SUDAS, URU and base station
A SUDAS has at least one URU, wherein the at least one URU is configured for relaying a signal between at least one base station and at least one user equipment by communicating with the at least one user equipment in a first frequency range and with at least one base station in a second frequency range. The SUDAS has a controller configured for determining a first solution for a resource allocation in the first frequency range. The base station is configured for determining a second solution for a resource allocation in the first frequency range using the first solution.
1. A shared user equipment-side distributed antenna system (SUDAS) comprising at least one UE-side radio unit (URU), wherein the at least one URU is configured for relaying a signal between at least one base station (BS) and at least one User Equipment (UE) by communicating with the at least one UE in a first frequency range and with the at least one BS in a second frequency range, the SUDAS comprising:
a controller configured for determining a first solution for a resource allocation in the first frequency range for a communication between the UE and the URU;
wherein the base station is configured for determining a second solution for a resource allocation in the second frequency range for a communication between the BS and the URU using the first solution.
2. The SUDAS of claim 1 , comprising a plurality of URU, wherein the controller is configured for determining a first solution for each of the plurality of URU so as to acquire a plurality of first solutions, wherein the base station is configured for determining the second solution based receiving information indicating the plurality of first solutions.
3. The SUDAS of claim 2 , further comprising a plurality of BS, wherein each of the URU is configured for communicating with each of the BS using an associated backend link in the second frequency range, wherein each BS is configured for determining a second solution for each backend link associated with the BS.
4. The SUDAS of claim 2 , wherein the plurality of BS is non-cooperative; and
wherein the SUDAS comprises a plurality of UE, wherein each URU is configured for communicating with at least one UE of the plurality of UE using an associated frontend link in the first frequency range, wherein each of the plurality of URU is configured for determining the first solution based on a combination of the frontend links associated with the URU.
5. The SUDAS of claim 1 ,
wherein the controller is configured for updating the first solution so as to acquire an updated first solution using the second solution.
6. The SUDAS of claim 5 , wherein the controller is configured for updating the first solution until a deviation between the updated first solution and the first solution is below or equal to a predefined threshold, wherein the updated first solution is used for communication.
7. The SUDAS of claim 5 , wherein the controller is configured for determine a power allocation in the first frequency range and a power allocation in the second frequency range and an allocation of subcarriers used in the first frequency range under the constraints C1, C2, C3 and C4 based on
C1:
∑
k
=
1
K
∑
i
=
1
N
F
Tr
(
P
[
i
,
k
]
(
P
[
i
,
k
]
)
H
)
≤
P
BS
,
C2:
∑
k
=
1
K
∑
i
=
1
N
F
Tr
(
F
[
i
,
k
]
(
H
B
→
S
[
i
]
P
[
i
,
k
]
(
P
[
i
,
k
]
)
H
(
H
B
→
S
[
i
]
)
H
+
I
M
)
(
F
[
i
,
k
]
)
H
)
≤
MP
S
,
C3:
∑
k
=
1
K
s
[
i
,
k
]
≤
1
∀
i
,
C4:
s
[
i
,
k
]
∈
{
0
,
1
}
∀
i
,
k
,
(
6
)
wherein Tr denotes the trace of a matrix, P [i,k] denotes an element of a precoding matrix P for UE k of in total K UE and in subcarrier i, (P [i,k] ) H denotes the Hermitian transpose of matrix P [i,k] , F denotes an amplification matrix, H denotes a M×N MIMO channel matrix, I denotes a unit matrix, s [i,k] describes an allocation of respective subcarrier i to UE k.
8. The SUDAS of claim 1 , wherein the controller is configured for determining the second solution based on Karush-Kuhn-Tucker conditions.
9. The SUDAS of claim 1 , wherein the URU is one of a plurality of URU in the SUDAS, wherein the controller is configured for determining the first solution so as to allocate equal power to each of the plurality of URU and/or equal power to a plurality of antennas of the BS.
10. The SUDAS of claim 1 , wherein the controller is adapted for determining the second resource allocation using the first resource allocation to obtain an optimization criterion for the UE.