5.3.1 Scrambling
36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS
For each codeword 
, the block of bits 
, where 
is the number of bits transmitted in codeword 
on the physical uplink shared channel in subframe(s)/slot/subslot, shall be scrambled with a UE-specific scrambling sequence prior to modulation, resulting in a block of scrambled bits 
according to the following pseudo code
Set i = 0
while 
if 
// ACK/NACK or Rank Indication placeholder bits
else
if 
// ACK/NACK or Rank Indication repetition placeholder bits
else // Data or channel quality coded bits, Rank Indication coded bits or ACK/NACK coded bits
end if
end if
i = i + 1
end while
where x and y are tags defined in TS 36.212 [3] clause 5.2.2.6 and where the scrambling sequence 
is given by clause 7.2. The scrambling sequence generator shall be initialised with 
at the start of each subframe where 
corresponds to the RNTI associated with the PUSCH transmission as described in clause 8 in TS 36.213 [4]. For AUL PUSCH,
For BL/CE UEs,
– if the PUSCH transmission is using sub-PRB allocations, the scrambling sequence generator shall be initialised with
at the first valid uplink subframe of every subframes comprising the allocated UL resource unit(s), where, and N is the number of BL/CE UL subframes for the PUSCH transmission as determined in clause 8.0 in [4].
– otherwise, the same scrambling sequence is applied per subframe to PUSCH for a given block of 
subframes. The subframe number of the first subframe in each block of 
consecutive subframes, denoted as 
, satisfies 
. For the 
block of 
subframes, the scrambling sequence generator shall be initialised with
where
and 
is the absolute subframe number of the first uplink subframe intended for PUSCH. The PUSCH transmission spans 
consecutive subframes including subframes that are not BL/CE UL subframes where the UE postpones the PUSCH transmission. For a BL/CE UE configured in CEModeA, 
. For a BL/CE UE configured with CEModeB, 
for frame structure type 1 and 
for frame structure type 2.
For PUSCH with a subframe duration, up to two codewords can be transmitted in one subframe, i.e., 
. In the case of single-codeword transmission, 
.