We need the ntn_config when reconfiguring the PHY layer for a new initial sync,
e.g. for calculating the DL Doppler frequency.
As a dedicated scheduled_response dl_config PDU it reaches the PHY layer too late,
as part of the phy_config.config_req it reaches the PHY layer in time with the
other configuration values.
Add symbol timing functions for NR_DL_FRAME_PARMS + optimization for slot timing
counterparts
Add two new functions for calculation symbol timestamp and symbol duration for
NR_DL_FRAME_PARMS. Also includes an optimization focused on removing
inefficiencies related slot-related counterparts.
1. Removed function pointers for functions get_samples_per_slot(),
get_samples_slot_timestamp() and get_slot_from_timestamp() as it does
not offer any advantage. The functions are now called directly from
everywhere.
2. Optimized these functions by removing loops where ever possible.
Add two new functions for calculation symbol timestamp and symbol
duration for NR_DL_FRAME_PARMS. These functions are not using
the existing indirection mechanism via function pointers as this
prevents the compiler from properly optimizing the code.
Hide normal table initialization of Ziggurat generator from outside to
force the usage of randominit() for RNG initialization. In this step,
remove the randominit() seed parameter and only rely on OAI_RNGSEED for
a consistent RNG initialization, as this parameter was used differently
("0" as fixed number or to force a random seed).
Now, only use OAI_RNGSEED env variable to force the usage of a fixed
seed.
Remove schedule response and update L1 threading documentation
This merge requests removes the somewhat superfluous "schedule response"
mechanism. "schedule response" was run after running the scheduler
itself and copied various FAPI messages into a global msgDataTx
structure from which the various TX/RX jobs were triggered. It is not
necessary, though, given that the scheduler is run inside the tx_func()
(running the TX jobs of the L1), and so the scheduler output FAPI
messages can directly be read into a variable of the existing
NR_Sched_Rsp_t type. This allows to delete a couple of hundred lines of
code (while retaining functionality), and simplifies the msgDataTx type
(which is still there to trigger TX job (including the scheduler) from
the ru thread).
In short, prior, there was this call chain:
- tx_func() calls run_scheduler_monolithic() (through fptr
NR_slot_indication())
- get some memory through allocate_sched_response() which has enough
space for NR_Sched_Rsp_t type variable
- call the scheduler and fill the variable
- call nr_schedule_response() (through fptr NR_schedule_response())
which copies into L1: to msgDataTx for TX, to separate structures
for RX
this is changed to
- tx_func() runs one message at a time, hence we can use memory in the
data segment for NR_Sched_Rsp_t. It calls run_scheduler_monolithic()
through the fptr
- pointers into NR_Sched_Rsp_t are passed to the scheduler, which
fills as before
- we return, memory is in its right place and does not need an extra
copy.
Additionally, this merge request updates documentation on threading and
cleans up some unused code along the way.
The next commit will remove msgDataTx. We can therefore not use
msgDataTx to retain the PDSCH/DLSCH variables, and move them to the gNB.
Note that the only reason for NR_gNB_DLSCH_t after this commit is to
hold various large buffers (c, b, f). Future work could be done to
remove this, in which case the array inside PHY_VARS_gNB could be
deleted.
On this occasion, clean up the use of init_DLSCH_struct() and
reset_DLSCH_struct() (renamed destroy_DLSCH_struct()) and centralize
their call in phy_init_nr_gNB()/phy_free_nr_gNB(), and correct
simulators accordingly.
NTN: Fixing variable ULDLduplex issue for NTN bands
- Duplex is assumed to be static but for NTN bands (and also for some non NTN
bands), it is not static.
- Tx-RX Duplex is defined in section 5.4.4 of 38.101-5 (for NTN) specs v1809
- For example: In NTN-OTA testing, the GEO satellite operator configured in
band 256 the DL, UL frequencies with duplex of 185Mhz.
saves about 600MB of memory allocation
Move the definition of PRACH items and the PRACH list to the
defs_nr_commons.h file.
Do not re-write the entire structure in nr_schedule_rx_prach(), as it is
quite large now.
This commit introduces support for concurrent UL slot processing
Key changes:
- Increased number of UL actors from 1 to 2
- fix several issues related to writing to global variables inside
processSlotTX
- Ensure in-order execution of if_module calls by utilizing the
preexisting dynamic_barrier structure.
remove ul_ch_estimates_time to save memory
remove ul_ch_estimates_time that saves 50MB memory to access in RAM, and
make better quality scope data passing (no race)
Use memcpy in nr_prach.c to fill txdata buffer.
Remove global tables related to PRACH generation.
Add new function to compute modulo multiplicative inverse and use it
directly to get inverse instead of LUT.
Removed nr_ru table and compute the values in-place.
In UE, added new flag root_seq_computed in nrUE_config to only compute
the sequence once after new nrUE_config is received.
Remove most of m64 type usage
MMX instructions were first SIMD version, the registers management is complex
(_mm_empty()) so, it is better to remove it now and use more recent instructions
anyway, gcc/clang should replace it automatically as long as we enable sse2,
that should always be the case but for code understanding and for ARM porting
for example, it is better to explicitly remove it
Thomas Schlichter