This commit includes reorganization of
all of the SISO/MIMO channel modelling
support being moved into a single CM
file. Furthermore, it includes a bug
fix for the number of MCS simulation
tables (29 total, 0-28).
Previously, we thought the memset in the nr_ue_dl_indication()
was causing issues / exposing a race. This is not the case. The
memset is not problematic, the issue is that in the emulate_l1
mode we were not always configuring the DCI nbits before handling
the DCI when we are pushing high (15 Mbps) throughput traffic.
Instead of conditionally calling the pucch_scheduler
we now only call the functions we need from the stub
function directly. This is better because we are not
modifying the OAI MAC layer code and ensuring that we
are not calling the pucch_scheduler twice for the same
sfn/slot
Adding error checking before indexing in mac layer harq array
Adding error checking before writing ul_harq_sfn_slot
Added comments
Made a "static" free_uci_inds() actually static
We have gotten rid of filling the ACK/NACK with
the DLSCH and now only fill with the PUCCH. This
assumes that the MAC layer is properly decoding the
dl_tti_req and tx_data_req and allows us to
simply use the MAC layers scheduled SNF/Slot
to return the ACK NACK. There are some hacks added
in this commit which ensure that the PDCP packet
has the correct header (1st byte = 80) and now with
15Mbps we are seeing about 20% packet loss and
a gNB bug on the edge case (current frame is 1023
and the gNB schduler wants an ACK in frame 0 but the
scheduled UL_TTI_REQ has a frame of 1023).
It seems that the RA procedure in the gNB was modified so
the RAR is sent in a single tx_data_req. The emualted mode
was not previously handling this. We now only process the
PDU in the rx_ind that has a matching preamble. If any
other PDUs exist, we ignore them and only build Msg3 based
on this single matching RAR PDU.
Also, two bug fixes applied here in the emulate-l1 mode.
When we check if the pointer is NULL before CALLOCing,
then the gNB will crash. It seems that we are mostlikely
leaking memeory since the gNB only crashes with the old
change. By reverting these changes, the gNB does not crash.
We are seeing UE-to-UE IP traffic on this commit when
the tunnel interfaces are established (~50% of the time).
Sakthivel Velumani