At this point we are successfully able to build.
Additionally, we can run the scenario,
however, it does not pass. It seems that the gNB
is not connecting to the proxy correctly. Just
wanted to push the progress so far. FYI, the items
that had to be changed to correct the linking issues
were the following:
- mac_rrc_data_ind_ue vs. nr_mac_rrc_data_ind_ue
- rrc_data_req vs. nr_rrc_data_req
- mac_rrc_data_req_ue vs. nr_mac_rrc_data_req_ue
- rrc_data_req_ue vs. rrc_data_req_nr_ue
- rrc_data_req vs. nr_rrc_data_req
The listed functions should be declard in the LTE/NR
UE directory depending on the functionality. Several
were mixed. i.e.: LTE functions being called in NR UE.
Also, removing siWindowLength, siWindowLength_int,
SIBType, SIBPeriod, and siPeriod_int from the NR UE RRC.
These variable were not used in the NR UE and are defined
for LTE only.
Lastly, in the NR_IF_Module.c of the NR UE, the global
variable def_dci_pdu_rel15 is not accessible. Need to
revisit this. For not it is commented out.
- updated return function value to -1
- removed static variable for dmrs symbol selection for channel
- Updated sin cos quadrant check conditions
- removed casting from PTRS slope and related calculations
FEATURE STATEMENT:
- Introduce linear phase error noise model in Uplink at UE
- Perform common phase error (CPE) estimation and compensation at gNB
SOLUTION:
- A linear phase shift model is introduced in simulation.
- PTRS symbols are used to perform estimation of CPE from DMRS compensated signal
- The estimated values are interpolated in time domain and signal is compensated for the CPE.
- PTRS processing is done in Frequency Domain for each symbol in a slot and
LLR's are calculated for each symbol accordingly.
IMPLEMENTATION:
* sim.h/channle_sim.c
- Linear Phase Noise Generation model definition.
* nr_ul_channel_estimation.c/nr_ul_estimation.h
- CPE estimation from PTRS and DMRS compensated signal.
* nr_dmrs_rx.c/nr_refsig.h
- Regenerate PTRS symbols at gNB.
* nr_ulsch_demodulation.c
- Removed old PTRS processing code and move to a common PTRS processing function
* defs_gNB.h/init.c
- New PTRS variables definition and initialization
* nr_ulsch_ue.c
- Corrected PTRS parameter to get new PTRS symbols for each OFDM symbol
TESTING
* ulsim.c
- Added Phase noise, Enable PTRS signal and verified the output.
VERIFICATION
- The LLR are rotated back with estimated CPE and no error is observed in scrambling/decoding
Melissa Elkadi