4.2.0 Transport channel concatenation
25.2123GPPMultiplexing and channel coding (FDD)Release 17TS
When DL_DCH_FET_Config is configured with value 1, downlink transport blocks of transport channels with a transport channel number il are concatenated to form a concatenated transport channel. In this case, higher layers ensure that TTI values of transport channels that are concatenated are the same.
Let i1, i2, i3,…,iB denote in ascending order the transport channel numbers in i1 < i2 < i3 <… < iB he concatenated transport channel is treated as a regular transport channel in layer 1, inheriting the parameters of transport channel number i1, e.g., the transport channel number, and the rate matching attribute of the concatenated transport channel are i1 and 
respectively.All transport blocks of all the transport channels to be concatenated are serially concatenated into a single transport block, in ascending order. The bits input to the transport channel concatenation are denoted by 
for 
, and m = 1, …, 
, where ik denotes the TrCH number, m denotes the transport block number for the transport channel ik , and 
is the number of bits in each transport block of transport channel ik. The bits after transport channel concatenation are denoted by 
, where A =
denotes the total number of bits in the signle transport block of the concatenated transport channel. The 
bits are defined by the following set of relations:
,
for m = 1, …,
, and 
.