Resource allocation in multi data stream communication link
View Patent ↗Methods and corresponding systems for allocating resources in a communications system includes determining feasible sets of subchannels for allocation to a user subject to an allocation constraint. In one approach, a constraint matrix representing constraints for allocating subchannels to users in allocations of selected subchannels is computed, subject to the allocation constraint. Then a vector containing metrics corresponding to allocations of selected subchannels to the communication links is estimated. A binary decision vector representing an allocation of the subchannels to the users is computed using binary integer processing. In another approach a greedy heuristic allocation is used. The allocation constraint can be a restriction limiting multiple subchannels allocated to a user to be adjacent to one another. The metrics can be weighted capacities of allocations of selected subchannels to the users.
1. A method of allocating resources in a communications system comprising: in a processor
computing a constraint matrix, A, wherein A represents constraints for allocating K subchannels out of the resources in a communications system to M communications links in R allocations of selected k subchannels, wherein the R allocations are constrained by an allocation constraint;
estimating a vector, c, containing metrics associated with one or more of the resources and corresponding to allocating the R allocations to the M communication links;
computing a binary decision vector, x, representing an allocation of the K subchannels to the M communications links, wherein x is computed using binary integer processing according to the mathematical expression:
max
x
c
T
x
subject to the constraint that Ax=1, where x j ε{0,1} ∀j, wherein A is a matrix of zeros and ones, and 1=[1, . . . , 1] T is a c-length vector of ones where T indicates the transpose of an associated matrix.
2. The method of allocating resources according to claim 1 wherein the estimating the c vector includes estimating weighted metrics related to a weighted bit rate capacity of the allocation of the R allocations to the M communication links.
3. The method of allocating resources according to claim 1 wherein the estimating the c vector includes estimating weighted metrics related to a channel condition of channels using the R allocations.
4. The method of allocating resources according to claim 1 wherein the estimating the c vector includes estimating weighted metrics related to transmit powers of the M communication links.
5. The method of allocating resources according to claim 1 wherein the M communications links are communication links between an uplink receiver and a user, m, of M users, and wherein the estimating metrics of the c vector includes estimating the vector, c, containing metrics corresponding to allocating the R allocations to the M users.
6. The method of allocating resources according to claim 1 wherein the estimating the c vector includes estimating the c vector according to the formula:
c
m
,
j
=
w
m
∑
k
=
1
K
log
2
(
1
+
A
m
(
j
,
k
)
min
(
P
m
∑
l
=
1
K
A
m
(
j
,
l
)
,
P
^
m
,
k
)
γ
m
,
k
σ
2
)
wherein w m is a weight associated with a communication link, m, of the M communication links, and P m is a total power of the communication link m, and {circumflex over (P)} m,k is a power control level for communication link m using a subchannel k of the K subchannels, γ m,k is a channel gain and σ 2 is the ambient noise variance for communication link m using the subchannel k and A m (j,k) denotes the (j,k)th entry of matrix A m , A m being matrix A corresponding to communication link m.
7. The method of allocating resources according to claim 1 wherein the estimating the c vector includes estimating metrics related to R allocations using a space-time channel.
8. The method of allocating resources according to claim 1 wherein the computing the constraint matrix, A includes computing a constraint matrix, A, including constraints related to re-allocating, to a communication link m, one or more k subchannels used previously by the communication link m in a transmission that has been rescheduled.