The eNodeB (base station) decides on how to allocate uplink/downlink bandwidth.
- This diagram is from http://rfmw.em.keysight.com/wireless/helpfiles/89600b/webhelp/subsystems/lte/content/lte_overview.htm
The three slot lengths are specified by the "Dw/GP/Up Len" -parameter
Downlink pilot | guard period | Uplink pilot
Downlink pilot: P-SS, also PDSCH if length of pilot > 1 slot Guard period: PRACH format 4 begins in the guard period, otherwise no signal Uplink pilot: can contain PRACH and SRS, with exception of PUCCH and PUSCH
P-SS = Primary Synchronization Signal
PRACH = Physical Random Access Channel SRS = Signaling Reference Signal PUCCH = Physical Uplink Control Channel PUSCH = Physical Uplink Shared Channel
DwPTS = Downlink Pilot Time Slot, contains P-SS and PDSCH UpPTS = Uplink Pilot Time Slot GP = Guard Period
- 180kHz slice of bandwidth, composed of:
- 12x15kHz or 24x7.5kHz subcarriers