Radio frequency exposure mitigation
Methods and apparatuses for radio frequency exposure mitigation. A method for a user equipment (UE) to transmit a first channel includes receiving first information for a first downlink reference signal (DL RS) and a set of numbers of repetitions. The method further includes determining a first reference signal received power (RSRP) value for the first DL RS, a first spatial filter corresponding to the first DL RS, a first exposure value for the first spatial filter, and a first number of repetitions from the set of numbers of repetitions based on the first RSRP value and the first exposure value. The method further includes transmitting the first channel with the first number of repetitions using the first spatial filter.
1 . A method for transmitting a first channel, the method comprising:
identifying first information for a set of ranges of exposure values;
receiving second information for:
a first downlink reference signal (DL RS),
a set of ranges of reference signal received power (RSRP) values for the first DL RS,
a set of numbers of repetitions, and
a mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the set of numbers of repetitions;
determining:
a first RSRP value for the first DL RS,
a first spatial filter corresponding to the first DL RS,
a first exposure value for the first spatial filter, and
a first number of repetitions from the set of numbers of repetitions based on the first RSRP value, the first exposure value, and the mapping; and
transmitting the first channel with the first number of repetitions using the first spatial filter.
2 . The method of claim 1 , wherein the first exposure value corresponds to at least one of:
a power management maximum power reduction (P-MPR), and
an actual or virtual power headroom (PH).
3 . The method of claim 1 , further comprising:
determining:
a first range of RSRP values, from the set of ranges of RSRP values, that includes the first RSRP value, and
a first range of exposure values, from the set of ranges of exposure values, that includes the first exposure value, wherein the first number of repetitions is mapped to the first range of RSRP values and the first range of exposure values.
4 . The method of claim 1 , further comprising:
determining:
an offset value or a scaling factor based on the first exposure value,
a second RSRP value as a sum of the first RSRP value and the offset value or as a product of the first RSRP value and the scaling factor, and
a first range of RSRP values, from the set of ranges of RSRP values, that includes the second RSRP value, wherein the first number of repetitions is mapped to the first range of RSRP values.
5 . The method of claim 1 , further comprising:
determining a second number of repetitions to be one of:
the first number of repetitions,
a sum of the first number of repetitions and an offset value, or
a product of the first number of repetitions and a scaling factor; and
transmitting a second channel with the second number of repetitions,
wherein:
the first channel is a physical random access channel (PRACH),
the second channel is a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH) and is transmitted after the first channel, and
the offset value or the scaling factor is provided by an indication in a random access response (RAR) or a downlink control information (DCI) format that schedules transmission of the second channel.
6 . The method of claim 1 , further comprising:
receiving third information for:
a number of sets of time-frequency resources, and
a mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the number of sets of time-frequency resources; and
determining:
a first range of RSRP values, from the set of ranges of RSRP values, that includes the first RSRP value,
a first range of exposure values, from the set of ranges of exposure values, that includes the first exposure value, and
a first set of time-frequency resources, from the number of sets of time-frequency resources, that is mapped to the first range of RSRP values and the first range of exposure values,
wherein transmitting the first channel with the first number of repetitions comprises transmitting the first channel with the first number of repetitions in resources from the first set of time-frequency resources.
7 . The method of claim 1 , further comprising:
determining:
a second spatial filter corresponding to the first DL RS,
a second exposure value for the second spatial filter, and
a second number of repetitions, from the set of numbers of repetitions, based on the first RSRP value and the second exposure value; and
transmitting the first channel with the second number of repetitions using the second spatial filter.
8 . The method of claim 1 , further comprising:
receiving third information for a second DL RS;
determining:
a second RSRP value for the second DL RS,
a second spatial filter corresponding to the second DL RS,
a second exposure value for the second spatial filter, and
a second number of repetitions, from the set of numbers of repetitions, based on the second RSRP value and the second exposure value; and
transmitting the first channel with the second number of repetitions using the second spatial filter.
9 . A user equipment (UE) comprising:
a processor configured to identify first information for a set of ranges of exposure values; and
a transceiver operably coupled to the processor, the transceiver configured to receive first information for:
a first downlink reference signal (DL RS),
a set of ranges of reference signal received power (RSRP) values for the first DL RS,
a set of numbers of repetitions for transmission of a first channel, and
a mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the set of numbers of repetitions;
wherein the processor is further configured to determine:
a first RSRP value for the first DL RS,
a first spatial filter corresponding to the first DL RS,
a first exposure value for the first spatial filter, and
a first number of repetitions from the set of numbers of repetitions based on the first RSRP value, the first exposure value, and the mapping, and
wherein the transceiver is further configured to transmit the first channel with the first number of repetitions using the first spatial filter.
