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.
This commit fixes a bug caused by global variables in the gNB_MAC_INST
structure used to transfer MAC scheduler's results to the PHY layer.
When using several threads in the PHY layer, it may happen that the
MAC scheduler is called a second time by the second PHY thread for the
next slot before the content of the global variables in the gNB_MAC_INST
structure used to store the result of the MAC scheduler for the current
slot have been consumed by the first thread, leading to unpredictable
results (all of them certainly wrong).
The solution is to introduce a small memory management module for the
interface between the PHY threads and the MAC scheduler. The MAC
scheduler now fills the data structures passed to it, and not a
global variable anymore. The PHY layer manages the structures and
ensures that no data is overwritten before being fully consumed by
the various threads of the PHY layer.
Some care has to be taken because several PHY threads will access the
same structures at the same time for a given slot (in read mode, so
it's okay). A mechanism of reference counting has thus been introduced.
Only one CC is supported. This restriction should not be too hard
to remove if/when needed. (The code before this commit does not seem
to work for more than one CC anyway.)
This commit includes changes to the function
footprints for vaiours NR UE and gNB functions.
It does not updated the LTE code. For functions
shared by both LTE and 5G, we maintained the original
LTE footprint and argument structure.
Several of the simulators that use these functions
have been updated as well. The specific usage of these
functions which index into the int32_t buffers and
treat the first int16_t and the real and the second
as the complex should be modified in the near future.
The simulators have been changed: due to linker errors that would arise
otherwise, a lot of functions are defined in them to avoid such errors.
Some functions are also defined in header files; in this commit, we
define most functoins in nr_dummy_functions.c, which is compiled in, not
by including the C file, but by adding it to the target in
CMakeLists.txt
- nr_dlsim+nr_ulsim need NR_IF_Module_init(), so it cannot be in
nr_dummy_functions, but the others need it
- Link correcr NR_IF_Module_init() into these simulators, and reduce
overall link list
- Correctly link remaining simulators
Robert Schmidt