Is Demodulation reference signal allocated in both PUSCH and PUCCH or only in PUSCH?

Question

Are the demodulation reference symbols modulated using SC-FDMA like other PUSCH symbols or using OFDM. I have seen in a couple of places that OFDM is used for the DRMS, but I cannot find anything about it in 3GPP TS 36.211.

Any pointer would be appreciated?

Answer 1

DMRS is used for both PUCCH and PUSCH. If DMRS is bad the eNodeB does not decode PUCCH or PUSCH sent by UE. It is not optional like SRS (Sounding Reference Signal). SRS is used while allocating radio resource for an UE on uplink.