Wireless access network and method for allocating data subcarriers within a downlink subframe based on grouping of user stations
First Claim
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1. In a wireless-access network, a method for allocating time-frequency units of a downlink subframe to user stations, the method comprising:
- receiving feedbacks indicative of channel state transmitted from at least some of the user stations,classifying each of the user stations based on the feedbacks, wherein classifying comprises classifying user stations with a known channel state that have provided the feedback as closed-loop user stations and classifying open-loop user stations are user stations with an unknown channel state due to a lack of said feedback as open-loop user stations;
based on a predetermined radio frequency (RF) spacing threshold, identifying contiguous groups of subcarriers from group of subcarriers within a system bandwidth available for allocation by comparing each group'"'"'s RF spacing against said threshold, and determining groups of subcarriers that have RF spacing no more than the predetermined threshold;
allocating at least some of the contiguous groups of data subcarriers of the downlink subframe from the available contiguous groups to the closed-loop user stations by allocating adjacent groups of data subcarriers to the closed-loop user stations for at least a predetermined number of OFDMA symbols of the downlink subframe; and
after the allocation of the contiguous groups of data subcarriers to the closed-loop user stations, allocating remaining groups of data subcarriers of the downlink subframe to the open-loop user stations for each OFDMA symbol including by reallocating different groups of the remaining data subcarriers to the open-loop user stations for at least the predetermined number OFDMA symbols of the downlink subframe,wherein the remaining groups of subcarriers that are allocated to the open-loop user stations comprise groups of subcarriers that have frequency spans exceeding the predetermined spacing threshold by at least a group of subcarriers.
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Abstract
Embodiments of a wireless access network and method for allocation time and frequency resources are generally described herein. Other embodiments may be described and claimed. In some embodiments, a base station allocates contiguous groups of data subcarriers of a downlink subframe to closed-loop user stations, and allocates the remaining data subcarriers of the downlink subframe to open-loop user stations to increase frequency diversity.
22 Citations
32 Claims
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1. In a wireless-access network, a method for allocating time-frequency units of a downlink subframe to user stations, the method comprising:
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receiving feedbacks indicative of channel state transmitted from at least some of the user stations, classifying each of the user stations based on the feedbacks, wherein classifying comprises classifying user stations with a known channel state that have provided the feedback as closed-loop user stations and classifying open-loop user stations are user stations with an unknown channel state due to a lack of said feedback as open-loop user stations; based on a predetermined radio frequency (RF) spacing threshold, identifying contiguous groups of subcarriers from group of subcarriers within a system bandwidth available for allocation by comparing each group'"'"'s RF spacing against said threshold, and determining groups of subcarriers that have RF spacing no more than the predetermined threshold; allocating at least some of the contiguous groups of data subcarriers of the downlink subframe from the available contiguous groups to the closed-loop user stations by allocating adjacent groups of data subcarriers to the closed-loop user stations for at least a predetermined number of OFDMA symbols of the downlink subframe; and after the allocation of the contiguous groups of data subcarriers to the closed-loop user stations, allocating remaining groups of data subcarriers of the downlink subframe to the open-loop user stations for each OFDMA symbol including by reallocating different groups of the remaining data subcarriers to the open-loop user stations for at least the predetermined number OFDMA symbols of the downlink subframe, wherein the remaining groups of subcarriers that are allocated to the open-loop user stations comprise groups of subcarriers that have frequency spans exceeding the predetermined spacing threshold by at least a group of subcarriers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a wireless-access network, a method for allocating time-frequency units of a downlink subframe to user stations, the method comprising:
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receiving feedbacks indicative of channel state transmitted from at least some of the user stations, classifying each of the user stations based on the feedbacks, wherein classifying user stations with a known channel state that have provided the feedback as closed-loop user stations, and classifying user stations with an unknown channel state due to a lack of said feedback as open-loop user stations; based on a predetermined radio frequency (RF) spacing threshold, identifying contiguous groups of subcarriers from group of subcarriers within a system bandwidth available for allocation by comparing each group'"'"'s RF spacing against said threshold, and determines groups of subcarriers that have RF spacing no more than the predetermined threshold; allocating at least some of the identified contiguous groups of data subcarriers of the downlink subframe to the closed-loop user stations by allocating adjacent groups of data subcarriers to the closed-loop user stations for at least a predetermined number of OFDMA symbols of the downlink subframe; and after the allocation of the contiguous groups of data subcarriers to the closed-loop user stations, allocating remaining groups of data subcarriers of the downlink subframe to the open-loop user stations for each OFDMA symbol, wherein the remaining data subcarriers are allocated to the open-loop user stations by; partitioning, using a set of predetermined rules, a sequence of remaining contiguous data subcarriers that have frequency spans exceeding the predetermined spacing threshold by at least a group of subcarriers into multiple subsequences; and allocating some of the remaining data subcarriers associated with one of the multiple sequences to the open-loop user stations on a per-sequence basis to increase time and frequency diversity. - View Dependent Claims (14, 15)
