Optimization for unused symbols in NR UE
After processing TX frequency domain data skip IFFT call for symbols
that aren't used, the time domain buffer is memset instead.
Biggest benefit is when UE does not transmit PUSCH, or PUSCH is using <
14 symbols
feat(oran_fhlib_5g): O-RAN 7.2 FrontHaul Interface on Arm
This MR is enabling the 7.2 FHI on Arm systems.
Even though the performance are yet very bad (UE connection is very
difficult, 100Mbps DL, almost no UL), still I would like to merge this
now since the matter of making the FHI work is rather orthogonal to the
performance issues.
So merging this feature would provide a reliable settlement on top of
which we could then progressively enhance the porting of OAI to Arm.
Especially that would make our work easier by having less features to
rebase regularly on develop.
The main features this MR is made of are:
1. Make the xran patches dual
We provide patches for both E and F releases of xran that handles x86
targets as well as Arm targets. Both patches have been tested on both
types of machines (armix, broadbill). Thanks to @brobert and @changy
for their work on xran.
2. Perform 9-bits BFP compression with ArmRAL
Since the BFP compression implementation provided with xran does rely
heavily on AVX512, we provide an alternative implementation that is
relying on Arm's RAN Acceleration Library (ArmRAL).
As of writing this commit description, only 9-bits compression is
supported. Other IQ width will be added.
This upcoming change does not prevent review to be performed since the
BFP compression functions of ArmRAL are identical except for the IQ
width. Adding further IQ width is therefore very straightforward.
3. Fixes in oran_fhlib_5g to support Arm
The library oran_fhlib_5g needed few changes to successfully compile and
run on Arm systems. Thanks to @brobert for his work on oran_fhlib_5g.
Remove include of SIMDE Neon header sse_intrinsic.h to compile on ARM. Otherwise the error below is issued.
```
/usr/include/simde/arm/neon/get_lane.h:279:5: error: incompatible type for argument 1 of ‘vget_lane_f16’
279 | SIMDE_CONSTIFY_8_(vget_lane_f16, r, (HEDLEY_UNREACHABLE(), SIMDE_FLOAT16_VALUE(0.0)), lane, v);
removed the inclusion of neon.h
```
Shared memory realtime radio simulation
Realtime and near-realtime RFSimulator alternative without channel modelling.
The purpose of this library is to allow realtime simulation of gNB and nrUE.
The library is loaded using --device.name vrtsim. The server side (gNB) should
also configure --vrtsim.role server and --vrtsim.timescale according to
requirements.
Limitations:
- Only 1UE-to-1gNB connection supported
Future work:
- Telnet API
Fix ULSCH ID type to handle large max_nb_pusch values (ULSCH procedures)
The ULSCH_id variable is currently defined as uint8_t, which limits its
range to 0-255. However, gNB->max_nb_pusch can exceed this range
depending on the configuration (buffer_ul_slots and
MAX_MOBILES_PER_GNB). This can lead to incorrect behavior or undefined
results when max_nb_pusch is larger than 255. This commit changes the
type of ULSCH_id from uint8_t to int to accommodate larger values of
max_nb_pusch.
The issue was observed when running the OAI gNB with MAX_MOBILES_PER_GNB
set to 64 UEs. The root cause was traced back to the changes to UL
processing introduced in !2952.
remove ul_ch_estimates_time to save memory
remove ul_ch_estimates_time that saves 50MB memory to access in RAM, and
make better quality scope data passing (no race)
Add support for ARM build pipeline
Modify the existing python code to be able to build images where the
image tag can be prepended with a prefix, here arm_. This is preparatory
work to create the ARM build image pipeline, and reuse the existing
internal registry on porcepix to have x86 and ARM images coexist.
Fix various bugs in the build system to allow to build on a system with
as many cores as gracehopper.
Also, fix two programs (usim, nvram) to work correctly under ARM.
Miscelaneous improvements in PHY simulators
1: Add a SIGINT handler to NR PHY simulators
When using T2 virtual functions, it is important to properly stop DPDK
and free the device. Otherwise the virtual functions may be blocked and
a restart of the admin application is necessary.
If not carefully done, such kind of operation can lead to losing cores
to DPDK processes that cannot be stopped. This can lead to situations
where the machine is locked and can only be unlocked by a power cycle.
Always properly stopping DPDK and freeing the device reduces the risk of
such situation to happen.
Up to now, SIGINT was shutting down the PHY simulators without freeing
the device. This commit adds a signal handler to handle SIGINT in a way
that allow to properly free the device.
This feature is added to all the NR PHY simulators whether they use T2
or not in case it is now or later of any use.
