There are two reference signals analysed for LTE:-
1. RSRP - Reference Signal Received Power over the Reference Signal subcarriers
It is defined as the linear average over the power contributions (in[W]) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwith.
2. W-RSRP - Wideband RSRP Power over all Reference Signal subcarriers
It is the received power on one code measured on the primary CPICH. The reference point for the RSCP shall be the antenna connector of the UE. If Tx Diversity is applied on the primary CPICH the RSCP from each antenna shall be separately measured and summed summed together in [W] to a total RSCP on the primary CPICH. If the received diversity is in use bye the UE, the reported value shall not be lower than the corresponding CPICH RSCP of any of the individual received antenna branches.
There is only one reference signal in UMTS:-
RSCP - Reference (Received) Signal Code Power
RSRP is estimated over 15 kHz LTE subcarriers while UMTS RSCP is measured over 5 MHz bandwidth so no direct comparison between these two metrics
Total received LTE Reference Signal Power (W-RSRP) measured over all Reference Subcarriers is directly comparable to UMTS RSCP measured over 5 MHz and they are within 3 - 6 dB under certain conditions.