6.12 OFDM baseband signal generation
36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS
The time-continuous signal 
on antenna port 
in OFDM symbol 
in a downlink slot is defined by
for 
where 
and
. The variable 
equals 2048 for 
subcarrier spacing, 4096 for 
subcarrier spacing, 12288 for , 24576 for 
subcarrier spacing , and 82944 for .
For frame structure type 3, if PDCCH is to be transmitted in a subframe starting with OFDM symbol 
based on the received uplink control information that indicates channel occupancy time sharing ‘1’ as specified in [11], OFDM symbol 
in the previous subframe may be transmitted, given by
The OFDM symbols in a slot shall be transmitted in increasing order of 
, starting with 
, where OFDM symbol 
starts at time 
within the slot. In case the first OFDM symbol(s) in a slot use normal cyclic prefix and the remaining OFDM symbols use extended cyclic prefix, the starting position the OFDM symbols with extended cyclic prefix shall be identical to those in a slot where all OFDM symbols use extended cyclic prefix. Thus there will be a part of the time slot between the two cyclic prefix regions where the transmitted signal is not specified. For 
, there is one OFDM symbol per slot and one slot per subframe. For , there is one OFDM symbol per slot and one slot per 3ms.
Table 6.12-1 lists the value of 
that shall be used. Note that different OFDM symbols within a slot in some cases have different cyclic prefix lengths.
In case NB-IoT is supported, the OFDM baseband signal generation is defined in clause 10.2.8.
Table 6.12-1: OFDM parameters
|
Configuration |
Cyclic prefix length |
|
|
Normal cyclic prefix |
|
|
|
Extended cyclic prefix |
|
|
|
|
|
|
|
3072 for |
||
|
|
|
|
|
9216 for |
||
