OFDMA with adaptive subcarrier-cluster configuration and selective loading
First Claim
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1. A method, comprising:
- transmitting, at a first time by a base station, at least a first pilot symbol to a subscriber unit for measuring the at least a first pilot symbol and obtaining first channel and interference information for a plurality of orthogonal frequency division multiple access (OFDMA) subcarriers;
receiving, by the base station from the subscriber unit, after the transmitting of the at least first pilot symbol to the subscriber unit, first feedback of channel and interference information relating to a plurality of clusters, each cluster of the plurality of clusters having at least two OFDMA subcarriers of the plurality of OFDMA subcarriers, the receiving of the first feedback of channel and interference information includes receiving first indications of modulation and coding rates associated with each cluster of the plurality of clusters;
transmitting, by the base station to the subscriber unit, a first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receiving of the first feedback of channel and interference information;
transmitting, at a second time after the first time, by the base station, at least a second pilot symbol to the subscriber unit for measuring the at least second pilot symbol and obtaining second channel and interference information for the plurality of OFDMA subcarriers;
receiving, by the base station from the subscriber unit, after the transmitting of the at least second pilot symbol to the subscriber unit, second feedback of channel and interference information relating to the plurality of clusters, the receiving of the second feedback of channel and interference information includes receiving second indications of modulation and coding rates associated with each cluster of the plurality of clusters; and
transmitting, by the base station to the subscriber unit, a second allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receiving of the second feedback of channel and interference information.
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Abstract
A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.
428 Citations
16 Claims
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1. A method, comprising:
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transmitting, at a first time by a base station, at least a first pilot symbol to a subscriber unit for measuring the at least a first pilot symbol and obtaining first channel and interference information for a plurality of orthogonal frequency division multiple access (OFDMA) subcarriers; receiving, by the base station from the subscriber unit, after the transmitting of the at least first pilot symbol to the subscriber unit, first feedback of channel and interference information relating to a plurality of clusters, each cluster of the plurality of clusters having at least two OFDMA subcarriers of the plurality of OFDMA subcarriers, the receiving of the first feedback of channel and interference information includes receiving first indications of modulation and coding rates associated with each cluster of the plurality of clusters; transmitting, by the base station to the subscriber unit, a first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receiving of the first feedback of channel and interference information; transmitting, at a second time after the first time, by the base station, at least a second pilot symbol to the subscriber unit for measuring the at least second pilot symbol and obtaining second channel and interference information for the plurality of OFDMA subcarriers; receiving, by the base station from the subscriber unit, after the transmitting of the at least second pilot symbol to the subscriber unit, second feedback of channel and interference information relating to the plurality of clusters, the receiving of the second feedback of channel and interference information includes receiving second indications of modulation and coding rates associated with each cluster of the plurality of clusters; and transmitting, by the base station to the subscriber unit, a second allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receiving of the second feedback of channel and interference information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A base station, comprising:
a transceiver configured to; transmit, at a first time, at least a first pilot symbol to a subscriber unit for measuring the at least first pilot symbol and obtaining first channel and interference information for a plurality of orthogonal frequency division multiple access (OFDMA) subcarriers; receive, from the subscriber unit, after the transmission of the at least first pilot symbol to the subscriber unit, first feedback of channel and interference information relating to a plurality of clusters, each cluster of the plurality of clusters having at least two OFDMA subcarriers of the plurality of OFDMA subcarriers, the receipt of the first feedback of channel and interference information includes receiving first indications of modulation and coding rates associated with each cluster of the plurality of clusters; transmit, to the subscriber unit, a first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receipt of the first feedback of channel and interference information; transmit, at a second time after the first time, at least a second pilot, symbol to the subscriber unit for measuring the at least second pilot symbol and obtaining second channel and interference information for the plurality of OFDMA subcarriers; receive, from the subscriber unit, after the transmission of the at least second pilot symbol to the subscriber unit, second feedback of channel and interference information relating to the plurality of clusters, the receipt of the second feedback of channel and interference information includes receiving second indications of modulation and coding rates associated with each cluster of the plurality of clusters; and transmit, to the subscriber unit, a second allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers selected by the base station for use by the subscriber unit, after, and based on at least the receipt of the second feedback of channel and interference information. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
Specification