the version in develop is difficult to understand, and surprizing design
it loops only when avx2mod == 0 because when this test is false, the
size is always small i also spent time to understand, but i think i have
not changed it by not looping over the array.
- 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.
- rename as_nas_info_t member data to nas_data to have a uniq name to
trace between complex malloc/free of this pointer
- fix, maybe not perfect, these pais od malloc/free
- remove typedef name changes across transmission of these as_nas_info_t
over itti, as name changing makes it even more confusing
- remove globals that are likely possible races
- in as_message_decode() fix memcpy size, it is hard to understand the
initial idea, likely the author beleives a struct of struct makes a
intermediate pointer
- in network_api.c remove globals (static but used globally)
- remove casts that are there to hide gcc warnings on probable unaligned
access
- remain a weird mix of packed/unpacked versions of the same typedef,
but gcc is happy
the code creates a sink to read all traced packets and drop it. but
this works only if we send to a local address and if there is not
another sink (like if we trace both UE and gNB in the same machine).
this sink's purpose is only to prevent to get automatic packets back
from the kernel saying "no listener". So, instead of killing the trace
when we can't create the sink (as done previously), we now just let the
trace in operation.
- Better trace DLSCH decoding result
- Rename the decode result variable to separate with later ack/nack
encode of this decoding result from 3GPP (not trivial true=1 coding)
- Cleanup decodeResult usage
- Remove unused defines
Co-authored-by: Francesco Mani <email@francescomani.it>
Add gold sequence cache with dynamic size, private to each thread. It
periodically reorders by call rate. To free the gold sequences after end
of life time of a thread, use the pthread API.
Correctly compute the offset of data to unscramble in PUSCH processing
at the gNB. Rename variables to make them easier to spot (instead of
"s"), and remove a global variable.
Closes: #734
Add an API to allow out-of-order writes to a radio interface, unlike the
current interface.
this function is called in UE in this commit, even if the tx might
still be in order.
Later, i plan to improve UE pulti-threading, that will lead to out of
order tx. also, the gNB will benefit of this new function to replace
several specific pieces of code that reorder tx with over complex and
slow systems
Laurent THOMAS