Robert Schmidt
93b3a5aedb
Introduce SRS physical simulator and improvements This MR consists of two parts: - Introduces SRS physical simulator to test different configurations of SRS - Improvements in the SRS channel estimation (Addressing the comments from old, unfinished MR !2875) - rewrite nr_srs_channel_estimation() to loop over rx antennas and antenna ports to be able to parallelize - Improvements in timing_advance_offset and timing_advance_offset_nsec computation - Introduce SRS multi-symbol channel estimation - The channel impulse response is estimated from the averaged channel frequency response over multiple symbols - The channel frequency estimates are left as they are to be able to estimate doppler in the future - Simplify SRS channel estimation to handle memory alignment in the case of different SRS configurations (eg: comboffset) To use multiple symbols when running gNB, the following parameters needs to be edited in the function get_srs_resource() - srs_res->resourceMapping.startPosition with a range from {0,1,..,5} corresponds to the start symbol {13, 12, .. 8} with in a slot - srs_res->resourceMapping.nrofSymbols indicates the number of symbols {n1, n2, and n4} Make sure the that start symbol + number of symbols is < 14 The timing results for SRS in develop and srs_phy_simulator are as follows: Command used: sudo ./nr_ulsim -n1000 -s50 -S50 -R273 -W2 -y2 -z2 -E 1 -P develop |__ RX SRS time 124.94 us (1000 trials) (124.94 total [ms]) |__ Generate SRS sequence time 0.05 us (1000 trials) ( 0.05 total [ms]) |__ Get SRS signal time 19.41 us (1000 trials) ( 19.41 total [ms]) |__ SRS channel estimation time 89.11 us (1000 trials) ( 89.11 total [ms]) |__ SRS timing advance estimation time 13.10 us (1000 trials) ( 13.10 total [ms]) |__ SRS report TLV build time 2.80 us (1000 trials) ( 2.80 total [ms]) |__ SRS beam report build time 0.00 us ( 0 trials) |__ SRS IQ matrix build time 2.73 us (1000 trials) srs_phy_simulator |__ RX SRS time 211.93 us (1000 trials) (211.93 total [ms]) |__ Generate SRS sequence time 0.04 us (1000 trials) ( 0.04 total [ms]) |__ Get SRS signal time 19.55 us (1000 trials) ( 19.55 total [ms]) |__ SRS channel estimation time 152.05 us (1000 trials) (152.05 total [ms]) |__ SRS timing advance estimation time 36.67 us (1000 trials) ( 36.67 total [ms]) |__ SRS report TLV build time 2.96 us (1000 trials) ( 2.96 total [ms]) |__ SRS beam report build time 0.00 us ( 0 trials) |__ SRS IQ matrix build time 2.88 us (1000 trials) Note that in srs_phy_simulator, to compute timing offset ns, an oversampling factor of 2 is performed. Also, for peak detection, we average the channel estimates for every port.
OpenAirInterface License
It is distributed under OAI Public License V1.1.
The license information is distributed under LICENSE file in the same directory.
Please see NOTICE file for third party software that is included in the sources.
Where to Start
- General overview of documentation
- The implemented features
- System Requirements for Using OAI Stack
- How to build
- How to run the modems
Not all information is available in a central place, and information for specific sub-systems might be available in the corresponding sub-directories. To find all READMEs, this command might be handy:
find . -iname "readme*"
RAN repository structure
The OpenAirInterface (OAI) software is composed of the following parts:
openairinterface5g
├── charts
├── ci-scripts : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
├── CMakeLists.txt : Top-level CMakeLists.txt for building
├── cmake_targets : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
├── common : Some common OAI utilities, some other tools can be found at openair2/UTILS.
├── doc : Documentation
├── docker : Dockerfiles to build for Ubuntu and RHEL
├── executables : Top-level executable source files (gNB, eNB, ...)
├── maketags : Script to generate emacs tags.
├── nfapi : (n)FAPI code for MAC-PHY interface
├── openair1 : Layer 1 (3GPP LTE Rel-10/12 PHY, NR Rel-15 PHY)
├── openair2 : Layer 2 (3GPP LTE Rel-10 MAC/RLC/PDCP/RRC/X2AP, LTE Rel-14 M2AP, NR Rel-15+ MAC/RLC/PDCP/SDAP/RRC/X2AP/F1AP/E1AP), E2AP
├── openair3 : Layer 3 (3GPP LTE Rel-10 S1AP/GTP, NR Rel-15 NGAP/GTP)
├── openshift : OpenShift helm charts for some deployment options of OAI
├── radio : Drivers for various radios such as USRP, AW2S, RFsim, 7.2 FHI, ...
├── targets : Some configuration files; only historical relevance, and might be deleted in the future
└── tools : Tools for use by the developers/ci machines: code analysis and formatting
How to get support from the OAI Community
You can ask your question on the mailing lists.
Your email should contain below information:
- A clear subject in your email.
- For all the queries there should be [Query] in the subject of the email and for problems there should be [Problem].
- In case of a problem, add a small description.
- Do not share any photos unless you want to share a diagram.
- OAI gNB/DU/CU/CU-CP/CU-UP configuration file in
.confformat only. - Logs of OAI gNB/DU/CU/CU-CP/CU-UP in
.logor.txtformat only. - In case your question is related to performance, include a small description of the machine (Operating System, Kernel version, CPU, RAM and networking card) and diagram of your testing environment.
- Known/open issues are present on GitLab, so keep checking.
Always remember a structured email will help us understand your issues quickly.