Radio network node, user equipment and methods therein
Some embodiments herein relate to method in a user equipment for determining a transmit power to be used by the user equipment when transmitting in a radio communications network, which user equipment is served by a radio network node in the radio communications network. The user equipment receives, from the radio network node, an indication indicating a set of power control parameters out of multiple sets of power control parameters, which multiple sets of power control parameters are stored at the user equipment. The user equipment determines a transmit power based on the indicated set of power control parameters.
1. A method in a user equipment for determining a transmit power to be used by the user equipment when transmitting in a radio communications network, wherein the user equipment is served by a radio network node in the radio communications network, the method comprising:
receiving, from the radio network node, an indication indicating a set of power control parameters out of multiple sets of power control parameters, wherein the multiple sets of power control parameters are stored at the user equipment; and
determining the transmit power based on the indicated set of power control parameters; and
wherein the receiving further comprises to receive an accumulative power command, wherein the determining comprises to accumulate the accumulative power command with a previously used power command, and wherein different accumulations are done for different sets of power control parameters;
wherein the set of power control parameters comprise at least one of: a maximum transmit power; a target received power, a value indicating percentage of a pathloss that is to be taken into account when determining transmit power, a power offset value, and/or a power command value; and
wherein the determining comprises to determine transmit power using a formula defined as
P
PUSCH
,
c
(
i
)
=
min
{
P
CMAX
,
c
(
i
)
,
10
log
10
(
M
PUSCH
,
c
(
i
)
)
+
P
O
_
PUSCH
,
c
(
j
)
+
α
c
(
j
)
·
PL
c
+
Δ
TF
,
c
(
i
)
+
f
c
(
i
)
}
where:
P PUSCH,c (i) is a transmit power for subframe i over a physical uplink shared channel;
P CMAX,c (i) is a maximum transmit power;
M PUSCH,c (i) is a bandwidth of a Physical Uplink Shared Channel resource assignment expressed in number of resource blocks;
P O_PUSCH,c (j) is a target received power;
α c ϵ{0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1}, and is a value indicating percentage of a pathloss that is to be taken into account when determining transmit power;
PL c is a downlink path loss estimate;
Δ TF,c (i) is a power offset value; and
f c (i) is a power command value.
2. The method according to claim 1 , wherein the multiple sets of power control parameters comprise a specific set of power control parameters to apply for one or more subframes, and wherein the indication indicates a subframe comprised in the one or more subframes.
3. The method according to claim 1 , wherein:
the indication is comprised in an uplink grant message;
the indication is a pointer in a list of sets of power control parameters; and
the pointer indicates in the list what set of power control parameter to apply by the user equipment when determining transmit power.
4. The method according to claim 1 , further comprising:
receiving the multiple sets of power control parameters from the radio network node during configuration of the user equipment; and
storing the received multiple sets of power control parameters at the user equipment.
5. A user equipment for determining a transmit power to be used by the user equipment when transmitting in a radio communications network, wherein the user equipment is configured to be served by a radio network node in the radio communications network, wherein the user equipment comprises:
a memory configured to have multiple sets of power control parameters stored thereon;
a receiver configured to receive, from the radio network node, an indication indicating a set of power control parameters out of the stored multiple sets of power control parameters; and
a determining circuit configured to determine a transmit power based on the indicated set of power control parameters; and
wherein the receiver is further configured to receive an accumulative power command, and wherein the determining circuit is configured to accumulate the accumulative power command with a previously used power command, and to accumulate differently for different sets of power control parameters;
wherein the set of power control parameters comprise at least one of: a maximum transmit power; a target received power, a value indicating percentage of a pathloss that is to be taken into account when determining transmit power, a power offset value, and/or a power command value; and
wherein the determining circuit is configured to determine transmit power using a formula defined as
P
PUSCH
,
c
(
i
)
=
min
{
P
CMAX
,
c
(
i
)
,
10
log
10
(
M
PUSCH
,
c
(
i
)
)
+
P
O_PUSCH
,
c
(
j
)
+
α
c
(
j
)
·
PL
c
+
Δ
TF
,
c
(
i
)
+
f
c
(
i
)
}
where:
P PUSCH,c (i) is a transmit power for subframe i over a physical uplink shared channel;
P CMAX,c (i) is a maximum transmit power;
M PUSCH,c (i) is a bandwidth of a Physical Uplink Shared Channel resource assignment expressed in number of resource blocks;
P O_PUSCH,c (j) is a target received power;
α c ϵ{0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1}, and is a value indicating percentage of a pathloss that is to be taken into account when determining transmit power;
PL c is a downlink path loss estimate;
Δ TF,c (i) is a power offset value; and
f c (i) is a power command value.
6. The user equipment according to claim 5 , wherein the multiple sets of power control parameters comprise a specific set of power control parameters to apply for one or more subframes, and wherein the indication indicates a subframe comprised in the one or more subframes.
7. The user equipment according to claim 5 , wherein the receiver is configured to receive an uplink grant message comprising the indication, wherein the indication is a pointer in a list of sets of power control parameters, and wherein the pointer indicates in the list what set of power control parameter to apply in the determining circuit.
8. The user equipment according to claim 5 , wherein the receiver is further configured to receive the multiple sets of power control parameters from the radio network node during configuration of the user equipment; and the user equipment is configured to store the multiple sets of power control parameters at the memory.