5G/NR, 3GPP 38.215: SS-RSRP, CSI-RSRP

在LTE中，关于功率的测量基本都是关于RSRP和RSRQ的。NR中的RSRQ和RSRP和LTE中的几乎相同，但也有区别。因为在LTE中，RSRQ和RSRP是基于cell specific reference signal，但是在NR中，没有CRS，所以RSRP和RSRQ在NR中的定义是基于其他物理信号定义的。

38.215主要讲述了UE/UG-RAN 的measurements。目前38.215中提出的是SS-RSRP和CSI-RSRP。

SS-RSRP (Synchronization Signal Reference Signal Received Power)

SS reference signal received power (SS -RSRP) is defined as the linear average over the power contributions (in [W]) of the resource elements that carry secondary synchronization signals (SS). The measurement time resource(s) for SS-RSRP are confined within SS/PBCH Block Measurement Time Configuration (SMTC) window duration. If SS-RSRP is used for L1-RSRP as configured by reporting configurations as defined in 3GPP TS 38.214, the measurement time resources(s) restriction by SMTC window duration is not applicable.

同步信号在每个RE的平均功率。
测量在SMTC中的窗时段进行。

For SS-RSRP determination demodulation reference signals for physical broadcast channel (PBCH) and, if indicated by higher layers, CSI reference signals in addition to secondary synchronization signals may be used. SS-RSRP using demodulation reference signal for PBCH or CSI reference signal shall be measured by linear averaging over the power contributions of the resource elements that carry corresponding reference signals taking into account power scaling for the reference signals as defined in 3GPP TS 38.213. If SS-RSRP is not used for L1-RSRP, the additional use of CSI reference signals for SS-RSRP determination is not applicable.

除此之外，通过高层的配置，CSI参考信号可以和同步信号一起被使用。
如果SS-RSRP没有被用来作为L1的RSRP，那么格外的CSI参考信号也不适用。

SS-RSRP shall be measured only among the reference signals corresponding to SS/PBCH blocks with the same SS/PBCH block index and the same physical-layer cell identity.

If SS-RSRP is not used for L1-RSRP and higher-layers indicate certain SS/PBCH blocks for performing SS-RSRP measurements, then SS-RSRP is measured only from the indicated set of SS/PBCH block(s).

For frequency range 1, the reference point for the SS-RSRP shall be the antenna connector of the UE. For frequency range 2, SS-RSRP shall be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SS-RSRP value shall not be lower than the corresponding SS-RSRP of any of the individual receiver branches.

CSI-RSRP (CSI Reference Signal Received Power)

CSI reference signal received power (CSI-RSRP), is defined as the linear average over the power contributions (in [W]) of the resource elements that carry CSI reference signals configured for RSRP measurements within the considered measurement frequency bandwidth in the configured CSI-RS occasions.

CSI-RSRP是携带CSI信号在每个RE上的平均功率。

For CSI-RSRP determination CSI reference signals transmitted on antenna port 3000 according to 3GPP TS 38.211 shall be used. If CSI-RSRP is used for L1-RSRP, CSI reference signals transmitted on antenna ports 3000, 3001 can be used for CSI-RSRP determination.

如果CSI-RSRP被用来作为L1的参考信号，在天线端口3000和3001传输的CSI参考信号用来判决CSI-RSRP.

For intra-frequency CSI-RSRP measurements, if the measurement gap is not configured, UE is not expected to measure the CSI-RS resource(s) outside of the active downlink bandwidth part.

For frequency range 1, the reference point for the CSI-RSRP shall be the antenna connector of the UE. For frequency range 2, CSI-RSRP shall be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported CSI-RSRP value shall not be lower than the corresponding CSI-RSRP of any of the individual receiver branches.