10 . The UE of claim 9 , wherein the first exposure value corresponds to at least one of:
a power management maximum power reduction (P-MPR), and
an actual or virtual power headroom (PH).
11 . The UE of claim 9 , wherein:
the processor is further configured to determine:
a first range of RSRP values, from the set of ranges of RSRP values, that includes the first RSRP value, and
a first range of exposure values, from the set of ranges of exposure values, that includes the first exposure value, wherein the first number of repetitions is mapped to the first range of RSRP values and the first range of exposure values.
12 . The UE of claim 9 , wherein:
the processor is further configured to determine:
an offset value or a scaling factor based on the first exposure value,
a second RSRP value as a sum of the first RSRP value and the offset value or as a product of the first RSRP value and the scaling factor, and
a first range of RSRP values, from the set of ranges of RSRP values, that includes the second RSRP value, wherein the first number of repetitions is mapped to the first range of RSRP values.
13 . The UE of claim 9 , wherein:
the processor is further configured to determine a second number of repetitions to be one of:
the first number of repetitions,
a sum of the first number of repetitions and an offset value, or
a product of the first number of repetitions and a scaling factor,
the transceiver is further configured to transmit a second channel with the second number of repetitions,
the first channel is a physical random access channel (PRACH),
the second channel is a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH) and is transmitted after the first channel, and
the offset value or the scaling factor is provided by an indication in a random access response (RAR) or a downlink control information (DCI) format that schedules transmission of the second channel.
14 . The UE of claim 9 , wherein:
the transceiver is further configured to receive third information for:
a number of sets of time-frequency resources, and
a mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the number of sets of time-frequency resources;
the processor is further configured to determine:
a first range of RSRP values, from the set of ranges of RSRP values, that includes the first RSRP value,
a first range of exposure values, from the set of ranges of exposure values, that includes the first exposure value, and
a first set of time-frequency resources, from the number of sets of time-frequency resources, that is mapped to the first range of RSRP values and the first range of exposure values; and
the transceiver is further configured to transmit the first channel with the first number of repetitions in resources from the first set of time-frequency resources.
15 . The UE of claim 9 , wherein:
the processor is further configured to determine:
a second spatial filter corresponding to the first DL RS,
a second exposure value for the second spatial filter, and
a second number of repetitions, from the set of numbers of repetitions, based on the first RSRP value and the second exposure value; and
the transceiver is further configured to transmit the first channel with the second number of repetitions using the second spatial filter.
16 . The UE of claim 9 , wherein:
the transceiver is further configured to receive third information for a second DL RS,
the processor is further configured to determine:
a second RSRP value for the second DL RS,
a second spatial filter corresponding to the second DL RS,
a second exposure value for the second spatial filter, and
a second number of repetitions, from the set of numbers of repetitions, based on the second RSRP value and the second exposure value; and
the transceiver is further configured to transmit the first channel with the second number of repetitions using the second spatial filter.
17 . A base station comprising:
a processor configured to identify first information for a set of ranges of exposure values, and
a transceiver operably coupled to the processor, the transceiver configured to:
transmit second information for:
a first downlink reference signal (DL RS),
a set of ranges of reference signal received power (RSRP) values for the first DL RS,
a set of numbers of repetitions for reception of a first channel, and
a first mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the set of numbers of repetitions; and
receive the first channel with a first number of repetitions from the set of numbers of repetitions.
18 . The base station of claim 17 , wherein an exposure value, from the set of ranges of exposure values, corresponds to at least one of:
a power management maximum power reduction (P-MPR), and
an actual or virtual power headroom (PH).
19 . The base station of claim 17 , wherein the transceiver is further configured to:
transmit third information for:
a number of sets of time-frequency resources, and
a second mapping among:
the set of ranges of RSRP values,
the set of ranges of exposure values, and
the number of sets of time-frequency resources; and
receive the first channel in resources from a first set of time-frequency resources, wherein the first set of time-frequency resources is from the number of sets of time-frequency resources.
20 . The base station of claim 17 , wherein the transceiver is further configured to:
transmit an indication of an offset value or a scaling factor; and
receive a second channel with a second number of repetitions, wherein:
the first channel is a physical random access channel (PRACH),
the second channel is a physical uplink shared channel (PUSCH) or a physical uplink control channel (PUCCH) and is received after the first channel, and
the indication is provided in a random access response (RAR) or a downlink control information (DCI) format that schedules reception of the second channel, and
the second number of repetitions is one of:
the first number of repetitions,
a sum of the first number of repetitions and the offset value, or
a product of the first number of repetitions and the scaling factor.