Neighbor cell measurements
This disclosure relates to techniques for configuring, performing, and reporting neighbor cell measurements in a wireless communication system. A base station of a serving cell may provide configuration information relevant to performing layer 1 (L1) measurements based on reference signals of one or more neighbor cells. A UE may perform L1 inter-frequency measurements of the neighbor cell(s) based on the configuration. The UE may report the measurements.
1. An apparatus, comprising:
a processor configured to cause a user equipment device (UE) to:
establish a wireless link with a serving cell;
receive, from the serving cell, configuration information;
determine, based on the configuration information:
a first number of intra-frequency measurement layers; and
a second number of inter-frequency measurement layers;
select, based on at least the first number of intra-frequency measurement layers and the second number of inter-frequency measurement layers, a first measurement period to apply for inter-frequency layer 1 (L1) measurement on a first neighbor cell, wherein the first measurement period comprises whichever is larger between a measurement gap repetition period (MGRP) and a neighbor cell reference signal periodicity, wherein the neighbor cell reference signal periodicity is indicated by the configuration information;
receive, from the first neighbor cell, at least one reference signal;
perform at least one L1 measurement of the at least one reference signal applying the first measurement period for inter-frequency L1 measurement on the first neighbor cell; and
transmit, to the serving cell, a report of the at least one L1 measurement.
2. The apparatus of claim 1 , wherein the processor is further configured to cause the UE to:
determine, based on the configuration information, a second measurement period for inter-frequency L1 measurement on a second neighbor cell different from the first measurement period for inter-frequency L 1 measurement on the first neighbor cell;
receive, from the second neighbor cell, a second at least one reference signal; and
perform a second L1 measurement of the second at least one reference signal according to the second measurement period for inter-frequency L1 measurement on the second neighbor cell, wherein the report of the at least one L1 measurement includes a report of the second L1 measurement.
3. The apparatus of claim 1 ,
wherein the first measurement period for inter-frequency L1 measurement on the first neighbor cell is based on a total number of inter-frequency layers configured for L1 measurement during a measurement gap.
4. The apparatus of claim 1 ,
wherein the at least one L1 measurement includes one or more of:
an L1 reference signal received power (RSRP) measurement; or
an L1 signal to interference and noise ratio (SINR) measurement.
5. The apparatus of claim 1 ,
wherein the neighbor cell reference signal periodicity is a synchronization signal block (SSB) periodicity of the first neighbor.
6. The apparatus of claim 1 ,
wherein the neighbor cell reference signal periodicity is a channel state information (CSI) reference signal (CSI-RS) periodicity of the first neighbor cell.
7. The apparatus of claim 1 , further comprising a radio communicatively coupled to the processor.
8. A method, comprising:
establishing a wireless link with a serving cell;
receiving, from the serving cell, configuration information;
determining, based on the configuration information:
a first number of intra-frequency measurement layers; and
a second number of inter-frequency measurement layers;
selecting, based on at least the first number of intra-frequency measurement layers and the second number of inter-frequency measurement layers, a first measurement period to apply for inter-frequency layer 1 (L1) measurement on a first neighbor cell, wherein the first measurement period comprises whichever is larger between a measurement gap repetition period (MGRP) and a neighbor cell reference signal periodicity, wherein the neighbor cell reference signal periodicity is indicated by the configuration information;
receiving, from the first neighbor cell, at least one reference signal;
performing at least one L1 measurement of the at least one reference signal applying the first measurement period for inter-frequency L1 measurement on the first neighbor cell; and
transmitting, to the serving cell, a report of the at least one L1 measurement.
9. The method of claim 8 , further comprising:
determining, based on the configuration information, a second measurement period for inter-frequency L1 measurement on a second neighbor cell different from the first measurement period for inter-frequency L1 measurement on the first neighbor cell;
receiving, from the second neighbor cell, a second at least one reference signal; and
performing a second L1 measurement of the second at least one reference signal according to the second measurement period for inter-frequency L1 measurement on the second neighbor cell, wherein the report of the at least one L1 measurement includes a report of the second L1 measurement.
10. The method of claim 8 , wherein the first measurement period for inter-frequency L 1 measurement on the first neighbor cell is based on a total number of inter-frequency layers configured for L1 measurement during a measurement gap.
11. The method of claim 8 , wherein the at least one Li measurement includes one or more of:
an L1 reference signal received power (RSRP) measurement; or
an L1 signal to interference and noise ratio (SINR) measurement.
12. The method of claim 8 , wherein the neighbor cell reference signal periodicity is synchronization signal block (SSB) periodicity of the first neighbor cell.
13. The method of claim 8 ,
wherein the neighbor cell reference signal periodicity is a channel state information (CSI) reference signal (CSI-RS) periodicity of the first neighbor cell.
14. A method, comprising:
establishing a wireless link with a user equipment (UE) via a serving cell;
transmitting, to the UE from the serving cell, configuration information, the configuration information indicating:
a first number of intra-frequency measurement layers; and
a second number of inter-frequency measurement layers, wherein a first measurement period for inter-frequency layer 1, L1, measurement on a first neighbor cell is determinable identifiable based on at least the first number of intra-frequency measurement layers and the second number of inter-frequency measurement layers, wherein the first measurement period comprises whichever is larger between a measurement gap repetition period (MGRP) and a neighbor cell reference signal periodicity, wherein the neighbor cell reference signal periodicity is indicated by the configuration information;
transmitting, via the first neighbor cell, at least one reference signal; and
receiving, from the UE, a report of at least one L1 measurement of the at least one reference signal, wherein the first measurement period for inter- frequency L1 measurement on the first neighbor cell is applied in performing the at least one L1 measurement.
15. The method of claim 14 , wherein the configuration information further indicates a second L1 measurement configuration comprising a measurement period for inter-frequency L1 measurement based on a carrier specific scaling factor (CSSF), which is based in part on a total number of inter-frequency layers configured for L1 measurement during a measurement gap.
16. The method of claim 14 , wherein the at least one L1 measurement includes one or more of:
an L1 reference signal received power (RSRP) measurement; or
an L1 signal to interference and noise ratio (SINR) measurement.
17. The method of claim 14 ,
wherein the neighbor cell reference signal periodicity is a synchronization signal block (SSB) periodicity of the first neighbor cell.