New LDPC coding library interface for decoding and encoding complete slots in one call to the library
Previous attempts to integrate LDPC decoding relying on offloading show
the limitation of the original code segment coding interface for the
library implementing LDPC coding. In order to perform the offload and
therefore the decoding in an optimal fashion, it is relevant to provide
the implementation with the broader amount of data possible per call,
which is a slot. A previous MR related to T2 offload managed to offer
an interface for decoding transport blocks by modifying only
nr_ulsch_decoding.c. But this may not be sufficient for performing an
efficient decoding in any situation. Slots could be shared between
multiple transport blocks in case multiple UEs are connected to the RAN,
which makes the transport block size shrink and therefore degrades the
efficiency of the offloading.
This MR offers a broader interface with a gNB decoding entry point in
phy_procedures_nr_gNB.c. The file nr_ulsch_decoding.c now lets the
decoding library implement deinterleaving, rate-unmatching and decoding
for the slot. In gNB encoding and UE decoding and encoding as well,
tasks are partitioned in a similar fashion.
As it allows to feed the implementation with the broadest amount of data
possible, it allows to fit any coding solution in a library. This will
avoid further modification to OAI source code and addition of options to
select an implementation when integrating new decoding solutions. An
implementation of this interface will therefore be offered for every
existing decoding solution in OAI and solutions added in the future will
be provided as independent module code without any modification to the
core of OAI code. The way to choose the decoding solution and to
configure it was also unified using configmodule. The library can be
chosen through the option --loader.ldpc.shlibversion. The slot coding
solutions shipped with this MR can be configured through configmodule
(e.g., T2 address and isolated cores).
This MR includes three coding implementations:
- A wrapper around segment decoding libraries for test purpose: libldpc.so
- A one shot slot coding and encoding with the T2 board: libldpc_t2.so
- A decoder on FPGA using the XDMA driver: libldpc_xdma.so
Improvements brought by this MR:
- Easy integration of a wider variety of LDPC coding solution at gNB and UE
- Easy selection of the LDPC coding solution (option --ldpc-offload-enable is kept for now but it can be ultimately removed)
- T2:
* More efficient when many UEs are connected
* Decoding and encoding in nr-uesoftmodem
- Removed ntn_koffset, ntn_ta_common, ntn_ta_commondrift arguments in order to be used directly from SIB19
- Removed global NTN_UE_Koffset variable and it's use
- Introduced getter functions for ntn related parameters
- removed some whitespace noise.
- cleaned up CMakeLists.txt
- reintegrated task_manager.c into thread-pool.c
- cleaned up some unnecessary code
Co-authored-by: Cedric Roux <cedric.roux@eurecom.fr>
Co-authored-by: Mikel Irazabal <mikel.irazabal@openairinterface.com>
Refactor of includes in gNB/UE for improved header management
This merge request implements changes suggested by the Include What You Use
(IWYU) open source tool to streamline the project’s header file usage.
The adjustments ensure that each file includes only the necessary headers for
the symbols it uses, making the code more efficient and maintainable.
Unnecessary includes have been removed, and missing headers have been added
where required. This improves modularity and reduces inter-dependencies between
files, helping to avoid future build issues caused by unused or missing includes.
Each output has been manually reviewed.
Followed a similar approach as in !2953 (merged).
Affected folders/files:
- NR_MAC_gNB/main.c
- nr-softmodem.c
- unitary simulators: nr_dlsim, nr_ulsim, prachsim
- openair2/RRC/NR
- openair3/NGAP
- openair2/LAYER2/nr_pdcp
- openair2/SDAP/nr_sdap
Upon press of ^C, the UE triggers a NAS deregistration. This does not
work in do-ra or phy-test modes, because there is no NAS. Therefore, in
non-SA modes, just stop the UE directly.
Set SA mode as default
- Set standalone (SA) mode as the default.
- Adjust commands in Docker Compose files by removing --sa flags and
adding --nsa flags where applicable.
