Files
openairinterface5g/openair1
Laurent THOMAS d57ea715c0 Improve polar decoder/encoder
- Ensure packed struct through bitfield
- decoder tree buffer increase: i don't find evidence in the 3GPP
  standard of the max size of polar coded PDU.  even with this max size,
  the way this tree is built is not trivial.  so, it is hard to predict,
  i just put 8 system pages (32KB) that looks enough [1]
- a lot of reformatting

[1] https://arxiv.org/pdf/1804.04389
according to this paper, the largest polar code in 5G is in UL, so
likely the biggest problem will be in gNB, not the UE.  in DL, the max
output coded block is 512, in UL 1024.  probably the tree we discuss is
related to this size.

"frozen bits" means only bits we don't encode/decode because polar code
size is only by power of 2.
We see this in OAI code:  NR_POLAR_PUCCH_N_MAX is 10, so 2^10 is 1024,
that is the maximum size for 5G polar code length.  in the code, we
assert if N > 512: "N = %d, not done yet\n",
polarParams->N".  so, the today OAI code can't do PUCCH large blocks.

using current oai limitation of 2⁹ max code size, we can create up to
2^9+2⁸... nodes, so 1023 nodes in the tree.  the problem then is that
each node have variable size, depending on the 'level' (the power of 2
we are currently).  the algo provision large alpha and beta to be able
to store all lower levels in the tree (int leaf_sz = 1 << level)
therefore upper tree nodes are large (the top level for n=9 uses about
1.5KB) and the bottom nodes uses 64 bytes.  if all nodes are populated,
the size will be very large: 1.5KB + 2 * 800 + ....  but, we create
nodes in the tree only for the "information bits", so the payload, that
is limited to 128 bits (else we assert, the code is not "finished").
1.5KB * 128 is >> 8KB i allocated.  but, we can't create more than one
mode at top level, so there is maximum 1.5KB + 2 * 800, + 4 * 400 + 8 *
200 + 16 * 100 + remaining of 128-32 nodes of 64 bytes.  about 14KB.

i allocated 1024*sizeof(__m256i) bytes = 32KB that looks good.
2024-11-07 09:25:18 +01:00
..
2024-11-07 09:25:18 +01:00
2024-10-24 19:22:06 +02:00

This folder contains the software for layer 1 of the OpenAirInterface eNB and UE as well as the unitary simulators

|-- PHY			   // contains all signal processing related to physical layer (used in real-time AND simulation)

General remarks: every directory contains at least defs.h (for declaration of structure and functions), vars.h (for definitions of variables), and extern.h (variables are defined only once in xxx-softmodem.c (for real-time HW operation) or a top-level simulation (in SIMULATION/xxx), if variables are needed in another file, use extern.h)

|   |-- CODING		   // turbo and convolutional (de-)coders, rate-matching, crc generation (implementation of 36-212)
|   |   `-- TESTBENCH      // This contains unitary testbenches for the different channel coders/decoders
|   |-- INIT		   // variables defined in vars.h are initialzed here (memory allocation)
|   |-- LTE_ESTIMATION     // estimation for LTE
|   |-- LTE_REFSIG 	   // reference signals for LTE (sync and pilot sequences) reference signals from 36-211 
|   |-- NR_REFSIG 	   // reference signals for NR (sync and pilot sequences) reference signals from 38-211
|   |-- LTE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 36-211,36-212
|   |-- LTE_UE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 36-211,36-212
|   |-- NR_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 38-211,38-212
|   |-- NR_UE_TRANSPORT      // these are the top level routines for different transport and physical channels (for example DL-SCH, PSS) implements a subset of 38-211,38-212
|   |-- NBIoT_TRANSPORT      // these are the top level routines for different transport and physical channels for NB-IoT
|   |-- MODULATION	   // modulation and demodulation includes FFT/SC-FDMA front-end processing from 36-211
|   |-- TOOLS		   // tools like (I)FFT, vector operations, matrix multiplication, etc.
|   |   `-- FFTTEST        // unitary testbench for FFT routines
|   |-- defs.h		  // top level defs.h (includes spec_defs, impl_defs and all defs.h of subdirectories)
|   |-- extern.h
|   |-- impl_defs.h       // non-LTE openair implementation
|   |-- impl_defs_top.h   // general implementaion defs
|   |-- spec_defs.h
|   |-- spec_defs_top.h
|   |-- types.h
|   `-- vars.h		  
|-- SCHED		  // schedules the different LTE eNB functions
|   |-- defs.h
|   |-- extern.h
|   |-- phy_procedures_lte_eNb.c // LTE PHY procedures for eNB (from 36-213) 
|   |-- phy_procedures_lte_common.c  // LTE PHY procedures common for UE and eNB (from 36-213)
|   |-- prach_procedures.c  //LTE PRACH  procedures (from 36-213)
|   |-- ru_procedures.c  //RU  procedures
|   |-- fapi_l1.c  //L1 side of the FAPI interface
|   |-- phy_mac_stub.c  //MAC stub that generates channels when used in phy-test-mode
|   |-- rt_compat.h
|   `-- vars.h
|-- SCHED_UE		  // schedules the different LTE UE functions
|   |-- phy_procedures_lte_ue.c  // LTE PHY procedures for UE (from 36-213)
|   |-- pucch_pc.c // power control for PUCCH
|   |-- pusch_pc.c // power control for PUSCH
|   |-- srs_pc.c // power control for SRS
|-- SCHED_NB_IOT		  // same as above for NB-IOT
|-- SCHED_NR		  // same as above for NR gNB
|-- SCHED_NR_UE		  // same as above for NR UE
|-- SIMULATION		 // contains simulation routines to test PHY
|   |-- LTE_PHY          // LTE simulation testbenches for unitary simulation of transport/physical channels
|   |   |-- pbchsim.c       // PBCH simulation testbench
|   |   |-- pdcchsim.c      // PCFICH/PHICH/PDCCH (DCI) simulation testbench
|   |   |-- dlsim.c         // PDSCH simulation testbench
|   |   |-- ulsim.c         // PUSCH simulation testbench
|   |   |-- pucchsim.c      // PUCCH simulation testbench
|   |-- RF  		    // RF simulation tools
|   |-- ETH_TRANSPORT
|   `-- TOOLS