Method and apparatus for repeater gain control for device collaboration in distributed multiple-input multiple-output systems

1 . A method, comprising:

determining, by a processor of an apparatus, a first compensation value for a first path loss on a first link between the apparatus and a user equipment (UE);

determining, by the processor, a second compensation value for a second path loss on a second link between the apparatus and a network node of a wireless network;

determining, by the processor, a repeater gain for uplink power control according to the first compensation value and the second compensation value; and

forwarding, by the processor, a radio signal from the UE to the network node according to the repeater gain.

2 . The method of claim 1 , further comprising:

determining, by the processor, a difference between a first target power level and a second target power level, wherein the first target power level is configured for the network node to receive radio signals on a direct link between the UE and the network node, and the second target power level is configured for the apparatus to receive radio signals on the first link; and

wherein the determining of the repeater gain for uplink power control is performed further according to the difference.

3 . The method of claim 2 , wherein the repeater gain for uplink power control is determined as a sum of the difference, the first compensation value, and the second compensation value.

4 . The method of claim 1 , wherein the determining of the first compensation value comprises:

determining whether the first path loss is fully compensated by the UE according to a first uplink power control compensation factor for the first link;

determining that the first compensation value is zero when the first path loss is fully compensated by the UE; and

determining the first compensation value according to the first uplink power control compensation factor and the first path loss when the first path loss is partially compensated by the UE.

5 . The method of claim 4 , wherein the first uplink power control compensation factor is configured by the network node or the UE.

6 . The method of claim 1 , further comprising:

measuring, by the processor, a reference signal (RS) transmitted by the UE; and

determining, by the processor, the first path loss based on the RS measurement.

7 . The method of claim 1 , further comprising:

measuring, by the processor, a reference signal (RS) transmitted by the network node; and

determining, by the processor, the second path loss based on the RS measurement.

8 . The method of claim 7 , further comprising:

receiving, by the processor, a report of an end-to-end path loss from the UE, wherein the end-to-end path loss is determined based on the RS transmitted by the network node and forwarded by the apparatus to the UE; and

determining, by the processor, the first path loss according to the end-to-end path loss and the second path loss.

9 . The method of claim 1 , wherein the determining of the second compensation value is performed according to the second path loss and a second uplink power control compensation factor for the second link.

10 . The method of claim 9 , wherein the second uplink power control compensation factor is configured by the network node.

11 . An apparatus, comprising:

a transceiver which, during operation, wirelessly communicates with a user equipment (UE) and a network node of a wireless network; and

a processor communicatively coupled to the transceiver such that, during operation, the processor performs operations comprising:

determining a first compensation value for a first path loss on a first link between the apparatus and the UE;

determining a second compensation value for a second path loss on a second link between the apparatus and the network node;

determining a repeater gain for uplink power control according to the first compensation value and the second compensation value; and

forwarding, via the transceiver, a radio signal from the UE to the network node according to the repeater gain.

12 . The apparatus of claim 11 , wherein, during operation, the processor further performs operations comprising:

determining a difference between a first target power level and a second target power level, wherein the first target power level is configured for the network node to receive radio signals on a direct link between the UE and the network node, and the second target power level is configured for the apparatus to receive radio signals on the first link; and

wherein the determining of the repeater gain for uplink power control is performed further according to the difference.

13 . The apparatus of claim 12 , wherein the repeater gain for uplink power control is determined as a sum of the difference, the first compensation value, and the second compensation value.

14 . The apparatus of claim 11 , wherein the determining of the first compensation value comprises:

determining whether the first path loss is fully compensated by the UE according to a first uplink power control compensation factor for the first link;

determining that the first compensation value is zero when the first path loss is fully compensated by the UE; and

determining the first compensation value according to the first uplink power control compensation factor and the first path loss when the first path loss is partially compensated by the UE.

15 . The apparatus of claim 14 , wherein the first uplink power control compensation factor is configured by the network node or the UE.

16 . The apparatus of claim 11 , wherein, during operation, the processor further performs operations comprising:

measuring, via the transceiver, a reference signal (RS) transmitted by the UE; and

determining the first path loss based on the RS measurement.

17 . The apparatus of claim 11 , wherein, during operation, the processor further performs operations comprising:

measuring, via the transceiver, a reference signal (RS) transmitted by the network node; and

determining the second path loss based on the RS measurement.

18 . The apparatus of claim 17 , wherein, during operation, the processor further performs operations comprising:

receiving, via the transceiver, a report of an end-to-end path loss from the UE, wherein the end-to-end path loss is determined based on the RS transmitted by the network node and forwarded by the apparatus to the UE; and

determining the first path loss according to the end-to-end path loss and the second path loss.

19 . The apparatus of claim 11 , wherein the determining of the second compensation value is performed according to the second path loss and a second uplink power control compensation factor for the second link.

20 . The apparatus of claim 19 , wherein the second uplink power control compensation factor is configured by the network node.