- Add a function to verify that only one mode is being used at a time.
- Update all relevant documentation.
THere are four possibilities, for the three options (phy_test, do_ra,
nsa):
- None is set -> SA
- Only one is set of each -> corresponding mode
Introduce a function softmodem_verify_mode() to check for these.
Currently, NR PDCP ticks are active only with monolithic gNB, triggered by the MAC scheduler in gNB_scheduler.c.
In F1 split mode, as there is no MAC, there’s no source to advance the NR PDCP timer via "nr_pdcp_wakeup_timer_thread()".
This commit introduces a dedicated thread for NR PDCP ticks in gNB-CU and CU-UP mode.
Without it, packet losses at the F1 uplink would cause indefinite buffering, as t-Reordering won't expire due to the lack of NR PDCP timer ticks.
A new phy scope based on ImGui and ImPlot. This scope uses a different concurrency model than previous
scopes.
The PHY thread writing the data first checks if the data is ready to be written. If its not, nothing is copied.
The GUI thread reads data if available and marks it ready to write. This makes sure that the PHY threads are not
busy copying data that would never be displayed.
Some of the scopes also have a freeze functionality that further limit the amount of data that needs to be copied
from PHY threads. If a scope is "frozen" it still allows the user to explore the data using plots zoom/pan functions
but doesn't cause PHY threads to perform extra writes on the displayed data.
A compile option was added to enable/disable the scope. Use cmake -DENABLE_IMSCOPE=ON to enable the scope.
Update CXX standard to 17; it is required by some libraries (e.g., dear imgui). The oldest gcc version in
use by a distribution supported is Ubuntu 20, which has gcc 9.4 with c++17 support.
Before this commit, the following will trigger a complete rebuild:
- create another git name (git checkout -b test)
- run cmake again manually (cmake ..)
- run ninja again
The top-level CMakeLists.txt uses add_definitions() to add git
information to all targets; if some git information changes, this will
mark all command lines as dirty, triggering the build.
There is an easy solution: instead of passing this information on the
command line, pass it in a header. This commit uses configure_file() to
generate a file oai_version.h in the build directory with the same
information. Various sources files, e.g., main executables, use this to
output the same information as before. It is then also not necessary to
use header guards, as cmake takes care to create this file.
If cmake is re-run, it will update the header, and trigger only files
including this header will be rebuilt (which can be shown with the above
stpes). The information passed is the same as before, and updates the
information when the old method would have updated it.
* strdup is returning a malloced string that needs to freed after use
> Direct leak of 90 byte(s) in 1 object(s) allocated from:
>0 0x7ffff745b9a7 in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:454
>1 0x555556c7b341 in main /executables/nr-uesoftmodem.c:461
>2 0x7ffff5e29d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
Remove netlink code, and the PDCP_USE_NETLINK macro, as there is no
known use, it makes the code more complicated, and is simply "technical
debt".
In 4G PDCP, a subtle change has been introduced, in pdcp_module_init()
of pdcp.c. Looking at the diff of this commit, it can be seen that there
is now a new "else-if (ENB_NAS_USE_TUN_W_MBMS_BIT)" branch that is under
what was the "if (PDCP_USE_NETLINK)" branch, while the code fragment was
actually inside the "else" branch of PDCP_USE_NETLINK. This seems to be
necessary: previously, if we did not use noS1 mode and we don't use any
TUN (i.e., the eNB), the else block would set up this interface. It is
important that this interface is brought up, because if we omit it,
RFsim will not work. It seems to me that this interface will regularly
create some traffic; without it, RFsim will be blocked, and the UE
cannot connect.
In short, it seems to be important to have the MBMS interface, which
injects traffic in the RFsim side, which will unblock RFsim. The change
in pdcp_module_init() preserves the total changes of the if-else
(PDCP_USE_NETLINK).
