최소 단어 이상 선택하여야 합니다.
최대 10 단어까지만 선택 가능합니다.
다음과 같은 기능을 한번의 로그인으로 사용 할 수 있습니다.
NTIS 바로가기다음과 같은 기능을 한번의 로그인으로 사용 할 수 있습니다.
DataON 바로가기다음과 같은 기능을 한번의 로그인으로 사용 할 수 있습니다.
Edison 바로가기다음과 같은 기능을 한번의 로그인으로 사용 할 수 있습니다.
Kafe 바로가기국가/구분 | United States(US) Patent 등록 |
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국제특허분류(IPC7판) |
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출원번호 | US-0807731 (2015-07-23) |
등록번호 | US-9219572 (2015-12-22) |
발명자 / 주소 |
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출원인 / 주소 |
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대리인 / 주소 |
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인용정보 | 피인용 횟수 : 4 인용 특허 : 364 |
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
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.
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 (OFDM
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; andtransmitting, 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. 2. The method of claim 1, further comprising transmitting, by the base station to the subscriber unit, a retraining request, the second feedback of channel and interference information being received after the transmitting of the retraining request. 3. The method of claim 1, wherein at least one OFDMA subcarrier of the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers is non-contiguous with other OFDMA subcarriers of the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers. 4. The method of claim 1, wherein the first and second indications of modulation and coding rates include a signal-to-interference-plus-noise ratio (SINR) index. 5. The method of claim 4, wherein an order of information in the first feedback of channel and interference information and the second feedback of channel and interference information is known to the base station, such that no cluster index is needed to indicate which SINR index in the first feedback of channel and interference information and the second feedback of channel and interference information corresponds to which cluster of the plurality of clusters. 6. The method of claim 1, wherein the receiving of the first feedback of channel and interference information and the second feedback of channel and interference information from the subscriber unit occurs on all clusters of the plurality of clusters. 7. The method of claim 1, wherein the second allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers is different from the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers. 8. The method of claim 1, wherein each of the first and second pilot symbols occupies an entire orthogonal frequency division multiplexing (OFDM) frequency bandwidth. 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; andtransmit, 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. 10. The base station of claim 9, wherein the transceiver is further configured to transmit, to the subscriber unit, a retraining request, the receipt of the second feedback of channel and interference information occurring after the transmission of the retraining request. 11. The base station of claim 9, wherein at least one OFDMA subcarrier of the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers is non-contiguous with other OFDMA subcarriers of the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers. 12. The base station of claim 9, wherein the first and second indications of modulation and coding rates include signal-to-interference-plus-noise ratio (SNR) index. 13. The base station of claim 12, wherein an order of information in the first feedback of channel and interference information and the second feedback of channel and interference information is known to the base station, such that no cluster index is needed to indicate which SNR index in the first feedback of channel and interference information and the second feedback of channel and interference information corresponds to which cluster of the plurality of clusters. 14. The base station of claim 9, wherein the receipt of the first feedback of channel and interference information and the second feedback of channel and interference information from the subscriber unit occurs on all clusters of the plurality of clusters. 15. The base station of claim 9, wherein the second allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers is different from the first allocation of OFDMA subcarriers of the plurality of OFDMA subcarriers. 16. The base station of claim 9, wherein each of the first and second pilot symbols occupies an entire orthogonal frequency division multiplexing (OFDM) frequency bandwidth.
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