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16. An apparatus comprising:
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a processor configured to; receive feedbacks indicative of channel state transmitted from at least some of the user stations, classify each of the user stations based on the feedbacks, wherein classifying comprises classifying user stations with a known channel state that have provided the feedback as closed-loop user stations and classify open-loop user stations are user stations with an unknown channel state due to a lack of said feedback as open-loop user stations; a time-frequency unit allocator configured to; based on a predetermined radio frequency (RF) spacing threshold, identify contiguous groups of subcarriers from group of subcarriers within a system bandwidth available for allocation by comparing each group'"'"'s RF spacing against said threshold, and determine groups of subcarriers that have RF spacing no more than the predetermined threshold; allocating at least some of the contiguous groups of data subcarriers of the downlink subframe from the available contiguous groups to the closed-loop user stations by allocating adjacent groups of data subcarriers to the closed-loop user stations for at least a predetermined number of OFDMA symbols of the downlink subframe; and after the allocation of the contiguous groups of data subcarriers to the closed-loop user stations, to allocate remaining groups of data subcarriers of the downlink subframe to the open-loop user stations for each OFDMA symbol including by reallocating different groups of the remaining data subcarriers to the open-loop user stations for at least the predetermined number OFDMA symbols of the downlink subframe. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. An apparatus comprising:
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a processor configured to; receive feedbacks indicative of channel state transmitted from at least some of the user stations, classify each of the user stations based on the feedbacks, wherein classifying comprises classifying user stations with a known channel state that have provided the feedback as closed-loop user stations and classify open-loop user stations are user stations with an unknown channel state due to a lack of said feedback as open-loop user stations; a time-frequency unit allocator configured to; based on a predetermined radio frequency (RF) spacing threshold, identify contiguous groups of subcarriers from group of subcarriers within a system bandwidth available for allocation by comparing each group'"'"'s RF spacing against said threshold, and determine groups of subcarriers that have RF spacing no more than the predetermined threshold; allocating at least some of the contiguous groups of data subcarriers of the downlink subframe from the available contiguous groups to the closed-loop user stations by allocating adjacent groups of data subcarriers to the closed-loop user stations for at least a predetermined number of OFDMA symbols of the downlink subframe; and after the allocation of the contiguous groups of data subcarriers to the closed-loop user stations, to allocate remaining groups of data subcarriers that have frequency spans exceeding the predetermined spacing threshold by at least a group of subcarriers of the downlink subframe to the open-loop user stations for each OFDMA symbol, wherein to allocate the remaining data subcarriers to the open-loop user stations, the time-frequency unit allocator systematically partitions a sequence of remaining contiguous data subcarriers into multiple subsequences, and allocates some of the remaining data subcarriers associated with one of the multiple sequences to the open-loop user stations on a per-sequence basis.
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29. A method of allocating time-frequency units of an OFDMA downlink subframe comprising:
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receive feedbacks indicative of channel state transmitted from at least some of the user stations, classify each of the user stations based on the feedbacks, wherein classifying comprises classifying user stations with a known channel state that have provided the feedback as closed-loop user stations and classify open-loop user stations are user stations with an unknown channel state due to a lack of said feedback as open-loop user stations; in response to said classifying, determining available blocks of time-frequency units with a narrower span in frequency and a wider span in time and allocating said blocks of time-frequency units to the user stations with a known channel state; and determining remaining blocks of time-frequency units with a wider span in frequency and allocating said remaining blocks of time-frequency units a narrower span in time to the user stations with an unknown channel state, wherein said determining comprises, based on a predetermined radio time-frequency (RF) span threshold, identifying blocks of time-frequency units with a narrower span in frequency and a wider span in time by comparing the spans against said threshold. - View Dependent Claims (30, 31, 32)
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Specification