Uplink power control method and communications device
An uplink power control method and a communications device are described. The method includes receiving, by a terminal device, power control indication information sent by a network device. The power control indication information indicates a first power offset set, and the first power offset set is any one of at least two power offset sets. The method further includes receiving, by the terminal device, a transmit power control (TPC) command sent by the network device. The TPC indicates a first offset in the first power offset set. The method includes determining, by the terminal device, uplink transmit power based on the first offset. Impact of cross interference is considered in determining the uplink transmit power. Thus, the method can meet requirements of future mobile communications and improve system performance.
1. An uplink power control method for a terminal device, wherein the method comprises:
receiving a power control indication information sent by a network device, wherein the power control indication information indicates a first power offset set, and the first power offset set is any one of at least two power offset sets;
receiving a transmit power control (TPC) command sent by the network device, wherein the TPC indicates a first offset in the first power offset set; and
determining an uplink transmit power for a physical uplink shared channel (PUSCH) based on the first offset, wherein the determining the uplink transmit power for the PUSCH comprises:
obtaining a transmit power adjustment amount f c (i) based on the first offset;
obtaining a maximum transmit power value ({circumflex over (P)} CMAX,c (i)) of the terminal device,
obtaining a transmit power value ({circumflex over (P)} PUCCH (i)) of a physical uplink control channel (PUCCH),
obtaining a quantity (M PUSCH,c (i)) of resource blocks (RBs) allocated by the network device to the terminal device during a transmission on the PUSCH,
obtaining a transmit power value (P o_PUSCH,c (i)) that the network device expects to receive and that is of the PUSCH,
obtaining a path loss compensation factor (α c (i)),
obtaining a downlink path loss estimate (PL c ), and
obtaining an offset (Δ TF,c ) related to a modulation and coding scheme (MCS);
wherein the terminal device calculates, on a per-subframe basis and exclusively using parameter values specified on a per-subframe basis, the uplink transmit power for the PUSCH is determined according to the following:
P
PUSCH
,
c
(
i
)
=
min
{
10
log
10
(
P
^
C
MAX
,
c
(
i
)
-
P
^
P
U
C
C
H
(
i
)
)
,
10
log
1
0
(
M
P
U
S
C
H
,
c
(
[
)
)
+
P
O_PUSCH
,
c
(
i
)
+
α
c
(
i
)
·
PL
c
+
Δ
TF
,
c
(
i
)
+
f
Lc
(
i
)
}
where:
P PUSCH,c (i) is the uplink transmit power for the PUSCH, and
i indicates a subframe identifier of a subframe for which the uplink transmit power for the PUSCH is determined.
2. The method according to claim 1 , wherein the receiving power control indication information comprises:
receiving a radio resource control (RRC) message sent by the network device, wherein the RRC message carries the power control indication information.
3. The method according to claim 1 , wherein the receiving power control indication information comprises:
receiving a downlink control information (DCI) sent by the network device, wherein the DCI carries the power control indication information.
4. The method according to claim 1 , wherein a preset bit of the TPC indicates the power control indication information.
5. The method according to claim 1 , wherein the at least two power offset sets are determined by the network device based on at least two interference intensity levels of cross interference of the terminal device to another terminal device,
wherein the cross interference is interference caused by uplink transmission of the terminal device to downlink reception of the another terminal device,
wherein a cell on which the terminal device camps is a serving cell, and
wherein a cell on which the another terminal device camps is a neighboring cell of the serving cell.
6. The uplink power control method for a terminal device of claim 1 , wherein the power control indication information indicates a second offset; and
wherein the determining an uplink transmit power is based on the first offset and the second offset.
7. The method according to claim 6 , wherein the power control indication information comprises first power control indication information and second power control indication information; and
wherein correspondingly, the receiving the power control indication information sent by a network device comprises:
receiving an RRC message sent by the network device, wherein the RRC message carries the first power control indication information, wherein the first power control indication information indicates a second power offset set, and wherein the second power offset set comprises at least one second offset; and
receiving a downlink control information (DCI) sent by the network device, wherein the DCI carries the second power control indication information, and wherein the second power control indication information indicates the second offset in the second power offset set.
