Transmission and access with multiple transmission reception points
In an embodiment a wireless device receives configuration parameters, of a cell, indicating: a first reference signal (RS) of a first transmission reception point (TRP) of the cell; a second RS of a second TRP of the cell; random access channel (RACH) resources of a RACH of the cell; and a power offset value. The wireless device measures a first received power value of the first RS and measures a second received power value of the second RS. The wireless device selects, based on the measuring and the power offset value, an RS from the first RS and the second RS. Then, the wireless device transmits a preamble, associated with the selected RS, via the RACH resources.
1. A method comprising:
receiving, by a wireless device, configuration parameters, of a cell, indicating:
a first reference signal (RS) of a first transmission reception point (TRP) of the cell;
a second RS of a second TRP of the cell;
random access channel (RACH) resources of a RACH of the cell; and
a power offset value for the first TRP;
measuring:
a first received power value of the first RS; and
a second received power value of the second RS;
selecting, after adjusting the first received power value by the power offset value, an RS from the first RS and the second RS; and
transmitting a preamble, to a TRP that is associated with the RS from the first TRP and the second TRP, via the RACH resources.
2. The method of claim 1 , wherein the configuration parameters further indicate:
a first RS group associated with the first TRP and comprising the first RS;
a second RS group associated with the second TRP and comprising the second RS; and
an association between the preamble and the RS.
3. The method of claim 2 , further comprising applying the power offset value to RSs in the first RS group, and selecting the RS from the RSs in the first RS group and the second RS group.
4. The method of claim 1 , further comprising determining a transmission power for the preamble based on the RS, wherein the preamble is transmitted based on the transmission power.
5. The method of claim 1 , wherein the first received power value comprises a first RS received power (RSRP) value and the second received power value comprises a second RSRP value.
6. The method of claim 1 , wherein the selecting the RS, after adjusting the first received power value by the power offset value, comprises applying the power offset value to the first received power value of the first RS.
7. The method of claim 6 , wherein the applying the power offset value to the first received power value comprises adding or deducting the power offset value from the first received power value of the first RS.
8. The method of claim 1 , wherein the selecting the RS from the first RS and the second RS comprises selecting the first RS based on the first received power value being higher than the second received power value of the second RS.
9. The method of claim 1 , wherein the RACH resources comprise time domain resources and frequency domain resources of a RACH occasion.
10. The method of claim 1 , wherein:
the first RS is selected as the RS in response to the first received power value being higher than the second received power value of the second RS after the adjusting; and
the second RS is selected as the RS in response to the second received power value being higher than the first received power value of the first RS after the adjusting.
11. A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device:
receive configuration parameters, of a cell, indicating:
a first reference signal (RS) of a first transmission reception point (TRP) of the cell;
a second RS of a second TRP of the cell;
random access channel (RACH) resources of a RACH of the cell; and
a power offset value for the first TRP;
measure:
a first received power value of the first RS; and
a second received power value of the second RS;
select, after adjusting the first received power value by the power offset value, an RS from the first RS and the second RS; and
transmit a preamble, to a TRP associated with the RS from among the first TRP and the second TRP, via the RACH resources.
12. The wireless device of claim 11 , wherein the configuration parameters further indicate:
a first RS group associated with the first TRP and comprising the first RS;
a second RS group associated with the second TRP and comprising the second RS; and
an association between the preamble and the RS.
13. The wireless device of claim 12 , wherein the instructions further cause the wireless device to apply the power offset value to RSs in the first RS group, and select the RS from RSs in the first RS group and the second RS group.
14. The wireless device of claim 11 , wherein the instructions further cause the wireless device to determine a transmission power for the preamble based on the RS, wherein the preamble is transmitted based on the transmission power.
15. The wireless device of claim 11 , wherein the first received power value comprises a first RS received power (RSRP) value and the second received power value comprises a second RSRP value.
16. The wireless device of claim 11 , wherein to select the RS, after adjusting the first received power value by the power offset value, the instructions further cause the wireless device to apply the power offset value to the first received power value of the first RS.
17. The wireless device of claim 16 , wherein to apply the power offset value to the first received power value, the instructions further cause the wireless device to add or deduct the power offset value from the first received power value of the first RS.
18. The wireless device of claim 11 , wherein to select the RS from the first RS and the second RS, the instructions further cause the wireless device to select the first RS based on the first received power value being higher than the second received power value of the second RS.
19. The wireless device of claim 11 , wherein:
the first RS is selected as the RS in response to the first received power value being higher than the second received power value of the second RS after the adjusting; and
the second RS is selected as the RS in response to the second received power value being higher than the first received power value of the first RS after the adjusting.
20. A system comprising:
a base station comprising:
one or more first processors; and
first memory storing first instructions that, when executed by the one or more first processors, cause the base station to:
transmit configuration parameters of a cell, the configurations parameters indicating:
a first reference signal (RS) of a first transmission reception point (TRP) of the cell;
a second RS of a second TRP of the cell;
random access channel (RACH) resources of a RACH of the cell; and
a power offset value for the first TRP; and
a wireless device comprising:
one or more second processors; and
second memory storing second instructions that, when executed by the one or more second processors, cause the wireless device to:
receive, from the base station, the configuration parameters;
measure:
a first received power value of the first RS; and
a second received power value of the second RS;
select, after adjusting the first received power value by the power offset value, an RS from the first RS and the second RS; and
transmit a preamble, to a TRP of the base station associated with the RS from the first TRP and the second TRP, via the RACH resources.