Remove function pointers that were used in the past to implement the
F1(-U) interface in 4G, i.e., to have different functions to handle
split/monolithic operations. As we don't have F1 in 4G anymore (see
commit 9dc2282249), we don't need the
function pointers anymore.
On that occasion, rename the 5G functions by prepending nr_ to them;
this allows to refactor the interface in 5G further (which is not the
focus of this changeset).
Integration: `2024.w28`
See merge request oai/openairinterface5g!2856
* !2847 UE setting wrong frequency in 5G rfsimulator SA test
* !2850 NR UE MAC DCI 00 BWP handling
* !2852 \[E2 agent\] Move UE RRC_CONNECTED state signaling
* !2851 Minor code cleanup and fixes
* !2842 UE assertion for msg1_SubcarrierSpacing in RA
* !2831 PUSCH power control state
* !2838 NR UE UL FAPI PDU length fix
* !2723 add initial NTN support for NR UE
* !2764 Adding 7.2 containerfiles and docker-compose
* !2827 Increase RX_DATA.indication PDU Length to 32 bits
- Reworked nrLDPC_decoder_offload.c to process all segments in a TB with a single call to LDPCdecoder() or LDPCencoder().
- Perform CRC checks on the T2.
- Modified nr_ulsch_decoding (gNB decoder) to:
- Count processed segments.
- Properly perform CRC checks.
- Created a constant NR_LDPC_MAX_NUM_CB to define the maximum number of codeblocks.
- Conditional library loading:
- On gNB: Load ldpc_t2 library if offload is enabled using the --ldpc-offload-enable flag.
- On UE: Load both ldpc_t2 and ldpc libraries since only encoder offload is supported.
- General cleanup of nrLDPC_decoder_offload.c for improved readability and maintainability.
- Modified the structure of LDPC encoder/decoder/offload parameters:
- Introduced a structure for code block (CB) related parameters.
- Removed parameter E from the encoder and offload parameter structures for clarity.
- Replaced E with perCB->E_cb in the UE encoder code.
- Phy config update and Sidelink frame parameters initialisation
- PSBCH scheduler to trigger TX PSBCH/RX PSBCH actions
- Sidelink indication with rx ind to trigger send SL-MIB to MAC
- Enable Scope for PSBCH use -d or --dqt
- Enable system testing of PSBCH for example using RFSIMULATOR:
- UE1 is a SYNCRONISATION SOURCE UE which transmits PSBCH
started using command -
sudo ./nr-uesoftmodem --sl-mode 2 --sync-ref 4 --rfsim --rfsimulator.serveraddr server
- UE2 syncs onto UE1 during sidelink search, gets the timing and continues to receive PSBCH
started using command -
sudo ./nr-uesoftmodem --sl-mode 2 --rfsim --rfsimulator.serveraddr 127.0.0.1
- In the default use case 2 Sidelink SSBs sent over 16 frames.
- In case SL-SSB configuration needs to be changed use -O option in the above command like
-O ../../../targets/PROJECTS/NR-SIDELINK/CONF/sidelink_preconfig_1txpool.conf
The main thread of nr-uesoftmodem (executing main()) is mostly working;
it is thus not necessary to set high priority. Instead, the threads
created with threadCreate() will receive higher priority, if possible
(as determined by the availability of SYS_NICE capability).
To inform if SYS_NICE is not present, print a warning in main().
set_latency_target() attempts to set keep "low latency" by
- writing a specific latency to /dev/cpu_dma_latency
- setting manually the minimum CPU processor frequency to be the maximum
There is no functionality to undo this after stopping the softmodem(s),
and most users are probably not even aware that OAI does this. It is
generally preferable to set this beforehand using a governor or by
disabling sleep states (as outlined in the tutorial, and in a follow-up
commit in the performance tuning docs).
The previous mlockall() call, to lock memory to RAM, is retained in a
new function. There were additional mlockall() calls, which have been
replaced with lock_memory_to_ram(), where necessary.
Laurent THOMAS