Why SS-RSRP is measured in 5G NR instead of PS-RSRP?

Hello Experts.

We know in SS block we have PSS SSS PBCH(DMRS in that).
According to 3gpp specs we measure SSRSRP which is defined as the RSRP from SSS .

Any specific reason for measuring SSS?

The center 20 RB carry the SSS. It also carries the reference signals.
So, the UE does not have to scan the entire NR bandwidths.
Remember, NR supports bandwidths of upto 400MHz, and scanning this entire range will drain the UE’s bandwidth.

Why not PSS and Why SSS for measuring this?

I think SS-RSRP means SS Block RSRP, not secondary sync. signal RSRP

hi , i am not expert but as i understood. there are different types of measurements, ss-rsrp is mainly used in idle mode to avoid searching for detailed positions of reference signals (thats why there is no cell specific reference signal in 5g ) , in connected mode csi-rsrp(its ue specific) is mainly used . why ss not ps is used because after ue reads ss ue can detemine the phyical cell id so ue can choose between cells . thats my understanding i am not expert you can read this for more info : https://www.etsi.org/deliver/etsi_ts/138200_138299/138215/15.02.00_60/ts_138215v150200p.pdf

1 Like

First off, SS-RSRP doesn’t only refer to RSRP measured over secondary synchronisation signals. It may refer to RSRP measured over DMRS within PBCH or RSRP measured over CSI-RS. However, The question why SS-RSRP doesn’t refer to RSRP measured over primary synchronisation signals remains there. It may be due to ease of implementation or some other design decision at the time of specification finalisation.