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>
Separate the large pullRadioVector() call, which forms the central
portion of the receive path burst processing. Break out RACH, normal
burst, and demodulation into separate methods. This makes the burst
handling from the FIFO read to soft bit output somewhat more
manageable.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
The call into table lookup will loop on values outside of the
table range. With continuously increasing phase, this leads
to an eventual permanent hard spin. Wrap the phase value to
prevent that from happening.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
As we add more channel combintions including but not limited to
new devices, signal processing schemes, and diversity, we'll
need to handle more special cases. Add string descriptions for
just a bit more sanity.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
This patch allows multiple signalVectors to be stored within
a single radioVector object. The motivation is to provide
a facility for diversity and/or MIMO burst handling. When
no channel value is specified, single channel bevhaviour
is maintained.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Stack allocating the correlation output generates a call to the copy
constructor of an zero valued vector. We can avoid this extra copy
constructor with a pointer reference and dynamic allocation.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Allow non-in-place use of the delay setting. Internally, the delay call
creates a new vector and copies the contents back into the original.
Instead, provide the option to return the computed output vector
directly and remove an an extra copy in the process.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
On Beagle Board the call into the sinc() function is generating a lot of
load on the peak interpolation. Simplify the sinc() function with a
dedicated table lookup. Eventually, this table may be removed in favour
of using a precomputed filterbank for fractional delay determination.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Set a transceiver high level length value that specifies the largest
number of complex or real filter taps that we will encounter. This
allows preallocation of head room and prevents an extra allocation and
copy on every incoming receive burst.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
With testing on current UHD releases, currently 003.005.xxx series,
timeout errors on both receive and transmit are recoverable on network
and USB based devices. Remove the fatal error conditions.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Clock indications passed up to GSM core originate on the transciever
downlink side. Set priority to keep the flow of clock updates
consistent.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
This includes ARM Cortex A8 and A15 powered device such as Beagle
Board, Gumstix driven E100 USRP, and Arndale board. Set the reduced
SPS value automatically for the user.
For x86, if we don't support SSE3, then the architecture is
probably ancient and not with using. Drop the sampling down anyways
to at least make an attempt. Non floating point SIMD devices (e.g.
Raspberry Pi) also fall in this category
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Preallocate and compute a bank of fractional sample delay filters.
The number of filters to allocate is specified by the DELAYFILTS
preprocessor definition with a default value of 64. The filters
themselves are sinc pulse generated with 20 taps and Blackman-harris
windowed .
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Currently the code allocations a signalVector and then copies
into a radioVector. This is unnecessary because the latter is
a derived class making the first allocation unnecessary.
Modify the radioVector constructor to allow direct use in the
case above.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
This prevents the use of a copy constructor in the downlink
modulator and prevents a secondary memory allocation during
the convolution. Avoid both cases by dynamically allocating
with preloaded head room. The latter provides enough memory
before the first sample in the burst to cover the length
of the filter taps.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Complex-complex block multiples are used for phase rotation of
bursts. Optimization targeted from perf profiling.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
B2xx is a USB based device so use the USRP1 based adaptive flow
control window for transmit bursts. This adds additional stability
primarily on ARM platforms.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Similar to the existing Intel SSE cases, add support for NEON vector
floating point SIMD processing. In this case, use ARM assembly
directly as the NEON intrinsics do not generate preferential code
output.
Currently support NEON vectorized convolution and floating point
integer conversions.
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>
USRPping and sigProcLibTest are in an unmaintained state,
while the intended functionality remains unknown. Stored
filter taps are also unused and should also be removed.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Collect the slot information into an indpendent state object. This
will allow us to easily create multiple instances of internal state
variables without having to replicate the transceiver object itself.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
For multiple transceiver connections, it is inappropriate to
allocate all sockets in the transceiver constructor due to not
knowing how many connections are avaialble in advance and for
error checking purposes. Instead, store the base socket address
port combination and setup the sockets in the initialization
call.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
The current status and operability of this compile option is
unknown. Remove due to lack of use, demand, and maintenance.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Underruns are only explicitly set on the downlink side. Overruns
are logged but unused. In either case, reset indicators to false
to avoid sending false state information.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
Tom Tsou