Downlink resource allocation and mapping
Embodiments of the present invention provide for downlink resource allocation among a plurality of users. Other embodiments may be described and claimed.
1. A method, comprising:
identifying downlink resource requirements for transmission of orthogonal frequency-division multiplexing (OFDM) symbols to a plurality of users over a time unit of a wireless channel, wherein the downlink resource requirements are arranged as distributed virtual resource elements;
sorting the plurality of users according to their respective downlink resource requirements to provide a sorted list of the plurality of users, wherein a size of a first downlink resource requirement for a first user of the plurality of users is different than a size of a second downlink resource requirement for a second user of the plurality of users and the sorted list is in an order of decreasing downlink resource requirements;
determining available downlink resource elements of the time unit of the wireless channel, wherein the available downlink resource elements are physical resource elements of one or more resource blocks assigned for distributed transmission, wherein individual resource blocks of the one or more resource blocks are to include information transmitted to more than one user;
computing indices for the available downlink resource elements; and
assigning the available downlink resource elements to the plurality of users based at least in part on the sorted list and the computed indices, wherein said assigning the available downlink resource elements is done in a manner to distribute the assigned downlink resource elements across the plurality of users with a desired measure of evenness and/or spacing between adjacent assigned downlink resource elements.
2. The method of claim 1 , wherein a number of available downlink resource elements is greater than a number of required downlink resource elements, the method further comprising:
assigning a downlink resource requirement to a dummy user that is equal to a difference between the number of available downlink resource elements and the number of required downlink resource elements; and
assigning the available downlink resource elements to the plurality of users and to the dummy user.
3. The method of claim 1 , wherein a number of available downlink resource elements is greater than a number of required downlink resource elements, the method further comprising:
assigning the available downlink resource elements in a manner to provide a desired measure of spacing based at least in part on a spacing factor, S, defined by:
S
=
⌈
N
ARE
/
N
RRE
⌉
,
where N ARE is the number of available downlink resource elements and N RRE is the number of required downlink resource elements.
4. The method of claim 1 , wherein said assigning of the available downlink resource elements to each of the plurality of users is in accordance with a mapping scheme and the method further comprises:
assigning available downlink resource elements of another time unit of the wireless channel to each of the plurality of users in accordance with another mapping scheme that is varied from the mapping scheme.
5. The method of claim 4 , wherein the other mapping scheme is varied from the mapping scheme by a cyclical shift and/or a reversal.
6. The method of claim 1 , wherein the plurality of users are distributed users and the method further comprises:
assigning a first set of downlink resource elements of the time unit to one or more localized users prior to said determining the available downlink resource elements.
7. The method of claim 1 , wherein said assigning the available downlink resource elements to the plurality of users in a manner to distribute the assigned downlink resource elements across the plurality of users with a desired measure of evenness and/or spacing between adjacent assigned resource elements further comprises:
computing indices, q i for the available downlink resource elements by
q
i
=
int
(
i
l
n
∑
k
=
n
K
l
k
)
,
i
=
1
,
…
,
l
n
,
where I n is a resource requirement for an n th user of the plurality of users, and K is a number of the plurality of users; and
assigning the available downlink resource elements to the plurality of users by {V n (i)=S qi }, where V n (i) is an i th downlink resource requirement of the n th user and S qi is a q i th available downlink resource element.
8. The non-transitory machine-accessible method of claim 1 , wherein said assigning of the available downlink resource elements to each of the plurality of users is in accordance with a mapping scheme and the associated instructions, when executed, further results in the machine:
assigning available downlink resource elements of another time unit of the wireless channel to each of the plurality of users in accordance with another mapping scheme that is varied from the mapping scheme.
9. An apparatus comprising:
a scheduler configured to:
identify downlink resource requirements for transmission of orthogonal frequency-division multiplexing (OFDM) symbols to a plurality of users over a time unit of a wireless channel, wherein the downlink resource requirements are arranged as distributed virtual resource elements;
sort the plurality of users according to their respective downlink resource requirements to provide a sorted list of the plurality of users, wherein a size of a first downlink resource requirement for a first user of the plurality of users is different than a size of a second downlink resource requirement for a second user of the plurality of users and the sorted list is in an order of decreasing downlink resource requirements;
determine available downlink resource elements of the time unit of the wireless channel, wherein the available downlink resource elements are physical resource elements of one or more resource blocks assigned for distributed transmission, wherein individual resource blocks of the one or more resource blocks are to include information transmitted to more than one user;
compute indices for the available downlink resource elements; and
assign the available downlink resource elements to the plurality of users based at least in part on the sorted list and the computed indices, wherein said assignment of the available downlink resource elements is done in a manner to distribute the assigned downlink resource elements across the plurality of users with a desired measure of evenness and/or spacing between adjacent assigned downlink resource elements; and
transmit circuitry operatively coupled to the scheduler and configured to receive information to be transmitted to the plurality of users and to map the received information to the available downlink resource elements based at least in part on assignments of the available downlink resource elements to the plurality of users provided by the scheduler.
