Beamformer accounting for non-homogeneity of offered traffic distribution among cells
A system and method for beamforming beams including: matching weights T to a distribution of resources for each of the beams based on a traffic variation for each of the beams; calculating, with a signal processor for each of the beams based on the weights T, a power scalar β and a weighted minimum mean squared error (WMMSE) matrix W WMSE ; and transmitting/receiving the beams based on the power scalar β and the WMMSE matrix W WMSE , where the power scalar β satisfies a total power constraint of an antenna subsystem.
1. A non-transient computer-readable storage medium having instructions embodied thereon, the instructions being executable by one or more processors to perform a method for beamforming beams, the method comprising:
matching weights T to a distribution of resources for each of the beams based on a traffic variation for each of the beams;
calculating, with a signal processor for each of the beams based on the weights T, a power scalar β and a Weighted Minimum Mean Squared Error (WMMSE) matrix W WMSE ; and
transmitting/receiving the beams based on the power scalar β and the WMMSE matrix W WMSE ,
wherein the power scalar β satisfies a total power constraint of an antenna subsystem, and wherein the WMMSE matrix W WMSE is calculated as:
W
WMSE
=
β
*
HT
†
(
TH
†
HT
†
+
K
σ
2
t
r
(
TT
†
)
P
t
o
t
I
K
)
-
1
T
,
P tot is the total power constraint, H is a N×K channel matrix, K is a count of beams, and σ 2 is the noise variance at the receiver.
2. The method of claim 1 , wherein the traffic variation comprises a predicted offered traffic demand based on usage patterns for each of the beams.
3. The method of claim 1 , wherein the traffic variation comprises a predicted offered traffic demand based on a population density for each of the beams.
4. The method of claim 1 , wherein the traffic variation comprises a predicted offered traffic demand based on a traffic Quality of Service guarantee.
5. The method of claim 1 , wherein the traffic variation comprises an actual offered traffic demand.
6. The method of claim 1 wherein the beamforming comprises determining, based on the WMMSE matrix W WMSE , a Beam Weight Vector (BWV) to apply to feed signals for the beams.
7. The method of claim 1 , wherein the weights T comprise a K×K diagonal matrix with positive real entries.
8. The method of claim 1 , wherein the power scalar β is calculated as Trace(W WMSE W WMSE H ).
9. The method of claim 1 , wherein the WMMSE matrix W WMSE is subject to a total error constraint: argmin W,β E[∥e∥] 2 , s. t. E[∥Ws∥] 2 =P tot .
10. A beamformer system for beams comprising:
a traffic module to match weights T to a distribution of resources for each of the beams based on a traffic variation for each of the beams;
a WMMSE module to calculate, for each of the beams based on the weights T, a power scalar β and a Weighted Minimum Mean Squared Error (WMMSE) matrix W WMSE ; and
an antenna subsystem to receive/transmit the beams based on the power scalar β and the WMMSE matrix W WMSE ,
wherein the power scalar β satisfies a total power constraint of the antenna subsystem, and wherein the WMMSE matrix W WMSE is calculated as:
W
WMSE
=
β
*
HT
†
(
TH
†
HT
†
+
K
σ
2
t
r
(
TT
†
)
P
t
o
t
I
K
)
-
1
T
,
P tot is the total power constraint, H is a N×K channel matrix, K is a count of beams, and σ 2 is the noise variance at the receiver.
11. The beamformer system of claim 10 , wherein the traffic variation comprises a predicted offered traffic demand based on usage patterns for each of the beams.
12. The beamformer system of claim 10 , wherein the traffic variation comprises a predicted offered traffic demand based on a population density for each of the beams.
13. The beamformer system of claim 10 , wherein the traffic variation comprises a predicted offered traffic demand based on a traffic Quality of Service guarantee.
14. The beamformer system of claim 10 , wherein the traffic variation comprises an actual offered traffic demand.
15. The beamformer system of claim 10 , wherein the antenna subsystem determines a Beam Weight Vector (BWV) applied to feed signals for the beams.
16. The beamformer system of claim 10 , wherein the weights T comprise a K×K diagonal matrix with positive real entries.
17. The beamformer system of claim 10 , wherein the power scalar β is calculated as Trace(W WMSE W WMSE H ).
18. The beamformer system of claim 10 , wherein the WMMSE matrix W is subject to a total error constraint: argmin W,β E[∥e∥] 2 , s. t. E[∥Ws∥] 2 =P tot .