Method and apparatus for modular MIMO
A method for operating a user equipment (UE) comprises receiving configuration information about L uplink (UL) reference signals (RSs), M downlink (DL) RSs, and a calibration report, where the L UL RSs are associated with the M DL RSs; transmitting the UL RSs according to the configuration information; measuring the DL RSs; determining, based on the measured DL RSs and a reference DL RS, calibration information; and transmitting the calibration report including the calibration information.
1. A user equipment (UE) comprising:
a transceiver configured to:
receive configuration information about L uplink (UL) reference signals (RSs), M downlink (DL) RSs, and a calibration report, wherein the L UL RSs are associated with the M DL RSs, where L≥1 and M≥1; and
transmit the L UL RSs according to the configuration information; and
a processor operably coupled to the transceiver, the processor configured to:
measure the M DL RSs; and
determine, based on the measured M DL RSs and a reference DL RS, calibration information,
wherein the transceiver is further configured to transmit the calibration report including the calibration information.
2. The UE of claim 1 , wherein:
when L=1, M=N RRH , and a UL RS is associated with the M DL RSs, or
when L=M=N RRH , each UL RS is associated with a corresponding DL RS,
where N RRH is a number of remote radio heads (RRHs) or transmission and reception points (TRPs).
3. The UE of claim 1 , wherein the calibration information includes calibration phase or calibration amplitude coefficients selected from respective codebooks.
4. The UE of claim 3 , wherein:
an n p -bit phase shift keying (PSK) codebook is used for calibration phases, or
an n a -bit codebook comprising equidistance points in [0,1] in dB-scale or linear-scale is used for calibration amplitudes,
wherein the configuration information further includes n p or n a , where n p ≥1 and n a ≥1.
5. The UE of claim 1 , wherein:
the processor is further configured to determine the reference DL RS based on the measured M DL RSs, and
the calibration information includes the reference DL RS.
6. The UE of claim 1 , wherein the configuration information includes the reference DL RS.
7. The UE of claim 1 , wherein the processor is further configured to dynamically or semi-persistently trigger transmission of L UL RS, reception of M DL RS, or calibration reporting based on downlink control information (DCI) or a medium access control-control element (MAC-CE).
8. A base station (BS) comprising:
a processor configured to generate configuration information about L uplink (UL) reference signals (RSs), M downlink (DL) RSs, and a calibration report, wherein the L UL RSs are associated with the M DL RSs, where L≥1 and M≥1; and
a transceiver operably coupled to the processor, the transceiver configured to:
transmit the configuration information;
receive the L UL RSs; and
receive the calibration report including calibration information,
wherein the calibration information is based on measured M DL RSs and a reference DL RS.
9. The BS of claim 8 , wherein:
when L=1, M=N RRH , and a UL RS is associated with the M DL RSs, or
when L=M=N RRH , each UL RS is associated with a corresponding DL RS,
where N RRH is a number of remote radio heads (RRHs) or transmission and reception points (TRPs).
10. The BS of claim 8 , wherein the calibration information includes calibration phase or calibration amplitude coefficients selected from respective codebooks.
11. The BS of claim 10 , wherein:
an n p -bit phase shift keying (PSK) codebook is used for calibration phases, or
an n a -bit codebook comprising equidistance points in [0,1] in dB-scale or linear-scale is used for calibration amplitudes,
wherein the configuration information further includes n p or n a , where n p ≥1 and n a ≥1.
12. The BS of claim 8 , wherein the calibration information includes the reference DL RS, wherein the reference DL RS is based on the measured M DL RSs.
13. The BS of claim 8 , wherein the configuration information includes the reference DL RS.
14. The BS of claim 8 , wherein L UL RS reception, MDL RS transmission, or calibration reporting is dynamically or semi-persistently triggered via downlink control information (DCI) or a medium access control-control element (MAC-CE).
15. A method for operating a user equipment (UE), the method comprising:
receiving configuration information about L uplink (UL) reference signals (RSs), M downlink (DL) RSs, and a calibration report, wherein the L UL RSs are associated with the M DL RSs, where L≥1 and M≥1;
transmitting the L UL RSs according to the configuration information;
measuring the M DL RSs; and
determining, based on the measured M DL RSs and a reference DL RS, calibration information, and
transmitting the calibration report including the calibration information.
16. The method of claim 15 , wherein:
when L=1, M=N RRH , and a UL RS is associated with the M DL RSs, or
when L=M=N RRH , each UL RS is associated with a corresponding DL RS,
where N RRH is a number of remote radio heads (RRHs) or transmission and reception points (TRPs).
17. The method of claim 15 , wherein the calibration information includes calibration phase or calibration amplitude coefficients selected from respective codebooks.
18. The method of claim 17 , wherein:
an n p -bit phase shift keying (PSK) codebook is used for calibration phases, or
an n a -bit codebook comprising equidistance points in [0,1] in dB-scale or linear-scale is used for calibration amplitudes,
wherein the configuration information further includes n p or n a , where n p ≥1 and n a ≥1.
19. The method of claim 15 , wherein:
the reference DL RS is determined based on the measured M DL RSs, or
the reference DL RS is included in the configuration information, and
the calibration information includes the reference DL RS.
20. The method of claim 15 , further comprising dynamically triggering reception of L UL RS, transmission of M DL RS, or calibration reporting based on downlink control information (DCI) or a medium access control-control element (MAC-CE).