In the uplink two refremnce signals, sent by UE
SRS- Sounding RS
DMRS- Demodulation reference signals
Usage:
DMRS - used for demodulating EndB data or control signals being received by UE
SRS – used for channel estimation, SRS is your CSI, used for Scheduling
Dimensinging:
DMRS Sent in every slot
Pusch – occupies 40% of resource
pucch – occupies (14-43)% of resource