Variable stayout distance for beamhopping satellite
A system and method for scheduling a variable stayout distance when beam hopping, the method including providing an illumination area of a satellite and candidate beam centers disposed in the illumination area; measuring a respective scan angle from an antenna boresight to a respective beam center of the candidate beam centers; and determining a reuse factor k for each of the candidate beam centers, based on a proportion of the respective scan angle to a maximum scan angle. Each candidate beam center may be processed sequentially. Prior to adding each candidate beam center to a current beam center set, checking whether a candidate beam center meets the stayout distance criteria from all beam centers already in the beam center set.
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 scheduling a variable stayout distance when beam hopping, the method comprising:
providing an illumination area of a satellite and candidate beam centers disposed in the illumination area;
measuring a respective scan angle from an antenna boresight to a respective beam center of the candidate beam centers;
determining a reuse factor k, for each of the candidate beam centers, based on a proportion of the respective scan angle to a maximum scan angle; and
setting the reuse factor k for each of the candidate beam centers by choosing either a next smallest reuse factor k1 or a next largest reuse factor k2 from a set of reuse factors based on a probability p.
2. The method of claim 1 , wherein the illumination area comprises imaginary cells superimposed on the illumination area, each cell has a cell center, and wherein each of the candidate beam centers comprises one of the cell centers.
3. The method of claim 2 , wherein the centers of the imaginary cells are restricted to a hexagonal lattice.
4. The method of claim 2 wherein the centers of the imaginary cells are not restricted to a hexagonal lattice.
5. The method of claim 1 , wherein imaginary cells are substantially hexagonal in shape.
6. The method of claim 1 , wherein the reuse factor k for each of the candidate beam centers is calculated as
k
=
F
(
S
)
=
k
min
×
(
1
-
(
S
S
max
)
α
)
+
k
max
×
(
S
S
max
)
α
with α being 2.
7. 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 scheduling a variable stayout distance when beam hopping, the method comprising:
providing an illumination area of a satellite and candidate beam centers disposed in the illumination area;
measuring a respective scan angle from an antenna boresight to a respective beam center of the candidate beam centers;
determining a reuse factor k, for each of the candidate beam centers, based on a proportion of the respective scan angle to a maximum scan angle; and
generating a current beam center set by sequentially adding a respective candidate beam center of the candidate beam centers when the respective candidate beam center is outside a respective reuse distance D from each of the candidate beam centers already in the current beam center set.
8. The method of claim 7 , wherein the candidate beam centers are ordered by a traffic metric associated with each of the candidate beam centers.
9. The method of claim 7 , further comprising setting the reuse factor k for each of the candidate beam centers by choosing either a next smallest stayout distance k1 or a next largest reuse factor k2 from a set of stayout distances based on a probability p,
wherein the illumination area comprises substantially hexagonal imaginary cells superimposed on the illumination area, each cell has a cell center, and each of the candidate beam centers comprises one of the cell centers, and
wherein the reuse factor k for each of the candidate beam centers is calculated as
k
=
F
(
S
)
=
k
min
×
(
1
-
(
S
S
max
)
α
)
+
k
max
×
(
S
S
max
)
α
with α being 2.
10. A beam forming system to schedule using a variable stayout distance when beam hopping, the system comprising:
a satellite covering an illumination area and candidate beam centers disposed in the illumination area; and
a stayout scheduler to measure a respective scan angle from an antenna boresight to a respective beam center of the candidate beam centers, and to determine a reuse factor k, for each of the candidate beam centers, based on a proportion of the respective scan angle to a maximum scan angle,
wherein the stayout scheduler sets the reuse factor k for each of the candidate beam centers by choosing either a next smallest reuse factor k1 or a next largest reuse factor k2 from a set of stayout distances based on a probability p.
11. The system of claim 10 , wherein the illumination area comprises imaginary cells superimposed on the illumination area, each cell has a cell center, and wherein each of the candidate beam centers comprises one of the cell centers.
12. The system of claim 11 , wherein the centers of the imaginary cells are restricted to a hexagonal lattice.
13. The system of claim 11 , wherein the centers of the imaginary cells are not restricted to a hexagonal lattice.
14. The system of claim 11 , wherein imaginary cells are substantially hexagonal in shape.
15. The system of claim 10 , wherein the reuse factor k for each of the candidate beam centers is calculated as
k
=
F
(
S
)
=
k
min
×
(
1
-
(
S
S
max
)
α
)
+
k
max
×
(
S
S
max
)
α
with α being 2.
16. The system of claim 10 , wherein the stayout scheduler generates a current beam center set by sequentially adding a respective candidate beam center of the candidate beam centers when the respective candidate beam center is outside a respective reuse distance D from each of the candidate beam centers already in the current beam center set.
17. The system of claim 16 , wherein the candidate beam centers are ordered by a traffic metric associated with each of the candidate beam centers.
18. The system of claim 16 , wherein the stayout scheduler sets the reuse factor k for each of the candidate beam centers by choosing either a next smallest reuse factor k1 or a next largest reuse factor k2 from a set of stayout distances based on a probability p,
wherein the illumination area comprises substantially hexagonal imaginary cells superimposed on the illumination area, each cell has a cell center, and each of the candidate beam centers comprises one of the cell centers, and
wherein the reuse factor k for each of the candidate beam centers is calculated as
k
=
F
(
S
)
=
k
min
×
(
1
-
(
S
S
max
)
α
)
+
k
max
×
(
S
S
max
)
α
with α being 2.