Reference signal placement within different subbands of the same OFDM symbol
Aspects provide a way for RS in different sub-bands within the same OFDM symbol to have different RS placement designs, e.g., different dependence/independence on cell ID. A base station apparatus transmits a first RS in a first resource set using a first RS placement, wherein the first resource set comprises a first subband of an OFDM symbol. The apparatus also transmits a second RS in a second resource set using a second RS placement, wherein the second resource set comprises a second subband of the OFDM symbol. A UE apparatus identifies a first resource set comprising a first subband in a plurality of subbands of an OFDM symbol transmitted by base station, determines whether a RS tone location utilized with the first subband is dependent upon an identifier of the base station, and receives the RS based on a result of the determining.
1. A method of wireless communication at a base station, comprising:
transmitting a first reference signal (RS) from the base station to a User Equipment (UE) in a first subband comprised in a plurality of subbands of an orthogonal frequency division multiplexed (OFDM) symbol using a first RS placement that is dependent on a cell identifier (cell ID) corresponding to the base station; and
transmitting a second RS from the base station to the UE in a second subband comprised in the plurality of subbands of the OFDM symbol using a second RS placement that is independent of the cell ID corresponding to the base station, wherein the second RS comprises a UE specific RS,
wherein the first subband and the second subband each comprise contiguous subcarriers of the OFDM symbol, wherein the first subband is different than the second subband.
2. The method of claim 1 , wherein the cell ID comprises a virtual cell ID.
3. The method of claim 1 , further comprising:
transmitting a master information block (MIB) or a master system information block (MSIB) indicating that the first RS placement is dependent on the cell ID corresponding to the base station.
4. The method of claim 1 , wherein the first RS comprises a first common RS (CRS).
5. The method of claim 4 , wherein the second RS placement for the second RS is based on a carrier frequency used to transmit the second RS.
6. The method of claim 4 , further comprising:
transmitting a master information block (MIB) or a system information block (SIB) indicating that the second RS placement for the second RS is independent of the cell ID corresponding to the base station.
7. The method of claim 1 , wherein the first RS comprises at least one of a mobility reference signal, a beam training signal, and a refinement signal.
8. The method of claim 7 , wherein the cell ID comprises at least one of a virtual cell ID, or a measurement ID.
9. The method of claim 7 , wherein the first RS placement is further dependent on a symbol index of the OFDM symbol.
10. The method of claim 1 , further comprising:
transmitting a third RS that is different than the first RS and the second RS, wherein the third RS comprises a channel state information reference signal (CSI-RS).
11. The method of claim 1 , wherein the UE specific RS is associated with a data transmission from the base station to the UE.
12. The method of claim 1 , wherein the second RS is sent with data for the UE.
13. The method of claim 12 , wherein the UE specific RS corresponds to a pilot that is received from the base station together with the data for the UE.
14. An apparatus for wireless communication at a base station comprising:
a memory; and
at least one processor coupled to the memory and configured to cause the apparatus to:
transmit a first reference signal (RS) from the base station to a User Equipment (UE) in a first subband comprised in a plurality of subbands of an orthogonal frequency division multiplexed (OFDM) symbol using a first RS placement that is dependent on a cell identifier (cell ID) corresponding to the base station; and
transmit a second RS from the base station to the UE in a second subband comprised in the plurality of subbands of the OFDM symbol using a second RS placement that is independent of the cell ID corresponding to the base station, wherein the second RS comprises a UE specific RS,
wherein the first subband and the second subband each comprise contiguous subcarriers of the OFDM symbol, wherein the first subband is different than the second subband.
15. The apparatus of claim 14 , wherein the at least one processor is further configured to cause the apparatus to transmit at least one of a master information block (MIB) or a master system information block (MSIB) indicating that the first RS placement for the first RS is dependent on the cell ID corresponding to the base station.
16. The apparatus of claim 14 , wherein the at least one processor is further configured to cause the apparatus to transmit at least one of a master information block (MIB) or a system information block (SIB) indicating that the second RS placement for the second RS is independent of the cell ID corresponding to the base station.
17. The apparatus of claim 14 , wherein the at least one processor is further configured to cause the apparatus to:
transmit a third RS that is different than the first RS and the second RS, wherein the third RS comprises a channel state information reference signal (CSI-RS).
18. The apparatus of claim 14 , wherein the UE specific RS is associated with a data transmission from the base station to the UE.
19. The apparatus of claim 18 , wherein the UE specific RS corresponds to a pilot that is received from the base station together with the data transmission for the UE.
20. A method of wireless communication at a user equipment (UE) comprising:
identifying a first subband comprised in a plurality of subbands of an orthogonal frequency division multiplexed (OFDM) symbol for a first reference signal (RS) transmitted by a base station;
determining a first RS placement for the first RS in the first subband comprised in the plurality of subbands of the OFDM symbol, wherein the first RS placement is dependent upon a cell identifier (cell ID) of the base station;
receiving the first RS from the base station based on the first RS placement determined by the UE;
identifying a second subband in the plurality of subbands of the OFDM symbol for a second RS;
determining a second RS placement for the second RS in the second subband comprised in the plurality of subbands of the OFDM symbol, wherein the second RS placement is independent of the cell ID of the base station, and wherein the second RS comprises a UE specific RS; and
receiving the second RS from the base station based on the second RS placement determined by the UE,
wherein the first subband and the second subband each comprise contiguous subcarriers of the OFDM symbol, wherein the first subband is different than the second subband.
21. The method of claim 20 , wherein the first RS comprises a common RS.
22. The method of claim 20 , further comprising:
receiving a third RS that is different than the first RS and the second RS, wherein the third RS comprises a channel state information reference signal (CSI-RS).
23. The method of claim 20 , wherein the UE specific RS is associated with a data transmission from the base station to the UE.
24. The method of claim 20 , wherein the UE specific RS is received together with data for the UE.
25. The method of claim 24 , wherein the UE specific RS corresponds to a pilot that is received from the base station together with the data for the UE.
26. The method of claim 20 , further comprising:
receiving a third RS that is different than the first RS and the second RS, wherein the third RS comprises a channel state information reference signal (CSI-RS).
27. An apparatus for wireless communication, comprising:
a memory; and
at least one processor coupled to the memory and configured to cause the apparatus to:
identify a first subband in a plurality of subbands of an orthogonal frequency division multiplexed (OFDM) symbol for a first reference signal (RS) transmitted by a base station;
determine a first RS placement for the first RS in the first subband comprised in the plurality of subbands of the OFDM symbol, wherein the first RS placement is dependent upon a cell identifier (cell ID) of the base station;
receive the first RS from the base station based on the first RS placement determined by the UE;
identify a second subband in the plurality of subbands of the OFDM symbol for a second RS;
determine a second RS placement for the second RS in the second subband comprised in the plurality of subbands of the OFDM symbol, wherein the second RS placement is independent of the cell ID of the base station, and wherein the second RS comprises a UE specific RS; and
receive the second RS from the base station based on the second RS placement determined by the UE,
wherein the first subband and the second subband each comprise contiguous subcarriers of the OFDM symbol, wherein the first subband is different than the second subband.
28. The apparatus of claim 27 , wherein the UE specific RS is associated with a data transmission from the base station to the UE.
29. The apparatus of claim 28 , wherein the UE specific RS corresponds to a pilot that is received from the base station together with the data transmission for the UE.