2: Make nr_ulschsim functional
There were two issues that were making nr_ulschsim non functional:
1. The channel output was not copied to decoder input (llr array)
2. The test on decoding successful outcome was wrong
The result was that nr_ulschsim was succesfull whatever were its
arguments. This changeset fixes the two issues so that nr_ulschsim is
now functional.
Harmonize and update Frequency Range computation to the current values
specified by the standard
3GPP TS 38.101-1 Version 19.0.0 Table 5.1-1: Definition of frequency
ranges
- FR1 from 410 MHz to 7125 MHz
- FR2 from 24.25 GHz to 71 GHz
1. Change the name of `openair1/SIMULATION/NR_PHY/nr_dummy_functions.c` into `openair1/SIMULATION/NR_PHY/nr_unitary_common.c` for naming coherence after adding the SIGINT handler which is not a dummy function.
2. Instead of being built once for every NR PHY simulators, the common functions source file is built once as an object and linked to each simulator.
The ULSCH_id variable is currently defined as uint8_t, which limits its
range to 0-255. However, gNB->max_nb_pusch can exceed this range
depending on the configuration (buffer_ul_slots and MAX_MOBILES_PER_GNB).
This can lead to incorrect behavior or undefined results when max_nb_pusch
is larger than 255. This commit changes the type of ULSCH_id from uint8_t
to int to accommodate larger values of max_nb_pusch.
The issue was observed when running the OAI gNB with MAX_MOBILES_PER_GNB set
to 64 UEs. The root cause was traced back to the changes to UL processing
introduced in !3166 (!2952).
Even though the remaining NR PHY simulators do not use the T2, we may still feature them with a SIGINT handler for proper termination on SIGINT and for a matter of completeness.
The remaining NR PHY simulators are:
* nr_pbchsim
* nr_prachsim
* nr_psbchsim
* nr_pucchsim
There was two issues that were making nr_ulschsim non functional:
1. The channel output was not copied to decoder input (llr array)
2. The test on decoding successful outcome was wrong
The result was that nr_ulschsim was succesfull whatever were its arguments.
This commit fixes the two issues so that nr_ulschsim is now functional.
When using T2 virtual functions, it is important to properly stop DPDK and free the device.
Otherwise the virtual functions may be blocked and a restart of the admin application is necessary.
Up to now, SIGINT was shutting down the PHY simulators without freeing the device.
This commit adds a signal handler to handle SIGINT in a way that allow to properly free the device.
This feature is first added to the PHY simulators that use the T2 which are `nr_ulsim`, `nr_dlsim`, `nr_ulschsim` and `nr_dlschsim`.
Various libraries in this commit use the log headers (that is the
direct dependency). The log headers in turn include the T headers
(transitive dependency). Building on gracehopper with its many cores
triggers the build of these libraries before T headers have been
generated.
To resolve this and force the generation of T headers before building
the libraries, correctly express their dependency on the log headers,
which in turn ensures that T headers have been generated.
Depending on log_headers is preferrable because it is really the headers
that we depend on. Using instead e.g., utils, would trigger build of
source files, that we don't need for these libraries. This commit is
part of a larger cleanup that I have that is not merged yet. Follow-up
work will generalize this in the repo, and ensure that every(!) library
builds.
We have to add CONFIG_LIB, as the log module has a direct dependency
onto the configuration module (it uses it). I am not sure why this was
not relevant before.
fix(nrLDPC_decoder): fix numIter increment
The logs of ./nr_ulsim -n100 -m19 -s12 -S12 -z2 -L4 were showing that sometimes
the decoding of one segment was failing while the CRC check succeeded. This was
happening because the iteration counter numIter was not properly managed so that
when the last iteration was successful to decode the segment still numIter at
the exit was equal to numMaxIter plus 1 so that decoding was considered to have
failed. In other words the last iteration if it occured was always wasted.
This commit offers to solve this problem by simply moving the iteration counter
increment at the end of the iteration loop while remaining careful at fixing the
tests relying on this counter.
Post-Scriptum:
After a first review, we decided to make the counter more standard from a C code
perspective. The counter now counts from 0 to numMaxIter minus 1. If it reaches
numMaxIter, it means that decoding was unsuccessful.
The idea is to make LDPC iteration accounting more standard from a C coding perspective by making two changes:
1. Now the iteration counter starts at 0 for the first iteration and goes up to max_ldpc_iterations - 1 for the last iteration.
If it is equal to max_ldpc_iterations, it means that decoding failed.
2. A chain of useless returns in the UE DLSCH decoding call chain was removed.
Robert Schmidt