4.2.11A Sub-frame segmentation for the 1.28 Mcps option
25.2223GPPMultiplexing and channel coding (TDD)Release 17TS
In the 1.28Mcps TDD, it is needed to add a sub-frame segmentation unit between 2nd interleaving unit and physical channel mapping unit when the TTI of the CCTrCh is greater than 5msec. In this case, the operation of rate-matching guarantees that the size of bit streams is an even number and can be subdivided into 2 sub-frames. The transport channel multiplexing structure for uplink and downlink is shown in figure 1A.
The input to the sub-frame segmentation unit is segmented into timeslot chunks, where each timeslot chunk contains all of the bits that are to be transmitted in a given timeslot position in both of the sub-frames.
The input bit sequence is denoted by where i is the timeslot number and Xi is the number of bits transmitted in timeslot i in a radio frame. The two output bit sequences per radio frame are denoted by yi,n,1, yi,n,2, yi,n,3, …, yi,n,Yi where n is the sub-frame number in current radio frame and Yi is the number of bits per sub-frame for timeslot i. The output sequences are defined as follows:
= , n = 1 or 2, k = 1…Yi
where
Yi = (Xi / 2) is the number of bits in timeslot i per sub-frame,
is the kth bit of the input bit sequence and
is the kth bit of the output bit sequence corresponding to the nth sub-frame