Implement the #define variables required for synchronization: These
variables include offset and payload size values that vary from the Uu
interface, in relation to the PSS, SSS and PBCH elements. We also
introduce the new sl_mode command line flag, which is used to switch
between the Uu interface and SL interface. This will allow us to modify
exisitng PSS and SSS functions, without copying complete 5G functions
and only changing a few lines to support sidelink mode.
Fixing formatting for softmodem-common.h
1. Adding a "SL" frequency for Sidelink mode. The
importance of this variable is to ensure that
when we are in mode 1 (UE+UE+gNB), that the slot
configuration and frequencies do not overlap. This
SL frequency is important for rotation and allows
us to utilize the OFDM modulation and demodulation
functions that already exist in OAI.
2. Adding sl_mode to the command line for proper UE
deployment when in SL mode. sl_mode can be set to 0,
1, or 2. sl_mode 0 indicates no-Sidelink at all,
mode 1 is gNB, UE, and UE (3GPP defines mode numbers).
sl_mode 2 indicated UE to UE communications with no
gNB at all.
3. New functions for calculating the carrier frequency
for SL mode.
Different threads (e.g., RRC, DU tasks) might access the scheduler at
the same time as the thread that drivers the scheduler itself
(ru_thread). To avoid data races, introduce this mutex.
Most functions of the scheduler are only used internally and have been
marked static in the previous commit. The remaining ones, in this
commit, either lock the scheduler mutex sched_lock, or a comment has
been added of the assumption of how such function is to be locked (e.g.,
if it might be called from different places, or if it is called by a
function that already locks the scheduler).
fill_default_secondaryCellGroup() is moved to nr_rrc_config.c.
Furthermore, the signature is changes to return the NR_CellGroupConfig
from the functions, instead of filling a pre-allocated structure (which
is, in all cases, allocated just before calling
fill_default_secondaryCellGroup().
There is a problem with this function: the function also fills the
ServingCellConfig (a parameter to this function). This behavior has not
been changed.
Robert Schmidt