8. The method according to claim 6 , wherein the second offset is determined by the network device based on a cross interference intensity level of cross interference of the terminal device to another terminal device,
wherein the cross interference is interference caused by uplink transmission of the terminal device to downlink reception of the another terminal device,
wherein a cell on which the terminal device camps is a serving cell, and
wherein a cell on which the another terminal device camps is a neighboring cell of the serving cell.
9. The method according to claim 6 , wherein the determining uplink transmit power based on the first offset and the second offset comprises:
obtaining a transmit power adjustment amount based on the first offset; and
determining the uplink transmit power based on the adjustment amount and the second offset.
10. A communications device, wherein the communications device comprises:
a receiver,
a processor; and
a non-transitory storage medium carrying a program code, wherein the program code, when executed by the processor facilitates performing a programmed processor-implemented method comprising:
receiving, by the receiver in cooperation with the processor, power control indication information sent by a network device, wherein the power control indication information indicates a first power offset set, and the first power offset set is any one of at least two power offset sets;
receiving, by the receiver in cooperation with the processor, a transmit power control (TPC) command sent by the network device, wherein the TPC indicates a first offset in the first power offset set; and
determining, by the processor, an uplink transmit power for a physical uplink shared channel (PUSCH) based on the first offset, wherein the determining the uplink transmit power for the PUSCH comprises:
obtaining a transmit power adjustment amount f c (i) based on the first offset;
obtaining a maximum transmit power value ({circumflex over (P)} CMAX,c (i)) of the terminal device,
obtaining a transmit power value ({circumflex over (P)} PUCCH (i)) of a physical uplink control channel (PUCCH),
obtaining a quantity (M PUSCH,c (i)) of resource blocks (RBs) allocated by the network device to the terminal device during a transmission on the PUSCH,
obtaining a transmit power value (P o_PUSCH,c (i)) that the network device expects to receive and that is of the PUSCH,
obtaining a path loss compensation factor (α c (i)),
obtaining a downlink path loss estimate (PL c ), and
obtaining an offset (Δ TF,c ) related to a modulation and coding scheme (MCS);
wherein the communication device calculates, on a per-subframe basis and exclusively using parameter values specified on a per-subframe basis, the uplink transmit power for the PUSCH is determined according to the following:
P
PUSCH
,
c
(
i
)
=
min
{
10
log
10
(
P
^
C
MAX
,
c
(
i
)
-
P
^
P
U
C
C
H
(
i
)
)
,
10
log
1
0
(
M
P
U
S
C
H
,
c
(
[
)
)
+
P
O_PUSCH
,
c
(
i
)
+
α
c
(
i
)
·
PL
c
+
Δ
TF
,
c
(
i
)
+
f
Lc
(
i
)
}
where:
P PUSCH,c (i) is the uplink transmit power for the PUSCH, and
i indicates a subframe identifier of a subframe for which the uplink transmit power for the PUSCH is determined.
11. The communications device according to claim 10 , wherein the method further comprises receiving, by the receiver in cooperation with the processor, a radio resource control (RRC) message sent by the network device, wherein the RRC message carries the power control indication information.
12. The communications device according to claim 10 , wherein the method further comprises receiving, by the receiver in cooperation with the processor, a downlink control information (DCI) sent by the network device, wherein the DCI carries the power control indication information.
13. The communications device according to claim 10 , wherein a preset bit of the TPC indicates the power control indication information.
14. The communications device according to claim 10 , wherein the at least two power offset sets are determined by the network device based on at least two interference intensity levels of cross interference of the terminal device to another terminal device,
wherein the cross interference is interference caused by uplink transmission of the terminal device to downlink reception of the another terminal device,
wherein a cell on which the terminal device camps is a serving cell, and
wherein a cell on which the another terminal device camps is a neighboring cell of the serving cell.