransmissions by default" made OpenBTS style filler table behavior
optional. When enabled, dummy bursts were automatically loaded into the
filler table, but the table was not updated and only filler busts were
retransmitted.
Enable the restransmit state flag when the filler table option is
specified. Only preload filler table and enable retransmissions on
channel zero.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Device specific timing settings for the E100 and E110 were missing from
the Tx/Rx offset table. Add E1XX identifier and offsets to the device
list and offset table respectively.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
UHD requires a small amount of time to align multiple streams at
startup. Delay the startup by 100 ms relative to the queried device time
(actual delay inclusive of control latencies will be less).
The following error is only relevant to dual-channel UHD devices (e.g.
Fairwaves UmTRX and Ettus B210).
UHD Error:
The receive packet handler failed to time-align packets.
1002 received packets were processed by the handler.
However, a timestamp match could not be determined.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Recent versions of UHD require setting the sample rate before creating
streamers otherwise the following exception occurs.
Boost_105300; UHD_003.007.000-0-g7fef199d
terminate called after throwing an instance of
'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::math::rounding_error> >'
what(): Error in function boost::math::round<d>(d): Value -nan can not be represented in the target integer type.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Allow command line setting of the DSP frequency in UHD. All channels
will be tuned with the same offset. Dual-channel tuning with the B210,
which uses a single LO, will override the command line offset value
and set the DSP frequency automatically.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
The main difference between existing UmTRX dual channel is the
single LO on B210 transmit and receive front-ends vs. independent
tuning paths. In order to support dual-ARFCN frequencies, baseband
offset conversion must be applied by tuning the FPGA CORDIC for
each channel. For B210, the following tuning order is applied.
1. If the new frequency of channel A is within the baseband range
of channel B, then retune both channels with the RF centered
and equal valued positive and negative baseband shifts.
2. If the new frequency of channel A is not with the baseband range
of channel B, then retune channel A directly (without manual
applied offset). Channel B will no longer be tuned to the
previous frequency.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
With dual-channels on B210, we lose the ability to reset both
channels to a synchronized state. Instead, let the timestamp
clock start with an arbitary value, which is the first
timestamp received from the device, instead of a near-zero
value. This approach also makes integration for device, in
general, with free-running timestamp clocks.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Change from the original USRP1 rate of 52 MHz. On B2XX we can use
26 MHz, which is closer to the default 32 MHz of the device.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Burst selection at a particular time works in the following order
of priority.
1. Slot is disabled with channel combination set to NONE (default)
1. Burst exists in priority queue for the current time.
2. Filler table entry is used
This patch sets default behaviour to force all filler table entries
to zero and disallows filler table changes. This effectively means
that only bursts received from upper layers will be transmitted and
nothing will be automatically transmitted in the absence or delay
of incoming burts at a particular time.
New Command line option "Enable C0 filler table" allows reverting
to previous idle burst generation and retransmission behaviour on
TRX0. Retransmission cannot be enabled on non-C0 channels.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
We don't require any parameters stored in the configuration table,
so don't bother with the existence of the persistent database file.
This also removes an unnecessary step during initial setup since
relevant parameters can be configured from the command line.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Equalization is currently disabled by default. As such, we don't need to
run channel estimates or even track the update state, which would
otherwise be allocating/decallocating the channel state vector at
regular intervals.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
On startup errors we get a segfault if we stop and shutdown. This
is because we try to send a stop stream command to the device before
it has been created. Setup a check for running status before
attempting to stop the physical device.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Create new main executable with full command line option parsing
of relevant parameters. Database configuration table still exists
(and must exist because of the global gConfig object), but can
be bypassed with command line options.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
We support one TSC value per each transceiver object. Only channel
zero can set this value. Other channels can attempt to set the TSC
value, but will error if the TSC does not match the existing value.
In either case, non-zero channels do not manipulate the gloabl TSC
setting.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Each ARFCN channel may be independently configureted and possibly on
separate hardware, so don't share a single vector for noise estimate
calculations. Allow a non-pointer based iterator so we can get away
with using the default copy constructor.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
The transceiver has the ability to detect bursts below the noise floor,
but little hope in successful decoding, so don't even try. We still use
the detected burst to differentiate against noise vs actual data.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
In errant cases, GSM core may send bursts with invalid slot values,
which is allowed by the GSM::Time object. If we find a burst like this
coming into the transceiver, then drop it immediately.
Signed-off-by: Thomas 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>
Tom Tsou