10. The apparatus of claim 9 , wherein a number of available downlink resource elements is greater than a number of required downlink resource elements and the scheduler is further configured to assign a downlink resource requirement to a dummy user that is equal to a difference between the number of available downlink resource elements and the number of required downlink resource elements; and assign the available downlink resource elements to the plurality of users and to the dummy user.
11. The apparatus of claim 9 , further comprising:
receive circuitry operatively coupled to the scheduler and configured to receive feedback information from one or more localized users.
12. The apparatus of claim 11 , wherein the plurality of users are distributed users and the scheduler is further configured to assign a first set of downlink resource elements of the time unit to the one or more localized users, based at least in part on the received feedback information, prior to a determination of the available downlink resource elements.
13. A non-transitory machine-accessible medium having associated instructions, which, when executed, results in a machine:
identifying downlink resource requirements for transmission of orthogonal frequency-division multiplexing (OFDM) symbols to a plurality of users over a time unit of a wireless channel, wherein the downlink resource requirements are arranged as distributed virtual resource elements;
sorting the plurality of users according to their respective downlink resource requirements to provide a sorted list of the plurality of users, wherein a size of a first downlink resource requirement for a first user of the plurality of users is different than a size of a second downlink resource requirement for a second user of the plurality of users and the sorted list is in an order of decreasing downlink resource requirements;
determining available downlink resource elements of the time unit of the wireless channel, wherein the available downlink resource elements are physical resource elements of one or more resource blocks assigned for distributed transmission, wherein individual resource blocks of the one or more resource blocks are to include information transmitted to more than one user;
computing indices for the available downlink resource elements; and
assigning the available downlink resource elements to the plurality of users based at least in part on the sorted list and the computed indices, wherein said assigning the available downlink resource elements is done in a manner to distribute the assigned downlink resource elements across the plurality of users with a desired measure of evenness and/or spacing between adjacent assigned downlink resource elements.
14. The non-transitory machine-accessible medium of claim 13 , wherein a number of available downlink resource elements is greater than a number of required downlink resource elements, and the associated instructions, when executed, further results in the machine:
assigning a downlink resource requirement to a dummy user that is equal to a difference between the number of available downlink resource elements and the number of required downlink resource elements; and
assigning the available downlink resource elements to the plurality of users and to the dummy user.
15. A system comprising:
a scheduler configured to:
identify downlink resource requirements for transmission of orthogonal frequency-division multiplexing (OFDM) symbols to a plurality of users over a time unit of a wireless channel, wherein the downlink resource requirements are arranged as distributed virtual resource elements;
sort the plurality of users according to their respective downlink resource requirements to provide a sorted list of the plurality of users, wherein a size of a first downlink resource requirement for a first user of the plurality of users is different than a size of a second downlink resource requirement for a second user of the plurality of users and the sorted list is in an order of decreasing downlink resource requirements;
determine available downlink resource elements of the time unit of the wireless channel, wherein the available downlink resource elements are physical resource elements of one or more resource blocks assigned for distributed transmission, wherein individual resource blocks of the one or more resource blocks are to include information transmitted to more than one user;
compute indices for the available downlink resource elements; and
assign the available downlink resource elements to the plurality of users based at least in part on the sorted list and the computed indices, wherein said assignment of the available downlink resource elements is done in a manner to distribute the assigned downlink resource elements across the plurality of users with a desired measure of evenness and/or spacing between adjacent assigned downlink resource elements;
transmit circuitry operatively coupled to the scheduler and configured to receive information to be transmitted to the plurality of users and to map the received information to the available downlink resource elements based at least in part on assignments of the available downlink resource elements to the plurality of users provided by the scheduler; and
a plurality of substantially omnidirectional antennas, operatively coupled to the transmit circuitry, wherein at least a first antenna of the plurality of substantially omnidirectional antennas is configured to transmit the mapped information over a wireless medium.
16. The system of claim 15 , wherein the plurality of users are distributed users and system further comprises:
receive circuitry operatively coupled to the scheduler and the plurality of substantially omnidirectional antennas and configured to receive feedback information over the wireless medium from one or more localized users; and
the scheduler being further configured to assign a first set of downlink resource elements of the sub-frame to the one or more localized users, based at least in part on the received feedback information, prior to a determination of the available downlink resource elements.